Central Air Conditioners TP Snopr
Central Air Conditioners TP Snopr
Central Air Conditioners TP Snopr
of Energy. Though it is not intended or expected, should any discrepancy occur between
the document posted here and the document published in the Federal Register, the
Federal Register publication controls. This document is being made available through the
DEPARTMENT OF ENERGY
RIN 1904-AB94
Energy Conservation Program: Test Procedures for Central Air Conditioners and Heat
Pumps
SUMMARY: The U.S. Department of Energy (DOE) proposes to revise its test procedures for
central air conditioners and heat pumps established under the Energy Policy and Conservation
Act. DOE proposed amendments to the test procedure in a June 2010 notice of proposed
rulemaking (NOPR), an April 2011 supplemental notice of proposed rulemaking (SNOPR), and
an October 2011 SNOPR. DOE provided additional time for stakeholder comment in a
December 2011 extension of the comment period for the October 2011 SNOPR. DOE received
further public comment for revising the test procedure in a November 2014 Request for
Information for energy conservation standards for central air conditioners and heat pumps. DOE
proposes in this SNOPR: a new basic model definition as it pertains to central air conditioners
1
and heat pumps and revised rating requirements; revised alternative efficiency determination
methods; termination of active waivers and interim waivers; revised procedures to determine off
mode power consumption; changes to the test procedure that would improve test repeatability
and reduce test burden; clarifications to ambiguous sections of the test procedure intended also to
improve test repeatability; inclusion of, amendments to, and withdrawals of test procedure
revisions proposed in published test procedure notices in the rulemaking effort leading to this
supplemental notice of proposed rulemaking; and changes to the test procedure that would
reference of updated industry standards. DOE welcomes comments from the public on any
DATES: DOE will accept comments, data, and information regarding this supplemental notice
of proposed rulemaking (SNOPR) before and after the public meeting, but no later than
ADDRESSES: Any comments submitted must identify the SNOPR for test procedures for
central air conditioners and heat pumps, and provide docket number EE-2009–BT–TP–0004
and/or regulatory information number (RIN) number 1904-AB94. Comments may be submitted
submitting comments.
2
2. E-mail: RCAC-HP-2009-TP-0004@ee.doe.gov. Include the docket number EE-2009–
3. Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office,
possible, please submit all items on a CD, in which case it is not necessary to include
printed copies.
Technologies Office, 950 L’Enfant Plaza, SW., Suite 600, Washington, DC, 20024.
Telephone: (202) 586-2945. If possible, please submit all items on a CD, in which case it
For detailed instructions on submitting comments and additional information on the rulemaking
Docket: The docket, which includes Federal Register notices, public meeting attendee
lists and transcripts, comments, and other supporting documents/materials, is available for
review at www.regulations.gov. All documents in the docket are listed in the regulations.gov
index. However, some documents listed in the index, such as those containing information that
page will contain a link to the docket for this notice on the www.regulations.gov site. The
3
www.regulations.gov web page will contain simple instructions on how to access all documents,
including public comments, in the docket. See section V for information on how to submit
Renewable Energy, Building Technologies Program, EE-2J, 1000 Independence Avenue, SW.,
Ashley.Armstrong@ee.doe.gov.
Johanna Hariharan, U.S. Department of Energy, Office of the General Counsel, GC-33,
1000 Independence Avenue, SW., Washington, DC, 20585-0121. Telephone: (202) 287-6307.
E-mail: Johanna.Hariharan@hq.doe.govmailto:.
For further information on how to submit a comment, review other public comments and
the docket, or participate in the public meeting, contact Ms. Brenda Edwards at (202) 586-2945
or by email: Brenda.Edwards@ee.doe.gov.
following industry standards into 10 CFR Part 430: ANSI/AHRI 210/240-2008 with Addenda 1
and 2: Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment,
2012; AHRI 210/240-Draft: Performance Rating of Unitary Air-Conditioning & Air- Source
4
Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning and Heat Pump Equipment,
2010; ASHRAE 23.1-2010: Methods of Testing for Rating the Performance of Positive
Temperatures of the Refrigerant; ASHRAE Standard 37-2009, Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment; ASHRAE 41.1-2013:
Standard Method for Temperature Measurement; ASHRAE 41.6-2014: Standard Method for
the Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500,
http://www.ahrinet.org/site/686/Standards/HVACR-Industry-Standards/Search-Standards. A
TP-0004-0045).
5
Table of Contents
6
1. Indoor Fan Speed Settings
2. Requirements for the Refrigerant Lines and Mass Flow Meter
3. Outdoor Room Temperature Variation
4. Method of Measuring Inlet Air Temperature on the Outdoor Side
5. Requirements for the Air Sampling Device
6. Variation in Maximum Compressor Speed with Outdoor Temperature
7. Refrigerant Charging Requirements
8. Alternative Arrangement for Thermal Loss Prevention for Cyclic Tests
9. Test Unit Voltage Supply
10. Coefficient of Cyclic Degradation
11. Break-in Periods Prior to Testing
12. Industry Standards that are Incorporated by Reference
13. Withdrawing References to ASHRAE Standard 116-1995 (RA 2005)
14. Additional Changes Based on AHRI 210/240-Draft
15. Damping Pressure Transducer Signals
F. Clarification of Test Procedure Provisions
1. Manufacturer Consultation
2. Incorporation by Reference of ANSI/AHRI Standard 1230-2010
3. Replacement of the Informative Guidance Table for Using the Federal Test Procedure
4. Clarifying the Definition of a Mini-Split System
5. Clarifying the Definition of a Multi-Split System
G. Test Procedure Reprint
H. Improving Field Representativeness of the Test Procedure
1. Minimum External Static Pressure Requirements for Conventional Central Air
Conditioners and Heat Pumps
2. Minimum External Static Pressure Adjustment for Blower Coil Systems Tested with
Condensing Furnaces
3. Default Fan Power for Coil-Only Systems
4. Revised Heating Load Line
5. Revised Heating Mode Test Procedure for Products Equipped with Variable-Speed
Compressors
I. Identified Test Procedure Issues DOE may Consider in Future Rulemakings
1. Controlling Variable Capacity Units to Field Conditions
2. Revised Ambient Test Conditions
3. Performance Reporting at Certain Air Volume Flow Rates
4. Cyclic Test with a Wet Coil
5. Inclusion of the Calculation for Sensible Heating Ratio
J. Compliance with other Energy Policy and Conservation Act Requirements
1. Test Burden
2. Potential Incorporation of International Electrotechnical Commission Standard 62301 and
International Electrotechnical Commission Standard 62087
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
7
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under the Treasury and General Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration Act of 1974
M. Description of Materials Incorporated by Reference
V. Public Participation
A. Attendance at Public Meeting
B. Procedure for Submitting Prepared General Statements For Distribution
C. Conduct of Public Meeting
D. Submission of Comments
E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
3. Testing Procedures.
A. Authority
Title III, Part B of the Energy Policy and Conservation Act of 1975 (EPCA or the Act),
Pub. L. 94-163 (42 U.S.C. 6291−6309, as codified), established the Energy Conservation
Program for Consumer Products Other Than Automobiles, a program covering most major
household appliances, including the single phase central air conditioners and heat pumps 1 with
rated cooling capacities less than 65,000 British thermal units per hour (Btu/h) that are the focus
Under EPCA, the program consists of four activities: (1) testing; (2) labeling; (3) Federal
energy conservation standards; and (4) certification, compliance, and enforcement. The testing
1
Where this notice uses the terms “HVAC” or “CAC/CHP”, they are in reference specifically to central air
conditioners and heat pumps as covered by EPCA.
2
For editorial reasons, upon codification in the U.S. Code, Part B was re-designated Part A.
8
requirements consist of test procedures that manufacturers of covered products must use as the
basis for certifying to DOE that their products comply with applicable energy conservation
standards adopted pursuant to EPCA and for representing the efficiency of those products. (42
U.S.C. 6293(c); 42 U.S.C. 6295(s)) Similarly, DOE must use these test procedures in any
enforcement action to determine whether covered products comply with these energy
conservation standards. (42 U.S.C. 6295(s)) Under 42 U.S.C. 6293, EPCA sets forth criteria
and procedures for DOE’s adoption and amendment of such test procedures. Specifically, EPCA
provides that an amended test procedure shall produce results which measure the energy
efficiency, energy use, or estimated annual operating cost of a covered product over an average
or representative period of use, and shall not be unduly burdensome to conduct. (42 U.S.C.
must publish proposed test procedures and offer the public an opportunity to present oral and
written comments on them. (42 U.S.C. 6293(b)(2)) Furthermore, DOE must review test
procedures at least once every 7 years. (42 U.S.C 6293(b)(1)(A)) DOE last published a test
procedure final rule for central air conditioner and heat pumps on October 22, 2007. 72 FR
59906. Finally, in any rulemaking to amend a test procedure, DOE must determine whether and
the extent to which the proposed test procedure would change the measured efficiency of a
system that was tested under the existing test procedure. (42 U.S.C. 6293(e)(1)) If DOE
determines that the amended test procedure would alter the measured efficiency of a covered
product, DOE must amend the applicable energy conservation standard accordingly. (42 U.S.C.
6293(e)(2))
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DOE’s existing test procedures for central air conditioners and heat pumps adopted
pursuant to these provisions appear under Title 10 of the Code of Federal Regulations (CFR) Part
430, Subpart B, Appendix M (“Uniform Test Method for Measuring the Energy Consumption of
Central Air Conditioners and Heat Pumps”). These procedures establish the currently permitted
means for determining energy efficiency and annual energy consumption of these products.
Some amendments proposed in this SNOPR will not alter the measured efficiency of central air
conditioners and heat pumps, and thus are being proposed as revisions to the current Appendix
M. Other amendments proposed in this SNOPR will alter the measured efficiency, as
represented in the regulating metrics of energy efficiency ratio (EER), seasonal energy efficiency
ratio (SEER), and heating seasonal performance factor (HSPF). These amendments are proposed
as part of a new Appendix M1. The test procedure changes proposed in this notice as part of a
new Appendix M1, if adopted, would not become mandatory until the existing energy
conservation standards are revised. (42 U.S.C. 6293(e)(2)) In revising the energy conservation
standards, DOE would create a cross-walk from the existing standards under the current test
procedure to what the standards would be if tested using the revised test procedure. DOE would
then use the cross-walked equivalent of the existing standard as the baseline for its standards
On December 19, 2007, the President signed the Energy Independence and Security Act
of 2007 (EISA 2007), Pub. L. 110-140, which contains numerous amendments to EPCA.
Section 310 of EISA 2007 established that the Department’s test procedures for all covered
products must account for standby mode and off mode energy consumption. (42 U.S.C.
6295(gg)(2)(A)) For central air conditioners and heat pumps, standby mode is incorporated into
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the SEER metric, while off mode power consumption is separately regulated. This SNOPR
includes proposals relevant to the determination of both SEER (including standby mode) and off
10 CFR 430.27 allows manufacturers to submit an application for an interim waiver and/r
a petition for a waiver granting relief from adhering to the test procedure requirements found
under 10 CFR Part 430, Subpart B, Appendix M. For those waivers that are active, however, 10
CFR 430.27(l) requires DOE to amend its regulations so as to eliminate any need for the
continuation of such waivers. To this end, this notice proposes relevant amendments to its test
B. Background
This SNOPR addresses proposals and comments from three separate rulemakings, two
guidance documents, and a working group: (1) proposals for off mode test procedures made in
earlier notices as part of this rulemaking (Docket No. EERE-2009-BT-TP-0004); (2) proposals
(3) stakeholder comments from a request for information regarding energy conservation
testing and rating split systems with blower coil units (Docket No. EERE-2014-BT-GUID-0033);
(5) a draft guidance document that deals with selecting units for testing, rating, and certifying
split-system combinations, including discussion of basic models and of condensing units and
evaporator coils sold separately for replacement installation (Docket No. EERE-2014-BT-GUID-
11
0032); and (6) the recommendations of the regional standards enforcement Working Group
DOE’s initial proposals for estimating off mode power consumption in the test procedure
for central air conditioners and heat pumps were shared with the public in a notice of proposed
rulemaking published in the Federal Register on June 2, 2010 (June 2010 NOPR; 75 FR 31224)
and at a public meeting at DOE headquarters in Washington, D.C. on June 11, 2010.
1, 2011, in response to comments received on the June 2010 NOPR and due to the results of
additional laboratory testing conducted by DOE. (April 2011 SNOPR) 76 FR 18105, 18127.
DOE received additional comments in response to the April 2011 SNOPR and proposed an
amended version of the off mode procedure that addressed those comments in a second SNOPR
on October 24, 2011 (October 2011 SNOPR). 76 FR 65616. DOE received additional
comments during the comment period of the October 24, 2011 SNOPR and the subsequent
Between the April 2011 and October 2011 SNOPRs, DOE published a direct final rule
(DFR) in the Federal Register on June 27, 2011 that set forth amended energy conservation
standards for central air conditioners and central air conditioning heat pumps, including a new
standard for off mode electrical power consumption. (June 2011 DFR) 76 FR 37408. Units
manufactured on or after January 1, 2015, are subject to that standard for off mode electrical
enforcement policy statement regarding off mode standards for central air conditioners and
12
central air conditioning heat pumps 3 (July 2014 Enforcement Policy Statement) specifying that
DOE will not assert civil penalty authority for violation of the off mode standard until 180 days
following publication of a final rule establishing a test method for measuring off mode electrical
power consumption.
DOE also pursued, in a request for information (RFI) published on April 18, 2011
(AEDM RFI) (76 FR 21673), and a NOPR published on May 31, 2012 (AEDM NOPR) (77 FR
32038), revisions to its existing alternative efficiency determination methods (AEDM) and
manufacturers may use modeling techniques as the basis to certify consumer products and
commercial and industrial equipment covered under EPCA. DOE also published a final rule
regarding AEDM requirements for commercial and industrial equipment only (Commercial
Equipment AEDM FR). 78 FR 79579. This SNOPR addresses the proposals made and
comments received in the AEDM NOPR applicable to central air conditioners and heat pumps
On June 13, 2014, DOE published a notice of intent to form a working group to negotiate
enforcement of regional standards for central air conditioners and requested nominations from
parties interested in serving as members of the Working Group. 79 FR 33870. On July 16, 2014,
the Department published a notice of membership announcing the eighteen nominations that
were selected to serve as members of the Working Group, in addition to two members from
Appliance Standards and Rulemaking Federal Advisory Committee (ASRAC), and one DOE
3
Available at: http://energy.gov/sites/prod/files/2014/07/f17/Enforcement%20Policy%20Statement%20-
%20cac%20off%20mode.pdf (Last accessed March 30, 2015.)
13
representative. 79 FR 41456. The Working Group identified a number of issues related to testing
and certification that are being addressed in this rule. In addition, all nongovernmental
participants of the Working Group approved the final report contingent on upon the issuance of
the final guidance on Docket No. EERE-2014-BT-GUID-0032 0032 and Docket No. EERE-
2014-BT-GUID-0033 consistent with the understanding of the Working Group as set forth in its
responds to comments on the August 19 and 20, 2014, guidance documents related to testing and
rating split systems, which are discussed in more detail in section III.A. The proposed changes
supplant these two draft guidance documents; DOE will not finalize the draft guidance
documents and instead will provide any necessary clarity through this notice and the final rule.
DOE believes the proposed changes are consistent with the intent of the Working Group.
On November 5, 2014, DOE published a request for information for energy conservation
standards (ECS) for central air conditioners and heat pumps (November 2014 ECS RFI). 79 FR
65603. In response, several stakeholders provided comments suggesting that DOE amend the
current test procedure. This SNOPR responds to those test procedure-related comments.
certification requirements and test procedure for central air conditioners and heat pumps based
14
DOE proposes to revise the basic model definition, add additional definitions for clarity,
make certain revisions to the testing requirements for determination of certified ratings, add
values, and add product-specific enforcement provisions. Some of the proposed revisions to the
certification requirements would impact the energy conservation standard and thus would not be
effective until the compliance date of any amended energy conservation standards.
DOE proposes to update requirements for Alternative Rating Methods (ARMs) used to
determine performance metrics for central air conditioners and heat pumps based on the
regulations for Alternative Efficiency Determination Methods (AEDMs) that are used to estimate
performance for commercial HVAC equipment. Specifically, for central air conditioners and
heat pumps, DOE proposes: (1) revisions to nomenclature regarding ARMs; (2) rescinding DOE
pre-approval of an ARM prior to use; (3) AEDM validation requirements; (4) a verification
testing process; (5) actions a manufacturer could take following a verification test failure; and (6)
consequences for invalid ratings. These proposed changes do not impact the energy conservation
standard.
DOE proposes to revise the test procedure such that tests of multi-circuit products, triple-
capacity northern heat pump products, and multi-blower products can be performed without the
need of an interim waiver or a waiver. Existing interim waivers and waivers, as applicable,
regarding these products would terminate on the effective date of a final rule promulgating the
proposals in this SNOPR. DOE also reaffirms that the waivers associated with multi-split
products have already terminated and that these products can also be tested using the current and
15
proposed test procedure. These proposed changes do not impact the energy conservation
DOE also proposes to clarify that air-to-water heat pump products integrated with
domestic water heating are not subject to central air conditioner and heat pump energy
conservation standards. Accordingly, the waiver regarding these products would terminate
effective 180 days after publication of a final rule that incorporates the proposals in this SNOPR.
DOE proposes revisions to the test methods and calculations for off mode power
consumption that were proposed or modified in the June 2010 NOPR, April 2011 SNOPR, and
October 2011 SNOPR. These revisions address comments received in response to the October
2011 SNOPR suggesting that test methods and calculations more accurately represent off- mode
power consumption in field applications. These proposed changes do not impact the energy
(1) Establishment of separate testing and calculations that would depend on whether the
tested unit is equipped with a crankcase heater and whether the crankcase heater is
(2) Alteration of the testing temperatures such that the crankcase heater is tested in
outdoor air conditions that are representative of the shoulder and heating seasons;
(3) Changing of the testing methodology for determining the power consumption of the
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(4) Changing of the calculation of the off mode power rating (PW,OFF) such that the off
mode power for the shoulder and heating seasons are equally weighted;
(5) Implementation of a time delay credit for energy consumption, including credits in
the form of scaling factors and multipliers for energy-efficient products that require
(6) Addition of an alternative energy determination method for determining off mode
(7) Inclusion of a means for calculating a basic model’s annual off mode energy use,
from which manufacturers could make representations about their products’ off mode
energy use.
DOE also proposes changes to improve the repeatability and reduce the test burden of the
test procedure. These proposed changes do not impact the energy conservation standard.
(3) Addition of a requirement to demonstrate inlet air temperature uniformity for the
(4) Addition of a requirement that outdoor air conditions be measured using sensors
measuring the air captured by the air sampling device(s) rather than the temperature
17
(5) Addition of a requirement that the air sampling device and the tubing that transfers
the collected air to the dry bulb temperature sensor be at least two inches from the
test chamber floor, and a requirement that humidity measurements be based on dry
bulb temperature measurements made at the same location as the corresponding wet
procedures;
(8) Allowance of an alternative arrangement for cyclic tests to replace the currently-
required damper in the inlet portion of the indoor air ductwork for single-package
ducted units;
(15) Provisions regarding damping of pressure transducer signals to avoid exceeding test
Lastly, DOE proposes clarifications of any sections of the test procedure that may be
ambiguous. Specifically, DOE proposes to add reference to an industry standard for testing
variable refrigerant flow multi-split systems; replace the informative guidance table for using the
18
test procedure; and clarify definitions of multi-split systems and mini-split systems, which DOE
now proposes to call single-zone-multiple-unit systems. These proposed changes do not impact
DOE notes that all the above-listed proposed changes to the test procedure would not
impact the energy conservation standard and as such are proposed as part of a revised Appendix
M. Given the extensive changes proposed for Appendix M, DOE has provided a full re-print of
Appendix M in the regulatory text of this SNOPR that includes the changes proposed in this
SNOPR as well as those proposed in the June 2010 NOPR and the April 2011 and October 2011
DOE also proposes various changes to the test procedure that would affect the energy
conservation standard and proposes incorporating these changes in a new appendix, Appendix
M1 to Subpart B of 10 CFR Part 430, which includes the text of Appendix M to Subpart B of 10
CFR Part 430 with amendments as proposed in this SNOPR. Specifically, DOE proposes the
following:
(1) Increase the minimum external static pressure requirements for conventional central
air conditioners and heat pumps to better represent the external static pressure
4
Conventional central air conditioners and heat pumps are those products that are not short duct systems (see
section III.F.2) or small-duct, high-velocity systems.
19
(2) Add a minimum external static pressure adjustment to correct for potentially
unrepresentative external static pressure conditions for blower coil systems tested
(4) Adjust the heating load line equation such that the zero load point occurs at 55 ºF for
Region IV, the adjustment factor is 1.3, and the heating load is tied with the heat
(5) Revise the heating mode test procedure to allow more options for products equipped
DOE proposes to make the test procedure revisions in this SNOPR as reflected in the
revised Appendix M to Subpart B of 10 CFR Part 430 effective on a date 180 days after
publication of the test procedure final rule in the Federal Register and mandatory for testing to
determine compliance with the existing energy conservation standards for central air
conditioners and heat pumps as of that date. DOE proposes to make the test procedure revisions
in this SNOPR as reflected in the proposed new Appendix M1 to Subpart B of 10 CFR Part 430
effective on the compliance date of the revised energy conservation standards for central air
conditioners and heat pumps and mandatory for testing to determine compliance with said
revised standards as of that date. DOE will address any comments received in response to this
As noted in section I.A, 42 U.S.C. 6293(e) requires that DOE shall determine to what
extent, if any, the proposed test procedure would alter the measured energy efficiency and
20
measured energy use. DOE has determined that some of these proposed amendments would
result in a change in measured energy efficiency and measured energy use for central air
conditioners and heat pumps. Therefore, DOE is conducting a separate rulemaking to amend the
energy conservation standards for central air conditioners and heat pumps with respect to the
revised test procedure, once its proposals become final. (Docket No. EERE-2014-BT-STD-
0048)
III. Discussion
This section discusses the revisions to the certification requirements and test procedure
A. Definitions, Testing, Rating, and Compliance of Basic Models of Central Air Conditioners
On August 19 and 20, 2014, DOE issued two draft guidance documents regarding the test
procedure for central air conditioners and heat pumps. One guidance document dealt with
testing and rating split systems with blower coil indoor units (Docket No. EERE-2014-BT-
GUID-0033); and the other dealt more generally with selecting units for testing, rating, and
units and evaporator coils sold separately for replacement installation (Docket No. EERE-2014-
BT-GUID-0032). The comments in response to these draft guidance documents are discussed in
this section of the notice. DOE has proposed changes to the substance of the draft guidance that
reflects the comments received as well as the recommendations of the regional standards
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proposed changes supplant the two draft guidance documents; DOE will not finalize the draft
guidance documents and instead will provide any necessary clarity through this notice and the
final rule.
In the August 20, 2014 draft guidance document (Docket No. EERE-2014-BT-GUID-
0032), DOE clarified that a basic model means all units of a given type (or class thereof) having
the same primary energy source, and which have essentially identical electrical, physical, and
functional characteristics that affect energy efficiency. 10 CFR 430.2. DOE noted that for split-
system units, this includes a condensing (outdoor) unit and a coil-only or blower coil indoor
unit. 5
In the guidance document, DOE also stated that if a company intended to claim ratings
for each combination of outdoor unit and indoor unit, it must certify all possible model
combinations as separate basic models. Only the basic model combinations that include a
highest sales volume combination (HSVC) indoor unit for a given outdoor unit must be tested,
while the other basic models may be rated with an ARM. Alternatively, the manufacturer could
make all combinations of a given model of outdoor unit part of the same basic model and not rate
all individual combinations. However, all combinations within the basic model would have to
have the same represented efficiency, based on the least efficient combination. This association
5
DOE notes that a blower coil indoor unit may consist of separate units, one that includes the indoor coil and
another that is an air mover, either a modular blower or a furnace. Alternatively, a blower coil indoor unit may be a
single unit that includes both the indoor coil and the indoor fan. Hence, in further discussion, “blower coil indoor
unit” may be any one of these three options.
22
In response to the draft guidance document, AHRI and Johnson Controls (JCI) stated that
there was a difference between DOE’s definition of Basic Model and the industry’s use of Basic
Johnson Controls specified that most manufacturers consider a specific outdoor model with all
combinations of indoor units to be a basic model and notes that DOE’s definition appeared to
allow outdoor units to be combined into a basic model if they share the same ratings. (Id.)
DOE reviewed AHRI’s Operations Manual for Unitary Small Air-Conditioners and Air-
Source Heat Pumps (Includes Mixed-Match Coils) (Rated Below 65,000 Btu/h) Certification
Program (AHRI OM 210/240 – January 2014). 6 This document specifies the following
definitions:
“A Split System BMG [Basic Model Group 7] consists of products with the same Outdoor
Unit used with several Indoor Unit combinations (i.e. horizontal, vertical, A-coil, etc.).
Same Outdoor Unit refers to models with the same or comparable compressor, used with
the same outdoor coil surface area and the same outdoor air quantity.”
“An ICM [Independent Coil Manufacturer] BMG consists of coils (Indoor Units) with
matching capacity ranges of 6,000 Btu/h and the following identical geometry
6
Available at: www.ahrinet.org/App_Content/ahri/files/Certification/OM%20pdfs/USE_OM.pdf (Last accessed
March 20, 2015.)
7
According to the AHRI General Operations Manual, a basic model is a product possessing a discrete performance
rating, whereas a basic model group is a set of models that share characteristics that allow the performance of one
model to be representative of the group, although the group does not have to share discrete performance. (General
OM – October 2013). Available at:
www.ahrinet.org/App_Content/ahri/files/Certification/OM%20pdfs/General_OM.pdf. (Last accessed March 24,
2015.)
23
parameters: air-handler, evaporator fan type, evaporator number of rows, type of
evaporator fin types, evaporator fins/inch, evaporator tube OD, evaporator expansion
device, fin length per slab, fin height per slab, number of slabs in the coil, fin material
type, tube material type, and total number of active tubes (refer to Table H1).”
In order to create consistency within the industry, DOE proposes to modify its basic
model definition for central air conditioners and heat pumps. Specifically, DOE proposes that
manufacturers would have a choice in how to assign individual models (for single-package units)
or combinations (for split systems) to basic models. Specifically, manufacturers may consider
each individual model/combination its own basic model, or manufacturers may assign all
individual models of the same single-package system or all individual combinations using the
same model of outdoor unit (for outdoor unit manufacturers (OUM)) or model of indoor unit (for
DOE believes that this proposal is consistent with the existing general definition of basic
model which refers to all units having the same primary energy source and having essentially
identical electrical, physical, and functional characteristics that affect energy consumption or
energy efficiency. However, DOE proposes to further define the physical characteristics
(i) for split-systems manufactured by independent coil manufacturers (ICMs) and for
small-duct, high velocity systems: all individual combinations having the same model of
24
indoor unit, which means the same or comparably performing indoor coil(s) [same face
area; fin material, depth, style (e.g. wavy, louvered), and density (fins per inch); tube
pattern, material, diameter, wall thickness, and internal enhancement], indoor fan(s)
[same air flow with the same indoor coil and external static pressure, same power input],
controls.
(ii) for split-systems manufactured by outdoor unit manufacturers (OUMs): all individual
combinations having the same model of outdoor unit, which means the same or
comparably performing compressor(s) [same displacement rate (volume per time) and
same capacity and power input when tested under the same operating conditions],
outdoor coil(s) [same face area; fin material, depth, style (e.g. wavy, louvered), and
density (fins per inch); tube pattern, material, diameter, wall thickness, and internal
enhancement], outdoor fan(s) [same air flow with the same outdoor coil, same power
The proposed requirements for single-package models combine the requirements listed
describing the characteristics of the same models of indoor units and same models of outdoor
units. DOE requests comment on its proposal to modify the definition of “basic model”, as well
as the proposed physical characteristics required for assigning individual models or combinations
25
If manufacturers assign each individual model or combination to its own basic model,
DOE proposes that each individual model/combination must be tested and that an AEDM cannot
be applied. This option would limit a manufacturer’s risk in terms of noncompliance but would
OUMs) or model of indoor unit (for ICMs) to a single basic model, DOE further proposes that,
in contrast to the draft guidance document and DOE’s current regulations, each individual
combination within a basic model (i.e., having the same model of outdoor unit for OUMs, or
having the same model of indoor unit for ICMs) must be certified with a rating determined for
that individual combination. In other words, individual combinations within the same basic
model that have different SEER ratings, for example, would be certified with their individual
ratings, rather than with the lowest SEER of the basic model. However, only one individual
combination in each basic model would have to be tested (see section III.A.3.a), while the others
may be rated using an AEDM. This option reduces testing burden but increases risk.
Specifically, if any one of the combinations within a basic model fails to meet the applicable
standard, then all of the combinations within the basic model fail, and the entire basic model
must be taken off the market (i.e., the model of outdoor unit for OUMs and the model of indoor
unit for ICMs). All combinations offered for sale (e.g., for OUMs, based on a given model of
outdoor unit which is the basis of the basic model) must be certified, and all of these
combinations within the basic model must meet applicable standards. DOE notes that under this
proposed rule, ICMs and OUMs will continue to have an independent obligation to test, provide
26
By way of example, a manufacturer has two models of outdoor units, models A and B.
Each of models A and B can be paired with any of three models of indoor units – models 1, 2,
and 3. Per the guidance document, the manufacturer could either: (1) make each combination a
separate basic model (i.e., A-1, A-2, A-3, B-1, B-2, and B-3), test the HSVC for each model of
outdoor unit (A and B), and rate the other basic models with an ARM; (2) make each
combination a separate basic model and test each of them; or (3) make combinations A-2 and A-
3 part of basic model A-1 (and similarly B-2 and B-3 part of B-1) and represent the efficiency of
all three with the same certified rating at the least efficient combination in the basic model. In
this proposal, the manufacturer could either: (1) make each combination a separate basic model
and test and rate each combination; or (2) make combinations A-2 and A-3 part of basic model
A-1 (and similarly B-2 and B-3 part of B-1), test the HSVC combination for the model of
outdoor unit, and test or use an AEDM to rate the efficiency of all other combinations in the
basic model.
DOE notes that unlike in the current “basic model” definition that contains less detail on
what constitutes essentially identical characteristics, under DOE’s new proposal, manufacturers
would not be able to assign different models of outdoor units (for OUMs) or models of indoor
units (for ICMs) to a single basic model Based on a review of certification data, it appears that
most manufacturers are not currently doing this, so DOE expects this proposal to have limited
27
Additional rating and certification requirements for single-package models and multi-
Revisions to the test procedure as proposed in section III.D of this SNOPR enable the
determination of off mode power consumption, which reflects the operation of the contributing
components: crankcase heater and low-voltage controls. Varying designs of these components
produce different off mode power consumption. DOE proposes that if individual combinations
that are otherwise identical are offered with multiple options for off mode related components,
manufacturers at a minimum must rate the individual combination with the crankcase heater and
controls which are the most consumptive (i.e., would result in the largest value of PW,OFF). If a
manufacturer wishes to also make representations for less consumptive off mode options for the
same individual combination, the manufacturer may provide separate ratings, but the
manufacturer must differentiate the individual model numbers for these ratings. These individual
combinations would be within the same basic model. DOE discusses this in relation to single-
DOE also proposes to clarify that a central air conditioner or central air conditioning heat
pump may consist of: a single-package unit; an outdoor unit and one or more indoor units (e.g., a
single-split or multi-split system); an indoor unit only (rated as a combination by an ICM with an
OUM’s outdoor unit); or an outdoor unit only (with no match, rated by an OUM with the coil
specified in this test procedure). DOE has proposed adding these specifications to the definition
of central air conditioner or central air conditioning heat pump in 10 CFR 430.2. In the
certification reports submitted by OUMs for split systems, DOE proposes that manufacturers
28
must report the basic model number as well as the individual model numbers of the indoor
2. Additional Definitions
In order to specify differences in the proposed basic model definition for ICMs and
With respect to any given basic model, a manufacturer could be an ICM or an OUM.
DOE notes that the use of the term “manufacturer” in these definitions refers to any person who
12).
DOE also proposes to define variable refrigerant flow (VRF) systems as a kind of multi-
split system. DOE notes that not all VRF systems are commercial equipment. Therefore, the
proposed definition also clarifies that VRF systems that are single-phase and less than 65,000
btu/h are a kind of central air conditioners and central air conditioning heat pumps.
DOE also proposes to modify the definition of indoor unit. DOE noted in market
research that ICMs may not always provide cooling mode expansion devices with indoor units.
Therefore to provide clarity in the testing and rating requirements, DOE proposes to change the
29
definition of “indoor unit” to clarify that it may not include the cooling mode expansion device.
Also, for reasons discussed in section III.A.3.f, DOE proposes to include the casing in the
Indoor unit transfers heat between the refrigerant and the indoor air, and consists of an
indoor coil and casing and may include a cooling mode expansion device and/or an air
moving device.
DOE proposes to specify in Appendix M that if the indoor unit does not ship with a
cooling mode expansion device, the system should be tested using the device as specified in the
installation instructions provided with the indoor unit, or if no device is specified, using a TXV.
DOE notes that the AHRI program does not appear to assume that the expansion device is
necessarily provided with the coil, i.e., AHRI’s operations manual specifies that for testing for
the AHRI certification program, the ICM must provide an indoor coil and expansion device.
Finally, DOE is proposing to clarify several other definitions currently in 10 CFR 430.2
with minor wording changes and move them to 10 CFR 430, Subpart B, Appendix M. The
proposed definition of central air conditioner or central air conditioning heat pump in 10 CFR
430.2 refers the reader to the additional central air conditioner-related definitions in Appendix
M. Locating all of the relevant definitions in the appendix will make it easier to find and
reference them. DOE also proposes to remove entirely the definitions for “condenser-evaporator
coil combination” and “coil family” as those terms no longer appear in the proposed regulations.
30
3. Determination of Certified Rating
During the regional standards Working Group meetings, participants invested a great deal
of time and energy discussing the relationship between system ratings and an effective
enforcement plan. As part of the negotiations, the Working Group requested that DOE issue
guidance regarding the applicability of regional standards to indoor units and outdoor units
indoor and outdoor units. DOE developed two draft guidance documents to address these issues.
After consideration of the Working Group’s discussions and the comments received on the two
draft guidance documents, DOE determined that regulatory changes would be necessary to
implement the approach agreed to by the Working Group. DOE is proposing several of those
regulatory changes as part of this rulemaking. The remainder of the necessary regulatory
rulemaking.
During the pendency of the rulemakings (CAC TP and Regional Standards), DOE
reaffirms its commitment to the approach advocated by the Working Group, subject to
consideration of comments received in the rulemakings to effectuate the necessary changes to the
regulations. The following sections describe the two guidance documents and DOE’s proposals
In the August 20, 2014 draft guidance document (Aug 20 Guidance) (EERE-2014-BT-
GUID-0032), DOE proposed to clarify that when selecting which split-system air conditioner
31
and heat pump units to test (in accordance with the DOE test procedure), a unit of each outdoor
model must be paired with a unit of one selected indoor model. 10 CFR 429.16(a)(2)(i).
Specifically, the manufacturer must test the condenser-evaporator coil combination that includes
the model of evaporator coil that is likely to have the largest volume of retail sales with the
particular model of condensing unit. 10 CFR 429.16(a)(2)(ii) (This combination is also known
as the highest sales volume combination or HSVC.) That is, the HSVC for each condensing unit
may not be rated using an ARM. (See section III.B regarding DOE’s proposal to switch from
The guidance further stated that for any other split-system combination that includes the
same outdoor unit model but a different indoor unit model than the HSVC, manufacturers may
determine represented values of energy efficiency (including those values that, for each
or heat pump basic model combination either by testing the combination in accordance with the
DOE test procedure or by applying an ARM that has been approved by DOE in accordance with
the provisions of 10 CFR 429.70(e)(1) and (2). 10 CFR 429.16(a)(2)(ii)(A) and (B)(1).
In the August 19, 2014 draft guidance document (August 19 Guidance) (EERE-2014-BT-
GUID-0033), DOE proposed to clarify that split-system central air conditioners other than those
with single-speed compressors may be tested and rated using a blower coil only if the
condensing unit is sold exclusively for use with a blower coil indoor unit. 10 CFR
429.16(a)(2)(ii). The guidance stated that there is no provision in the Code of Federal
Regulations (CFR) permitting use of a blower coil for testing and rating a split-system central air
32
conditioner where the condensing unit is also offered for sale with a coil-only indoor unit, and
that, furthermore, there is no provision in the CFR permitting the use of a blower coil for testing
Commenters generally agreed with the information in the August 20 Guidance regarding
selecting units for testing, rating, and certifying split-system combinations. In addition, in
response to the August 19 Guidance, DOE received nearly identical comments from several
stakeholders generally agreeing with the intent of the guidance to emphasize that single-speed
compressor products must be tested and rated with a coil-only system as HSVC. (Docket No.
3) These stakeholders, as well as Mortex, clarified that other combinations besides the HSVC,
including blower coil combinations, can be rated through testing or using an ARM. (Id.; Mortex,
“Split-system central air conditioners with single-speed compressors must be tested and
rated using a coil-only for the HSVC. 10 CFR 429.16(a)(2)(ii). Such single-speed
systems may be rated with other coil-only and blower coil indoor units through the use of
blowercoil for testing and rating a condensing unit with a single-speed compressor for the
HSVC, unless:
33
• [Version 2] the unit is sold and installed only with blower-coil indoor units.”
AHRI and several manufacturers disputed that when using a compressor other than single
speed, the HSVC can never be a blower coil unless it is exclusively used with a blower coil.
AHRI and the manufacturers reported that many multi-stage capacity products are tested and
rated with high efficiency blower coil or furnace products as the HSVC even though those
systems are also rated for coil-only use. (Docket No. EERE-2014-BT-GUID-0033, AHRI No. 8
No. 10 at p. 2; Rheem, No. 2 at p. 2; Carrier, No. 7 at p. 1) Johnson Controls responded that they
test and rate multi-speed compressor units with blower coils or furnace/coils as the HSVC. (JCI,
No. 5 at p. 3). AHRI and the manufacturers reported that not allowing this could limit the
application of high performing products, and that it is important for units designed for blower
coil to also be rated as coil-only to offer certain consumers a compromise of cost and
performance. AHRI and the manufacturers proposed the following modified language:
“Split-system central air conditioners other than those with single-speed compressors
(two-stage or multi-stage) may be tested and rated using a blower-coil only as HSVC
only if the condensing unit design intent is for use with a blower-coil indoor unit (e.g. the
evaporator coil that is likely to have the largest volume of retails sales with the particular
34
(Docket No. EERE-2014-BT-GUID-0033, AHRI No. 8 at p. 3; Nordyne, No. 9 at p. 2;
After reviewing the comments, DOE proposes to make changes to 10 CFR 429.16 to
revise the testing and rating requirements for single-split-system air conditioners. (See section
will occur in two phases. In the first phase, prior to the compliance date of any amended energy
conservation standards, DOE proposes only a slight change to the current requirements.
Specifically, DOE proposes that for single-split-system air conditioners with single capacity
condensing units, each model of outdoor unit must be tested with the model of coil-only indoor
unit that is likely to have the largest volume of retail sales with the particular model of outdoor
unit. For split-system air conditioners with other than single capacity condensing units each
model of outdoor unit must also be tested with the model of coil-only indoor unit likely to have
the largest sales volume unless the model of outdoor unit is sold only with model(s) of blower
coil indoor units, in which case it must be tested and rated with the model of blower coil indoor
unit likely to have the highest sales volume. However, any other combination may be rated
through testing or use of an AEDM. (See section III.B regarding proposed changes from ARM
to AEDM.) Therefore, both single capacity and other than single capacity systems may be rated
with models of both coil-only or blower coil indoor units, but if the system is sold with a model
35
In the second phase, DOE anticipates that any amended energy conservation standards
will be based on blower coil ratings. Therefore, DOE proposes that all single-split-system air
conditioner basic models be tested and rated with the model of blower coil indoor unit likely to
have the largest volume of retail sales with that model of outdoor unit. Manufacturers would be
required to also rate all other blower coil and coil-only combinations within the basic model but
would be permitted do so through testing or an AEDM. DOE believes that this proposal will
offer the benefits of design for high performance through the use of blower coils as well as
providing appropriate representations for coil-only combinations. In addition, given that most
basic models are currently submitted as blower coil ratings, this change will align DOE
requirements with industry practice. This proposed change would also be accounted for in the
parallel energy conservation standards rulemaking, and is contingent upon any proposed
36
Table III.1: Test Requirements for Single-Split-System Non-Space-Constrained Air
37
In order to facilitate these changes, DOE also proposes definitions of blower coil indoor
• Blower coil indoor unit means the indoor unit of a split-system central air
blower housed with the coil or a separate designated air mover such as a furnace
• Blower coil system refers to a split-system that includes one or more blower coil
indoor units.
• Coil-only indoor unit means the indoor unit of a split-system central air
conditioner or heat pump that includes a refrigerant-to-air heat exchanger coil and
may include a cooling-mode expansion device, but does not include an indoor
blower housed with the coil, and does not include a separate designated air mover
• Coil-only system refers to a system that includes one or more coil-only indoor
units.
DOE notes that these proposed testing requirements, when combined with the proposed
definition for basic model, require that each basic model have at least one rating determined
38
DOE also proposes that in the certification report, manufacturers state whether each
DOE seeks comment on its proposed changes to the determination of certified ratings for
The current requirements for split-system heat pumps in 10 CFR 429.16 require testing a
condenser-evaporator coil combination with the evaporator coil likely to have the largest volume
of retail sales with the particular model of condensing unit. The coil-only requirement does not
apply to split-system heat pumps, because central heat pump indoor units nearly always include
In this notice, DOE proposes to slightly modify the wording explaining this requirement;
specifically, the requirement would use the more general terms “indoor unit” and “outdoor unit,”
rather than “evaporator coil” and “condensing unit,” since the requirement addresses heat pumps.
DOE also proposes to apply this same test requirement to space-constrained split-system air
conditioners and heat pumps. The current requirements in 10 CFR 429.16 do not specifically
call out space-constrained systems, and as such, the current coil-only requirements for split-
system air conditioners apply to space-constrained split-system air conditioners. Therefore, this
proposal will change test procedures for space-constrained split-system air conditioners but will
39
not change, other than in nomenclature, the test procedures for space-constrained split-system
heat pumps.
The current requirements in 10 CFR 429.16(a)(2)(ii) specify that multi-split systems and
mini-split systems designed to always be installed with more than one indoor unit (now proposed
combination” as defined in 10 CFR 430.2. For multi-split systems, each model of condensing
unit currently must be tested with a non-ducted tested combination and a ducted tested
combination. Furthermore, current requirements for testing with a coil-only indoor unit do not
apply to mini-splits or multi-splits, as the general use of these terms in the industry refers to
The current requirements also state that for other multi-split systems that include the
same model of condensing unit but a different set of evaporator coils, whether the evaporator
coil(s) are manufactured by the same manufacturer or by a component manufacturer (i.e., ICM),
the rating must be: (1) set equal to the rating for the non-ducted indoor unit system tested (for
systems composed entirely of non-ducted units), (2) set equal to the rating for the ducted indoor
unit system tested (for systems composed entirely of ducted units), or (3) set equal to the mean of
the values for the two systems (for systems having a mix of non-ducted and ducted indoor units).
40
In this notice, DOE proposes a slight modification to the testing requirements for single-
zone-multiple-coil and multi-split systems, and adds similar requirements for testing multi-
circuit systems (see section III.C.2 for more information about these systems). DOE also
clarifies that these requirements apply to VRF systems that are single-phase and less than 65,000
Btu/h (see section III.A.3.c for more details). For all multi-split, multi-circuit, and single-zone-
multiple-coil split systems, DOE proposes that at a minimum, each model of outdoor unit must
be tested as part of a tested combination (as defined in the CFR) composed entirely of non-
ducted indoor units. For any models of outdoor units also sold with short-ducted indoor units, a
second “tested combination” composed entirely of short-ducted indoor units would be required
to be tested. DOE also proposes the manufacturers may rate a mixed non-ducted/short-ducted
combination as the mean of the represented values for the tested non-ducted and short-ducted
combinations.
Under the proposed definition of basic model, these three combinations (non-ducted,
short-ducted, and mixed) would represent a single basic model. When certifying the basic model,
manufacturers should report “***” for the indoor unit model number, and report the test sample
size as the total of all the units tested for the basic model, not just the units tested for each
combination. For example, if the manufacturer tests 2 units of a non-ducted combination and 2
units of a short-ducted combination, and also rates a mix-match combination, the manufacturer
should specify “4” as the test sample size for the basic model, while providing the rating for each
combination. DOE also proposes that manufacturers be allowed to test and rate specific
individual combinations as separate basic models, even if they share the same model of outdoor
41
unit. In this case, the manufacturer must provide the individual model numbers for the indoor
units rather than stating “***”. Table III.2 provides an example of both situations.
Individual
Basic Individual Model Model (Indoor Sample Ducted Non-ducted Mix
Model (Outdoor Unit) Unit) Size Rating Rating Rating
ABC ABC *** 4 14 15 14.5
ABC1 ABC 2-A123; 3-JH746 2 17
DOE requests comment on whether additional requirements are necessary for multi-split
systems paired with models of conventional ducted indoor units rather than short-duct indoor
units.
DOE also notes that the test procedure currently allows testing of only non-ducted or
short-ducted systems, and not combinations of the two. Therefore to rate individual mix-match
combinations, manufacturers would have to test 4 units – 2 ducted and 2 short-ducted. DOE
requests comment on whether manufacturers should have the ability to test mix-match systems
using the test procedure rather than rating them using an average of the other tested systems.
DOE also requests comment on whether manufacturers should be able to rate mix-match systems
using other than a straight average, such as a weighting by the number of non-ducted or short-
ducted units. Finally, DOE requests comment on whether the definition of “tested combination”
given more flexibility, such as testing with more than 5 indoor units.
42
In reviewing the market for multi-split systems, DOE determined that some are sold by
OUMs with only models of small-duct, high velocity (SDHV) indoor units, or with a mix of
models of short-duct and SDHV units. (See section III.F.2 regarding the proposed definition of
short ducted systems.) These kinds of units are not currently explicitly addressed in DOE’s test
requirements. Therefore, DOE proposes to add a requirement that for any models of outdoor
units also sold with models of SDHV indoor units, a “tested combination” composed entirely of
SDHV indoor units must be used for testing and rating. However, such a system must be
DOE notes that multi-split systems consisting of a model of outdoor unit paired with
models of non-ducted or short-ducted units must meet the energy conservation standards for
split-system air conditioners or heat pumps, while systems consisting of a model of outdoor unit
paired with models of small-duct, high-velocity indoor units must meet SDHV standards. DOE
proposes to add a limitations section in 429.16 that would require models of outdoor units that
are rated and distributed in combinations that span multiple product classes to be tested and
certified as compliant with the applicable standard for each product class. Even if a manufacturer
sells a combination including models of both SDHV and other non-ducted or short-ducted indoor
units, DOE proposes that the manufacturer may not provide a mix-match rating for such
combinations. DOE requests comment on whether manufacturers would want to rate such
combinations, and if so, how they would prefer to rate them (i.e., by by taking the mean of a
sample of tested non-ducted units and a sample of tested SDHV units or by testing a combination
on non-ducted and SDHV units), and whether the SDHV or split-system standard would be most
appropriate.
43
DOE understands that manufacturers of multi-split systems commonly only test one
sample rather than complying with the sampling plan requirements in 429.16(a)(2)(i), which
require a sample of two. DOE may consider moving toward a single unit sample for single-zone
multiple-coil and multi-split system models, but in order to do so, DOE requires information on
manufacturing and testing variability associated with these systems. In particular, DOE requires
data to allow it to understand how a single unit sample may be representative of the population.
DOE also requests information on what tolerances would need to be applied to the ratings of
these units based on a single unit sample in order to account for the variability.
The current requirements in 10 CFR 429.16(a) require that each condensing unit of a split
system must be tested using the HSVC associated with that condensing unit. There are no
current requirements for testing each model of indoor unit of a split system. Non-HSVC
combinations can be rated using an ARM, assuming the condensing unit of the combination has
a separate HSVC rating based on testing. DOE understands that ICMs typically do not test all of
their models of indoor units, but rather use OUM test data for outdoor units to generate ratings
for their models. (See section III.B on AEDMs for further information.) In this notice, DOE
proposes that ICMs must test and provide certified ratings for each model of indoor unit (i.e.,
basic model) with the least-efficient model of outdoor unit with which it will be paired, where
the least- efficient model of outdoor unit is the outdoor unit in the lowest-SEER combination as
certified by the OUM.. If more than one model of outdoor unit (with which the ICM wishes to
44
rate the model of indoor unit) has the same lowest-SEER rating, the ICM may select one for
testing purposes. This applies to both conventional (i.e., non-short-duct, non-SDHV) split-
systems and SDHV systems. ICMs must rate all other individual combinations of the same
model of indoor unit, but may determine those ratings through testing or use of an AEDM.
DOE understands that this proposal would increase test burden for ICMs beyond the
testing they currently conduct to meet ARM validation requirements. However, DOE believes
this burden is outweighed by the benefit of providing more accurate ratings for models of indoor
units sold by ICMs. Additional discussion regarding potential test requirements for ICMs can be
DOE understands that the proposed definition of basic model for an ICM, including what
constitutes the “same” model of indoor unit and thus would be required to be tested, is important
for accurately assessing the test burden for manufacturers as a result of this test proposal. DOE
seeks comment on the basic model definition in section III.A.1. DOE also seeks comment on the
e. Single-Package Systems
In the current regulations, 10 CFR 429.16(a)(2)(i) states that each single-package system
a must have a sample of sufficient size tested in accordance with the applicable provisions of
Subpart B. In this notice, DOE proposes that the lowest SEER individual model within each
basic model must be tested. DOE expects that in most cases, each single-package system will
represent its own basic model. However, based on the proposal for the definition of basic model
45
in section III.A.1, this may not always be the case. DOE notes that regardless, AEDMs do not
apply to single-package models – manufacturers may either test and rate each individual single-
package model, or if multiple individual models are assigned to the same basic model per the
proposed requirements in the basic model definition, the manufacturer would be required to test
only the lowest SEER individual model within the basic model and use that to determine the
package units meeting the requirements proposed in the basic model definition to be assigned to
the same basic model. DOE also requests comment on whether, if manufacturers are able to
assign multiple individual models to a single basic model, manufacturers would want to use an
AEDM to rate other individual models within the same basic model other than the lowest SEER
individual model. Finally, DOE requests comment on whether manufacturers would want to
employ an AEDM to rate the off-mode power consumption for other variations of off-mode
associated with the basic model other than the variation tested.
DOE also proposes to specify this same requirement for space-constrained single-
package air conditioners and heat pumps, which are currently not explicitly identified in the test
requirement section.
f. Replacement Coils
DOE stated in the August 20 Guidance that an individual condensing unit or coil must
meet the current Federal standard (National or regional) when paired with the appropriate other
46
new part to make a system when tested in accordance with the DOE test procedure and sampling
plan.
In response, AHRI and manufacturers commented that they believed the intent of the
guidance was to clarify how the outdoor section of a split system used in a replacement situation
can be tested and rated to meet the appropriate efficiency requirements. However, they felt this
language should not apply to the indoor coil. AHRI stated that indoor coil is rarely changed and
when it is, such as for an irreparable leak, it requires an exact replacement. In addition, they note
that warranties can extend up to 10 years. Commenters also expressed the view that the
guidance would not result in an improvement to installed product efficiency. (Docket No.
pp. 2-3; Ingersoll Rand, No. 3 at p. 2; Lennox, No. 4 at p. 2; Nordyne, No. 9 at p. 2) AHRI and
the manufacturers recommended removing indoor coils from the draft guidance language on
Johnson Controls added further detail that using the term coil does not differentiate
between service parts (listed with part numbers) and finished component assemblies (listed as a
coil model) or between evaporator coils and condenser coils. Johnson Controls added that
replacement parts cannot be rated as a finished coil assembly because the replacement parts do
not contain sheet metal parts required to complete the installation. They also added that where
the physical characteristics of an evaporator coil are significantly different when compared to a
new system, replacing the old evaporator coil with a new coil model rather than a replacement
47
part could result in increased cost and reduced performance, reliability, and comfort. (Docket
Mortex also commented that replacement with a different evaporator coil design and size
could lead to issues of fitting or size constraint problems and refrigerant metering and charging
differences. The end result (if design air volume rate is hampered and refrigerant circuit
performance is modified) could lead to less efficiency than the pre-failure situation. (Docket No.
DOE also notes that the ASRAC regional standards enforcement Working Group agreed
that manufacturers do not need to keep track of components including uncased coils. (Docket
In consideration of the comments and the Working Group proposals, DOE notes that its
proposed definition of “indoor unit” refers to the box rather than just a coil. Accordingly, legacy
indoor coil replacements and uncased coils would not meet the definition of indoor unit.
Furthermore, by defining air conditioners and heat pumps as consisting of a single-package unit,
an outdoor unit and one or more indoor units, an indoor unit only, or an outdoor unit only, legacy
indoor coil replacements and uncased coils would not meet the definition of a central air
conditioner or heat pump. Hence, they would not need to be tested or certified as meeting the
standard.
48
g. Outdoor Units with No Match
For split-system central air conditioners and heat pumps, current DOE regulations require
that manufacturers test the condensing unit and “the evaporator coil that is likely to have the
largest volume of retail sales with the particular model of condensing unit” (commonly referred
2010, the U.S. Environmental Protection Agency (EPA) banned the sale and distribution of those
central air conditioning systems and heat pump systems that are designed to use HCFC-22
refrigerant. 74 Fed. Reg. 66450 (Dec. 15, 2009). EPA’s rulemaking included an exception for
the manufacture and importation of replacement components, as long as those components are
inquired how to test and rate individual components—because these components are sold
separately, there are no highest sales volume combinations. Because the EPA prohibits
distribution of new HCFC-22 condensing unit and coil combinations (i.e., complete systems),
there is no such thing as a HSVC, and hence, testing and rating of new HCFC-22 combinations
DOE expects that the HCFC-22 indoor and outdoor units remaining on the market are
part of legacy offerings that were initially sold five or more years ago. These components of
HCFC-22 systems were in production for sale as part of matched systems before the EPA
regulations became effective on January 1, 2010. While EPA’s rulemaking bans the sale of
HCFC-22 systems that are charged with refrigerant while allowing sale of uncharged
49
components of such systems, EPA’s rule has no effect on the efficiency rating of these systems
or on requirements for DOE efficiency standards that they must meet. The DOE test procedure
used prior to January 15, 2010 that would have been used to rate these systems is no longer valid,
thus these ratings can no longer be used as the basis for representing their efficiency. The
individual indoor coils and outdoor units of such systems that could potentially meet the current
standard may continue to be manufactured only if the manufacturer uses a valid test procedure to
Generally, when a model cannot be tested in accordance with the DOE test procedure,
manufacturers must submit a petition for a test procedure waiver for DOE to assign an
alternative test method. 10 CFR 430.27(a)(1) Instead, DOE proposes in this notice a test
procedure that may be used for rating and certifying the compliance of these outdoor units. DOE
proposes in this notice to specify coil characteristics that should be used when testing models of
outdoor units that do not have a HSVC. Specifically, these requirements include limitations on
coil tube geometries and dimensions and coil fin surface area. These outdoor unit models, when
tested with the specified indoor units, must meet applicable Federal standards. (See section
III.A.4 for more information on compliance.) This proposal is consistent with the regional
replacement outdoor unit unless it is certified as part of a combination that meets the applicable
would be effective (i.e., allowed for use for such certifications) 30 days after it is finalized and
would be required for use for such systems (i.e., rather than any granted waiver test procedure)
50
In response to the August 20, 2014 draft guidance document, Carrier requested
clarification that the finalized guidance would replace DOE’s draft guidance document issued on
January 1, 2012, regarding central air conditioning systems and air conditioning heat pump
systems that are designed to use dry R-22 condensing units. (Docket No. EERE-2014-BT-
GUID-0032, Carrier, No. 7 at p. 2) If finalized, this proposed test procedure would replace both
the 2012 guidance document for dry R-22 units as well as the 2014 draft guidance document on
discussed whether each basic model of split-system air conditioner or heat pump has to meet the
applicable standard. DOE stated that compliance with standards is based on the statistical
concept that an entire population of units (where “unit” refers to a complete system) of a basic
model must meet the standard, recognizing that efficiency measurements for some units may be
better or worse than the standard due to manufacturing or testing variation. Manufacturers apply
the statistical formulae in 10 CFR 429.16 to demonstrate compliance, and DOE applies the
Further, DOE stated that the only condensing units and coils that may be installed in the
region are those that can meet the regional standard when tested and rated as a new system in
accordance with the test procedure and sampling plan as described above.
51
In response, AHRI and several manufacturers recommended the following additions to
“Compliance with national or regional standards is based on the statistical concept that an
entire population of units (where “unit” refers to a complete system) of a basic model
including Highest Sales Volume Tested Combination and all other combinations must
meet the standard, recognizing that some individual units may perform slightly better or
In addition, Carrier commented that with respect to the discussion about selection of units
for testing, the HSVC should be determined for the applicable region. (Docket No. EERE-2014-
AHRI and several manufacturers recommended the following addition to the paragraph
“In summary, DOE interprets for the regional standard to require that the least efficient
rating combination for a specified model of condensing unit must be 14 SEER with a coil
only rating where 14 SEER is the regional standard. Any model that has a certified
combination below the regional standard cannot be installed in the region. This
interpretation of the regional standard also applies to units shipped without refrigerant
charge.”
52
(Docket No. EERE-2014-BT-GUID-0032, AHRI, No. 8 at p. 2; Rheem, No. 2 at p. 3;
“Given the different Federal standards, National and regional, the least efficient rating
combination for a specified model of condensing unit must: (i) in the regions where the
regional standard applies, be rated and certified on as performing at or above the current
regional standard with a coil only rating; and (ii) where the National standard applies, be
rated and certified as performing at or above the current National standard with a coil
only rating. For purposes of clarity, any basic model that has a certified combination
below the current regional standard cannot be installed in the region. This interpretation
In contrast, Carrier also suggested that the guidance document discussion of unit
selection and basic models should replace references to “Federal standard” with “Federal
The regional standards enforcement Working Group suggested the regional standards
required clarification because a particular condensing unit may have a range of efficiency ratings
when paired with various indoor evaporator coils and/or blowers. The Working Group provided
the following four recommendations to clarify the regional standards: that (1) the least-efficient
rated combination for a specified model of condensing unit must be 14 SEER for models
53
installed in the Southeast and Southwest regions; (2) the least-efficient rated combination for a
specified model of condensing unit must meet the minimum EER for models installed in the
Southwest region; (3) any condensing unit model that has a certified combination that is below
the regional standard(s) cannot be installed in that region; and (4) a condensing unit model
certified below a regional standard by the original equipment manufacturer cannot be installed in
a region subject to a regional standard(s) even with an independent coil manufacturer’s indoor
coil or air handler combination that may have a certified rating meeting the applicable regional
After reviewing stakeholder comments and the Working Group report, DOE agrees that
all individual models or combinations within a basic model must meet the applicable national or
regional standard. DOE proposes to add requirements to the relevant provisions of section
430.32 that the least-efficient combination of each basic model must comply with the regional
In addition, as noted in section III.A.1, DOE proposes that if any individual combination
within a basic model fails to meet the standard, the entire basic model (i.e., model of outdoor
unit) must be removed from the market. In order to clarify the limitations on sales of models of
outdoor units across regions with different standards, DOE proposes to add a limitation in
section 429.16 that any model of outdoor unit that is certified in a combination that does not
meet all regional standards cannot also be certified in a combination that meets the regional
standard(s). Outdoor unit model numbers cannot span regions unless the model of outdoor unit
is compliant with all standards in all possible combinations. If a model of outdoor unit is
54
certified below a regional standard, then it must have a unique individual model number for
5. Certification Reports
DOE proposes to clarify what basic model number and individual model numbers must
Type Number 1 2 3
Number unique
Single Package Package N/A N/A
to the basic
model
Air Mover (or
N/A if rating
Number unique
Split System coil-only system
to the basic Outdoor Unit Indoor Unit(s)
(rated by OUM) or fan is part of
model
indoor unit
model number)
Number unique
Outdoor Unit
to the basic Outdoor Unit N/A N/A
Only
model
55
Split-System or Number unique
SDHV (rated by to the basic Outdoor Unit Indoor Unit(s) N/A
ICM) model
Each basic model number must be unique in some way so that all individual models or
not public and will not be displayed in DOE’s database. Several proposed requirements are
relation to test procedure changes. In addition, several other requirements are discussed in this
section.
In order for DOE to replicate the test setup for its assessment tests, DOE proposes that
systems report the number of indoor units tested with the outdoor unit, the nominal cooling
capacity of each indoor unit and outdoor unit, and the indoor units that are not providing heating
or cooling for part-load tests. Manufacturers that wish to certify systems that operate with
multiple indoor fans within a single indoor unit shall report the number of indoor fans; the
nominal cooling capacity of the indoor unit and outdoor unit; which fan(s) are operating to attain
the full-load air volume rate when controls limit the simultaneous operation of all fans within the
single indoor unit; and the allocation of the full-load air volume rate to each operational fan
56
Similarly, DOE proposes that for those models of indoor units designed for both
horizontal and vertical installation or for both up-flow and down-flow vertical installations, the
orientation used during certification testing shall be included on the certification test reports.
DOE also proposes that the maximum time between defrosts as allowed by the controls
be included on the certification test reports. For units with time-adaptive defrost control, the
frosting interval used during the Frost Accumulation tests and the associated procedure for
manually initiating defrost at the specified time, if applicable, should also be included on the
DOE also proposes that for variable-speed units, the compressor frequency set points and
the required dip switch/control settings for step or variable components should be included. For
variable-speed heat pumps, DOE proposes that manufacturers report whether the unit controls
restrict use of minimum compressor speed operation for some range of operating ambient
conditions, whether the unit controls restrict use of maximum compressor speed operation for
any ambient temperatures below 17°F, and whether the optional H42 low temperature test was
Finally, DOE proposes that manufactures report air volume rates and airflow-control
settings.
increases reporting burden because manufacturers must spend additional time to add such
57
content to the report. However, DOE believes that a knowledgeable person in the field would
not find the additional information difficult to provide and could do so in a reasonable amount of
time. Thus, DOE does not believe that the added reporting requirements are significantly
6. Represented Values
DOE proposes to make several additions to the represented value requirements in 10 CFR
429.16. First, DOE proposes to add a requirement that the represented value of cooling capacity,
heating capacity, and sensible heat ratio (SHR) shall be the mean of the values measured for the
sample. Second, DOE proposes to move the provisions currently in 10 CFR 430.23 regarding
calculations of various measures of energy efficiency and consumption for central air
conditioners to 10 CFR 429.16. Specifically, while Part 430 would refer to the test procedure
appendix and section therein to use for each metric and the rounding requirements for test results
of individual units, Part 429 would refer to how to calculate annual operating cost for the sample
based on represented values of cooling capacity and SEER, and how to round the represented
values based on the sample for other measures of energy efficiency and consumption. DOE
proposes minor changes to the calculations of annual operating cost to address changes proposed
in Appendix M and M1. Table III.3 shows the proposed rounding requirements for each section.
58
Table III.3 Rounding Proposals
≥20,000 Btu/h and <38,000 nearest 100 Btu/h nearest 200 Btu/h
Btu/h
≥38,000 Btu/h and <65,000 nearest 250 Btu/h nearest 500 Btu/h
Btu/h
Annual operating cost N/A nearest dollar per year
DOE proposes to verify during assessment or enforcement testing the cooling capacity
certified for each basic model or individual combination. DOE proposes to measure the cooling
capacity of each tested unit pursuant to the test requirements of 10 CFR Part 430. The results of
the measurement(s) will be compared to the value of cooling capacity certified by the
manufacturer. If the measurement is within five percent of the certified cooling capacity, DOE
will use the certified cooling capacity as the basis for determining SEER. Otherwise, DOE will
use the measured cooling capacity as the basis for determining SEER.
DOE also proposes to require manufacturers to report the cyclic degradation coefficient
(CD) value used to determine efficiency ratings. In this proposal, DOE would run CD testing as
59
part of any assessment or verification testing, except when testing an outdoor unit with no match.
If the measurement is 0.02 or more greater than the certified value, DOE would use the
measurement as the basis for calculation of SEER or HSPF. Otherwise, DOE would use the
certified value. For models of outdoor units with no match, DOE would always use the default
value.
1. General Background
For certain consumer products and commercial equipment, DOE’s existing regulations
allow the use of an alternative efficiency determination method (AEDM) or alternative rating
method (ARM), in lieu of actual testing, to estimate the ratings of energy consumption or
efficiency of basic models by simulating their energy consumption or efficiency at the test
conditions required by the applicable DOE test procedure. The simulation method permitted by
DOE for use in rating split-system central air conditioners and heat pumps, in accordance with
mathematical tools that predict the performance of non-tested individual or basic models. They
are derived from mathematical models and engineering principles that govern the energy
efficiency and energy consumption of a particular basic model of covered product based on its
design characteristics. (In the context of this discussion, the term “covered product” applies both
to consumer products and commercial and industrial equipment that are covered under EPCA.)
60
These computer modeling and mathematical tools can provide a relatively straightforward means
given covered product and reduce the burden and cost associated with testing certain covered
products that are inherently difficult or expensive to test. When properly developed, they can
On April 18, 2011, DOE published a Request for Information (AEDM RFI) in the
Federal Register. 76 FR 21673. Through the AEDM RFI, DOE requested suggestions,
comments, and information relating to the Department’s intent to expand and revise its existing
AEDM and ARM requirements for consumer products and commercial and industrial equipment
covered under EPCA. In response to comments it received on the AEDM RFI, DOE published a
Notice of Proposed Rulemaking (AEDM NOPR) in the Federal Register on May 31, 2012. 77
FR 32038. DOE also held a public meeting on June 5, 2012, to present proposals in the AEDM
NOPR and to receive comments from stakeholders. In the AEDM NOPR, DOE proposed the
elimination of ARMs, and the expansion of AEDM applicability to those products for which
DOE allowed the use of an ARM (i.e., split-system central air conditioners and heat pumps). 77
meet in order to use an AEDM as well as a method that DOE would employ to determine if an
AEDM was used appropriately along with specific consequences for misuse of an AEDM. 77
FR at 32055-56.
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The purpose of the AEDM rulemaking was to establish a uniform, systematic, and fair
approach to the use of modeling techniques that would enable DOE to ensure that products in the
marketplace are correctly rated -- irrespective of whether they are rated based on physical testing
comments, and information related to its proposal and accepted written comments on the AEDM
NOPR through July 2, 2012. DOE subsequently formed a working group through the Appliance
Standards and Rulemaking Federal Advisory Committee (ASRAC) (see the Notice of Intent To
Form the Commercial HVAC, WH, and Refrigeration Certification Working Group and Solicit
WH, and Refrigeration Equipment, published on March, 12, 2013, 78 FR 15653), which
addressed revisions to the AEDM requirements for commercial and industrial equipment covered
by EPCA and resulted in the subsequent publishing of a SNOPR on October 22, 2013 (78 FR
62472) and a final rule on December 31, 2013 (78 FR 79579). In the final rule, DOE made,
DOE verification testing requirements for the AEDM process for commercial HVAC equipment.
In this notice, DOE proposes modifications to the central air conditioners and heat pump
AEDM requirements proposed in the AEDM NOPR with consideration of the comments
received on the AEDM NOPR specific to these products, as well as the requirements
implemented for commercial HVAC equipment in the December 2013 AEDM final rule.
62
2. Terminology
In the AEDM NOPR, DOE proposed to eliminate the term “alternate rating method”
(ARM) and instead use the term “alternative efficiency determination method” (AEDM) to refer
to any modeling technique used to rate and certify covered products. 77 FR 32038, 32040 (May
31, 2012). DOE proposed to refer to any technique used to model product performance as an
AEDM, but recognized that there are product-specific considerations that should be accounted
for in the development of an AEDM and thus, in the proposed methodology for validating
DOE received a number of comments in response to its proposal to solely apply the term
AEDM to any modeling technique used to rate and certify covered products. Bradford White
Corporation (Bradford White), United Technologies Climate, Controls & Security and ITS
Carrier (UTC/Carrier), and Nordyne, LLC (Nordyne) agreed with DOE that one term should be
combine requirements for ARMs and AEDMs, but did not differentiate between the terminology
and the methodological changes proposed. (AAON, No. 40 at p. 2) DOE also received a number
of comments, both written and at the public meeting, regarding the differences in ARM and
AEDM methodology. Those comments are discussed in section III.B.3 of this document. In
addition, DOE received numerous comments regarding the validation of AEDMs for different
8
Unless otherwise specified, further references in this section (section III.B) to comments received by DOE are to
those associated with the AEDM rulemaking (Docket No. EERE-2011-BT-TP-0024). References to the public
meeting are to the June 5, 2012 public meeting on the AEDM NOPR, the transcript of which is in the AEDM
rulemaking docket.
63
In response to comments received, DOE is continuing to propose the use of one term,
AEDM, to refer to all modeling techniques used to develop certified ratings of covered products.
DOE believes that since the two methods are conceptually similar, the use of one term is
appropriate. DOE would like to clarify that the use of one term to refer to all modeling
techniques used to develop certified ratings of covered products and equipment does not indicate
a uniform process or requirements for their use across all covered products, nor does it imply that
DOE will not include any of the current ARM provisions as part of the proposed AEDM
provisions. Further, similar to the differences between AEDMs for distribution transformers and
commercial HVAC products, DOE proposes validation requirements that will account for the
conditioners and central heat pumps must be approved by the Department before use. (10 CFR
429.70(e)(2)) Manufacturers who elect to use an ARM to rate untested basic models pursuant to
10 CFR 429.16(a)(2)(ii)(B)(1) must, among other requirements, submit to the Department full
documentation of the rating method including a description of the methodology, complete test
data on four mixed systems per each ARM, and product information on each indoor and outdoor
unit of those systems. Furthermore, manufacturers are not permitted to use the ARM as a rating
64
In the AEDM RFI, DOE requested comment on the necessity of a pre-approval
requirement for AEDMs and/or ARMs. 76 FR 21673, 21674 (April 18, 2011). Based on the
comments received in response to the AEDM RFI, DOE perceived no benefit in the additional
burden imposed by a pre-approval requirement and that a pre-approval process could cause time-
to-market delays. Pursuant to those comments, DOE proposed in the AEDM NOPR to eliminate
the pre-approval process currently in place for central air conditioner and heat pump ARMs. 77
FR 32038, 32040-41 (May 31, 2012). DOE believed that this would reduce the burden currently
necessary request for approval before bringing products to market. Furthermore, DOE believed
that elimination of the pre-approval requirement would promote innovation because an ARM
would not need to be approved or re-approved to account for any changes in technology. Id.
In the AEDM NOPR, DOE sought comment regarding its proposal to eliminate the pre-
approval requirement for ARMs for central air conditioners and heat pumps and received mixed
the pre-approval requirement. (Modine, No. 42 at p. 1) Lennox International, Inc. (Lennox) and
Unico, Inc. (Unico), however, suggested that removal of the pre-approval requirement could lead
to incorrect ratings and unfair competition in the marketplace, which could negatively impact
(JCI) commented that it was particularly important that manufacturers continue to be allowed to
use pre-approved ARMs because the new AEDM provisions, by eliminating pre-approval,
introduce regulatory risk that is not present under current ARM requirements. (JCI, No. 66 at pp.
2)
65
Other interested parties specifically recommended that participation in a voluntary
could reduce or eliminate the need for pre-approval. AHRI, Rheem Manufacturing Company
(Rheem), Goodman Global, Inc. (Goodman), and Unico suggested that DOE should consider
pre-approval for manufacturers not participating in a VICP, and that at a minimum, review by a
Goodman, No. 53 at p. 1; Unico, No. 54 at p. 5) Likewise, Lennox agreed that if DOE does not
maintain pre-approval in general, it could still require pre-approval for those who do not
participate in a VICP . (Lennox, No. 46 at pp. 2 and 4) Lennox and Rheem commented that a
pre-approval requirement for manufacturers who do not participate in a VICP could protect
DOE does not agree with JCI’s suggestion that the elimination of pre-approval could
create additional burden for manufacturers in cases where they fail to meet certified ratings and
are subsequently required to re-substantiate their AEDM. DOE also does not agree with Rheem
Lennox, and Unico who claim that the elimination of pre-approval will lead to incorrect ratings
in the marketplace or create unfair competition. Pre-approval of an ARM that is used to certify a
basic model rating does not mean that the basic model is correctly rated. Products that are
certified using an approved ARM are subject to the same assessment testing and enforcement
actions as those products certified through testing and/or use of an AEDM. Further, DOE
currently has the authority to review approved ARMs at any time, including review of
9
A Voluntary Industry Certification Program, or VICP, is an independent, third-party program that conducts
ongoing verification testing of members’ products.
66
documentation of tests used to support the ARM. DOE may also test products that were certified
using an ARM to determine compliance with the applicable sampling provisions, as well as with
federal standards. Should DOE determine that products were incorrectly rated, DOE may
require that the ARM is no longer used. Similarly, AEDMs used to certify ratings are subject to
review at any time, as well as the potential for suspension should DOE determine that products
were incorrectly rated. Additionally, as discussed in section III.A.3.a, each basic model must
have at least one rating determined through testing; no basic model can be rated solely using an
AEDM, which reduces the likelihood of significant error. Finally, use of a pre-approved ARM
does not insulate a manufacturer from responsibility for the accuracy of their ratings, and the
misconception that it does presents another reason to eliminate DOE review. Most
manufacturers have not updated their ARMs and submitted the revised ARM for DOE review as
required by regulation since prior to the last standards update and, thus, are effectively using
unapproved or outdated ARMs currently. For these reasons, it is DOE’s view that the elimination
of the pre-approval process would not have a substantive detrimental effect on the accuracy of a
manufacturer’s ratings, will improve manufacturers’ ability to introduce new products into the
marketplace, and will not represent a significant change from the status quo.
For the forgoing reasons, in this SNOPR, DOE proposes to eliminate the pre-approval
process for ARMs for split-system central air conditioners and heat pumps. As stated in the
AEDM NOPR, DOE believes that this will reduce time-to-market delays, facilitate innovation,
and eliminate the time required to complete the approval process. Furthermore, DOE
emphasizes that the Department’s treatment of products that are currently rated and certified with
67
the use of an ARM does not differ from its treatment of products currently rated and certified
using an AEDM, except for the pre-approval requirement. (See for example 10 CFR 429.70(c).)
In addition, DOE proposes that manufacturers may only apply an AEDM if it (1) is
derived from a mathematical model that estimates performance as measured by the applicable
DOE test procedure; and (2) has been validated with individual combinations that meet current
Federal energy conservation standards (as discussed in the next section). Furthermore, DOE
DOE to audit AEDMs through simulations, review of data and analyses, and/or certification
testing.
4. AEDM Validation
meant to reduce confusion and allow for easier development and utilization of AEDMs by
air conditioner and heat pump products would have required manufacturers to:
a. Test a minimum of five basic models, including at least one basic model from each
b. Test the smallest and largest capacity basic models from the product class with the
c. Test the basic model with the highest sales volume from the previous year, or the basic
model which is expected to have the highest sales volume for newly introduced basic models.
68
d. Validate only with test data that meets applicable Federal energy conservation
comments from stakeholders addressing specific products covered by the AEDM rule.
Comments applicable to the proposed requirements for central air conditioner and heat pump
Commenter responses with regard to the minimum sample size of one unit each of five
different basic models were mixed, with some commenters agreeing with DOE’s proposal and
some offering alternative sample sizes. Both AAON and Goodman agreed with DOE’s proposal
that a minimum of one unit each of five basic models be tested to validate the AEDM. (AAON,
No. 40 at p. 6; Goodman, No. 53 at p. 2) AHRI, however, commented that it was not realistic for
a manufacturer who produces two basic models, for example, to be required to validate an
AEDM based on a minimum sample of five units of the same two basic models. (AHRI, Public
burdensome to require testing of at least five basic models for small manufacturers who
manufacture or wish to use an AEDM for only a few basic models compared to manufacturers
who offer many basic models and many product classes. AHRI recommended that DOE require
testing of only 3 basic models if the AEDM is to be applied to 15 or fewer basic models. (AHRI
No. 61 at p. 3) United Cool Air agreed with AHRI’s concerns and stated that to obtain data that
are statistically robust enough to meet the validation requirements, testing of at least two to five
69
units of many basic models would be necessary, which may be too burdensome for built-to-order
and small manufacturers. This would be particularly burdensome in cases where models used
for testing cannot be sold. (United Cool Air, No. 51 at pp. 7, 10, and 11) Acknowledging the
amount of work and complex testing required for validation of an AEDM, Zero Zone, Inc. (Zero
Zone) noted that it would be difficult for small manufacturers to comply. Zero Zone
recommended that small manufacturers could be exempt or have a different sample size
Other stakeholders commented on the validation requirements for specific products. JCI
stated that testing of five units is unnecessarily burdensome and suggested that testing a
minimum of three units would be sufficient to validate HVAC AEDMs. (JCI, No. 66 at p. 6)
First Co. stated that DOE’s proposed requirements would unreasonably burden small
manufacturers, especially independent coil manufacturers because they would not have
knowledge of which condensing unit model is expected to have the highest sales volume in the
coming year. First Co. stated that this proposed requirement is unnecessary and should be
eliminated given that the proposed validation requirements already include testing of the smallest
and largest capacity basic model from the product class with the highest sales volume, and that
the current minimum number of tests required for obtaining ARM approval is four. (First Co.,
No. 45 at p. 2) JCI agreed with First Co., stating that the proposal would create an
overrepresentation of the highest sales volume product class because the highest sales volume
basic model is most likely from that product class, and along with the requirement to test the
smallest and largest capacity basic model from that product class, would require testing of three
basic models from the highest sales volume product class. (JCI, No. 66 at p. 7) Goodman, on the
70
other hand, stated that an additional test beyond the currently required four tests would not cause
DOE notes that in its proposed revisions to the determination of certified ratings for
central air conditioners and heat pumps (discussed in section III.A.3), manufacturers must test
each basic model; specifically for split-system air conditioners and heat pumps, OUMs must test
each model of outdoor unit with at least one model of indoor unit (highest sales volume), and
ICMs must test each model of indoor unit with at least one model of outdoor unit (lowest SEER).
Manufacturers would only be able to use AEDMs for other individual combinations within the
same basic model – in other words, other combinations of models of indoor units with the same
model of outdoor unit. DOE does not seek to require additional testing to validate an AEDM
beyond what is proposed under 10 CFR 429.16(a)(1)(ii). Therefore, the testing burden required
to validate an AEDM would depend on the number of basic models each manufacturer must rate.
Furthermore, because ICMs must test each model of indoor unit with the lowest-SEER model of
outdoor unit with which it is paired, First Co.’s concerns related to predicting the highest sales
volume model would no longer be relevant. DOE requests comment on its proposal related to the
Regarding the proposed requirement to test a basic model from each applicable product
class for HVAC products, Goodman believes that the current definition of “product class” does
not address the specific issues raised by split-system central air conditioners and heat pumps,
which consist of separate indoor and outdoor coils that only function as intended when paired
with one another to form a unitary split-system central air conditioner or heat pump. Hence,
71
Goodman suggested that DOE consider the following product types to constitute individual
validation classes: split-system air conditioners, split-system heat pumps, single-package air
separate validation classes for the categories mentioned by Goodman, but also proposed that
central air conditioners and heat pumps should include distinct validation classes for space-
United Cool Air stated that DOE did not properly address classification of space-constrained
HVAC systems. (United Cool Air, No. 51 at p. 4, 13) United Cool Air’s comments align with
comments from Carrier that DOE should create a separate product class for space-constrained
equipment.
In response, DOE notes that the proposed testing requirements in 429.16 require testing
at least one individual model/combination within each basic model. Therefore, by default
manufacturers would be testing all basic models from each product class in which they
manufacture units.
Regarding selection of basic models for validating an AEDM, both Nordyne and
Goodman agreed with DOE’s proposal that the basic models selected for validating an AEDM
must include the smallest capacity basic model as well as the largest capacity basic model (or a
basic model within 25 percent of the largest capacity). (Nordyne, No. 55 at p. 2; Goodman, No.
53 at p. 2) Rheem, however, disagreed and stated that the requirement to test the smallest and
largest capacity basic model was too restrictive and does not account for outliers or differences
72
in technology across product classes. (Rheem, No. 59 at p. 4) Furthermore, Lennox noted that
the manufacturer is most suited to determine which models should be used for validation and that
requirements for particular capacities do not account for variation in product design and
DOE’s intention when proposing to require that a manufacturer test both the smallest and
largest capacity basic models within the product class with the highest sales volume was to
ensure that the AEDM could accurately predict the efficiency of those products at the extremes
of a manufacturer’s product line. As variations in product design and construction across all
capacities should be accounted for when testing all basic models, DOE withdraws the proposal
regarding selecting the smallest and largest capacity basic models from the product class with the
highest sales volume for testing for validation of the AEDM. DOE notes that in the proposed
revisions to the determination of certified ratings, each basic model must be tested and an AEDM
can only be used to certify other individual combinations that are part of the same basic model.
c. Use of the Highest Sales Volume Basic Model for Validating an AEDM
Many interested parties recommended that DOE continue to require that split-system
manufacturers test each condensing unit they manufacture with the evaporator coil that is likely
to have the largest volume of retail sales (i.e., the highest sales volume combination, or HSVC)
because the data resulting from these test combinations are critical to independent coil
manufacturers (ICMs) in determining accurate ratings for their products since they must
determine their ratings based on pairings with condensing units offered by other manufacturers.
AHRI stated that DOE should retain requirements for testing based on the HSVC for central air
73
conditioners and heat pumps. (AHRI, No. 61 at p. 2) UTC/Carrier agreed that DOE should allow
(UTC/Carrier, No. 56 at p. 1) Lennox disagreed with removing the requirement for testing based
on HSVC because the current AHRI certification program and independent coil manufacturing
industry depend on this requirement, and the data from HSVC test results are used by
independent coil manufacturers (ICMs) as the input to their ARM. (Lennox, No. 46 at p. 4)
Unico stated that DOE should maintain the current ARM requirements for central air
conditioners and heat pumps because as an indoor coil manufacturer, Unico relies on the
accuracy of the ratings published by the manufacturer of the outdoor unit and decreasing the
accuracy of those ratings would increase their own risk of failure. Unico stressed that it was
particularly important for DOE to allow manufacturers’ rating methodology to rely on curve fit
data, and specifically proposed that for validating an AEDM, matched system manufacturers
should test at least the highest sales volume combination for each outdoor unit. (Unico, No. 54
at pp. 2, 4, and 6) Mortex Products, Inc. (Mortex) stated that in order for ICMs to rate indoor
coils accurately using the ARM, the system manufacturer's HSVC data is necessary, and if
HSVC data were no longer obtained from tests, but generated using an AEDM, the accuracy of
DOE recognizes the concerns of stakeholders who commented that eliminating the
requirement to test the HSVC for split-system products could increase the burden on ICMs.
DOE does not intend to eliminate that requirement and notes that such requirement is proposed
to be retained in this notice, as discussed in section III.A.3.a. However, DOE also proposes
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additional requirements for ICMs that are discussed in section III.B.5. DOE also notes that the
ARM provisions in the current regulations do not clearly apply to ICMs, and most ICMs do not
DOE’s proposal in the AEDM NOPR required re-validation when the HSVC changes. In
response, Goodman stated that for split-system CACs and HPs, testing the highest or expected
highest sales volume combination basic model would be appropriate as long as DOE does not
require re-validation of the AEDM if another basic model subsequently becomes the highest
sales volume combination. Determination of the highest volume basic model should be based on
sales data of the prior year, or sales data or forecasts of the year of the AEDM's validation.
(Goodman, No. 53 at p. 3) United Cool Air was also concerned that additional testing would be
required if the highest selling basic model changed. (United Cool Air, No. 51 at p. 9)
In response to the concerns of Goodman and United Cool Air regarding re-validation if
the HSVC changed, DOE agrees that re-validation should not be required if test data used to
validate the AEDM was based on an expected HSVC that subsequently becomes a lower sales
volume model and is not proposing such a requirement in this notice. DOE agrees with
Goodman that determination of the highest volume basic model should be based on sales data of
the prior year, sales data or forecasts of the year of the AEDM's validation, or other similar
information. Selection of the highest volume basic model should reflect a good faith effort by
the manufacturer to predict the combination most likely to result in the highest volume of sales.
DOE notes that it may verify compliance with this HSVC testing requirement.
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d. Requirements for Test Data Used for Validation
In AEDM NOPR, DOE did not propose requirements on the test data used for validation
of an AEDM because any non-testing approaches to certifying central air conditioners and heat
pumps via an ARM were to be approved by DOE prior to use. 77 FR 32043. However, if DOE
adopts the current proposal to remove the pre-approval requirement, certified ratings generated
using an AEDM would be unreliable without other requirements to validate the AEDM against
actual test data. Therefore, DOE proposes in this notice to adopt requirements on test data
similar to those used for validation for commercial HVAC and water heating equipment, as
published in the AEDM final rule 78 FR 79579, 79584 (Dec. 31, 2013). Specifically, (1) for
energy-efficiency metrics, the predicted efficiency using the AEDM may not be more than 3
percent greater than that determined through testing; (2) for energy consumption metrics, the
predicted efficiency using the AEDM may not be more than 3 percent less than that determined
through testing; and (3) the predicted efficiency or consumption for each individual combination
calculated using the AEDM must comply with the applicable Federal energy conservation
standard. Furthermore, the test results used to validate the AEDM must meet or exceed the
applicable Federal standards, and the test must have been performed in accordance with the
applicable DOE test procedure. If DOE has ordered the use of an alternative test method for a
particular basic model through the issuance of a waiver, that is the applicable test procedure.
manufacturer’s lab and within a basic model should be more limited than lab-to-lab variability.
DOE proposes tolerances for verification testing of 5 percent to account for added lab-to-lab
variability.
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5. Requirements for Independent Coil Manufacturers
In the AEDM NOPR, DOE did not propose a statistical sampling requirement for
independent coil manufacturers (ICMs) that would be distinct from the sampling required to
validate an AEDM for HVAC products. 77 FR at 32043. In response, Unico commented that
ICMs should test coils of each fin-pattern, varying the number of rows, fin density, tube type,
circuiting, and frontal area. (Unico, No. 54 at p. 4) Mortex stated that their ARMs are based on
data from a "matched system" tested by an OUM. Mortex uses an ARM to simulate the
performance of their own coil in a matched system by substituting the geometry of the indoor
evaporator coil used by the manufacturer of the condensing unit with the geometry of their own
While DOE understands that ICMs currently use ratings from OUMs to predict the
efficiency of their coil models, as discussed in section III.A.3.d, DOE is now proposing to
require that ICMs test each of model of indoor units (i.e., basic models) with the least efficient
model of outdoor unit with which it will be paired. In order to validate an AEDM for split-
systems rated by ICMs for other individual combinations within each basic model, DOE also
proposes that ICMs must use the individual combinations the ICMs would be required to test
under the proposed text in 10 CFR 429.16. DOE seeks comment on this proposal.
In regard to Unico’s suggestion to test indoor units with coils of varying fin-patterns,
DOE refers stakeholders to the definition of a basic model in section III.A.1, and particularly
what constitutes the same model of indoor unit. DOE notes that the manner in which
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manufacturers apply the basic model provisions would impact what models of indoor units are
DOE may randomly select and test a single unit of a basic model pursuant to 10 CFR
429.104. This authority extends to all DOE covered products, including those certified using an
AEDM. In the AEDM NOPR, DOE clarified that a selected unit would be tested using the
(IEC), “General requirements for the competence of testing and calibration laboratories,”
In this notice, DOE proposes further verification testing methods. Specifically, DOE
proposes that verification testing conducted by the DOE will be (1) on a retail unit or a unit
provided by the manufacturer if a retail unit is not available, (2) at an independent, third-party
testing facility or a manufacturer’s facility upon DOE’s request if the former is not capable of
testing such a unit, and (3) conducted with no communication between the lab and the
DOE also proposes clarification of requirements for determining that a model does not
meet its certified rating, as proposed in the AEDM NOPR. Specifically, DOE proposes that an
individual combination would be considered as having not met its certified rating if, even after
applying the five percent tolerance between the test results and the rating as specified in the
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proposed 10 CFR 429.70(e)(5)(vi), the test results indicate the individual combination being
tested is less efficient or consumes more energy than indicated by its certified rating. DOE notes
that this approach will not penalize manufacturers for applying conservative ratings to their
products. That is, if the test results indicate that the individual combination being tested is more
efficient or consumes less energy than indicated by its certified rating, DOE would consider that
individual combination to meet its certified rating. DOE seeks comment on whether this is a
reasonable approach to identify an individual combination’s failure to meet its certified rating.
In the AEDM NOPR, DOE also proposed the actions DOE would take in response to
individual models that fail to meet their certified ratings. 77 FR at 32056. Many stakeholders
submitted comments suggesting that DOE should determine the cause of the test failure prior to
taking any additional action. UTC/Carrier commented that failure of a single unit test result
could be a result of a defective unit and further urged DOE to define a process to contest test
results from a third party lab. (UTC/Carrier, No. 56 at p. 2) JCI had a similar concern regarding
potential errors in test set-up and proposed that DOE should work with the manufacturer to
determine the root cause of the failure, performing additional testing if necessary. (JCI, No. 66
at p. 8) Rheem agreed with JCI that DOE should work with the manufacturer to determine
whether the root cause is associated with test variability, AEDM model inaccuracy, or
manufacturing variability. Rheem added that DOE should clarify what constitutes a “failure” as
well as develop a detailed plan for selection, testing, evaluation, manufacturer notification, and
resolution. (Rheem, No. 59 at p. 4) Lennox also agreed that DOE should not immediately
require modification of an AEDM without first finding the cause of the failure. (Lennox, No. 46
at pp. 4-5) Additionally, Ingersoll Rand requested that DOE allow for a dialogue with the
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manufacturer to ensure that the sample unit was not defective and that the test was set up
correctly. (Ingersoll Rand, Public Meeting Transcript, No. 69 at p. 187) AHRI agreed that it
would be valuable to specify particular steps manufacturers and DOE must take in the case of a
test failure and incorporate a defective sample provision, and recommended that DOE provide
data, a failure report, and other necessary information to the manufacturer for proper analysis of
Unico and manufacturers of products other than HVAC suggested that DOE should not
only share the data with the manufacturer, but also allow the manufacturer to review or witness
testing done by a lab. This would allow for better understanding of potential discrepancies in
test results and ensure that failure was not merely a result of variation in test set-up. (Unico, No.
in commissioning of their equipment prior to the assessment test since proper set-up is critical.
AHRI added that manufacturers should have an opportunity to repair a unit, if defective, while it
is in the assessment lab. (AHRI, No. 61 at pp. 6-7; Carrier, Public Meeting Transcript, No. 69 at
p. 218) Further, UTC/Carrier urged DOE to specify an appeals process for tests that a
manufacturer believes were tested with improper test set-up. (UTC/Carrier, Public Meeting
DOE agrees that determining the root cause of the failure to meet certified ratings is
important; however, DOE stresses that this would be the manufacturer’s responsibility. DOE is
aware that in order to determine the cause of the failure, the manufacturer will need to review the
data from DOE’s testing. DOE therefore proposes that when an individual combination fails to
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meet certified ratings, DOE will provide to the manufacturer a test report that includes a
description of test set-up, test conditions, and test results. DOE will provide the manufacturer
with an opportunity to respond to the lab report by presenting all claims regarding testing
validity, and if the manufacturer was not on-site for initial set-up, to purchase an additional unit
from retail to test following the requirements in 429.110(a)(3). This process is designed to
provide manufacturers the opportunity to raise concerns about the test set-up, taking into account
various comments from stakeholders. DOE will consider any response offered by the
manufacturer within a designated time frame before deciding upon the validity of the test results.
Only after following these steps will the Department make a determination that the rating for the
basic model is invalid and require the manufacturer to take subsequent action, as described in
section III.B.7.
In the AEDM NOPR, DOE proposed a method of determining whether a model meets its
certified rating whereby the assessment test result would be compared to the certified rating for
that model. If the test result was not within the tolerance in the proposed section 429.70(c), the
model would be considered as having not met its certified rating. In this case DOE proposed to
require that manufacturers re-validate the AEDM that was used to certify the product within 30
days of receiving the test report from the Department. DOE also proposed to require that
manufacturers incorporate DOE’s test data into the re-validation of the AEDM. If after inclusion
of DOE’s test data and re-validation, the AEDM-certified ratings change for any models, then
the manufacturer would be required to re-rate and re-certify those models. The manufacturer
would not be required to perform additional testing in this re-validation process unless the
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manufacturer finds it necessary in order to meet the requirements enumerated in the proposed
commented that the failure of a single test unit to meet its certified rating should not
automatically necessitate re-validation, but suggested that the manufacturer should decide on the
appropriate course of action. (Zero Zone, No. 64 at p. 3) UTC/Carrier commented that DOE
should not require re-validation based on a single unit’s test result because the failure could be a
require manufacturers to incorporate DOE test data into their AEDM if a model is determined
not to meet its certified rating because they believe that DOE data may be erroneous and only the
best available data should be used to validate an AEDM. (Lennox, No. 46 at p. 5) JCI stated that
without additional information as to why a particular product failed a test, it is not reasonable to
assume that all models rated with the AEDM must be re-rated. (JCI, No. 66 at pp. 9-10).
In consideration of the above mentioned comments, DOE proposed to allay concerns via
the proposal in section III.B.6, which provides manufacturers an opportunity to review the data
from DOE’s testing and present claims regarding testing validity. Based on these comments,
DOE also proposes an exception to re-validation of the AEDM in cases where the determination
of an invalid rating for that basic model is the first for models certified with an AEDM. In such
cases, the manufacturer must conduct additional testing and re-rate and re-certify the individual
combinations within the basic model that were improperly rated using the AEDM.
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DOE also proposes that if DOE has determined that a manufacturer made invalid ratings
on individual combinations within two or more basic models rated using the manufacturer’s
AEDM within a 24 month period, the manufacturer must test the least efficient and most
efficient combination within each basic model in addition to the combination specified in
429.16(a)( 1)(ii). The twenty-four month period begins with a DOE determination that a rating is
invalid through the process outlined above. If DOE has determined that a manufacturer made
invalid ratings on more than four basic models rated using the manufacturer’s AEDM within a
Finally, DOE proposes additional requirements for manufacturers to regain the privilege
of using an AEDM, including identifying the cause(s) for failure, taking corrective action,
performing six new tests per basic model, and obtaining DOE authorization.
DOE created this proposal under the expectation that each manufacturer will use only a
single AEDM for all central air conditioner and central air conditioning heat pumps. DOE
requests comment on whether manufacturers would typically apply more than one AEDM and if
In the AEDM NOPR, DOE explained that if a model failed to meet the applicable Federal
energy conservation standard during assessment testing, DOE may pursue enforcement testing
pursuant to 10 CFR 429.110. DOE also stated that if an individual model was determined to be
noncompliant, then all other individual models within that basic model would be considered
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noncompliant. This is consistent with DOE’s approach for all covered products. All other basic
models rated with the AEDM would be unaffected pending additional investigation.
Furthermore, DOE proposed that if a noncompliant model was used for validation of an AEDM,
enumerated in 10 CFR 429.70. Notably, DOE did not propose that manufacturers must re-test
FR 32056.
In response, JCI agreed that all AEDM-rated models should not be disqualified if one
DOE reiterates that for central air conditioners and central air conditioning heat pumps, if
combinations within that basic model would be considered noncompliant. DOE is not proposing
in this SNOPR that other basic models rated with the AEDM be considered non-compliant.
However, DOE notes that an AEDM must be validated using test data for individual
combinations that meet the current Federal energy conservation standards. Therefore, if a
noncompliant model was used for validation of an AEDM, manufacturers would be expected to
re-validate the AEDM in order to continue using it. The requirements for additional testing based
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C. Waiver Procedures
10 CFR 430.27(l) requires DOE to publish in the Federal Register a notice of proposed
rulemaking to amend its regulations so as to eliminate any need for the continuation of waivers
and as soon thereafter as practicable, DOE will publish a final rule in the Federal Register. As of
the issuance date of this notice, a total of four waivers (and one interim waiver) for central air
conditioner and heat pump products are active. They are detailed in the Table III.4, with the
section reference to this notice included for discussion regarding DOE’s proposed amended
DOE notes that four waivers previously associated with both commercial equipment and
consumer products, as listed in Table III.3, were terminated for consumer products as of the
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October 22, 2007 Final Rule (72 FR 59906, 59911) and for commercial equipment as of the May
16, 2012 Final Rule (77 FR 28928, 28936). In this SNOPR, DOE reaffirms that these waivers
have been terminated for consumer products and that the products in question can be tested using
the current and proposed test procedure for central air conditioners and heat pumps.
Variable Refrigerant Flow Zoning Air Conditioners and Heat Pumps 4/9/2007
DOE has granted two waivers to Daikin Altherma for the air-to-water heat pump with
integrated domestic water heating; one on June 18, 2010 and a second on March 2, 2011. 75 FR
34731 and 76 FR 11438. As described in Daikin’s petitions, the Daikin Altherma system
consists of an air-to-water heat pump that provides hydronic space heating and cooling as well as
domestic hot water functions. It operates either as a split system with the compressor unit
which all system components are combined in a single outdoor unit. In both the single-package
and the split-system configurations, the system can include a domestic hot water supply tank that
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is located indoors. These waivers were granted on the grounds that the existing DOE test
procedure contained in Appendix M to Subpart B of 10 CFR Part 430 addresses only air-to-air
heat pumps and does not include any provisions to account for the operational characteristics of
an air-to-water heat pump, or any central air-conditioning heat pump with an integrated domestic
According to the definition set forth in EPCA and 10 CFR 430.2, a central air conditioner
is a product, other than a packaged terminal air conditioner, which is powered by single phase
electric current, air cooled, rated below 65,000 Btu per hour, not contained within the same
cabinet as a furnace, the rated capacity of which is above 225,000 Btu per hour, and is a heat
pump or a cooling unit only. (42 U.S.C. 6291(21)) The heat pump definition in EPCA and 10
CFR 430.2 requires that a heat pump utilize a refrigerant-to-outdoor air heat exchanger,
effectively excluding heat pump products classified as air-to-water. (42 U.S.C. 6291(24)) In
addition, because the definition of a central air conditioner, which also applies to heat pumps,
requires products to be “air cooled,” products that rely exclusively on refrigerant-to-water heat
exchange on the indoor side are effectively excluded from the definition of, and the existing
Based upon the description in the waiver petitions for the Daikin Altherma air-to-water
heat pumps with integrated domestic water heater, DOE has determined that these products rely
exclusively on refrigerant-to-water heat exchange on the indoor side, and thus would not be
subject to the central air conditioner or heat pump standards and would not be required to be
tested and rated for the purpose of compliance with DOE standards for central air conditioners or
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heat pumps. Thus, if this interpretation is adopted, these waivers would terminate on the
DOE granted ECR International (ECR) an interim waiver on August 6, 2013, for its line
of Enviromaster International (EMI) products. 78 FR 47681. ECR describes in its petitions that
its multi-zone air conditioners and heat pumps each comprise a single outdoor unit combined
with two or more indoor units, which each comprise a refrigeration circuit, a single air handler, a
single control circuit, and an expansion valve, intended for independent zone-conditioning. The
outdoor unit contains one fixed-speed compressor for each refrigeration circuit; all zones utilize
the same condenser fan and defrost procedures but refrigerant is not mixed among the zones. 78
FR at 47686. These products are similar to multiple-split (or multi-split) air conditioners or heat
pumps, which are defined and covered by current test procedure (Appendix M to Subpart B of 10
CFR Part 430). However, they are distinct from, and therefore not classified as, multi-split
products due to differences in refrigerant circuitry. The separate refrigeration circuits of the
ECR product line are not amenable to the test procedures for multi-split systems, specifically the
procedures calling for operation at different levels of compressor speed or staging, because the
individual compressors are not necessarily variable-speed. Hence, alternative procedures have
been developed, as described in the interim waiver. DOE proposes to address products such as
the ECR product line in the DOE test procedure. DOE also proposes to define such a product as
a “multi-circuit air conditioner or heat pump” and provide testing requirements for such for such
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For the duration of the interim waiver period, either until 180 days after the publication of
the interim waiver (the interim waiver period) or until DOE issued its determination on the
petition for waiver, whichever occurred earlier, DOE granted ECR permission to use the
proposed alternative test procedure to test and rate its multi-circuit products. 78 FR 47681, 47682
(Aug. 6, 2013). The requirements in the alternative test procedure comprise methods to establish
air volume rate, procedures for testing, and adjustments to equations used to calculate SEER and
HSPF. Following publication of the Notice of Grant of Interim Waiver, DOE received no
comments regarding this alternative test procedure. After the interim waiver period, DOE did
not issue a final decision and order on ECR’s petition for waiver, therefore, the interim waiver
will terminate upon the publication of a test procedure final rule for central air conditioners and
heat pumps, and the alternative test procedure included therein shall cease from being applicable
to testing and rating ECR’s multi-circuit products and multi-circuit products in general, absent
amendments regarding provisions for testing such products. Therefore, DOE proposes in this
notice testing requirements for manufacturers who wish to certify multi-circuit products.
According to Appendix M to Subpart B of 10 CFR Part 430, Section 2.4.1b, systems with
multiple indoor coils are tested in a manner where each indoor unit is outfitted with an outlet
plenum connecting to a common duct so that each indoor coil ultimately connects to an airflow
measuring apparatus. 10 In testing a multi-circuit system in this manner, the data collection,
performance measurement, and reporting is done only on the system level. ECR took issue with
this, citing inadequate data accountability, and thus argued in its petition for waiver to
individually test each indoor unit. Id. Current test procedures for systems with multiple indoor
10
When the indoor units are installed in separate indoor chambers for the test, the test procedure allows common
ducting to a separate airflow measuring apparatus for each indoor chamber.
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coils, however, produce ratings that are repeatable and accurate even though monitoring of all
indoor units are not required by regulation, or common industry practice. DOE also notes that
the common duct testing approach has been adopted by industry standards and is an accepted
method for testing systems having multiple indoor units. ECR’s petition did not identify specific
differences between the indoor units of its new product line and the indoor units of multi-splits
that would make the common-duct approach unsuitable for its products. Further, the interim
waiver approach of using multiple airflow measuring devices, one for each indoor unit,
represents unnecessary test burden. Therefore, DOE proposes to adopt for multi-circuit products
the same common duct testing approach used for testing multi-split products.
The alternative test procedure in the interim waiver calls for separate measurement of
performance for each indoor unit for each required test condition, and requires that all indoor
units be operating during each of these separate measurements. The overall system performance
for the given test condition is calculated by summing the capacities and power inputs measured
for all of the indoor units and adding to the power input sum the average of the power
measurements made for outdoor unit for the set of tests. Id. In contrast, DOE’s current proposal
involves use of the common duct to measure the full system capacity, thus allowing use of a
single test for each operating condition. DOE requests comment on whether this method will
yield accurate results that are representative of the true performance of these systems.
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3. Termination of Waiver and Clarification of the Test Procedure Pertaining to Multi-Blower
Products
On August 28, 2008, DOE published a decision and order granting Cascade Group, LLC
a waiver from the Central Air Conditioner and Heat Pump Test Procedure for its line of multi-
blower indoor units that may be combined with one single-speed heat pump outdoor unit, one
two-capacity heat pump outdoor unit, or two separate single-speed heat pump outdoor units. 73
FR 50787, 50787–97. DOE proposed revisions to the test procedure in the June 2010 NOPR to
accommodate the certification testing of such products. 75 FR 31237. NEEA responded in the
subsequent public comment period, recommending DOE defer action on test procedure changes
until such a product is actually being tested, certified and sold. (NEEA, No. 7 at pp. 4-5).
Mitsubishi recommended DOE either use AHRI Standard 1230-2010 to rate such a product or
does not amend the test procedure to allow coverage of such a product. (Mitsubishi, No. 12 at p.
2).
DOE notes that AHRI Standard 1230-2010, which provides testing procedures for
products with variable speed or multi-capacity compressors, may not be suitable for testing the
subject products, which are equipped with single-speed compressors; however, the test
procedure, as proposed in the June 2010 NOPR enables testing of such products. DOE therefore
retains its proposal in the June 2010 NOPR to adopt that test procedure, except for the following
revisions.
The proposal in the June 2010 NOPR amended Appendix M to Subpart B of 10 CFR Part
430 with language in sections 3.1.4.1.1e and 3.1.4.2e that suggested that test setup information
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may be obtained directly from manufacturers. DOE is revising that proposal to eliminate the
need for communication between third-party test laboratories and manufacturers, such that the
test setup is conducted based on information found in the installation manuals included with the
unit by the manufacturer. DOE is proposing that much of that information be provided to DOE
as part of certification reporting. These proposed modifications regarding test setup can be found
in section 3.1.4.1.1d and 3.1.4.2e of the proposed Appendix M in this notice. DOE requests
comment on its proposals for multi-blower products, including whether individual adjustments of
each blower are appropriate and whether external static pressures measured for individual tests
may be different.
Because the proposed test procedure amendments would allow testing of Cascade Group,
LLC’s line of multi-blower products, DOE proposes to terminate the waiver currently in effect
for those multi-blower products effective 180 days after publication of the test procedure final
rule.
On February 5, 2010, DOE granted Hallowell International a waiver from the DOE
Central Air Conditioner and Heat Pump Test Procedure for its line of boosted compression heat
pumps. 75 FR 6014, 6014–18. DOE proposed revisions to its test procedures in the June 2010
NOPR to accommodate the certification testing of such products. 75 FR 31223, 31238 (June 2,
2010). NEEA expressed support for DOE’s proposal in the subsequent public comment period
but urged DOE to ensure that the northern climate test procedure can be used by variable speed
systems that can meet the appropriate test conditions, and that the procedures can accurately
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assess the performance of these systems relative to more conventional ones. (NEEA, No. 7 at p.
5). NEEA also urged DOE to require publishing of Region V ratings for heat pumps. Mitsubishi
supported DOE’s proposed changes to cover triple-capacity, northern heat pumps but requested
that DOE reevaluate the testing of inverter-driven compressor systems to permit better
demonstration of the system’s capabilities at heating at low ambient conditions. (Mitsubishi, No.
12 at p. 3).
DOE believes that the test procedure as proposed in the June 2010 NOPR, along with the
proposed revisions to the test procedure for heating tests conducted on units equipped with
represents an average period of use of such products. Because the proposed test procedure
heat pump products, DOE proposes to terminate the waiver currently in effect for those products
effective 180 days after publication of the test procedure final rule.
In the June 2010 NOPR, DOE proposed a first draft of testing procedures and
calculations for off mode power consumption. 75 FR 31223, 31238 (June 2, 2010). In the
following April 2011 SNOPR, DOE proposed a second draft, revising said testing procedures
and calculations based on stakeholder-identified issues and changes to the test procedure
proposals in the 2010 June NOPR and on DOE-conducted laboratory testing. 76 FR 18105,
18111 (April 1, 2011). In the October 2011 SNOPR, DOE proposed a third draft, further
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revising the testing procedures and calculations for off mode power consumption based primarily
on stakeholder comments regarding burden of test as received during the April 2011 SNOPR
comment period. 76 FR 65616, 65618-22 (Oct. 24, 2011). From the original and extended
comment period of the October 2011 SNOPR DOE received stakeholder comments, which are
the basis of DOE’s proposed fourth draft in this notice, further revising testing procedures and
calculations for off mode power consumption. None of the proposals listed in this section impact
1. Test Temperatures
In the October 2011 SNOPR, DOE proposed to base the off mode power consumption
rating (PW,OFF) on an average of wattages P1 and P2, which would be recorded at the different
outdoor ambient temperatures of 82 °F and 57 °F, respectively. DOE intended that, for systems
with crankcase heater controls, the measurement at the higher ambient temperature would
measure the off mode contribution that was more representative of the shoulder seasons. The
lower measurement was intended to represent off mode power use for an air conditioner during
In response to the October 2011 SNOPR, a joint comment from Pacific Gas and Electric
and Southern California Edison, hereafter referred to as the California State Investor Owned
Utilities (CA IOUs), and a joint comment from the American Council for an Energy-Efficient
Economy (ACEEE) and Appliance Standards Awareness Program (ASAP) expressed concern
that the 57 °F test point could create a loophole wherein a crankcase heater could be designed to
turn on just below 57 °F and result in an underestimation of the system’s energy consumption.
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The off mode power consumption would be underestimated because the energy consumption of
the crankcase heater would not be included in either P1 or P2. (CA IOUs, No. 33 at p. 2;
ACEEE and ASAP, No. 34 at p. 2) A joint comment from the Northwest Energy Efficiency
Alliance (NEEA) and the Northwest Power and Conservation Council (NPCC), hereafter
referred to as the Joint Efficiency Advocates, also disputed DOE’s proposal to test units at two
fixed temperatures and disagreed with DOE’s contention that the proposed P2 test temperature
(57 °F) is sufficiently low that the crankcase heater would be energized. (Joint Efficiency
Advocates, No. 35 at p. 3)
Both the CA IOUs and the Joint Efficiency Advocates proposed that DOE require
manufacturers to specify the temperature at which the crankcase heater turns on and off, and then
to run one off mode test 3-5 °F below the point at which the crankcase heater turns on (“on” set
point temperature) and the other off mode test 3-5 °F above the temperature at which the
crankcase heater turns off (“off” set point temperature). (CA IOUs, No. 33 at p. 2; Joint
Efficiency Advocates, No. 35 at p. 3) However, the Joint Efficiency Advocates only proposed
this rating method for constant wattage crankcase heaters. (Joint Efficiency Advocates, No. 35
at p. 3) The Joint Efficiency Advocates stated that two measurements are insufficient for systems
that have a heater with wattage that varies according to temperature and suggested that the
crankcase heater power for systems with variable wattage be tested at three temperatures.
Specifically, the Joint Efficiency Advocates recommended testing at 3-5 °F below the “on” set
point temperature, at 47 °F, and at 17 °F. (Joint Efficiency Advocates, No. 35 at p. 4) The Joint
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crankcase heaters should be tested for off mode power use when cold (i.e., before the system is
In the December 2011 extension notice for comments on the October 2011 SNOPR, DOE
requested comment on the CA IOUs’ suggestion that the test procedure should measure P1 at a
temperature that is 3-5 °F above the manufacturer’s reported “off” set point and measure P2 at a
temperature that is 3-5 °F lower than the “on” set point. 76 FR 79135 (Dec. 21, 2011). The
Joint Efficiency Advocates commented in support of the CA IOU proposal. (Joint Efficiency
Advocates, No. 43 at p. 2) However, they also reiterated that crankcase heater power for systems
with variable wattage should be tested at three temperatures, namely, 3-5 °F below the “on” set
AHRI commented that DOE should modify the test procedure by having up to three
rating temperatures, depending on the manufacturer control protocol. The first test would be
conducted at 72 °F immediately after the B, C, or D test to verify whether the crankcase heater is
on. The second test would be conducted at 5 °F below the temperature at which the
manufacturer specifies the crankcase heater turns on. The third test would be conducted at 5 °F
below the temperature at which the crankcase heater turns off and would only apply to air
conditioners with crankcase heater controls that turn off the crankcase heater during winter.
AHRI commented that it could accept the CA IOUs proposal to test at 3-5 °F below the heater
turn-on temperature and at 3-5 °F above the heater turn-off temperature if DOE did not accept
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Many of the commenters’ recommended changes are reflected in this proposed rule.
which the crankcase heater is designed to turn on and turn off for the heating season, if
applicable. These temperatures are used in the proposed tests described in the following
paragraphs.
DOE proposes to replace the off mode test at 82 °F with a test at 72±2 °F and replace the
off mode test at 57 °F with a test at a temperature which is 5±2 °F below a manufacturer-
specified turn-on temperature. This approach maintains the intent of the off mode power
consumption rating (PW,OFF) as a representation of the off mode power consumption for the
shoulder and heating seasons, addresses AHRI’s proposed modification of the test procedure,
and addresses ACEEE and ASAP’s concerns regarding the potential for a loophole at the 57 °F
test point.
DOE does not propose to adopt an additional test point at a temperature of 17 °F, as
at a temperature 5 °F below the temperature at which the crankcase heater turns off, as
recommended by AHRI; (AHRI, No. 41 at p. 2) or at a temperature 3-5 °F above the heater turn-
off temperature, as recommended by the CA IOUs and the Joint Efficiency Advocates. (CA
heaters, which show that power input for such heaters is a linear function of outdoor ambient
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temperature (i.e., the input power can be represented with insignificant error as a constant times
the outdoor ambient temperature plus another constant). As such, DOE maintains that two test
points are adequate for characterizing the off mode power consumption for self-regulating
crankcase heaters by establishing a linear fit from the two test outputs. DOE also believes that
one of the two test points is adequate for characterizing the off mode power consumption for
constant wattage crankcase. DOE does not believe that the additional accuracy gained from
additional test points merits the additional test burden. The modifications in this proposal should
help to minimize the test burden while maintaining the accuracy of off mode power ratings.
Stakeholders submitted comments discussing the most appropriate way to weight P1 and
P2 in order to measure the total off mode power draw. In the October 2011 SNOPR, DOE
proposed to require calculation of the total off mode power consumption based upon an
arithmetic mean of the power readings P1 and P2. 76 FR 65616, 65621 (Oct. 24, 2011).
The Joint Efficiency Advocates opposed the DOE’s proposal in the October 2011
25% and P2 by 75%, because this weighting would be more representative of actual heater
operation than equally weighting P1 and P2. (Joint Utilities, No. 33 at p. 2) Conversely,
Goodman and AHRI opposed the CA IOUs’ proposal because there was inadequate data
available to support weighting P1 by 25% and P2 by 75%. Further, Goodman and AHRI stated
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that the CA IOUs’ proposal would not fairly differentiate between products with different
crankcase heater turn-on and turn-off temperatures. A unit with a lower turn-on and a higher
turn-off temperature would consume less overall energy, but a manufacturer would have no
incentive to use the lowest possible temperatures because the rating would not change.
AHRI, Goodman, and the Joint Efficiency Advocates suggested that average power
should be calculated by weighting the off mode hours using a bin method, in a manner consistent
with the calculations of seasonal active-mode. (AHRI, No. 41 at p.3; Goodman, No. 42 at p. 1;
provided a detailed methodology for calculating the off mode power rating in an excel
spreadsheet submitted with its written comments. (AHRI, No. 41 at p. 2) AHRI introduced bin
fractional bin-hours for the shoulder season. Goodman supported AHRI’s proposal. (Goodman,
No. 42 at p. 1) However, AHRI and Goodman commented that if DOE did not accept AHRI’s
proposed calculation, DOE should implement a 50% weighting of P1 and P2 as proposed in the
After reviewing the Off-Mode Power excel spreadsheet from AHRI and the comments
received from stakeholders, DOE retains its proposal from the October 2011 SNOPR, which
gives equal weighting to P1 and P2 for the calculation of the off mode power rating (PW,OFF). 76
FR 65616, 65620 (Oct. 24, 2011). Comments from the stakeholders did not provide any data
that support selection of specific weights for P1 and P2. Therefore DOE cannot confirm that
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AHRI’s suggested temperature bin-hour calculation method is representative of the off mode
In the October 2011 SNOPR, DOE proposed to adjust the measured off mode power
draw for systems with multiple compressors and apply a scaling factor to systems larger than 3
tons. 76 FR at 65621-22. The CA IOUs and the Joint Efficiency Advocates disagreed with
IOUs, No. 40 at p. 1) The CA IOUs commented that adjusting the off mode power draw for
systems with multiple compressors and applying a scaling factor to extra-large systems would
not represent actual off mode power consumption and recommended that DOE not reduce the
calculated off mode power based on the number of compressors. (CA IOUs, No. 33 at p. 2)
AHRI and Goodman disagreed with CA IOUs’ suggestion to eliminate the adjustment
based on the number of compressors as it may potentially discourage the development and use of
2) Moreover, AHRI requested that a similar credit be given to products using modulating
compressors due to the typical application where a higher charge is a requirement of the high
efficiency systems. (AHRI, No. 36 at p. 2) AHRI also disagreed with the idea of eliminating the
scaling factor proposed for rating larger compressors. (AHRI, No. 41 at p. 3) Lastly, AHRI
recommended that the measurement of the off mode power consumption and of the low-voltage
power from the controls for the shoulder season be divided by the number of compressors or
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number of discrete controls, as is currently done for the measurements in the heating season.
(AHRI, No. 36 at p. 2)
DOE is aware that some systems may require higher wattage heaters to protect system
reliability. Specifically, larger-capacity units may have larger-capacity compressors, which (at a
high level) have larger shells with more surface area that can cool them off, thus requiring more
heater wattage. They may also have more lubricant, thus it takes more heater wattage to heat up
the lubricant to acceptable level (for example after a power outage) before restart. To avoid
situations that force manufacturers to potentially compromise the reliability of their systems by
downsizing crankcase heater wattages to meet off mode power requirements, DOE proposes to
systems, which are highly efficient but also need to employ larger crankcase heaters for safe and
reliable operation given the additional shell surface area and lubricant. Therefore, DOE agrees
with AHRI’s recommendation and proposes that the off mode power consumption for the
shoulder season and heating season, as well as the low-voltage power from the controls, be
divided by the number of compressors to determine off mode power consumption on a per-
compressor basis.
The direct final rule also did not consider the possible applicability of the new off mode
standards to high-efficiency air conditioners and heat pumps that achieve high SEER and HSPF
ratings using both large heat exchangers and compressor modulation. The correlation of the use
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of modulating compressors with high refrigerant charge, which is indicative of larger heat
exchangers, was mentioned in the AHRI comment. (AHRI, No. 41 at p. 3) DOE does not want to
penalize manufacturers for selling high efficiency units. Therefore, DOE agrees with AHRI’s
recommendation to apply a multiplier to the calculation of the per-compressor off mode power
for the shoulder season and heating season for modulated compressors, but proposes a multiplier
2+). DOE requests comment on the multiplier of 1.5 for calculating the shoulder season and
In the October 2011 SNOPR, DOE proposed to measure the power from low-voltage
components, 𝑃𝑃𝑥𝑥 , after each of the two tests conducted at T1 and T2. 76 FR 65628-30. Although
this would ensure that the low-voltage power consumption at each temperature test point would
be removed from the respective off mode power consumption, AHRI expressed concern about
excessive manufacturer test burden. AHRI recommended that 𝑃𝑃𝑥𝑥 not be re-measured, as it does
not change with temperature and not re-measuring it avoids automatic and unwanted operation of
DOE agrees with AHRI that the low voltage power consumption does not change with
temperature, although slight and insignificant fluctuations in the low-voltage power may occur
due to the relationship of resistivity and conductivity to temperature. Moreover, DOE does not
believe that these fluctuations outweigh the test burden added from reconfiguring the system for
measuring the low-voltage power a second time. As such, the test procedure has been revised so
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that the measurement of 𝑃𝑃𝑥𝑥 is not repeated. DOE proposes to require that the measurement of 𝑃𝑃𝑥𝑥
occur after the measurement of the heating season total off mode power, 𝑃𝑃2𝑥𝑥 , which reduces test
Additionally, DOE is aware that many control types exist for crankcase heaters, and
certain control methodologies cycle the crankcase heater on and off during the 5-minute interval
during which 𝑃𝑃𝑥𝑥 is being measured. Since 𝑃𝑃𝑥𝑥 measures the power of functioning components,
only non-zero values of measured power should be used in the calculations. DOE has therefore
included in the proposed test procedure a requirement to record only non-zero data for the
determination of 𝑃𝑃𝑥𝑥 .
As a result of the proposed revisions to the test procedure discussed in section III.D.3 and
section III.D.4, the equations from the October 2011 SNOPR for determining P1 for crankcase
heaters without controls and for determining P2 for crankcase heaters with controls are
and
𝑃𝑃2 −𝑃𝑃1
𝑥𝑥 𝑥𝑥
𝑃𝑃2 = 𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 + 𝑃𝑃1,
respectively. 76 FR 65616, 65629-30 (Oct. 24, 2011). 𝑃𝑃1𝐷𝐷 is the off mode power with the
crankcase heater disconnected, which is equal to the low-voltage power, 𝑃𝑃𝑥𝑥 . 𝑃𝑃1𝑥𝑥 is the shoulder-
season total off mode power, 𝑃𝑃2𝑥𝑥 is the heating-season total off mode power, P1 is the per-
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compressor shoulder-season total off mode power, and P2 is the per-compressor heating-season
section III.D.4 (temperature-independence of 𝑃𝑃𝑥𝑥 ) of this notice allow for the simplification of the
equations that would be used to calculate power for crankcase heaters with or without controls.
The two proposed revisions are based on the following three premises: (1) The representations of
P1 and P2 would both be calculated on a per-compressor basis (as discussed in section III.D.3);
(2) The value of 𝑃𝑃𝑥𝑥 would not vary with temperature and would thus be the same at T1 as it is at
T2 (as discussed in section III.D.4); (3) The following would apply under the proposed method:
𝑃𝑃2 = 𝑃𝑃2𝑥𝑥 – 𝑃𝑃𝑥𝑥 ; 𝑃𝑃1 = 𝑃𝑃1𝑥𝑥 – 𝑃𝑃𝑥𝑥 . (As discussed in the October 2011 SNOPR at 76 FR 65629).
Applying the three premises to the equations for P1 and P2 from the October 2011 SNOPR
𝑃𝑃1𝑥𝑥
𝑃𝑃1 =
𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
and
𝑃𝑃2𝑥𝑥
𝑃𝑃2 =
𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
AHRI commented that language in the October 2011 SNOPR may have caused
stakeholders to infer that every blower coil indoor unit combination and every coil-only indoor
unit combination must be tested to determine off mode power consumption. (AHRI, No. 36 at p.
2) AHRI recommended that DOE only require testing of the outdoor condensing unit for the
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highest sale-volume combination of each basic model to determine the off mode power
consumption and allow use of an alternative rating method (ARM) to reduce test burden.
(AHRI, No. 36 at p. 2)
In this SNOPR, DOE proposes generally that each basic model would be required to have
all applicable represented values (SEER, EER, HSPF, or PW,OFF) of a specified individual
combination determined through testing. The other individual combinations within each basic
model may be tested or rated using AEDMs. As such, only one individual combination within
each basic model would be required to be tested to determine off mode power consumption.
Additionally, upon reviewing the test procedures of furnace products, DOE found that the
indoor off mode power in coil-only split-systems (that would be installed in the field with a
furnace) was accounted for in the furnace test methodology. The indoor power for coil-only
systems consists of the controls for the electronic expansion valve drawing power from control
boards either indoor in the furnace assembly or outdoor in the condensing unit. To avoid double-
counting indoor off mode power between two products, DOE proposes to exclude measurement
of the low-voltage power if the controls for the indoor components receive power from a control
board dedicated to a furnace assembly. For blower coil indoor units in which the air mover is a
furnace, the same proposal applies. For blower coil indoor units in which the designated air
mover is not a furnace, since the off mode power of the indoor components is not accounted for
in any other product’s test methodology, DOE proposes to adopt language to include the low-
voltage power from the indoor unit when measuring off mode power consumption for blower
coil systems.
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DOE requests comment on its proposal to exclude low-voltage power from the indoor
unit when measuring off mode power consumption for coil-only split-system air conditioners and
for blower coil split system air conditioners for which the air mover is a furnace. DOE also
requests comment on its proposal to include the low-voltage power from the indoor unit when
measuring off mode power consumption for blower coil split-system air conditioners with an
indoor blower housed with the coil and for heat pumps.
AHRI and Goodman suggested adding a credit for crankcase heaters that incorporate a time
delay before turning on during the shoulder season. (AHRI, No. 41 at p. 2; Goodman, No. 42 at
p. 1) The off mode period in the calculation methodology designates extended periods during
which the unit is idle. DOE proposes to adopt an energy consumption credit that would be
proportional to the duration of the delay, as implemented in the calculation of the off mode
energy consumption for the shoulder season, E1, in the proposed off mode test procedure. DOE
is also proposing, for products in which a time delay relay is installed but the duration of the
delay is not specified in the manufacturer’s installation instructions shipped with the product or
in the certification report, a default period of non-operation of 15 minutes out of every hour,
potential instances of the misuse of this incentive, DOE also proposes requiring manufacturers to
report the duration of the crankcase heater time delay for the shoulder season and heating season
that was used during certification testing. DOE is also considering adding a verification method
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to 429.134. DOE requests comment on the proposed method for accounting for the use of a time
delay, the default period of non-operation, and the possibility of a verification test for length of
time delay.
The June 2010 NOPR proposed a test procedure that would measure the average off
mode power consumption, PW,OFF, of a central air conditioner or heat pump. 75 FR 31238-39.
Additionally, the amended energy conservation standards for central air conditioners and heat
pumps in the June 2011 DFR included standards for off mode power consumption that were
The Joint Efficiency Advocates and the CA IOUs commented that the test procedure
should calculate energy use and not average power draw. (Joint Efficiency Advocates, No. 43 at
p. 3; CA IOUs, No. 33 at p. 1) The CA IOUs stated that DOE should measure energy use
because control systems on the crankcase heater can save power by reducing run time, which is
not captured by a power-draw metric. (CA IOUs, No. 33 at p. 1) The Joint Efficiency Advocates
also requested that any standards promulgated should be based on energy use. (Joint Efficiency
Advocates, No. 43 at p. 2)
To maintain consistency with the off mode standards, the test procedure must measure off
mode power consumption rather than energy use. However, DOE recognizes that adopting a
bin-based approach to calculate PW,OFF does not provide a final off mode value that is indicative
of actual power consumption. DOE is aware of alternative methods to determine a power rating.
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However, in consideration of testing burden, DOE proposes to implement a method of
calculation that would closely approximate the actual off mode power consumption via a simple
average of the shoulder and heating season measured values. Although this metric will not
directly translate into instantaneous off mode power consumption, annual energy costs, or
representative of average off mode power consumption. The average off mode power
calculation can be used for ranking models based on their performance when idle, as well as for
DOE is aware that measurement of energy use for a specified test period would enable
calculation of annual energy consumption and operating costs and, on a larger scale, national
energy savings and national energy consumption solely due to equipment idling. Therefore,
DOE has proposed optional equations that a manufacturer could use to determine the actual off
mode energy consumption, based on the hours of off mode operation and off mode power for the
consumption would be specific to a single location and its unique set of cooling, heating, and
AHRI and Bristol Compressors submitted comments expressing concern that regulating
crankcase heater energy consumption could have a negative impact on product reliability (AHRI,
No. 41 at pp. 1-2; Bristol, No. 39 at p. 1) Bristol Compressors remarked that simply turning the
crankcase heater off at specific outdoor ambient temperatures would expose many compressors
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to conditions that would reduce the effective life of the product or, at worst, cause immediate
failure. Bristol requested that DOE allow additional time for research on technological options
that could save energy in a manner similar to controls based on outdoor ambient temperature, but
that do not impact the reliability of the product. (Bristol, No. 39 at p. 1) AHRI asked DOE to
conduct further research to determine if regulating crankcase heater energy consumption has a
negative impact on product reliability and to consider additional amendments to the test
DOE expects that this proposed off mode test method will allow manufacturers to meet
the June 2011 off mode standards without causing a shift in the reliability of the overall market
of central air conditioners and heat pumps. DOE requests comments on the issue of compressor
reliability as it relates to crankcase heater operation in light of the test method proposed in this
rule.
In the April 2011 SNOPR DOE proposed modifications to the laboratory tests and
algorithms for determining the off mode power of central air conditioners and heat pumps. 76
FR 18105, 18107–09 (April 1, 2011). DOE received comments indicating that the April 2011
SNOPR was overly burdensome, and the October 2011 SNOPR proposed a revised method that
Following the October 2011 SNOPR, the Joint Efficiency Advocates stated that, while
minimizing test burden is important, DOE is also obligated by statute to prescribe a test
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procedure that measures the energy use of a covered product during a representative average use
cycle or period of use. (42 U.S.C 629(b)(3)) The Joint Efficiency Advocates stated that the
Department’s proposal was far from accomplishing that statutory requirement. (Joint Efficiency
Advocates, No. 35 at p. 2) The CA IOUs noted that the test procedure revisions presented in the
October 2011 SNOPR would not encourage innovative designs of heating systems in off mode,
and that the results produced by the test procedure would be misleading to consumers, because
the reported values would not be indicative of actual power draw if DOE were to require
measurements based on fixed outdoor temperatures and use a simple average of P1 and P2. (CA
IOUs, No. 33 at p. 1)
However, in the December 2011 extension notice, DOE proposed to consider the
suggestion by the CA IOUs to use the actual outdoor temperatures at which the crankcase heater
turns on or off to measure P1 and P2, as discussed in section III.D.2. The CA IOUs subsequently
submitted comments that reaffirmed this proposal, and recommended that DOE consider its
proposals to use a weighted average of P1 and P2 and to not adjust power draw for systems with
multiple compressors or large-capacity systems. (CA IOUs, No. 40 at p.1) The Joint Efficiency
Advocates conveyed strong support for the CA IOUs’ proposal and remarked that the test
procedure would not be indicative of actual energy use if DOE did not adopt the CA IOUs’
As previously discussed, DOE must develop test procedures to measure energy use that
balance test burden with measurement accuracy. The off mode test procedures published in the
original NOPR and the first SNOPR were judged by stakeholders to be too complex and
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burdensome. As a result, DOE proposed a test method in the second SNOPR that was simplified
and designed to result in comparatively less test burden. The simplified test procedure, however,
may have impacted the ability to provide a measurement that is representative of an average use
cycle or period of use. In this third SNOPR, DOE has made additional revisions and believes
that this new proposed off mode test procedure limits test burden to a reasonable extent and will
provide a means for measuring off mode power use in a representative manner.
42 U.S.C. 6293(b)(3) states that any test procedure prescribed or amended shall be
reasonably designed to produce test results which measure energy efficiency and energy use of a
covered product during a representative average period of use and shall not be unduly
burdensome to conduct. This section discusses proposals to improve test procedure clarity and
to reduce test burden. None of the proposals listed in this section would alter the average
Indoor unit fan speed is typically adjustable during test set-up to assure that the provided
air volume rate is appropriate for the field-installed ductwork system serving the building in
which the unit is actually installed. The DOE test procedure accounts for these variable settings
by establishing specific requirements for external static pressure and air volume rate during the
test. For an indoor coil tested with an indoor fan installed, DOE’s test procedure requires that (a)
external static pressure be not less than a minimum value that depends on cooling capacity 11 and
11
Or heating capacity for heating-only heat pumps.
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product class, ranging from 1.10 to 1.20 inches of water column (in. wc.) for small-duct, high-
velocity systems and from 0.10 to 0.20 in. wc. for all other systems except non-ducted units (see
10 CFR Part 430, Subpart B, Appendix M, Table 2); and (b) the air volume rate divided by the
total cooling capacity not exceed a maximum value of 37.5 cubic feet per minute of standard air
(scfm) per 1000 Btu/h of cooling capacity12 (see 10 CFR Part 430, Subpart B, Appendix M,
Section 3.1.4.1.1).
Requirement (a) is more easily met using higher fan speeds, while requirement (b) is
more easily met by lower fan speeds. DOE realizes that more than one speed setting may meet
both the minimum static pressure and the maximum air volume rate requirements. Section
3.1.4.1.1(a)(6) of the current DOE test procedure for air conditioners and heat pumps allows
adjustment of the fan speed to a higher setting if the first selected setting does not meet the
minimum static pressure requirement at 95 percent of the cooling full-load air volume rate. 13
This step suggests that common test practice would be to initially select lower fan speeds to meet
the requirements before attempting higher speeds. However, the test procedure does not, for
cases in which two different settings could both meet the air volume rate and static pressure
requirements, explicitly specify that the lower of the two settings should be used for the test.
The fan power consumption would generally be less at lower speeds, but compressor power
consumption may be reduced at conditions of higher air volume rate—hence it is not known
prior to testing whether a higher or lower air volume rate will maximize the SEER or HSPF for a
given individual model. However, DOE is aware that efficiency ratings are generally better
12
Such a requirement does not exist for heating-only heat pumps.
13
For heating-only heat pumps, Section 3.1.4.4.3(a)(6) allows adjustment of the fan speed to a higher setting if the
first selected setting does not meet the requirements minimum static pressure requirement at 95 percent of the
heating full-load air volume rate.
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when products are tested at the lowest airflow-control settings intended for cooling (or heating)
operation that will satisfy both the minimum static pressure and maximum air volume rate
requirements. DOE therefore proposes that blower coil products tested with an indoor fan
installed be tested using the lowest speed setting that satisfies the minimum static pressure and
the maximum air volume rate requirements, if applicable, if more than one of these settings
For a coil-only system, i.e., a system that is tested without an indoor fan installed, the
pressure drop across the indoor unit must not exceed 0.3 inches of water for the A test (or A2 test
for two-capacity or variable-capacity systems), and the maximum air volume rate per capacity
must not exceed 37.5 cubic feet per minute of standard air (scfm) per 1000 Btu/h. (10 CFR Part
430, Subpart B, Appendix M, Section 3.1.4.1.1) For such systems, higher air volume rates
enhance the heat transfer rate of the indoor coil, and therefore may maximize the measured
system capacity and efficiency. In addition, the energy use and heat input attributed to the fan
energy for such products is a fixed default value in the test procedure, and is set at 365 W per
1,000 scfm (10 CFR Part 430, Subpart B, Appendix M, Section 3.3(d)). Thus, the impact from
fan power on the efficiency measurement if air volume rate is increased may be more modest
than for a unit tested with the indoor fan installed. However, a maximum external static pressure
of 0.3 in. wc. is specified for the indoor coil assembly in order to represent the field-installed
conditions. To minimize potential testing variability due to the use of different air volume rates,
DOE proposes to require for coil-only systems for which the maximum air flow (37.5 scfm/1000
Btuh) or maximum pressure drop (0.3 in wc) are exceeded when using the specified air flow rate,
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the highest air flow rate that satisfies both the maximum static pressure and the maximum air
volume rate requirements should be used. This is specified in section 3.1.4.1.1.c of Appendix M..
Improper fan speed implemented during testing may have a marked impact on product
repeatability. DOE therefore proposes to require that manufacturers include in their certification
report the speed setting and/or alternative instructions for setting fan speed to the speed upon
For consistency with the furnace fan test procedure, DOE proposes to add to Appendix M
(and also Appendix M1) the definition for “airflow-control setting” that has been adopted in
Appendix AA to refer to control settings used to obtain fan motor operation for specific
functions.
DOE requests comment on its proposals regarding requirements on fan speed settings
Section 2.2(a) of 10 CFR Part 430, Subpart B, Appendix M provides instructions for
insulating the “low-pressure” line(s) of a split-system. In the cooling mode, the vapor refrigerant
line connecting the indoor and outdoor units is operating at low refrigerant pressure. However,
in the heating mode, the vapor refrigerant line connecting the indoor and outdoor units operates
at high pressure, providing high pressure vapor to the indoor unit. To improve clarity and ensure
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that the language of the test procedure refers specifically to the actual functions of the refrigerant
lines, DOE proposes to refer to the lines as “vapor refrigerant line” and “liquid refrigerant line”.
Section 2.2(a) of 10 CFR Part 430, Subpart B, Appendix M and AHRI 210/240-2008
Section 6.1.3.5 both require insulation on the vapor refrigerant line and do not state what
insulation, if any, is required on the liquid refrigerant line. Differences in product design and in
the parts manufacturers decide to ship with the unit may lead to varying interpretations regarding
the need to insulate the liquid refrigerant line during the test and may therefore introduce test
variability. Furthermore, there may be unnecessary burden on test laboratories if they choose to
add insulation when manufacturers do not to ship liquid refrigerant line insulation with the unit.
While DOE wishes to clarify requirements for insulation of refrigerant lines, there are two
factors that make such a determination difficult: (1) there may be reasons both for insulating and
for not insulating the liquid refrigerant tubing—if not insulated, additional subcooling of the
refrigerant liquid as it passes through the line prior to its expansion in the indoor unit may
increase cooling capacity and thus increase the measured SEER. However, the increased
subcooling of the liquid would increase the load on the outdoor coil during the heating mode of a
heat pump, which may slightly reduce evaporating temperature and thus both reduce heat pump
capacity and increase compressor power input. On the other hand, insulating the liquid line
would result in higher measurements of HSPF for a heat pump when compared with
measurements with the liquid line not insulated, but would result in lower measurements of the
SEER; (2) DOE has observed that installation manuals for air conditioners and heat pumps
generally indicate that liquid lines should be insulated in special circumstances (e.g., running the
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line through a warm space or extra-long refrigerant line runs), but do not provide guidance on the
Because DOE seeks to minimize test variability associated with the use of insulation, this
notice includes a proposal for determining the insulation requirement for the test based on the
materials and information included by the manufacturer with the test unit. Under this proposal,
test laboratories would install the insulation shipped with the unit. If the unit is not shipped with
insulation, the test laboratory would install the insulation specified in the installation manuals
included with the unit by the manufacturer. Should the installation instructions not provide
sufficient guidance on the means of insulating, liquid line insulation would be used only if the
product is a heating-only heat pump. These proposed requirements are intended to reduce test
burden and improve test repeatability for cooling and heating products, as well as heating-only
products. DOE requests comment on its proposal to require that test laboratories install the
insulation included with the unit or, if insulation was not furnished with the unit, follow the
comment on its proposal to require liquid line insulation of heating-only heat pumps.
indoor space conditioning capacity, uninsulated surfaces of the refrigerant lines and the mass
flow meter may also contribute to thermal losses. DOE does not believe that preventing the
incremental thermal losses associated with the mass flow meter components and its support
structure would make a measurable impact on efficiency measurements. However, DOE does
recognize the possibility that thermal loss might reduce the efficiency measurement, particularly
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during heating mode tests if the mass flow meter is placed on the test chamber floor, which
might be cooler than the air within the room. To enhance test repeatability among various
laboratories that may use different mass flow meters with varying materials for support
structures, DOE proposes to require use of a thermal barrier to prevent such thermal transfers
between the flow meter and the test chamber floor if the meter is not mounted on a pedestal or
other support elevating it at least two feet from the floor. DOE proposes to add these
requirements to Appendix M, section 2.10.3. DOE requests comment on this means to prevent
conditioning equipment, temperature or humidity levels in the room may vary during testing.
For this reason, a portion of the air approaching the outdoor unit’s coil is sampled using an air
sampling device (see Appendix M, section 2.5). The air sampling device, described in ASHRAE
Standard 41.1-2013, consists of multiple manifolded tubes with a number of inlet holes, and is
often called an air sampling tree. If, during testing, the air entering the outdoor unit of a product
is monitored only on one of its faces and there is significant spatial variation of the room’s air
conditions, the measured conditions for the monitored face may not be indicative of the average
To ensure that the measurements account for variation in the conditions in the outdoor
room of the test chamber, DOE proposes to require demonstration of air temperature uniformity
over all of the air-inlet surfaces of the outdoor unit using thermocouples, if sampling tree air
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collection is performed only on one face of the outdoor unit. Specifically, DOE would require
that the thermocouples be evenly distributed over the inlet air surfaces such that there is one
thermocouple measurement representing each square foot of air-inlet area. The maximum
temperature between the measurements at the warmest location and at the coolest location,
would be 1.5 °F (DOE proposes to add these requirements to Appendix M, section 2.11.b). This
is the same maximum spread allowable for measurement of indoor unit capacity using
thermocouple grids, as described in 10 CFR Part 430, Subpart B, Appendix M, Section 3.1.8, in
which the maximum spread among the measured temperatures on the thermocouple grid in the
outlet plenum of the indoor coil must not exceed 1.5 °F dry bulb. If this specified measurement
of temperature uniformity cannot be demonstrated, DOE would require sampling tree collection
of air from all air-inlet surfaces of the outdoor unit. DOE seeks comment for the proposed 1.5 °F
maximum spread for demonstration of outdoor air temperature uniformity, the proposed one
square foot per thermocouple basis for thermocouple distribution, and the proposed requirement
that an air sampling device be used on all outdoor unit air-inlet surfaces if temperature
uniformity is not demonstrated. DOE proposes to add these requirements to Appendix M, section
2.11.b.
To ensure test repeatability, DOE seeks to ensure that temperature measurements taken
during the test are as accurate as possible. DOE is aware that measurement of outdoor inlet
temperatures is commonly based on measurements of the air collected by sampling devices that
use high-accuracy dry bulb temperature and humidity measurement devices, and that the
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accuracy of these devices may be better than that of thermocouples. DOE proposes to require
that the dry bulb temperature and humidity measurements, that are used to verify that the
required outdoor air conditions have been maintained, be measured for the air collected by the air
sampling devices (e.g., rather than being measured by temperature sensors located in the air
stream approaching the air inlets). DOE requests comment on this proposal.
In evaluating various test setups and laboratory conditions, DOE has observed that
certain setup conditions of the air sampling equipment could lead to measurement error or
variability between laboratories. Specifically, the temperature of air collected by indoor and
outdoor room air sampling devices could potentially change as it passes through the air
collection system, leading to inaccurate temperature measurement if the air collection devices or
the conduits conducting the air to the measurement location are in contact with the chamber floor
or with ambient air at temperatures different from the indoor or outdoor room. To prevent this
potential cause of error or uncertainty, DOE proposes to require that no part of the room air
sampling device or the means of air conveyance to the dry bulb temperature sensor be within two
inches of the test chamber floor. DOE also proposes to require those surfaces of the air sampling
device and the means of air conveyance that are not in contact with the indoor and outdoor room
air be insulated.
taking of dry bulb and wet bulb measurements in different locations, if there is significant cool
down of air between the two locations. While ASHRAE Standard 41.1-2013 provides an
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example of an air sampling device with a dry bulb and wet bulb thermometer placed close
together, the figure is merely illustrative. To minimize measurement error or uncertainty, DOE
proposes to require that humidity measurements and dry bulb temperature measurements used to
determine the moisture content of air be made at the same location in the air sampling device.
As discussed in section III.E.14, DOE has also proposed several amendments to air
sampling procedures that are included in a draft revision of AHRI 210/240-2008. DOE requests
comments on all of these related proposals, including its proposal to require that the air sampling
device and its components be prevented from touching the test chamber floor, to require
insulation of those surfaces of the air sampling device and components that are not in contact
with the chamber room air, and that dry bulb temperature and humidity measurements used to
determine the moisture content of air be made at the same location in the air sampling device.
When testing an air conditioner or heat pump with a variable-speed compressor, the
compressor must be tested at three different speeds: maximum, intermediate, and minimum.
Some air conditioners and heat pumps with a variable-speed compressor operate such that their
maximum allowed compressor speed varies with the outdoor temperature. However, the test
procedure does not explicitly state whether the maximum compressor speed refers to a fixed
value or a temperature-dependent value. As such, DOE proposes that the maximum compressor
speed be fixed during testing through modification of the control algorithm used for the
particular product such that the speed does not change with the outdoor temperature. DOE
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7. Refrigerant Charging Requirements
with a range of boiling points. Gaseous charging of refrigerant blends is inappropriate because it
can result in higher concentrations of the higher-vapor pressure constituents being charged into
the unit, which can alter refrigerant performance characteristics and thus, unit performance.
DOE recognizes that technicians certified to handle refrigerants via the Environment Protection
Agency’s (EPA) Section 608 Technician Certification Program, as mandated by 40 CFR 82.161,
ensure consistent practices within the context of the DOE test procedure, DOE proposes to
require that near-azeotropic and zeotropic refrigerant blends be charged in the liquid state rather
than the vapor state. This is found in section 2.2.5.8 of Appendix M. DOE requests comments
on this proposal.
Current language in Appendix M to Subpart B of 10 CFR Part 430 does not prohibit
testers from changing the amount of refrigerant charge in a system during the course of air
conditioner and heat pump performance tests. Changing the amount of refrigerant may result in
a higher SEER and/or a higher HSPF that does not reflect the actual performance of a unit in the
field. In the June 2010 NOPR, DOE proposed to adopt into the test procedure select parts of the
2008 AHRI General Operations Manual that contains language disallowing changing the
refrigerant charge after system setup. (75 FR 31234-5) AHRI and NEEA supported this
proposal. (AHRI, No. 6 at p. 3; NEEA, No. 7 at p. 4) To ensure that performance tests reflect
operation in the field, and to improve consistency in results between test facilities, DOE intends
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to retain the proposal made in the June 2010 NOPR. Specifically, DOE retains the proposed
requirement that once the system has been charged with refrigerant consistent with the
installation instructions shipped with the unit (or with other provisions of the test procedure, if
the installation instructions are not provided or not clear), all tests must be conducted with this
charge.
DOE is aware that refrigerant charging instructions are different for different products,
but that in some cases, such instructions may not be provided. More specifically, the appropriate
charging method may vary among products based upon their refrigerant metering devices. The
thermostatic expansion valve (TXV) type metering device is designed to maintain a specific
degree of superheat. 14 Electronic expansion valve (EXV) type metering devices function
similarly to TXV type metering devices, but use sensors, a control system, and an actuator to set
the valve position to allow more sophisticated control of the degree of superheat. Fixed orifice is
another type of expansion device commonly used for air conditioners. In contrast to a TXV or
EXV, a fixed orifice does not actively respond to system pressures or temperatures to maintain a
fixed degree of superheat. The refrigerant charge can affect the measured system efficiency.
Systems with different expansion devices react differently to variation in the charge, and they
also generally require different procedures for ensuring that the system is properly charged. As
the charging operation may differ among these types of metering devices, and misidentification
may lead to inconsistent charging and unrepeatable testing, DOE proposes to require
manufacturers to report the type of metering device used during certification testing.
14
The degree of superheat is the extent to which a fluid is warmer than its bubble point temperature at the measured
pressure, i.e., the difference between a fluid’s measured temperature and the saturation temperature at its measured
pressure.
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If charging instructions are not provided in the manufacturer’s installation instructions
shipped with the unit, DOE proposes standardized charging procedures to ensure consistent
testing in a manner that reflects field practices. For a unit equipped with a fixed orifice type
metering device for which the manufacturer’s installation instructions shipped with the unit do
not provide refrigerant charging procedures, DOE proposes that the unit be charged at the A or
A2 test condition, requiring addition of charge until the superheat temperature measured at the
suction line upstream of the compressor is 12 °F with tolerance discussed in section III E.14. 15
For a unit equipped with a TXV or EXV type metering device for which the manufacturer’s
installation instructions shipped with the unit do not provide refrigerant charging procedures,
DOE proposes that the unit be charged at the A or A2 condition, requiring addition of charge
until the subcooling 16 temperature measured at the condenser outlet is 10 °F with tolerance
For heating-only heat pumps for which refrigerant charging instructions are not provided
in the manufacturer’s installation instructions shipped with the unit, the proposed standardized
charging procedure would be followed while performing refrigerant charging at the H1 or H12
condition. DOE also proposes that charging be done for the H1 or H12 test condition for
cooling/heating heat pumps which fail to operate properly in heating mode when charged using
15
The range of superheating temperatures was generalized from industry-accepted practice and state-level authority
regulations on refrigerant charging for non-TXV systems.
16
The degree of subcooling or subcooling temperature is the extent to which a fluid is cooler than its refrigerant
bubble point temperature at the measured pressure, i.e., the bubble point temperature at a fluid’s measured pressure
minus its measured temperature. Bubble point temperature is the temperate at a given pressure at which vapor
bubbles just begin to form in the refrigerant liquid.
17
The range of subcooling temperatures was generalized from manufacturer-published and technician-provided
service instructions and are typical of industry practice.
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the standardized charging procedure for the A or A2 test condition. In such cases, some of the
tests conducted using the initial charge may have to be repeated to ensure that all tests (cooling
and heating) are conducted using the same refrigerant charge. DOE proposes to add these
to units for which the installation instructions shipped with the unit do not provide charging
instructions.
DOE understands that manufacturers may provide installation instructions with different
charging procedures for the indoor and outdoor units. In such cases, DOE proposes to require
charging based on the installation instructions shipped with the outdoor unit for outdoor unit
manufacturer products and based on the installation instructions shipped with the indoor unit for
Single-package central air conditioners and heat pumps may be shipped with refrigerant
already charged into the unit. Verifying the proper amount of refrigerant charge is valuable for
increasing test repeatability. To this end, DOE believes that the benefits of installing pressure
gauges on a single-package unit to help verify charge and to monitor refrigerant conditions
generally outweigh the potential drawbacks associated with connecting the gauges (e.g.,
refrigerant transfer from the product into the gauges and hoses or refrigerant leakage);
calculating the superheat or subcooling quantities used to determine whether the unit is charged
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properly requires knowledge of the refrigerant pressure, and the quantity of charge transferred
from the unit when connecting a pressure gauge set is generally a very small percentage of the
unit’s charge. Further, assessing the refrigerant charge may improve repeatability of the tests
and measured efficiency. DOE therefore proposes that refrigerant line pressure gauges be
installed during the setup of single-package and split-system central air conditioner and heat
pump products, unless otherwise specified by the instructions. DOE also proposes that the
refrigerant charge be verified per the charging instructions and, if charging instructions are not
provided in the installation instructions shipped with the unit, the refrigerant charge would be
verified based on the standardized charging procedure described above. DOE requests
As discussed in section III.E.14, DOE has also proposed several amendments to charging
procedures that are included in a draft revision of AHRI 210/240-2008. DOE requests comment
10 CFR Part 430, Subpart B, Appendix M, Section 2.5(c) requires use of damper boxes in
the inlet and outlet ducts of ducted units to prevent thermal losses during the OFF period of the
compressor OFF/ON cycle for the cooling or heating cyclic tests. However, DOE is aware that
installation of such dampers for single-package ducted units can be burdensome because the unit
must be located in the outdoor chamber and there may be limited space in the chamber and in
between the inlet and outlet ducts to install the required transition ducts, insulation, and dampers.
To preserve the intent of the air damper boxes, reduce testing burden, and accommodate
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variations in chamber size, DOE proposes an alternative testing arrangement to prevent thermal
losses during the compressor OFF period that would eliminate the need to install a damper in the
inlet duct that conveys indoor chamber air to the indoor coil.
The proposed alternative testing arrangement would allow the use of a duct configuration
that relies on changes in duct height, rather than a damper, to eliminate natural convection
thermal transfer out of the indoor duct during OFF periods of the “cold” or heat generated by the
system during the ON periods. An example of such an arrangement would be an upturned duct
installed at the inlet of the indoor duct, such that the indoor duct inlet opening, facing upwards, is
sufficiently high to prevent natural convection transfer out of the duct. DOE also proposes to
require installation of a dry bulb temperature sensor near the inlet opening of the indoor duct at a
centerline location not higher than the lowest elevation of the duct edges at the inlet.
Measurement and recording of dry bulb temperature at this location would be required at least
every minute during the compressor OFF period to confirm that no thermal loss occurs. DOE
proposes a maximum permissible variation in temperature measured at this location during the
DOE seeks comment on its proposal in section 2.5(c) of Appendix M to allow, for cyclic
tests, alternative arrangements to replace the currently-required damper in the inlet portion of the
indoor air ductwork for single-package ducted units. DOE also requests comment on the
proposed requirements for ensuring that there are no thermal losses during the OFF portion of
the test, including the location of the proposed dry bulb temperature sensor, the requirements for
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recorded temperatures, and the ±1.0 °F allowable variation in temperature measured by this
sensor.
The current DOE test procedure references ARI Standard 210/240-2006 Section 6.1.3.2
for selecting the proper electrical voltage supply, which generally requires that, for tests
210/240), the tests be conducted at the product’s nameplate rated voltage and frequency. This
section also requires that Standard Rating tests be performed at 230 V for air-cooled equipment
rated with 208-230 V dual nameplate voltages, and that all other dual nameplate voltage
equipment be tested at both voltages or at the lower of the two voltages if only a single Standard
Rating is to be published. DOE recognizes that nameplate voltages may differ for indoor and
outdoor units. This may result in a difference of voltage supplied to the indoor and outdoor units
in accordance with the current test requirement. DOE realizes that, in most cases, this voltage
difference that may occur during testing is not representative of field operation where indoor and
outdoor units are typically supplied with the same voltage. As such, DOE proposes to clarify
that the outdoor voltage supply requirement supersedes the indoor requirement if the provisions
result in a difference for the indoor and outdoor voltage supply. That is, both the indoor and
outdoor units shall be tested at the same voltage supplied to the outdoor unit.
The cooling coefficient of degradation, CDc , is the ratio of the EER measured for cycling
(or intermittent) operation to the EER that would be measured for steady operation. The heating
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coefficient of degradation, CDh , is a similar factor that characterizes efficiency reduction for
cycling operation during heat pump operation. The test procedures to determine these two
coefficients are the same except for the testing conditions and unit operation mode, and the
changes discussed in this section are applied to both metrics. Therefore, for the sake of
simplicity and clarity, only the cooling coefficient of degradation is discussed here.
The current test procedure gives manufacturers the option to use a default cyclic
degradation coefficient (CD) value of 0.25 instead of running the optional cyclic test. In response
to the June 2010 NOPR, which proposed some modifications related to the optional tests but not
the default value, NEEA commented that its laboratory testing demonstrated that the default
value 0.25 is not representative of system performance, especially for TXV-equipped systems,
and instead supported using the actual tested values in determining ratings. (NEEA, No. 7 at pp.
6-7) DOE reviewed results from its own testing of 19 split-system and single-package air
conditioners and heat pumps from 1.5 to 5 tons and found that the tested CD values range from
0.02 to 0.18, with an average of 0.09. It also found no correlation between CD and SEER, EER,
or cooling capacity. DOE also reviewed the AHRI 210/240-Draft (see section III.E.14), which
updates the cooling CDc value to 0.2. DOE believes this default value may be more in-line with
actual tested values, and DOE proposes to update the default cooling CDc value in Appendix M to
0.2. At this time, DOE is not proposing to update the default heating CDh value. In evaluating
appropriate default values, DOE also reviewed its testing requirements to measure CD.
DOE is aware of various issues that occur when conducting the test procedure to measure
the degradation coefficient, such as the inability to attain stable capacity measurements from
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cycle to cycle and burdensome testing time to attain stability, and believes that these are
symptoms of cyclic instability. DOE believes that the variation in cooling capacity during the
test to determine CDc is exacerbated by the short compressor on-time specified for each cycle and
by the effect of response time, sensitivity, and repeatability errors. DOE understands the
importance of having a minimally burdensome test procedure. However, DOE recognizes that
the current test method for measuring CDc , although clear in description and intent, does not
provide requirements for cyclic stability of measured capacity over successive on-cycles during
the test. Therefore, DOE proposes the following procedure based on cyclic testing data to clarify
the test procedure, address cyclic stability, and offer default procedures to allow for test burden
relief.
DOE has obtained cyclic test data that show that as cycles are tested, either capacity
reaches steady-state or capacity fluctuates constantly and consistently. Therefore, DOE proposes
that before determiningCDc , three “warm up” cycles for a unit with a single-speed compressor or
two-speed compressor or two “warm up” cycles for a unit with a variable speed compressor must
be conducted. Then, conduct a minimum of three complete cycles after the warm-up period,
taking a running average of CDc after each additional cycle. If after three cycles, the average of
three cycles does not differ from the average of two cycles by more than 0.02, the three-cycle
average should be used. If it differs by more than 0.02, up to two more valid cycles will be
conducted. If the average CDc of the last three cycles are within 0.02 of or lower than the previous
three cycles, use the average CDc of all valid cycles. After the fifth valid cycle, if the average CDc of
the last three cycles is more than 0.02 higher than the previous three cycles, the default value will
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be used. The same changes are proposed for the test method to determine the heating coefficient
of degradation.
Given these changes to address, DOE proposes that unlike the current test procedure,
manufacturers must conduct the specified testing required to measure CD for each tested unit.
The default value may only be used if stability or the test tolerance is not achieved or when
DOE requests comment regarding the proposed revisions to the cyclic test procedure for
the determination of both the cooling and heating coefficient of degradation. DOE also requests
additional test data that would support the proposed specifications, or changes to, the number of
warm-up cycles, the cycle time for variable speed units, the number of cycles averaged to obtain
20, 2012, as part of the extended comment period on the October 2011 SNOPR. In these
supplementary comments, AHRI requested that DOE implement an optional 75-hour break-in
period for testing central air conditioners and heat pumps. It stated that scroll compressors,
which are the type of compressors most commonly used in central air conditioners and heat
pumps, achieve their design efficiency after 75 hours of operation, so the allowance for a break-
in period of this length would ensure that the product being tested is operating as intended by the
manufacturer and would provide a result that is more representative of average use. AHRI also
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cited a study of compressor break-in periods to justify this period of time, 18 and added that, while
AHRI’s certification program for central air conditioners and heat pumps does not specify a
minimum break-in period, it does allow manufacturers to specify a break-in period for their
central air conditioners and heat pumps would be consistent with a similar provision in the DOE
test procedures for commercial heating and air-conditioning equipment, which DOE adopted in a
final rule published May 16, 2012. 77 FR 28928. As stated in the final rule, the purpose of
including this option for testing commercial HVAC equipment was to ensure that the equipment
being tested would have time to achieve its optimal performance prior to conducting the test.
DOE placed a maximum limit of 20 hours on the allowed period of break-in, regardless of the
break-in period recommended by the manufacturer, explaining that such a limit was necessary to
minimize the burden imposed by this provision. In addition, DOE required that manufacturers
who use the optional break-in period report the duration of their break-in as part of the test data
underlying the certification that is required to be maintained under 10 CFR 429.71. DOE stated
that it would use the same break-in period for any DOE-initiated testing as the manufacturer used
in its certified ratings or, in the case of ratings based upon use of an alternate efficiency
determination method (AEDM), the maximum 20-hour break-in period. 77 FR 28928, 28944.
18
Khalifa, H.E. “Break-in Behavior of Scroll Compressors” (1996). International Compressor Engineering
Conference. Paper 1145.
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After consideration of the potential improvement in performance and increased test
burden that may result from implementation of an optional 75-hour break-in period, DOE
believes that the lengthy break-in period is not appropriate or justified. In reviewing the paper
that AHRI cited in its comments, DOE noted that, while the data indicate that products with
scroll compressors do appear to converge upon a more consistent result after compressor break-
in periods exceeding 75 hours, the most significant improvement in compressor performance and
reduction in variation among compressor models both appear to occur during roughly the first 20
hours of run time. 19 Moreover, scroll compressors in use at the time of this paper’s publication in
1996 may have required longer break-in periods to address the surface quality of the internal
components resulting from the manufacturing processes of that time, whereas compressors in use
today have benefitted from improvements in the manufacturing technology for scroll
compressors over the past 20 years. In addition, while the paper also supports AHRI’s comment
that smaller compressors require more time to reach their optimal performance than larger
compressors, it does not show the absolute size of the compressors that were studied and makes
comparisons based only on their relative sizes. Therefore, it is difficult to precisely determine
how this data would apply to a central air conditioner or heat pump compressor versus a
commercial air conditioner or heat pump. Finally, since DOE determined in the May 16, 2012
commercial HVAC equipment final rule that a 20 hour maximum break-in time would be
sufficient for small commercial air-conditioning products, which are of a capacity similar to
central air-conditioning products, DOE does not see justification for a break-in period longer
19
Ibid. pp. 442-443.
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In consideration of AHRI’s comments on the merits of conducting a break-in period prior
to testing of central air conditioners and heat pumps, DOE proposes in this SNOPR to allow
manufacturers the option of specifying a break-in period to be conducted prior to testing of these
products under the DOE test procedure. However, due to the excessive test burden that could be
imposed by allowing lengthy break-in times, DOE proposes to limit the optional break-in period
to 20 hours, which is consistent with the test procedure final rule for commercial HVAC
equipment. DOE also proposes to adopt the same provisions as the commercial HVAC rule
regarding the requirement for manufacturers to report the use of a break-in period and its
duration as part of the test data underlying their product certifications, the use of the same break-
in period specified in product certifications for testing conducted by DOE, and use of the 20 hour
hours prior to testing as part of the DOE test procedure for central air conditioners and heat
pumps.
In the June 2010 NOPR, DOE proposed two “housekeeping” updates throughout
Appendix M regarding test procedure references. 75 FR 31243. The first is an update of the
2008, which provides additional test unit installation requirements and requirements on apparatus
used during testing. The second update involves changes to references from 10 CFR 430.22 to
10 CFR 430.3, as the listing of those materials incorporated by reference was relocated. In the
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public comment period following the NOPR, AHRI expressed support for updating the test
procedure to reference current AHRI and ASHRAE standards. (AHRI, No. 6 at p. 6). DOE is
maintaining its position in the June 2010 NOPR for both proposals and therefore implemented
the reference updates in the reprint of Appendix M of this notice. However, DOE proposes in
this SNOPR to incorporate by reference the 210/240 standard having the most recent
amendments at the time of this notice, i.e., ANSI/AHRI 210/240-2008 with Addendum 2. 20 The
changes incorporated by these amendments relate to replacing the Integrated Part Load Value
(IPLV) efficiency metric with the Integrated Energy Efficiency Ratio (IEER) metric, as well as
adding the methodology for determining IEER for water- and evaporatively-cooled products.
These changes are relevant only to commercial equipment and are not relevant to the DOE test
procedure for central air conditioners and heat pumps. Therefore updating references to the
latest version of ANSI/AHRI 210/240 will not impact the ratings or energy conservation
In addition, in this SNOPR, DOE proposes to update the IBR from ASHRAE Standard
37-2005, Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment to
ASHRAE Standard 37-2009, Methods of Testing for Rating Electrically Driven Unitary Air-
Conditioning and Heat Pump Equipment; ASHRAE 41.9-2000, Calorimeter Test Standard
Standard Methods for Volatile-Refrigerant Mass Flow Measurements Using Calorimeters; and
20
ANSI/AHRI 210/240-2008 with Addendum 2 is named as such but includes changes per an Addendum 1 on the
same standard.
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Certified Aerodynamic Performance Rating. None of these updates includes significant changes
to the sections referenced in the DOE test procedure and thus will not impact the ratings or
energy conservation standards for central air conditioners and heat pumps. 21
Additionally, DOE proposes to update the IBR from ASHRAE 41.1-1986 (Reaffirmed
Method for Temperature Measurement, as well as the IBR to ASHRAE 41.6-1994, Standard
Method for Measurement of Moist Air Properties to ASHRAE 41.6-2014, Standard Method for
Humidity Measurement. In the updated versions of these standards, specifications for measuring
wet-bulb temperature were moved from ASHRAE 41.1 to ASHRAE 41.6. None of these
updates includes significant changes to the sections referenced in the DOE test procedure and
thus will not impact the ratings or energy conservation standards for central air conditioners and
heat pumps.
Also, DOE proposes to update the IBR from ASHRAE 23-2005, Methods of Testing for
Rating Positive Displacement Refrigerant Compressors and Condensing Units to ASHRAE 23.1-
2010 Methods of Testing for Rating the Performance of Positive Displacement Refrigerant
Compressors and Condensing Units That Operate at Subcritical Temperatures of the Refrigerant.
ASHRAE 23 has been withdrawn and has been replaced by ASHRAE 23.1 and ASHRAE 23.2.
ASHRAE 23.2 deals with supercritical pressure conditions, which are not relevant to the DOE
test procedure, so will not be referenced. None of these updates includes significant changes to
21
ASHRAE 37-2009 only updates to more recent versions of other standards it references. ASHRAE/AMCA 51-
07/210-07 made slight changes to the figure referenced by DOE, which DOE has determined to be insignificant.
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the sections referenced in the DOE test procedure and thus will not impact the ratings or energy
DOE also proposes to revise its existing IBRs to AHRI 210/240-2008 with Addendums 1
and 2, ANSI/AHRI 1230-2010 with Addendum 2, ASHRAE 23.1-2010 (updated from ASHRAE
23-2005), ASHRAE 37-2009 (updated from 2005), ASHRAE 41.1-2013 (updated from 1986
version), ASHRAE 41.2-1987, ASHRAE 41.6-2014 (updated from 1994 reaffirmed in 2001
version), ASHRAE 41.9-2011 (updated from 2000 version), and ASHRAE/AMCA 51-07/210-07
(updated from 1999 version) to incorporate only the sections currently referenced or proposed to
be referenced in the DOE test procedure. DOE requests comment on its proposed sections for
incorporation and specifically on whether any additional sections may be necessary to conduct a
test of a unit.
DOE also proposes to revise the definition of “continuously recorded” based on changes
to ASHRAE 41.1. ASHRAE 41.1-86 specified the maximum time intervals for sampling dry-
bulb temperature. The updated version, ASHRAE 41.1-2013 does not contain specifications for
sampling intervals. DOE proposes to require that dry-bulb temperature, wet bulb temperature,
dew point temperature, and relative humidity data be “continuously recorded,” that is, sampled
and recorded at 5 second intervals or less. DOE is proposing this requirement as a means of
verifying that temperature condition requirements are met for the duration of the test. DOE
requests comment on its revised sampling interval for dry-bulb temperature, wet bulb
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13. Withdrawing References to ASHRAE Standard 116-1995 (RA 2005)
In the June 2010 NOPR, DOE proposed referencing ASHRAE Standard 116-1995 (RA
2005) within the DOE test procedure to provide additional informative guidance for the
equations used to calculate SEER and HSPF for variable-speed systems. 75 FR 31223, 31243
(June 2, 2010). In the subsequent public comment period, AHRI expressed support for DOE’s
proposal to reference ASHRAE 116. (AHRI, No. 6 at p. 6). However, in section III.H.4 of this
notice, DOE proposes to change the heating load line, and as such the equations for HSPF in
ASHRAE Standard 116 are no longer applicable. In order to prevent confusion, DOE proposes
in this notice to withdraw the proposal made in the June 2010 NOPR to reference ASHRAE 116
for both HSPF and SEER and is removing those instances of references to said standard from the
test procedure.
Appendix M only references ASHRAE 116 in one other location, regarding the
requirements for the air flow measuring apparatus. Upon review, DOE has determined that
NOPR, DOE also proposes to revise its reference for the requirements of the air flow measuring
apparatus to ASHRAE Standard 37-2009 rather than ASHRAE 116, and proposes to remove the
incorporation by reference to ASHRAE 116 from the code of federal regulations related to
In August 2015, AHRI provided a draft version of AHRI 210/240 for the docket that will
supersede the 2008 version once it is published. (AHRI Standard 210/240-Draft, No. 45, See
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EERE-2009-BT-TP-0004-0045) The draft version includes a number of revisions from the 2008
version, some of which already exist in DOE’s test procedure, and some of which do not.
Regarding test installation requirements, the AHRI 210/240-Draft added new size
requirements for the inlet duct to the indoor unit. If used, the inlet duct size to the indoor unit is
required to equal the size of the inlet opening of the air-handling (blower-coil) unit or furnace,
with a minimum length of 6 inches. Regarding the testing procedure, the AHRI 210/240-Draft
added new external static pressure requirements for units intended to be installed with the airflow
to the outdoor coil ducted. These new requirements provide for testing of these products more
consistently with the way that they are intended to be used in the field. Also regarding the
testing procedure, the AHRI 210/240-Draft specified a new requirement for the dew point
temperature of the indoor test room when the air surrounding the indoor unit is not supplied from
the same source as the air entering the indoor unit. DOE proposes to adopt these three revisions
in this SNOPR.
The AHRI 210/240-Draft includes several differences as compared to the current DOE
test procedure for setting air volume rates during testing. Specifically:
(b) For systems tested with indoor fans installed in which the fans have permanent-split-
pressure requirements for operating modes other than full-load cooling; and
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(c) A criterion is defined for acceptable air flow stability for systems tested with
constant-air-volume indoor fans (these are fans with controls that vary fan speed to
DOE proposes to adopt these changes because they will improve repeatability and the
The AHRI 210/240-Draft also includes a more thorough procedure for setting of
refrigerant charge than exists in the DOE test procedure. The new approach addresses potential
installation instructions and indicates how to address ranges of target values provided in
instructions. DOE is proposing these changes because they improve test repeatability. The AHRI
210/240-Draft also specifies both a target value tolerance and a maximum tolerance but does not
specify in what circumstances each of these apply. DOE proposes to adopt the maximum
tolerance only. However, DOE may consider adopting only the target value tolerance or both the
target value and maximum tolerance. DOE requests comment on the appropriate use of the
target value and maximum tolerances, as well as data to support the appropriate selection of
tolerance. DOE notes that the tolerances adopted in the DOE test procedure should be
achievable by test lab personnel without the presence or direct input of the manufacturer.
Finally, the AHRI 210/240-Draft includes specifications for air sampling that provide
more detail than provided in existing standards. DOE proposes to incorporate these
specifications by reference in order to improve test procedure repeatability and consistency. The
proposal currently cites the AHRI 210/240-Draft, which is not possible for the final rule
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associated with this rulemaking. However, DOE expects that the AHRI standard will be
finalized in time to allow the final rule to amend the CFR to incorporate this material.
DOE notes that the final published version of what is currently the AHRI 210/240-Draft
may not be identical to the current draft. If AHRI makes other than minor editorial changes to the
sections DOE references in this SNOPR after publication of this SNOPR, DOE proposes to
adopt the current draft content into its regulations and not incorporate by reference the modified
test procedure.
into the DOE test procedure, includes requirements for maximum allowable variation of specific
measurements for a valid test. Specifically, Table 2 of the standard indicates that the test
operating tolerance (total observed range) of the nozzle pressure drop may be no more than 2
percent of the average value of reading. Section 5.3.1 of the standard indicates that the nozzle
pressure drop (or the nozzle throat velocity pressure) may be measured with manometers or
electronic pressure transducers. These measurements are made to determine air flow. Section
8.7.2 of the standard requires that measurements shall be recorded at equal intervals that span
DOE is aware that when nozzle pressure drop measurements are made with pressure
transducers and recorded using a computer-based data acquisition system, high frequency
pressure fluctuations can cause observed pressure variations in excess of the 2 percent test
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operating tolerance, even when air flows are steady and non-varying. DOE proposes to add
clarifying language in the test procedure that would allow for damping of the measurement
measurements. The proposal would allow for damping of the measurement system so that the
time constant for response to a step change in pressure (i.e. the time required for the indicated
measurement to change 63% of the way from its initial value to its final value) is no more than
five seconds. This damping could be achieved in any portion of the measurement system.
Examples of damping approaches include adding flow resistance to the pressure signal tubing
between the pressure tap and the transducer, using a transducer with internal averaging of its
output, or filtering the transducer output signal, digital averaging of the measured pressure
signals. DOE requests comment on this proposal, including on whether the proposed maximum
Ensuring repeatability of test results requires that all parties that test a unit use the same
set of instructions to set up the unit, conduct the test, and calculate test results. A test laboratory
may be tempted to contact the product’s manufacturer or other sources of information not
referenced or allowed by the test procedure if there is a lack of clarity in the installation
instructions shipped with the unit or ambiguities within the test procedure itself. Currently,
certain sections of the DOE test procedure for central air conditioners and heat pumps in
Appendix M to Subpart B of 10 CFR Part 430 permit such consultation with the manufacturer.
In the June 2010 NOPR, DOE proposed to allow lab-manufacturer communication as long as test
unit installation and laboratory testing are conducted in complete compliance with all
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requirements in the DOE test procedure and the unit is installed according to the manufacturer’s
installation instructions. 75 FR 31223, 31235 (June 2, 2010). In the subsequent public comment
period, AHRI expressed support regarding DOE's proposal. (AHRI, No. 6 at p. 3). Mitsubishi
also supported adding test procedure to clarify that interaction with the manufacturer is allowed.
(Mitsubishi, No. 12 at p. 2). NEEA did not object to DOE’s proposal. (NEEA, No. 7 at p. 4).
Because the reliance upon such consultation could lead to variability in test results among
laboratories by manufacturers providing different testing instructions, DOE seeks to limit such
occurrences to the maximum extent possible by ensuring that all required testing conditions and
product setup information is either specified in the test procedure, certified to DOE, or stated in
installation manuals shipped with the unit by the manufacturer. DOE believes that the proposed
revisions in this rule provide such clarity and allow for models to be tested and rated in an
will no longer need to contact the manufacturer for advice on implementation of the test
procedure. If questions arise about a specific test procedure provision, the test lab and/or the
manufacturer should seek guidance from DOE. DOE believes that this change will eliminate
inconsistent testing due to different test laboratories seeking and receiving different information
regarding unclear instructions. Thus, DOE proposes the following changes to the test procedure
to address test procedure provisions that may be ambiguous or unclear in their intent and also
withdraws the proposal it made in the June 2010 NOPR that placed no restrictions on
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1. Manufacturer Consultation
DOE proposes to clarify the test procedure provisions regarding the specifications for
refrigerant charging prior to testing, with input on certain details from the AHRI 210/240-Draft,
as discussed in section III.E.14. Section 2.2.5 of the test procedure provides refrigerant charging
instructions but also states, “For third-party testing, the test laboratory may consult with the
manufacturer about the refrigerant charging procedure and make any needed corrections so long
as they do not contradict the published installation instructions.” The more thorough refrigerant
charging requirements proposed in this notice should preclude the need for any manufacturer
consultation, since they include steps to take in cases where manufacturer’s installation
requirements. Consultation with the manufacturer should thus become unnecessary, and DOE
proposes to remove the current test procedure’s allowance for contacting the manufacturer to
receive charging instructions. In instances where multiple sets of instructions are specified or are
included with the unit and the instructions are unclear on which set to test with, DOE proposed in
the June 2010 NOPR to use the instructions "most appropriate for a normal field installation.” 75
FR 31235, 31250. (June 2, 2010) NEEA supported this proposal. (NEEA, No. 7 at p. 4). DOE
proposes to maintain this position in this rulemaking, proposing the use of field installation
criteria if instructions are provided for both field and lab testing applications.
In the June 2010 NOPR, DOE proposed requirements for the low-voltage transformer
used when testing coil-only air conditioners and heat pumps, and required metering of such low-
voltage component energy consumption during all tests. 75 FR 31238. In the April 2011
SNOPR, in response to the June 2010 NOPR public meeting comments, DOE proposed revised
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requirements such that metering of low-voltage component energy consumption is required
during only the proposed off mode testing, citing that such changes would require adjustments to
the standard levels currently being considered. 76 FR 18109. The proposal therein consisted of
language that suggested that test setup information may be obtained directly from manufacturers.
In the effort to remain objective during testing, DOE is hereby revising certain language in the
proposal such that communication between third party test laboratories and manufacturers are
eliminated, and such information when needed for test setup can be found in the installation
Regarding the use of an inlet plenum, section 2.4.2 of the test procedure states, “When
testing a ducted unit having an indoor fan (and the indoor coil is in the indoor test room), the
manufacturer has the option to test with or without an inlet plenum installed. Space limitations
within the test room may dictate that the manufacturer choose the latter option.” To eliminate the
need for the test laboratory to confirm with the manufacturer whether the inlet plenum was
installed during the manufacturer’s test, DOE proposes to require manufacturers to report on
their certification report whether the test was conducted with or without an inlet plenum
installed.
Further, it is unclear in certain sections of the test procedure which “test setup
instructions” are to be referenced for preparing the unit for testing. Ambiguous references to
“test setup instructions” and/or “manufacturer specifications” may lead to the use of instructions
or specifications provided by the manufacturer that are possibly out-of-date or otherwise not
applicable to the products being tested. DOE therefore proposes to amend references in the test
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procedure to test setup instructions or manufacturer specifications by specifying that these refer
to the test setup instructions included with the unit. DOE proposes to implement this change in
(VFR) Multi-Split Air-Conditioning and Heat Pump Equipment” with Addendum 2 (AHRI
Standard 1230-2010) prescribes test requirements for both consumer and commercial variable
refrigerant flow multi-split systems. On May 16, 2012, DOE incorporated this standard by
reference into test procedures for testing commercial variable refrigerant flow multi-split systems
at 10 CFR 431.96. 77 FR 28928. DOE recognizes that consumer variable refrigerant flow
consistency of testing consumer and commercial variable refrigerant flow multi-split systems,
DOE proposes to incorporate by reference the sections of AHRI Standard 1230-2010 that are
relevant to consumer variable refrigerant flow multi-split systems (namely, sections 3 (except
3.8, 3.9, 3.13, 3.14, 3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31), 5.1.3, 5.1.4,
6.1.5 (except Table 8), 6.1.6, and 6.2) into the existing test procedure for central air conditioners
and heat pumps at Appendix M to Subpart B of 10 CFR Part 430. To ensure that there is no
confusion with future definition changes in industry test procedures, DOE is including the terms
combination”, “Variable refrigerant flow system” and “Variable-speed compressor system” into
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10 CFR 429.16 requires the use of a “tested combination,” as defined in 10 CFR 430,
subpart B, Appendix M, section 1.B, when rating multi-split systems. In response to a May 27,
2008 letter from AHRI to DOE, DOE proposed changes in the “tested combination” definition in
the June 2010 NOPR. 75 FR 31223, 31231 (June 2, 2010). In comments responding to the
NOPR, AHRI urged DOE to adopt AHRI Standard 1230-2010 for all requirements pertaining to
multi-split systems. (AHRI, No. 6 at pp. 1-2) Mitsubishi recommended likewise. (Mitsubishi,
No. 12 at p. 1) AHRI Standard 1230-2010, published after the June 2010 NOPR, duplicates most
of the requirements for tested combinations that DOE proposed in the June 2010 NOPR except
for the following requirements, which DOE proposes in this notice to adopt to reduce
manufacturer test burden: lower the maximum number of indoor units matched to an outdoor
unit; and the option to use another indoor model family if units from the highest sales volume
model family cannot be combined so that the sum of their nominal capacities is in the required
range of the outdoor unit’s nominal capacity (between 95 and 105 percent) . The proposal in
June 2010 NOPR also used the term “nominal cooling capacity,” which may be ambiguous;
DOE also intends to clarify that such a term should be interpreted as the highest cooling capacity
listed in published product literature for 95 °F outdoor dry bulb temperature and 80 °F dry bulb,
67 °F wet bulb indoor conditions, and for outdoor units as the lowest cooling capacity listed in
published product literature for these conditions. If incomplete or no operating conditions are
reported, the highest (for indoor units) or lowest (for outdoor units) such cooing capacity shall be
used. Finally, AHRI 1230 uses the term “model family” but does not define the term. DOE
requests comment on an appropriate definition of “model family” for DOE to adopt in the final
rule. In summary, DOE proposes to omit AHRI’s definition of tested combination, found in
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section 3.26, from the IBR of AHRI Standard 1230-2010 into Appendix M to Subpart B of 10
CFR Part 430, and make amendments to the proposal from the June 2010 NOPR.
During testing for ducted systems with indoor fans installed, the rise in static pressure
between the air inlet and the outlet (called external static pressure (ESP)) must be adjusted to a
prescribed minimum that varies with system cooling capacity. The minimum ESPs are 0.10 in.
wc. for units with cooling capacity less than 28,800 Btu/h; 0.15 in. wc. for units with cooling
capacity from 29,000 Btu/h to 42,500 Btu/h; and 0.20 in. wc. for units with cooling capacity
greater than 43,000 Btu/h. Multi-split systems are composed of multiple indoor units, which
may be designed for installation with short-run ducts. Such indoor units generally cannot deliver
the minimum ESPs prescribed by the current test procedure. Hence, lower minimum ESP
In the June 2010 NOPR, DOE proposed lower minimum ESP requirements for ducted
multi-split systems: 0.03 in. wc. for units less than 28,800 Btu/h; 0.05 in. wc. for units between
29,000 Btu/h and 42,500 Btu/h; and 0.07 in. wc. for units greater than 43,000 Btu/h. 75 FR at
31232. In its comments, AHRI urged DOE to adopt the minimum ESP requirements from AHRI
Standard 1230-2010 as DOE was aware that the standard was being developed at that time.
AHRI expressed concern over the potential abuse of lower multi-split minimum ESPs
they were concerned that the lower ESP were allowed for very specific installation applications
which could not be assured by the manufacturer, and thus might be used more widely than
intended. AHRI therefore argued against changing ESP requirements. (AHRI, No. 6 at p. 2).
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establishing minimum ESP requirements that are the same as those of conventional systems.
(NEEA, No. 7 at p. 2) AHRI Standard 1230-2010 does not include minimum ESP requirements
for multi-split systems with short-run ducted indoor units. In order to accommodate the design
differences of these indoor units, DOE proposes to omit Table 8 of AHRI Standard 1230-2010
from the IBR into Appendix M and to set minimum ESP requirements for systems with short-run
ducted indoor units at the levels and cooling capacity thresholds as proposed in the June 2010
NOPR. Furthermore, DOE proposes to implement these requirements by (a) defining the term
“Short duct systems,” to refer to ducted systems whose indoor units can deliver no more than
0.07 in. wc. ESP when delivering the full load air volume rate for cooling operation, and (b)
adding the NOPR-proposed minimum ESP levels to Table 3 of Appendix M (this is the table that
specifies minimum ESP), indicating that these minimum ESPs are for short duct systems. DOE
proposes using the new term “Short duct system” rather than “Multi-split system” for these
minimum ESPs because multi-circuit or mini-split systems could potentially also include similar
short-ducted indoor units. DOE proposes a limitation in the level of ESP that eligible indoor
units can deliver in order to prevent the potential abuse of the reduced ESP requirement
mentioned by AHRI. DOE requests comment on these proposals, including the value of
DOE notes that in conjunction with the adopted portions of the AHRI Standard 1230-
2010 , the following sections of the proposed test procedure found in Appendix M may apply to
testing VRF multi-split systems: section 1 (definitions); section 3.12 (rounding of space
conditioning capacities for reporting purposes); sections 2.2.a, 2.2.b, 2.2.c, 2.2.1, 2.2.2, 2.2.3(a),
2.2.3(c), 2.2.4, 2.2.5, and 2.4 to 2.12 (test unit installation requirements); Table 3 in section
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3.1.4.1.1c (external static pressure requirements); section 3.1 except section 3.1.3 and 3.1.4
(general requirements of the testing procedure); sections 3.3, 3.4, and 3.5 (procedures for
cooling-mode tests); sections 3.7, 3.8, 3.9, and 3.10 (procedures for heating-mode tests); section
3.13 (procedure for off mode average power rating); and section 4 (calculations of seasonal
performance descriptors).
particular the specific sections of Appendix M and AHRI 1230-2010 that DOE proposes to apply
3. Replacement of the Informative Guidance Table for Using the Federal Test Procedure
The intent of the set of four tables at the beginning of “Section 2, Testing Conditions” of
the current test procedure (10 CFR Part 430, Subpart B, Appendix M) is to provide guidance to
product class, system configuration, modulation capability, and special features of products.
DOE recognizes that the current table format may be difficult to follow. Therefore, DOE has
developed a more concise table and proposes using it in place of the current table. DOE requests
comment on this proposed change and/or whether additional modifications to the new table
Current definitions in 10 CFR Part 430, Subpart B, Appendix M define a mini-split air
conditioner and heat pump as “a system that has a single outdoor section and one or more indoor
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sections, which cycle on and off in unison in response to a single indoor thermostat.” When
DOE introduced this definition, mini-split systems solely employed one or more non-ducted or
short-duct wall-, ceiling-, or floor-mounted indoor units (i.e., non-conventional units), and the
market for mini-split products reflected such type and quantity of indoor units. It was common
understanding that when testing or purchasing a mini-split system, the system would have a non-
would alleviate ambiguity in how to categorize mini-split products. To differentiate the two
types of products, DOE proposes deleting the definition of mini-split air conditioners and heat
pumps, and adding two definitions for: (1) single-zone-multiple-coil split-system, representing a
split-system that has one outdoor unit and that has two or more coil-only or blower coil indoor
units connected with a single refrigeration circuit, where the indoor units operate in unison in
that has one outdoor unit and that has one coil-only or blower coil indoor unit connected to its
other component(s) with a single refrigeration circuit. DOE seeks comment on this proposal.
A multiple-split (or multi-split) system is currently defined in 10 CFR Part 430, Subpart
B, Appendix M as “a split-system having two or more indoor units, which respond to multiple
thermostats.” Technologies exist on the market that operate like multi-split systems but
incorporate multiple outdoor units into the same package. To clearly define what arrangement
qualifies as a multi-split system, DOE proposes to clarify the definition of multi-split system to
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specify that multi-split systems are to have only one outdoor unit. (DOE notes that it proposes to
separately define multi-circuit units as units that incorporate multiple outdoor units into the same
package. This is discussed in section III.C.2.) Finally, DOE proposes to clarify that if a model
of outdoor unit could be used both for single-zone-multiple-coil split-systems and for multi-split-
The test procedure changes proposed in this SNOPR as well as in the June 2010 NOPR,
April 2011 SNOPR, and October 2011 SNOPR occur throughout large portions of Appendix M
to 10 CFR Part 430 Subpart B. In order to improve clarity regarding the proposed test
procedure, in the regulatory text for this SNOPR, DOE has reprinted the entirety of Appendix M,
including all changes proposed in this SNOPR as well as those in the previous NOPR and
SNOPRs that are still applicable. Table III.6 lists those proposals from the previous notices that
appear without modification in this regulatory text reprint, and provides reference to the
respective revised section(s) in the regulatory text. Table III.7 lists those proposals from the
previous notices that either are proposed to be withdrawn or amended in this SNOPR or propose
no amendments to the test procedure, and provides reference to the respective preamble section
for the discussion of the revision, including stakeholder comments from the original proposal,
and the revised section(s) in the regulatory text, if any. The proposed amendments to Appendix
is only printing the proposed regulatory text for Appendix M1 where it differs from the proposed
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regulatory text for Appendix M. Proposed changes relevant to Appendix M1 are discussed in
section III.H.
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Table III.6. Proposals from Prior Notices Adopted without Modification in this SNOPR
Section Proposal to… Reference Action Preamble Discussion Regulatory Text Location*
A.7. Add Calculations for Sensible Heat Ratio 75 FR 31229 Upheld III.I.5 3.3c, 4.6
A.10. Add Definitions Terms Regarding Standby Power 75 FR 31231 Upheld None Definitions
Change the Magnitude of the Test Operating Tolerance 3.3d Table, 3.5h Table, 3.7a Table, 3.8.1
75 FR 31234 Upheld None
Specified for the External Resistance to Airflow Table, 3.9f Table
B.5.
Change the Magnitude of the Test Operating Tolerance 3.3d Table, 3.5h Table, 3.7a Table, 3.8.1
75 FR 31234 Upheld None
Specified for the Nozzle Pressure Drop Table
the Cyclic Test To Align With the Temperature Sensors 75 FR 31235 Upheld None 3.4c, 3.5i, 3.7e, 3.8
Applicable: Equation
When Determining the Cyclic Degradation Coefficient CD, 3.3b, 3.7a, 3.9e, 3.11.1.1, 3.11.1.3,
75 FR 31236 Upheld None
Correct the Indoor-Side Temperature Sensors Used During 3.11.2a
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the Cyclic Test To Align With the Temperature Sensors
B.9. Clarify Inputs for the Demand Defrost Credit Equation 75 FR 31236 Upheld None 3.9.2a
B.10. Add Calculations for Sensible Heat Ratio 75 FR 31237 Upheld III.I.5 3.3c, 4.6
3.6.2 Table
III.D Add Calculation of the Energy Efficiency Ratio for Cooling 76 FR 18111 Upheld None 4.7
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Mode Steady-State Tests
III.E Revise Off-Mode Performance Ratings 75 FR 31238 Upheld III.D Definitions, 3.13, 4.3, 4.4
III.A Reduce Testing Burden and Complexity 76 FR 65618 Upheld III.D Definitions, 3.13, 4.3, 4.4
III.B Add Provisions for Individual Component Testing 76 FR 65619 Upheld III.D Definitions, 3.13, 4.3, 4.4
III.C Add Provisions for Length of Shoulder and Heating Seasons 76 FR 65620 Upheld III.D Definitions, 3.13, 4.3, 4.4
III.D.1 Add Provisions for Large Tonnage Systems 76 FR 65621 Upheld III.D Definitions, 3.13, 4.3, 4.4
III.D.2 Add Requirements for Multi-Compressor Systems 76 FR 65622 Upheld III.D Definitions, 3.13, 4.3, 4.4
* Section numbers in this column refer to the proposed Appendix M test procedure in this notice.
155
Table III.7. Proposals from Prior Notices Withdrawn or Amended in this SNOPR or Proposed No Change to the Test
Procedure
Section Proposal to… Reference Action Preamble Discussion Regulatory Text Location*
10 CFR 430.2
Modify Definition of Tested Combination 75 FR 31230 Amended III.F.2
Definitions
A.9. Add Minimum ESP for Short Duct Systems 75 FR 31230 Amended III.F.2 3.1.4.1.1c. Table
B.1. Modify the Definition of “Tested Combination” 75 FR 31231 Amended III.F.2 10 CFR 430.2
156
Definitions
Add Minimum ESP for Short Duct Systems 75 FR 31232 Amended III.F.2 3.1.4.1.1c. Table
B.15. Add Parameters for Establishing Regional Standards 75 FR 31239 Withdrawn† None None
B.15b. Add New Hot-Dry Region Bin Data 75 FR 31240 Withdrawn† None None
B.16. That Calculate SEER and HSPF for Variable Speed 75 FR 31243 Withdrawn III.E.13 None
Systems
B.17. Update Test Procedure References 75 FR 31243 Amended III.E.12 10 CFR 430.3
157
Definitions
* Section numbers in this column refer to the proposed Appendix M test procedure in this Notice, unless otherwise specified.
** These items were discussed in the NOPR or SNOPR but did not propose changes to the test procedure.
†
Associated proposals regarding the SEER Hot-Dry metric, as indicated, are withdrawn because DOE withdrew the SEER Hot-Dry metric in the April 2011 SNOPR. 76 FR
18110.
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H. Improving Field Representativeness of the Test Procedure
DOE received comments from stakeholders during the public comment period following
the November 2014 ECS RFI requesting changes to the test procedure that would improve field
representativeness. Such changes would impact the rated efficiency of central air conditioners
and heat pumps. As discussed in section I.A, any amendments proposed in this SNOPR that
would alter the measured efficiency, as represented in the regulating metrics of EER, SEER, and
HSPF, are proposed as part of a new Appendix M1 to Subpart B of 10 CFR Part 430. The test
procedure changes proposed as part of a new Appendix M1, if adopted, would not become
mandatory until the existing energy conservation standards are revised to account for the changes
to rated values. (42 U.S.C. 6293(e)(2)) These changes, including the relevant stakeholder
1. Minimum External Static Pressure Requirements for Conventional Central Air Conditioners
Most of the central air conditioners and heat pumps used in the United States use
ductwork to distribute air in a residence, using either a fan inside the indoor unit or housed in a
separate component, such as a furnace, to move the air. External static pressure (ESP) for a
central air conditioner or heat pump is the static pressure rise between the inlet and outlet of the
indoor unit that is needed to overcome frictional losses in the ductwork. The ESP imposed by
the ductwork affects the power consumed by the indoor blower, and therefore also affects the
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The current DOE test procedure 22 stipulates that certification tests for central air
conditioners and heat pumps which are not short duct systems (see section III.F.2) or small-duct,
high-velocity systems 23 (i.e., conventional central air conditioners and heat pumps) must be
performed with an ESP at or above 0.10 in. wc. if cooling capacity is rated at 28,800 Btu/h or
less; at or above 0.15 in. wc. if cooling capacity is rated from 29,000 Btu/h to 42,500 Btu/h; and
at or above 0.20 in. wc. if cooling capacity is rated at 43,000 Btu/h or more.
DOE decided in the June 2010 NOPR not to propose revisions to minimum external static
pressure requirements, stating that new values and a consensus standard were not readily
available. 75 FR 13223, 31228 (June 2, 2010). NEEA responded during the subsequent public
comment period that current ESP minimums were too low and recommended DOE adopt an ESP
test requirement of 0.5 in. wc. (NEEA, No. 7 at p. 3). Earthjustice commented that retention of
the existing ESP values is not supported by evidence. (Earthjustice, No. 15 at pp. 1-2). Southern
California Edison (SCE), the Southern California Gas Company (SCGC), and San Diego Gas
and Electric (SDGE) (together, the Joint California Utilities) included with its comments two
studies showing field measurements of ESP with an average of 0.5-0.8 in. w.c and urged the
Department to adopt an external static pressure test point of 0.5 in. wc. (Joint California
Utilities, No. 9 at p. 3). ACEEE suggested that field data is available for DOE to consider new
22
Table 3 of 10 CFR 430 Subpart B Appendix M
23
10 CFR 430 Subpart B Appendix M Section 1. Definitions defines a small-duct, high-velocity system as a system
that contains a blower and indoor coil combination that is designed for, and produces, at least 1.2 inches (of water)
of external static pressure when operated at the full-load air volume rate of 220-350 cfm per rated ton of cooling.
When applied in the field, small-duct products use high-velocity room outlets (i.e., generally greater than 1000 fpm)
having less than 6.0 square inches of free area.
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Stakeholders also commented in response to the November 2014 ECS RFI that the
current requirements for minimum ESP are unrepresentative of field practice. PG&E
commented that the ESP for central air conditioners and heat pumps needs to be set at 0.5 in. wc.
ACEEE advocated similarly: default ESP used in the current federal test procedure should be
raised from the current 0.1 to 0.2 in. wc. to at least 0.5 in. wc. to represent field practice. (Id.;
ACEEE, No. 21 at p. 2) ASAP & ASE & NRDC commented that the ESP in the current test
procedure is unrealistically low, adding that DOE should reference to the ESP values adopted by
the recently finalized furnace fan rulemaking which has an ESP value of 0.5 in. wc. 24 (Id.; ASAP
Central air conditioners and heat pumps are generally equipped with air filters when used
in the field. Section 3.1.4.1.1c of 10 CFR Part 430, Subpart B, Appendix M requires that any
unit tested without an air filter installed be tested with ESP increased by 0.08 in. wc. to represent
the filter pressure drop. University of Alabama commented during the public comment period of
the November 2014 ECS RFI that the actual combined ESP requirements in the field are
typically 3 to 5 times greater with more effective filters and typical duct designs. The
unrealistically low rating conditions result in little incentive for manufacturers to incorporate
improved fan wheel designs. Improvements in SEER gained by replacing inexpensive forward-
curve fan wheels will be negligible but demand and energy savings in actual installations will be
24
Docket No. EERE-2010-BT-TP-0010-0043.
161
Furnaces use the same ductwork as central air conditioners and heat pumps to distribute
air in a residence. NEEA & NPCC commented that the ESP selected for testing of furnace fans
is substantially higher than the 0.1 to 0.2 in. wc. prescribed by the federal CAC/HP test
procedure. They also mentioned that field data from Pacific Northwest shows that the minimum
required ESP is 0.5 in. wc. regardless of system capacity. NEEA & NPCC recommended that
the ESP requirement for measurement of cooling efficiency be close to 0.6 in. wc. because air
volume rates for cooling (and heating for heat pumps) are greater than typical furnace heating air
volume rates. However, they suggested DOE adopt the ESP level required for testing of furnace
fans as a simple approach. (Docket No. EERE-2014-BT-STD-0048, NEEA & NPCC, No. 19 at
p. 2).
In response to stakeholder comment over multiple public meetings that the minimum ESP
values intended for testing are indeed unrepresentative of the ESPs in field installations, and field
studies indeed demonstrating the same, DOE proposes in this SNOPR revising the ESP
requirements for most central air conditioners and heat pumps, e.g., those that do not meet the
proposed requirements for short duct systems or the established requirements for small-duct,
DOE is not considering revising the minimum ESP requirement for SDHV systems.
DOE is, however, proposing to establish a new category of ducted systems, short duct systems,
which would have lower ESP requirements for testing—this is discussed in section III.F.2.
162
To meet the requirement set forth in 42 U.S.C. 6293(b)(3) providing that test procedures
be reasonably designed to produce test results which measure energy efficiency of a covered
product during a representative average period of use, DOE reviewed available field data to
determine appropriate ESP values. DOE gathered field studies and research reports, where
publically available, to estimate field ESPs. DOE previously reviewed most of these studies
when developing test requirements for furnace fans. The 20 studies, published from 1995 to
2007, provided 1,010 assessments of location and construction characteristics of central air
conditioner or heat pump systems in residences, with the data collected varying by location,
representation of system static pressure measurements, and equipment’s age and ductwork
arrangement, vintage, and air-tightness. 79 FR 500 (Jan. 3, 2014). DOE observed measured
ESPs to range from 0.20 to 0.70 in. wc. DOE used three statistical approaches to determine an
average representation of ESP from the range of ESPs: a simple-average approach, a sample-
through equal weighting of the results from the three approaches, to obtain a “middle ground”
value of 0.32 in. wc. as the ESP representing a typical residence with a new space conditioning
system.
DOE is aware that units used in certification laboratory testing have not aged and are thus
not representative of seasoned systems in the field. Namely, dust, dander, and other airborne
particulates, commonly deposited as foulant onto in-duct components in field installations, are
unaccounted for in controlled testing environments. Foulant fills air gaps of the air filter and
evaporator coil and restricts air volume rate, thus increasing ESP. This occurrence is not
accounted for in certification testing environments. Therefore, DOE included an ESP adder for
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component foulant build-up to the test procedure to better reflect a representative average period
of use. To determine the value of this adder, DOE examined the aforementioned field studies
that captured the ESP contribution from vintage, and certainly fouled, air filters and evaporator
coils. From the contributing studies, DOE estimates an average pressure drop due to the filter’s
foulant of 0.13 in. wc. based on the difference in static pressure contributions between fouled
filters and clean filters. DOE also examined publicly available reference material and research to
determine the pressure drop from the build-up of foulant on evaporator coils. Three resources in
the public domain were identified that documented the impact of evaporator coil fouling on ESP
in applications. 25 From this literature, DOE estimates an average pressure drop resulting from
evaporator coil fouling of 0.07 in. wc. These additional pressure drops result in a total of 0.20 in.
wc. being added to the revised ESP value, as mentioned. DOE seeks comment on its proposal to
include in the ESP requirement a pressure drop contribution associated with average typical filter
and indoor coil fouling levels and its use of residential-based indoor coil and filter fouling
pressure drop data to estimate the appropriate ESP contribution. DOE also requests any data that
would validate the proposed ESP contributions or suggestions of adjustments that should be
made to improve representativeness of the values in this proposal. DOE notes that addition of
these pressure drop contributions is consistent with the approach adopted for testing of furnace
fans, which are tested without the filter and air conditioning coil, and for which the ESP selected
for testing reflects the field fouling associated with these components.
25
Siegel, J., Walker, I., and Sherman, M. 2002. “Dirty Air Conditioners: Energy Implications of Coil Fouling”
Lawrence Berkeley National Laboratory report, number LBNL-49757.
ACCA. 1995. Manual D: Duct Systems. Washington, D.C., Air Conditioning Contractors of America.
Parker, D. S., J. R. Sherwin, et al. 1997. “Impact of evaporator coil airflow in air conditioning systems” ASHRAE
Transactions 103(2): 395-405.
164
Consistent with the current motivation in current certification procedures to promulgate
policy that represents the majority of products in the field (10 CFR 429.16(a)(2)(ii)), DOE
selected the capacity with the largest volume of retail sales, 3 tons, as the rated cooling capacity
category to adopt the minimum ESP requirement based on the field data and the adjustments.
For the other cooling capacity categories, NEEA commented that ESP should not vary with
capacity. (NEEA, No. 7 at p. 3). DOE considered the stakeholder comment and the higher ESPs
indicative of larger homes, and proposes a compromise approach to use the current 0.05 in. wc.
In conclusion, DOE proposes to adopt, for inclusion into 10 CFR Part 430, Subpart B,
Appendix M1, for systems other than multi-split systems and small-duct, high-velocity systems,
minimum ESP requirements of 0.45 in. wc. for units with rated cooling capacity of 28,800 Btu/h
or less; 0.50 in. wc. for units with rated cooling capacity of 29,000 Btu/h or more and 42,500
Btu/h or less; and 0.55 in. wc. for units with rated cooling capacity of 43,000 Btu/h or more.
(DOE is not making such a revision in 10 CFR Part 430, Subpart B, Appendix M.) The
proposed minimum ESP requirements are shown in Table III.8. DOE is aware that such changes
will impact the certification ratings SEER, HSPF, and EER and is addressing such impact in the
current energy conservation standards rulemaking. 26 DOE requests comment on these proposals.
26
Docket No. EERE-2014-BT-STD-0048.
165
Table III.8: Proposed Minimum ESP Requirements for Central Air Conditioners and Heat
2. Minimum External Static Pressure Adjustment for Blower Coil Systems Tested with
Condensing Furnaces
As discussed in section III.H.1, DOE proposes to increase the minimum ESP required for
testing blower coil central air conditioners and heat pumps. DOE notes that there are three
different blower coil configurations: (1) an air handling unit which is a single piece of equipment
containing a blower and a coil; (2) a coil paired with a separately-housed modular blower; (3) a
coil paired with a separate furnace. The existing federal test procedure for central air
conditioners and heat pumps does not require different minimum ESPs for these different blower
coil configurations, even though the heat exchanger of a furnace may impose additional pressure
drop on the air stream. The additional pressure drop can contribute to higher blower power,
which may negatively affect the performance rating for a central air conditioner. Further,
27
DOE did not increase the ESP requirement for small-duct, high-velocity units because the existing values in the
test procedure represent field operations.
166
condensing furnaces, which have more heat transfer surface exposed to the flowing air than non-
Given the potential disadvantage associated with the rating of an air conditioner with a
condensing furnace as the designated air mover, DOE proposes an adjustment to the minimum
external static pressure requirement for a rated blower coil combination using a condensing
furnace as the air mover in order to mitigate the impact on air-conditioner ratings of furnace
conducted laboratory testing for two condensing and three non-condensing furnaces to determine
typical furnace heat exchanger pressure drop levels. DOE measured the pressure rise provided
by each furnace when operating in the maximum airflow-control setting at a representative air
volume rate, first as delivered and then with the furnace heat exchanger(s) removed. DOE
measured average furnace heat exchanger pressure drop equal to 0.47 in. wc. for the condensing
furnaces and 0.27 in. wc. for the non-condensing furnaces. The data suggest that condensing
furnace pressure drop is roughly 0.2 in. wc. higher than non-condensing furnace pressure drop.
However, DOE notes that cooling operation may be at lower air volume rates than the maximum
cooling air volume rate used in the tests, since furnaces can be paired with air-conditioners
having a range of capacities. Based on these results, DOE proposes to include in Appendix M1
of 10 CFR Part 430 Subpart B a requirement of a downward adjustment of the required ESP
equal to 0.1 in. wc. when testing an air conditioner in a blower-coil configuration (or single-
package configuration) in which a condensing furnace is in the air flow path. DOE is not making
such a revision in 10 CFR Part 430, Subpart B, Appendix M. DOE requests comments on this
proposal.
167
3. Default Fan Power for Coil-Only Systems
The default fan power is used to represent fan power input when testing coil-only air
conditioners, which do not include their own fans. 28 The default was discussed in the June 2010
NOPR, in which DOE did not propose to revise it due to uncertainty on whether higher default
values better represent field installations. 75 FR 31227 (June 2, 2010). In response to the June
2010 NOPR, Earthjustice commented that the existing default fan power for coil-only units in
the DOE test procedure is not supported by substantial evidence. ESPs measured from field data
show significant higher values than the requirements in the existing test procedure.
(Earthjustice, No. 15 at p. 2) However, to be consistent with the increase in ESP used for testing
blower coil products, as discussed in section III.H.1, this notice proposes updating the default fan
power (hereinafter referred to as “the default value”) used for testing coil-only products. DOE
used circulation blower electrical power data collected for the furnace fan rulemaking (79 FR
38129, July 3, 2014) to determine an appropriate default value for coil-only products.
DOE collected circulation blower consumption data from product literature, testing, and
exchanges with manufacturers as part of the furnace fan rulemaking. These data are often
provided in product literature in the form of tables listing air volume rate and circulation blower
electrical power input across a range of ESP for each of the blower’s airflow-control settings.
DOE collected such data for over 100 furnace fans of non-weatherized gas furnace products for
the furnace fan rulemaking. DOE used this database to calculate an appropriate default value to
represent circulation blower electrical power for typical field operating conditions for air
28
See 10 CFR 430 Subpart B Appendix M section 3.3.d.
168
conditioning, consistent with the required ESP values proposed for blower coil split-systems.
From the perspective of the furnace providing the air movement, the ESP is higher than that
required for testing blower coil systems to account for the cooling coil and the air filter that
would be installed for a coil-only test, since furnace airflow performance is determined without
the coil and filter installed. DOE used pressure drop associated with the filter equal to 0.08 in.
wc., consistent with the required ESP addition when testing without an air filter installed. In
addition, DOE estimates that the typical pressure drop associated with an indoor coil is 0.16 in.
wc. DOE added the resulting sum, 0.24 in. wc., to the required ESP levels for testing a blower
coil system to obtain the ESP levels it used to calculate the power input for furnaces in the
The air volume rate at which central air conditioner and heat pumps are required to
operate according to the DOE test procedure varies with capacity. Typically, units are tested and
operated in the field while providing between 350 and 450 cfm per ton of cooling capacity. For
the purpose of determining the appropriate default value, DOE investigated furnace fan
performance at the ESP values discussed above while providing 400 cfm per ton of cooling
capacity.
A product that incorporates a furnace fan can often be paired with one of multiple air
conditioners of varying cooling capacities, depending on the installation. For example, a non-
weatherized gas furnace model may be designed to be paired with either a 2, 3, or 4 ton coil-only
indoor unit. These combinations are possible because the circulation blower in the furnace has
169
configured to provide the target air volume rate for either 2, 3, or 4 ton coil-only indoor units by
designating a different airflow-control setting for cooling. For furnaces with multiple such
airflow-control settings that are suitable for air conditioning units, DOE calculated fan power for
each of these settings since they all represent valid field operating conditions.
DOE then organized the results of the calculations by blower motor technology used and
manufacturer, averaging over both to calculate an overall average default value. The distribution
of motor technology follows projected distribution of motors used in furnaces in the field in the
year 2021. By this time, there will be some small impact on this distribution associated with the
The default fan power in the existing DOE test procedure does not vary among different
capacities. DOE maintains the same approach for the adjusted default fan power. Using the
aforementioned methodology, DOE calculated the adjusted default fan power to be 441 W/1000
cfm and proposes to use this value in Appendix M1 of 10 CFR Part 430 Subpart B where
Appendix M included a default fan power of 365 W/1000 cfm. DOE is not making such
In the current test procedure, the heating seasonal performance factor (HSPF) determined
for heat pumps in heating mode is calculated by evaluating the energy usage of both the heat
pump unit (reverse refrigeration cycle) and the resistive heat component when matching the
house heating load for the range of outdoor temperatures representing the heating season. The
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temperature range is split into 5-degree “bins”, and an average temperature and total number of
hours are assigned to each bin, based on weather data for each climate region used to represent
the heating season—for the HSPF rating, this is Region IV. The amount of heating delivered at
each temperature increases as the temperature decreases. This amount is dependent on the size
of the house that the unit is heating. In addition, there is a relationship between the size of the
house and the capacity of the heat pump selected to heat it. For the current test procedure, the
heating load is proportional to the heating capacity of the heat pump when operating at 47 °F
outdoor temperature. The heating load is also proportional to the difference between 65 °F and
the outdoor temperature. The resulting relationship between heating load and outdoor
temperature is called the heating load line—it slopes downward from low temperatures, dropping
to zero at 65 °F. The slope of the heating load line affects HSPF both by dictating the heat pump
temperature, and also by changing the amount of auxiliary electric resistance heat required when
the unit’s heat pumping capacity is lower than the heating load line. The current test procedure
defines two load levels, called the minimum heating load line and maximum heating load line.
However, it is the minimum heating load line in region IV that is used to determine HSPF for
rating purposes. 29
Studies have indicated that the current HSPF test and calculation procedure overestimates
ratings because the current minimum heating load line is too low compared to real world
29
See 10 CFR 430 Subpart B Appendix M Section 1. Definitions.
171
situations. 30 In response to the November 2014 ECS RFI, NEEA and NPCC commented that the
federal test procedure does a poor job representing balance point temperatures and electric heat
energy use in the case of heat pump systems. They pointed out the inability of the test procedure
to capture dynamic response to heating needs, such as use of electric resistance (strip) heat
during morning or afternoon temperature setup (i.e., rewarming of the space after a thermostat
setback period). They also expressed concerns about capturing the use of electric resistance heat
during defrost cycles and at times when it shouldn’t be needed, such as when outdoor
DOE agrees with NEEA and NPCC and notes that the heating balance point determined
for a typical heat pump using the current minimum heating load line in Region IV is near 17 ºF,
while the typical balance point is in the range 26 to 32 ºF, resulting from installing a proper sized
unit based on the design cooling load according to ACCA Manual S, 2014. The low heating
balance point means that the test procedure calculation adds in much less auxiliary heat than
would actually be needed in cooler temperatures, thus inflating the calculated HSPF.
Furthermore, the zero load point of 65 ºF ambient, which is higher than the typical 50-60 ºF zero
load point, 31 causes the test procedure calculation to include more hours of operation at warmer
30
Erbs, D.G., C.E. Bullock, and R.J. Voorhis, 1986. “New Testing and Rating Procedures for Seasonal Performance
of Heat Pumps with Variable-Speed Compressors”, ASHRAE Transactions, Volume 92, Part 2B.
Francisco, Paul W., Larry Palmiter, and David Baylon, 2004. “Understanding Heating Seasonal Performance
Factors for Heat Pumps”, 2004 Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings.
Fairey, Philip, Danny S. Parker, Bruce Wilcox, and Matthew Lombardi, 2004. “Climatic Impacts on Seasonal
Heating Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER) for Air-Source Heat Pumps”,
ASHRAE Transactions, Volume 110, Part 2.
31
Francisco, Paul W., Larry Palmiter, and David Baylon, 2004. “Understanding Heating Seasonal Performance
Factors for Heat Pumps”, 2004 Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings.
172
outdoor temperatures, for which heat pump operation requires less energy input, again inflating
the calculated HSPF. These effects result in overestimation of rated HSPF up to 30% compared
to field performance, according to a paper by the Florida Solar Energy Center (FSEC). 32 For
these reasons, DOE reviewed the choice of heating load line for HSPF ratings and proposes to
modify it.
As part of this review, ORNL conducted building load analysis using the EnergyPlus
simulation tool on a prototype residential house based on the 2006 IECC code and summarized
the study in a report to DOE. 33 In general, the studies indicate that a heating load level closer to
the maximum load line and with a lower zero load ambient temperature is more representative
than the minimum load line presently used for HSPF rating values.
Based on the results from the ORNL studies, DOE proposes the new heating load line
(𝑇𝑇𝑧𝑧𝑧𝑧 −𝑇𝑇𝑗𝑗 )
𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 � = ∙ 𝐷𝐷𝐷𝐷𝐷𝐷 where,
𝑇𝑇𝑧𝑧𝑧𝑧 −𝑇𝑇𝑂𝑂𝑂𝑂
32
Fairey, Philip, Danny S. Parker, Bruce Wilcox, and Matthew Lombardi, 2004. “Climatic Impacts on Seasonal
Heating Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER) for Air-Source Heat Pumps”,
ASHRAE Transactions, Volume 110, Part 2.
33
ORNL, Rice, C. Keith, Bo Shen, and Som S. Shrestha, 2015. An Analysis of Representative Heating Load Lines
for Residential HSPF Ratings, ORNL/TM-2015/281, July. (Docket No. EERE-2009-BT-TP-0004-0046)
173
The proposed equation includes the following changes from the current heating load line used for
calculation of HSPF: 34
• The zero load temperature varies by climate region, as shown in Table III.6, and for
• The design heating requirement is a function of the adjustment factor, or the slope of the
• The heating load is tied with the nominal heat pump cooling capacity used for unit sizing
rather than the heating capacity (except for heating-only heat pumps).
Revised heating load hours were determined for the new zero load temperatures of each
climate region. The revised heating load hours are given below in Table III.9.
The proposed heating load line simulates the actual building load in different climate
regions, so the maximum and minimum heating load lines of the current test procedure are not
needed. The ORNL building simulation results show that the same equation matching the
34
Most commonly used heating load equation based on minimum design heating requirement and region IV: Qh(47)
* 0.77*(65-Tj)/60
174
building load applies well to all regions. DOE therefore proposes eliminating maximum and
DOE believes that it is more appropriate to base the heating load line on nominal cooling
capacity rather than nominal heating capacity, because heat pumps are generally sized based on a
residence’s cooling load. For the special case of heating-only heat pumps, which clearly would
be sized based on heating capacity rather than cooling capacity, DOE proposes that the nominal
heating capacity at 47 °F would replace the cooling capacity in the proposed load line equation.
The proposed altered heating load line would alter the measurement of HSPF. DOE
estimates that HSPF would be reduced on average about 16 percent for single speed heat pumps
and two capacity heat pumps. The impact on the measurement for variable-speed heat pumps is
discussed in section III.H.5. Consistent with the requirements of 42 U.S.C. 6293(e), DOE will
account for these changes in any proposed energy conservation standard, and this test procedure
proposal would not become effective until the compliance date of any new energy conservation
standard.
In response to the November 2014 ECS RFI, University of Alabama commented that the
current test procedure for central air conditioners and heat pumps include cooling bin data at 67
ºF and heating bin data at 62 ºF. This results in a dead band of 5 ºF. Because the current test
procedure prescribes the indoor temperature set point to be 70 ºF for heating, and 80 ºF for
cooling, the temperature difference of 10 ºF is inconsistent with the dead band of 5 ºF from the
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temperature bin. University of Alabama also suggested adopting 62 ºF and 52 ºF as the zero load
points for cooling and heating modes, respectively. (University of Alabama, No. 6 at p. 1-2)
The indoor dry bulb set temperature of 70 ºF for heating and 80 ºF for cooling represent
field set temperature for central air conditioners and heat pumps in a typical residential
household. These two temperatures are also used in other product or equipment classes such as
In this notice, DOE proposes to revise the heating load line which shifts the heating
balance point and zero load point to lower ambient temperatures. These amendments reflect
more representative unit field operations and energy use characteristics. The revised heating
load line lowers the zero load point for heating in region IV to 55 ºF. Given the cooling-mode
zero load point of 65 ºF, the proposed change would increase the temperature difference between
the heating and cooling zero load points to 10 ºF, which equals the temperature difference
between cooling and heating modes thermostat set points. The proposal would hence make these
values more consistent with each other, whether or not this consistency is necessary for accuracy
As a result of this proposed heating load line change, DOE also proposes that cyclic
testing for variable speed heat pumps be run at 47 °F instead of 62 °F, as required by the current
test procedure (see Appendix M, section 3.6.4 Table 11). The test would still be conducted using
minimum compressor speed. With the modified heating load line there would be no heat pump
35
See ANSI/AHRI Standard 340/360-2007 with Addenda 1 and 2, Performance rating of commercial and industry
unitary air-conditioning and heat pump equipment.
176
operation at 62 °F, so cyclic testing at 47 °F would be more appropriate. DOE seeks comment
on this proposal.
DOE proposes to make the changes to the test procedure as mentioned in this subsection
only in Appendix M1 of 10 CFR Part 430 Subpart B, and is not making such changes to
5. Revised Heating Mode Test Procedure for Products Equipped with Variable-Speed
Compressors
Inc., and an Oak Ridge National Lab (ORNL)/Tennessee Valley Authority (TVA) field test
found the heating performance of a variable speed heat pump, based on field data, is much lower
than the rated HSPF. 36 Therefore, DOE revisited the heating season ratings procedure for
variable speed heat pumps, is are found in section 4.2.4 of Appendix M of 10 CFR Part 430
Subpart B..
The HSPF is calculated by evaluating the energy usage of both the heat pump unit
(reverse refrigeration cycle) and the resistive heat component when matching the dwelling
heating load at each outdoor bin temperature. Currently, both the minimum and the maximum
capacities are calculated at each outdoor bin temperature to determine whether the variable speed
36
Larson, Ben, Bob Davis, Jeffrey Uslan, and Lucinda Gilman, 2013. Variable Capacity Heat Pump Field Study,
Final Report, Ecotope, Inc., Bonneville Power Administration, August.
Munk, J.D., Halford, C., and Jackson, R.K., 2013. Component and System Level Research of Variable Capacity
Heat Pumps, ORNL/TM-2013/36, August.
177
heat pump capacity can or cannot meet the building heating load. At an outdoor bin temperature
where the heat pump minimum capacity is higher than the building heating load, the heat pump
cycles at minimum speed. The energy usage at such outdoor bin temperature is determined by
the energy usage of the heat pump at minimum speed and the unit cyclic loss. At an outdoor bin
temperature where the heat pump maximum capacity is lower than the building heating load, the
heat pump operates at maximum speed. The energy usage at such outdoor bin temperature is
determined by the energy usage of the heat pump at maximum speed and of the additional
In the current test procedure, the capacity and the corresponding energy usage at
minimum speeds are determined by the two minimum speed tests at 47 °F and 62 °F (outdoor
temperature 37), assuming the capacity and energy usage is linear to the outdoor temperature and
the compressor speed does not change with the outdoor temperature. The capacity and the
corresponding energy usage at maximum speeds are determined by the two maximum speed tests
at 47 °F and at 17 °F, assuming the compressor speed does not change with the outdoor
temperature. Both the minimum and the maximum capacities and energy usages are also used to
estimate the heat pump operating capacity and energy usage when the heat pump operates at an
energy usage; at maximum speed, intermediate speed, and minimum speed at ambient
temperatures representing the heating season) calculated using the method in current test
37
All temperatures in section III.H.5, if not noted otherwise, mean outdoor temperature.
178
procedure to the efficiencies tested in the lab at each of the 5 °F bin temperatures representing
the heating season, and found two discrepancies where the efficiencies are not predicted
The first discrepancy occurs only for the variable speed heat pump that prevents
minimum speed operation at outdoor temperatures below 47 °F. In the mid-range outdoor
temperature range (17 – 47 °F), the efficiencies are over-predicted. The cause of this over-
prediction is that the unit’s actual minimum capacity is higher than the calculated minimum
capacity in the range of outdoor temperature 17 – 47 °F. The calculated minimum capacity is
based on the assumption that the unit can operate at the minimum speed in this range, which is
DOE considered two alternative methods to provide more accurate efficiency predictions
for mid-range outdoor temperatures. In the first method, the minimum capacity and the
corresponding energy usage for outdoor temperatures lower than 47 °F would be determined by
the minimum speed tests at 47 °F and the intermediate speed test at 35 °F, which are both
required test points in current test procedure. The new calculation method results in the capacity
and energy usage more representative of the unit operation performance in the temperature
region 35 – 47 °F. The HSPF calculated with this option agrees with the tested HSPF within 6%.
This option does not require additional testing beyond what is required in the current test
procedure.
179
In the second method, the minimum capacity and the corresponding energy usage for
outdoor temperature lower than 47 °F would be determined by minimum speed tests at 47 °F and
at 35 °F, where the test point of minimum speed at 35 °F is an additional test point that is not
required in the current test procedure. In addition, the intermediate capacity and the
corresponding energy usage would be modified for more accurate efficiency prediction at the
outdoor temperature range 17 – 35 °F. This is done by defining the medium speed test as the
average of the maximum and minimum speed and using the medium speed test at 17 °F and the
intermediate speed test at 35 °F to determine the intermediate capacity and the corresponding
energy usage, where the test at the medium speed at 17 °F is a test point not required in the
current test procedure. With this method, the unit’s calculated performance is well matched with
the unit’s actual operation in the outdoor temperature region 17 – 35 °F. The HSPF calculated
with this option aligns with the tested HSPF within 2%. However, this option requires two
additional test points, medium speed at 17 °F and minimum speed at 35 °F, which adds test
After considering these two alternative methods with regard to the current test procedure,
DOE further evaluated the impact of the proposed heating load line change (see section III.H.4)
on the variable speed HSPF rating. DOE found that efficiencies calculated with the modified
heating load line and with the current variable speed heat pump rating method match rather
closely with those calculated from a more detailed set of test data at each outdoor bin
temperature. The calculated HSPFs agree within 1 percent. Use of the proposed load line
greatly reduces the error in the test procedure calculation from the speed limiting controls at
ambient temperatures below 47 °F. The net effect is that the ratings calculation approach using
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the proposed load line with the current test points gives results close to those with more detailed
data sets. However, because this also removes an artificial HSPF benefit that such units were
obtaining, the net reduction in rated HSPF for such units could be as much as 26% 38. DOE
believes that this indicates that the modified heating load line is sufficient to address the HSPF
over-prediction issue for the variable speed heat pumps. Therefore, at this time, DOE does not
propose changes specifically to the variable speed test points or heating calculations in the
proposed Appendix M1. However, DOE notes that should stakeholder comments on this notice
provide sufficient justification to retract the proposal to adopt the proposed modified heating
load line, DOE would instead adopt, as part of Appendix M1, modifications to the variable speed
heating calculations for units that prevent minimum speed operation. DOE requests comment on
whether, in the case that the proposed heating load line is not adopted, DOE should modify the
HSPF rating procedure for variable speed heat pumps using option 1, which is less accurate but
has no additional test burden, or option 2, which is more accurate but with higher test burden.
The second potential discrepancy between the efficiencies (capacity divided by energy
usage) calculated using the method in the current test procedure with the efficiencies tested in the
lab at each outdoor bin temperature occurs at temperatures lower than 17 °F, where the test
procedure assumes the heat pump operates at the maximum speed. The capacity and the
corresponding energy usage at maximum speed at different outdoor bin temperatures are
determined by the two maximum speed tests at 47 °F and at 17 °F, assuming the compressor
speed does not change with the outdoor temperature. However, DOE found that some variable
speed heat pumps do not allow maximum speed operation when the outdoor temperature is
38
Rice et al. (2015) Review of Test Procedure for Determining HSPFs of Residential Variable-Speed Heat pumps.
(Docket No. EERE-2009-BT-TP-0004-0047)
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below 17 °F. For such units, the assumption in the current test procedure is not appropriate. The
impact of this discrepancy on the HSPF is not significantly changed by the proposed heating load
line revision.
DOE proposes as part of Appendix M1 that for the variable speed units that limit the
maximum speed operation below 17 °F and have a low cutoff temperature less than 12 °F, the
manufacturer could choose to calculate the maximum heating capacity and the corresponding
energy usage through two maximum speed tests at: (1) 17 °F outdoor temperature, and (2) 2 °F
outdoor temperature or at a low cutoff temperature, whichever is higher. 39 With this proposed
change, manufacturers could choose to conduct one additional steady state test, at maximum
higher.
The testing done by ORNL found that the unit efficiency at maximum speed below 17 °F
is slightly higher than the extrapolated values in the current test procedure, and this proposed
option would provide a more accurate prediction of heat pump low ambient performance not
only for those units that limit maximum speed operation below 17 °F, but also for those that do
not. 40 DOE therefore proposes to revise Appendix M1 such that, for variable speed units that do
not limit maximum speed operation below 17 °F, manufacturers would also have the option to
39
In the case that the low cutoff temperature is higher than 12 °F, the manufacturer would not be allowed to utilize
this option for calculation of the maximum heating load capacity.
40
EERE-2009-BT-TP-0004-0047.
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DOE believes that the proposed revision reflects field energy use more accurately.
However, DOE acknowledges that the limited test results available show very small
improvements in the accuracy of the rating method. Because the proposed revision adds an
additional test burden (one new test), DOE has proposed to make it optional rather than
mandatory. However, DOE would consider making this proposal mandatory for some or all
variable speed units, given additional information. Specifically, DOE requests test results and
other data that demonstrate whether HSPF results for other variable speed heat pumps would be
more significantly impacted by this proposed option, as well as whether the additional test
DOE notes that the proposed revision also adds additional complexity to the test
procedure in terms of which combinations of tests need to be conducted. In the current test
procedure, to calculate the maximum speed performance in the temperature range 17 - 45 °F, the
not required and performance at 35 °F may instead be calculated from the two maximum speed
tests at 17 °F and 47 °F. Therefore, even though manufacturers who choose to rate with the
optional low ambient point would no longer need the maximum speed 47 °F point to calculate
energy use at maximum speed below 17 °F, they would need either the maximum speed 47 °F
test point or 35 °F test point to calculate the capacity and energy use at maximum speed at 35 °F.
They may also wish to conduct the maximum speed 47 °F test point to rate heating capacity,
although in the proposed Appendix M1, this is only required for heating-only heat pumps.
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In summary, with the proposed option for calculating maximum speed performance
below 17 °F, manufacturers would test at both maximum speed at 2 °F (or low cutoff
temperature) and maximum speed at 17 °F. For rating at 35 °F, they would also test at either
nominal heating capacity (for units whose controls do not allow maximum speed operation at 47
°F), they may also choose to test at either maximum speed at 47 °F allowed by their standard
controls or cooling capacity maximum speed at 47 °F, respectively. Table III.10 lists the
maximum speed test combination options for the variable speed heat pumps. The test
Table III.10: Proposed Maximum Speed Heating Test Combination Options for Units
H42 (2 °F)* X X X X
Note: For units with a low cutoff temperature higher than 12 °F, options 2 through 5 are not available.
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DOE additionally notes that all proposed changes in this subsection would change the
efficiency ratings of units and are therefore proposed as part of Appendix M1 of 10 CFR 430
Subpart B. Such proposed changes would not appear in Appendix M of the same Part and
Subpart.
Various comments from stakeholders during the public comment period following the
publication of the November 2014 ECS RFI raised additional test procedure issues. The
stakeholders requested that DOE consider these issues when amending its test procedures. After
careful consideration of these issues, DOE believes that either they cannot be resolved or that
they require additional action at this time, and therefore declines to address them in this SNOPR.
Central air conditioners and heat pumps can be divided into single-speed, two-capacity,
or variable capacity (or speed) units based on capacity modulation. System controls are typically
more complex with the increasing modulating capability. The DOE test procedure prescribes
different testing requirements for units depending on whether they are single-speed, two-
capacity, or variable capacity (or speed) in order to characterize the efficiency ratings accurately.
In response to the RFI, stakeholders submitted several comments that address the more
complex operation of variable capacity central air conditioners and heat pumps. Stakeholders
also submitted comments highlighting the need for improvement in the test procedure’s ability to
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accurately predict energy use in the field, even for units that do not have variable capacity
capability. PG&E urged DOE to revise the current test procedure to reflect the more nuanced
operation of modern variable speed central air conditioners and heat pumps over the full range of
outdoor conditions, given that variable speed units operate differently from the traditional single-
Edison Electric Institute commented that the current test procedure for central air
conditions and heat pumps need to be updated to avoid “gaming” of system controls to maximize
rated SEER and EER, as there is an increase in using variable speed controls for motors,
NEEA & NPCC commented that the current test procedure does not appropriately test the
operation of variable capacity systems. These systems operate much differently in the field than
the forced operating conditions with which they are currently tested under waivers and
artificially created laboratory conditions. As a result, the efficiency ratings and estimated energy
use of these systems cannot be reliably determined. NEEA & NPCC also claimed that the field
data shows that systems from different manufacturers with identical HSPF and SEER ratings and
identical rated capacity will use significantly different amounts of energy under identical
environmental conditions. (NEEA & NPCC, No. 19 at p. 2) NEEA & NPCC also showed the
field energy use profiles for six units. They further commented that variable capacity systems
behave in a nearly infinite variety of ways under similar outdoor and indoor temperature
conditions, and much of this behavior occurs outside the bounds of the test procedure conditions.
(NEEA & NPCC, No. 19 at p. 4) NEEA and NPCC commented that test procedure updates to
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variable capacity equipment will have an impact on the energy savings of these systems. They
also commented that the test procedure more accurately representing the field energy use for heat
pump systems could vary significantly by climate zone. (NEEA & NPCC, No. 19 at p. 10)
ASAP, ASE, and NRDC commented that the current method for testing variable-capacity
units used by manufacturers who have obtained test procedure waivers may not provide good
Representative ratings of variable-capacity products will become more important in the future as
variable-capacity units become more widely adopted. (ASAP & ASE & NRDC, No. 20 at p. 1)
PG&E commented that central air conditioners and heat pumps should be tested at part
load and cyclic testing under conditions that represent field operations. (PG&E, No. 15 at p. 3)
However, PG&E did not provide further detail on what part load and cyclic conditions would be
field representative.
ACEEE commented that the current federal test procedure has been awkward for rating
new technologies, notably ductless equipment, and probably some types of modulating
As discussed in section III.H.5, DOE proposes to amend the testing requirements for
units equipped with a variable speed compressor during heating mode operation. These
proposed amendments would improve the field representativeness of variable speed units and
better characterize the field energy use. However, DOE acknowledges that further
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improvements as suggested by the stakeholders could be possible if more detailed field testing
data is available. DOE may consider in a future rulemaking additional amendments to improve
the test procedure’s representation of field energy use. In regards to ductless and modulating
equipment, DOE’s existing test procedure already covers testing and rating of these technologies.
Central air conditioners and heat pumps operate in a wide range of weather conditions
throughout the year. Further, both the range of temperature and humidity conditions associated
with most of these products’ energy use also varies from one climate region to another. The test
procedure prescribes calculation of seasonal energy efficiency metrics for cooling and heating
based on a finite set of test conditions intended to represent the range of operating conditions
DOE decided in the June 2010 NOPR not to propose modifications to convert to wet-coil
cyclic testing as data and information were not available to quantify subsequent impacts. 75 FR
31223, 31228 (June 2, 2010). In response to the June 2010 NOPR, SCE, SCGC and SDGE
submitted a joint comment recommending DOE require that manufacturers disclose performance
data at a range of test conditions, as specified in the Consensus Agreement. The joint comment
further explained that program designers need to know how equipment performs in a range of
conditions in order for rebate and incentive programs to be effective. This could also make it
possible for consumers to select products with performance characteristics that meet their needs.
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In the current AHRI certified directory 41, manufacturers report the full load capacity and
EER in addition to SEER for central air conditioners. Manufacturers also report heating
capacities and EERs at both 47°F and 17°F ambient test conditions in addition to the seasonal
efficiency metric HSPF for heat pumps. Cooling capacity and EER at full load are also reported
in addition to SEER for heat pumps. DOE believes that this rating data provides sufficient
information for determining rebate and incentive programs for program designers.
NREL commented that the existing DOE testing and certification requirements for
central air conditioners and heat pumps do not provide sufficient data to compare different units.
NREL also urged DOE to adopt different testing conditions for the hot dry and hot humid region.
NREL further commented that measurement of water condensation must be reported with higher
fidelity than the sensible heat ratio. Latent loads and moisture removal should be reported in
DOE does not intend to establish different test conditions for various regions of this
country. DOE believes that it would add significant burden to manufacturers to report the latent
loads and moisture removal in each test condition. In this SNOPR, DOE revises the certification
requirement to include reporting the sensible heat ratio. See section III.I.5 for more details.
DOE believes that the sensible heat ratio provides a good indication of the moisture removal
41
http://www.ahridirectory.org/ahridirectory/pages/home.aspx
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Stakeholders submitted a number of comments on the revised ambient test condition in
commented that the testing conditions prescribed in the federal test procedure for central air
conditioners and heat pumps are not representative of actual operation in the field. The outdoor
temperatures used for rating should be expanded from 2 to 3 for constant speed units and from 5
to 6 for multi-capacity and variable speed units. The rating points can be used to determine more
appropriate SEER and HSPF for climates outside of the current DOE zone 4 conditions.
Specifically, University of Alabama proposed the cooling indoor dry bulb and wet bulb
temperatures to be 77 ºF and 64.4 ºF, instead of the current requirement of 80 ºF and 67 ºF,
respectively. Heating indoor dry bulb temperature should use 68 ºF instead of the current
requirement of 70 ºF. For the outdoor conditions, testing at 113 ºF, 95 ºF, and 77 ºF have been
proposed for the cooling mode, and 41 ºF, 23 ºF, and 5 ºF have been proposed for the heating
PG&E commented that DOE should amend the test procedure to require testing at 76 ºF
dry bulb with 50% relative humidity indoor conditions to represent the comfort desired in
dwellings. (PG&E, No. 15 at p. 3) However, PG&E did not provide further detail on why the
revised test condition is more representative than the requirements in the current federal test
procedure.
PG&E also commented that the current cooling condition at 95 ºF does not fully capture
the peak load experienced by consumers in the hottest summer weather. PG&E further urged
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DOE to revise the test procedure to account for ambient dry bulb conditions of 105 ºF or 115 ºF
Moreover, PG&E commented that DOE should adopt the testing at outdoor ambient
temperatures that generate a performance map of the system for use in annual energy use
simulation. (PG&E, No. 15 at p. 3) However, there is no further detail provided regarding this
comment.
EEI suggested that DOE revise the indoor air inlet dry bulb/wet bulb temperatures to be
lowered from 80 ºF/67 ºF to 78 ºF/61 ºF, respectively. Such a change would create more realistic
indoor conditions that would require dehumidification to ensure properly managed indoor air
quality. (EEI, No. 18 at p. 4) However, EEI did not provide further detailed justifications why
such a change would create more realistic indoor conditions than the current federal testing
requirements.
NEEA and NPCC commented that the current federal test procedure does not capture
performance under the full range of operating conditions for which many of these systems are
designed. Some air conditioners perform significantly better at temperatures above 100 ºF than
others, but based on the current test procedure, there is no testing requirement for temperatures
above 95 ºF. For heat pumps, systems may perform differently above 47 ºF and below 17 ºF
conditions. NEEA and NPCC commented that the test procedure and the resulting ratings should
expose these differences and allow the market to properly select the systems that are most
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appropriate and most efficient for individual climate conditions. (NEEA & NPCC, No. 19 at p.
2)
ASAP, ASE, and NRDC commented that the test conditions defined in the current test
procedure do not reflect field conditions. Adding a test point for SEER ratings at an outdoor
temperature above 95 ºF and adding a test point for HSPF ratings at an outdoor temperature
test points would allow efficiency program administrators to incentivize equipment that will
perform well in their region. (ASAP & ASE & NRDC, No. 20 at p. 2)
DOE appreciates that there may be value in providing more performance data, and that
the range of operating conditions in the field may be more extensive than that represented by the
current test. However, the extensive study and test work that would have to be conducted to
properly assess and choose a better range of test conditions has not been completed. Hence,
although DOE has proposed some changes to the test conditions required for testing of variable-
speed heat pumps in heating mode, DOE has not proposed changes as extensive as the comments
suggest. DOE may consider additional changes addressing these issues in future test procedure
rulemakings.
Central air conditioners and heat pumps condition the indoor air to satisfy cooling and
heating requirements of a house. For ducted central air conditioners and heat pumps, indoor air
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is driven by the blower of the air handling unit or the furnace. Air volume rate affects the heat
transferred between the air conditioning device and indoor air, and also affects the performance
University of Alabama recommended that all performance results for central air
conditioners and heat pumps be reported within the air volume rate range of 375 to 425 cfm per
ton, and that the air volume rates be included in the reporting requirements. Higher air volume
rates will result in reduced dehumidification capability and cause thermal comfort issue.
The current DOE test procedure requires that full load air volume rate be no more than
37.5 standard cfm (scfm) per 1,000 Btu/h of cooling capacity (see 10 CFR Part 430, Subpart B,
Appendix M, Section 3.1.4.1.1), but the test procedure does not have a minimum air volume rate
requirement. DOE has proposed in this notice to require reporting of the cooling full load air
volume rate as part of certification reporting. See section III.I.5 for more details. The air
volume rate is also reported in the AHRI certification database. 42 DOE believes that these
requirements will ensure that air volume rates used for rating central air conditioners and heat
The DOE test procedure for central air conditioners and heat pumps prescribe specific
test conditions under which units are to be tested. These test conditions include both steady-state
42
AHRI Directory of Certified Product Performance: https://www.ahridirectory.org/ahridirectory/pages/home.aspx
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and cyclic tests. A dry coil test refers to the test conditions that do not result in moisture
condensing on the indoor coil, and a wet coil test refers to the test conditions that result in
moisture condensing on the indoor coil. DOE proposed in the June 2010 NOPR not to amend
the existing cyclic testing requirement from dry coil test to wet coil test. DOE concluded that
there was no sufficient data to show a greater benefit to using wet coil cyclic test versus the dry
In response to the RFI regarding central air conditioners and heat pumps (79 FR 65603,
November 5, 2014), ASAP & ASE & NRDC commented that the cyclic test in the current test
procedure is conducted using a dry coil, which is not representative of field conditions. Using
the same indoor conditions (i.e., 80 ºF dry bulb and 67 ºF wet bulb) for the cyclic tests as used
for the steady-state test would better reflect the cyclic performance of central air conditioners and
heat pumps. (ASAP & ASE & NRDC, No. 20 at p. 2) DOE believes this approach may have
merit, but has not sufficiently studied it to have proposed its inclusion in the test procedure at this
Air conditioning reduces air temperature and also reduces humidity. Cooling associated
with air temperature reduction is called sensible capacity, while cooling associated with
dehumidification is called latent capacity. The balance of these capacities for a given air
conditioner operating in a given set of operating conditions is represented as sensible heat ratio
(SHR), which is equal to sensible cooling divided by total cooling. Air conditioners can be
designed to operate with high or low SHR depending on the air conditioning needs. Similarly,
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an air conditioner can be optimized to maximize efficiency depending on the indoor humidity
level.
In the June 2010 NOPR, DOE proposed including the calculation for (SHR at the B, B1,
or B2 test condition (82 °F dry bulb, 65 °F wet bulb, outside air) in the test procedure. 75 FR
31223, 31229 (June 2, 2010). DOE received comments regarding the inclusion of calculations
for SHR in the subsequent public comment period. AHRI supported adoption of the SHR,
provided that it is based off the total net capacity and is a reported value only. (AHRI, No. 6 at
p. 4) Ingersoll Rand agreed with AHRI. (Ingersoll Rand, No. 10 at pp. 2-3) Lennox likewise
agreed with AHRI regarding adding calculations for SHR and further requested that DOE
provide calculations for SHR at outdoor ambient conditions of 82 °F. (Lennox, No. 11 at p. 1)
Building Science Corporation stated that the calculation of the SHR was a favorable step towards
outdoor and indoor conditions and reporting a metric for moisture removal efficacy. (Building
Science Corporation, No. 16 at p. 1) NEEA concurred with DOE’s proposal in the NOPR to add
calculations of sensible heat ratio (SHR) to the test procedure requirements. (NEEA, No. 7 at p.
6) The People’s Republic of China World Trade Organization Technical Barriers to Trade
National Notification and Enquiry Center (China WTO) suggested that SHR be calculated at the
DOE does not believe that measurements at multiple indoor or outdoor conditions are
necessary to obtain a SHR value that represents unit operation during an average use cycle or
period. (42 U.S.C. 6293(b)(3)) Therefore, DOE is maintaining its position in the NOPR to
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include calculation for sensible heat ratio at only the condition at which products are rated (82 °F
dry bulb, 65 °F wet bulb, outside air), and proposes to include this change to the revised
Appendix M test procedure in this notice. DOE notes that the addition of these calculations does
not add significant test burden because the existing measurement instruments, used for
determining the inputs for SEER, can also determine the inputs for SHR.
The June 2010 NOPR highlighted a Joint Utilities recommendation that DOE should
require all units be certified and rated for sensible heat ratio (SHR) at 82 °F ambient dry bulb
temperature. 75 FR 31223, 31229 (June 2, 2010). DOE believes that the existing certification
test procedures and ratings are sufficient to determine product efficiency; efforts to establish
dehumidification performance for central air conditioner and heat pumps are not currently
necessary given that the primary function of the subject products is not dehumidification, nor
In response to the RFI regarding central air conditioners and heat pumps (79 FR 65603,
related to the SHR. PG&E commented that the test procedure should adopt testing that
characterizes the sensible heat ratios for high (western dry climates, approximately 500 cfm/ton)
and low (eastern humid climates, approximately 350 cfm/ton) evaporator coil air volume rate.
commented that the test procedure should take into account a dehumidification requirement as
homes are getting tighter with fewer air changes. (Id.; EEI, No. 18 at p. 3) ASAP & ASE &
NRDC requested DOE require reporting sensible heat ratio for central air conditioners and heat
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pumps. Sensible heat ratio would provide more information to consumers and contractors about
appropriate units for their region and also allow efficiency program administrators to better
target efficiency programs for central air conditioners and heat pumps. (Id.; ASAP & ASE &
NRDC, No. 20 at p. 2)
In response to the stakeholder comments, DOE understands that air volume rate can be
controlled properly to suit the dehumidification purposes. However, manufacturers can design
their products to meet the needs of consumers in different climate regions. Therefore, DOE does
not intend at this time to develop a test procedure that requires different air volume rates based
on the climate region. DOE does, however, realize the merit of reporting SHR for consumer
choices. As such, DOE proposes to simply require the reporting of the SHR value calculated
based on full-load cooling test conditions at the outdoor ambient conditions proposed earlier in
1. Test Burden
EPCA requires that any test procedures prescribed or amended shall be reasonably
designed to produce test results which measure energy efficiency, energy use, or estimated
annual operating cost of a covered product during a representative average use cycle or period of
use, and shall not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3)) For the reasons
that follow, DOE has tentatively concluded that revising the DOE test procedure, per the
proposals in this SNOPR, to measure the energy consumption of central air conditioners and heat
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pumps in active mode and off mode would produce the required test results and would not result
As discussed in section IV.B of this SNOPR, the proposed test procedures to determine
the active-mode and standby-mode energy use would require use of the same testing equipment
and facilities that manufacturers are currently using for testing to determine CAC and CHP
ratings for certifying performance to DOE. While this notice proposes clarifications to the test
procedures, and proposes adopting into regulation the test procedures associated with a number
of test procedure waivers, most of the proposals would not affect test time or the equipment and
facilities required to conduct testing. Possible changes in test burden associated with the
proposals of this notice apply to off mode testing and requirements for testing of basic models by
ICMs.
The proposals include additional testing to determine off mode energy use, as required by
EPCA. (42 U.S.C. 6295(gg)(2)(A)) This additional testing may require investment in additional
temperature-controlled facilities. However, DOE’s proposal does not require that every
individual combination be tested for off mode, allowing sufficient use of AEDMs in order to
The proposals also call for testing to determine performance for ICMs. Specifically, the
proposals call for testing of one split system combination for each model of indoor unit sold by
an ICM. While this change would increase test burden for these manufacturers, DOE believes it
is the appropriate minimum test burden to validate ratings for these systems, as it is consistent
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with current requirements for OUMs, for which testing is required for every model of outdoor
process to certify products without the need of testing. In this notice, DOE revises and clarifies
such requirements, as detailed in section III.B, to continue to enable manufacturers who wish to
waivers, have already utilized the alternative test procedures provided to them for certification
testing. Thus, the inclusion of said alternative test procedures into the test procedure, as revised
modified off mode test procedure that is less burdensome than the proposals it made in the April
2011 SNOPR and October 2011 SNOPR and that addresses stakeholder comment regarding the
test burden of such prior proposals. Further discussion regarding test burden associated with the
proposals set forth in this notice for determining off mode power consumption can be found in
section III.D.
DOE set forth proposals to improve test repeatability, improve the readability and clarity
of the test procedure, and utilize industry procedures that manufacturers may be aware of in an
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effort to reduce the test burden. Sections III.E, III.F, and III.G presents additional detail
Although DOE proposes to change the current test procedure in a manner that would
impact measured energy efficiency, amend existing requirements, and increase the testing time
for such tests, DOE carefully considered the impact on testing burden and made efforts to
balance accuracy, repeatability, and test burden during the course of the development of such
Therefore, DOE determined that the proposed revisions to the central air conditioner and
heat pump test procedure would produce test results that measure energy consumption during a
period of representative use, and that the test procedure would not be unduly burdensome to
conduct.
Under 42 U.S.C. 6295(gg)(2)(B), EPCA directs DOE to consider IEC Standard 62301
and IEC Standard 62087 when amending test procedures for covered products to include standby
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DOE reviewed IEC Standard 62301, “Household electrical appliances – Measurement of
standby power” (Edition 2.0 2011-01), 43 and determined that the procedures contained therein
for preparation of the unit under test and for conducting the test are already set forth in the
amended test procedure, as proposed in this notice, for determining off mode power consumption
and for determining the components (cyclic degradation coefficient) that make up standby power
for central air conditioners and heat pumps. Therefore, DOE determined that referencing IEC
Standard 62301 is not necessary for the proposed test procedure that is the subject of this
rulemaking.
DOE reviewed IEC Standard 62087, “Methods of measurement for the power
consumption of audio, video, and related equipment” (Edition 3.0 2011-04), and determined that
it would not be applicable to measuring power consumption of HVAC products such as central
air conditioners and heat pumps. Therefore, DOE determined that referencing IEC Standard
62087 is not necessary for the proposed test procedure that is the subject of this rulemaking.
The Office of Management and Budget (OMB) has determined that test procedure
rulemakings do not constitute “significant regulatory actions” under section 3(f) of Executive
Order 12866, Regulatory Planning and Review, 58 FR 51735 (Oct. 4, 1993). Accordingly, this
action was not subject to review under the Executive Order by the Office of Information and
43
IEC Standard 62301 covers measurement of power consumption for standby mode and low power modes, as
defined therein.
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B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires preparation of an initial
regulatory flexibility analysis (IFRA) for any rule that by law must be proposed for public
comment, unless the agency certifies that the rule, if promulgated, will not have a significant
16, 2002), DOE published procedures and policies on February 19, 2003, to ensure that the
potential impacts of its rules on small entities are properly considered during the DOE
rulemaking process. 68 FR 7990. DOE has made its procedures and policies available on the
DOE reviewed this proposed rule, which would amend the test procedure for central air
conditioners and heat pumps, under the provisions of the Regulatory Flexibility Act and the
procedures and policies published on February 19, 2003. DOE tentatively concludes and
certifies that the proposed rule, if adopted, would not result in a significant impact on a
substantial number of small entities. The factual basis for this certification is set forth below.
For the purpose of the regulatory flexibility analysis for this rule, the DOE adopts the
Small Business Administration (SBA) definition of a small entity within this industry as a
manufacturing enterprise with 750 employees or fewer. DOE used the small business size
standards published on January 31, 1996, as amended, by the SBA to determine whether any
small entities would be required to comply with the rule. 61 FR 3280, 3286, as amended at 67
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FR 3041, 3045 (Jan. 23, 2002) and at 69 FR 29192, 29203 (May 21, 2004); see also 65 FR
30836, 30850 (May 15, 2000), as amended at 65 FR 53533, 53545 (Sept. 5, 2000). The size
standards are codified at 13 CFR Part 121. The standards are listed by North American Industry
Classification System (NAICS) code and industry description and are available at
www.sba.gov/idc/groups/public/documents/sba_homepage/serv_sstd_tablepdf.pdf.
Central air conditioner and heat pump manufacturing is classified under NAICS 333415,
“Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial
AHRI’s listing of central air conditioner and heat pump product manufacturer members and
surveyed the industry to develop a list of domestic manufacturers. As a result of this review,
DOE identified 22 manufacturers of central air conditioners and heat pumps, of which 15 would
be considered small manufacturers with a total of approximately 3 percent of the market sales.
DOE seeks comment on its estimate of the number of small entities that may be impacted by the
Potential impacts of the proposed test procedure on all manufacturers, including small
businesses, come from impacts associated with the cost of proposed additional testing. In the
June 2010 NOPR, DOE estimated the incremental cost of the proposed additional tests described
in 10 CFR Part 430, Subpart B, Appendix M (proposed section 3.13) to be an increase of $1,000
to $1,500 per unit tested, indicating that the largest additional cost would be associated with
conducting steady-state cooling mode tests and the dry climate tests for the SEER-HD rating).
75 FR at 31243 (June 2, 2010). DOE has eliminated tests associated with the SEER-HD rating
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from the proposals in this notice. DOE conservatively estimates that off mode testing might cost
$1,000 (roughly one-fifth of the $5000 cost of active mode testing—see 75 FR at 31243 (June 2,
2010)). Assuming two off mode tests per tested model, this is an average test cost of $2,000 per
model.
The proposals of this notice also require that ICMs test one combination of every basic
model (i.e., model of indoor unit). Based on a test cost estimate of $5000 and two tests per
model, the costs for this proposal are $10,000 for each basic model.
Because the incremental cost of running the extra off mode tests is the same for all
manufacturers, DOE believes that all manufacturers would incur comparable costs for testing to
certify off mode power use for basic models as a result of the proposed test procedure. DOE
expects that small manufacturers will incur less testing expense compared with larger
manufacturers as a result of the proposed testing requirements because they have fewer basic
models and thus require proportionally less testing when compared with large manufacturers that
have many basic models. DOE recognizes, however, that smaller manufacturers may have less
With respect to the provisions addressing AEDMs, the proposals contained herein would
not increase the testing or reporting burden of outdoor unit manufacturers who currently use, or
are eligible to use, an AEDM to certify their products. The proposal would eliminate the ARM
nomenclature and treat these methods as AEDMs, eliminate the pre-approval requirement for
product AEDMs, revise the requirements for validation of an AEDM in a way that would not
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require more testing than that required by the AEDM provisions included in the March 7, 2011
Certification, Compliance and Enforcement Final Rule (76 FR 12422) (“March 2011 Final
Rule”), and amend the process that DOE promulgated in the March 2011 Final Rule for
validating AEDMs and verifying certifications based on the use of AEDMs. Because these
AEDM-related proposals would either have no effect on test burden or decrease burden related to
testing (e.g., elimination of ARM pre-approval), DOE has determined these proposals would
result in no significant change in testing or reporting burden. The proposals contained herein
would not increase the testing or reporting burden of outdoor unit or independent coil
manufacturers besides the revision to the requirements for validation of an AEDM, of which
burden is outweighed by the benefit of providing more accurate ratings for models of indoor
To evaluate the potential cost impact of the other test-related proposals, DOE compared
the cost of the testing to the total value added by the manufacturers to determine whether the
impact of the proposed test procedure amendments is significant. The value added represents the
net economic value that a business creates when it takes manufacturing inputs (e.g., materials)
and turns them into manufacturing outputs (e.g., manufactured goods). Specifically, as defined
by the U.S. Census, the value added statistic is calculated as the total value of shipments
(products manufactured plus receipts for services rendered) minus the cost of materials, supplies,
DOE analyzed the impact on the smallest manufacturers of central air conditioners and
heat pumps because these manufacturers would likely be the most vulnerable to cost increases.
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DOE calculated the additional testing expense as a percentage of the average value added
statistic for the five individual firms in the 25 to 49 employee size category in NAICS 333415 as
reported by the U.S. Census (U.S. Bureau of the Census, American Factfinder, 2002 Economic
http://factfinder.census.gov/servlet/EconSectorServlet?_lang=en&ds_name=EC0200A1&_Secto
rId=31&_ts=288639767147). The average annual value for manufacturers in this size range
from the census data was $1.26 million in 2001$, per the 2002 Economic Census, or
approximately $1.52 million per year in 2009$ after adjusting for inflation using the implicit
price deflator for gross domestic product (U.S. Department of Commerce Bureau of Economic
Analysis, www.bea.gov/national/nipaweb/SelectTable.asp).
DOE also examined the average value added statistic provided by census for all
manufacturers with fewer than 500 employees in this NAICS classification as the most
representative value from the 2002 Economic Census data of the central air conditioner
manufacturers with fewer than 750 employees that are considered small businesses by the SBA
(15 manufacturers). The average annual value added statistic for all small manufacturers with
Given this data, and assuming the range of estimates of additional costs, $2,000 for
OUMs and $10,000 for ICMs for the additional testing costs, DOE concluded that the additional
costs for testing of a single basic model product under the proposed requirements would be up to
approximately 0.7 percent of annual value added for the 5 smallest firms, and approximately
0.13 percent of the average annual value added for all small central air conditioner or heat pump
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manufacturers (15 firms). DOE estimates that testing of basic models may not have to be
updated more than once every 5 years, and therefore the average incremental burden of testing
one basic model may be one fifth of these values when the cost is spread over several years.
DOE requires that only the highest sales volume split-system combinations be laboratory
tested. 10 CFR 430.24(m). The majority of central air conditioners and heat pumps offered by a
manufacturer are typically split-systems that are not required to be laboratory tested but can be
certified using an alternative rating method that does not require DOE testing of these units.
DOE reviewed the available data for five of the smallest manufacturers to estimate the
incremental testing cost burden for those small firms that might experience the greatest relative
burden from the revised test procedure. These manufacturers had an average of 10 models
over 100 such models. The additional testing cost for final certification for 10 models was
estimated at $4,000 to $100,000. Meanwhile, these certifications would be expected to last the
product life, estimated to be at least 5 years based on the time frame established in EPCA for
DOE review of central air conditioner efficiency standards. This test burden is therefore
estimated to be approximately 1.3 percent of the estimated 5-year value added for the smallest
five manufacturers. DOE believes that these costs are not significant given other, much more
significant costs that the small manufacturers of central air conditioners and heat pumps incur in
the course of doing business. DOE seeks comment on its estimate of the impact of the proposed
test procedure amendments on small entities and its conclusion that this impact is not significant.
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Accordingly, as stated above, DOE tentatively concludes and certifies that this proposed
rule would not have a significant economic impact on a substantial number of small entities.
Accordingly, DOE has not prepared an initial regulatory flexibility analysis (IRFA) for this
rulemaking. DOE will provide its certification and supporting statement of factual basis to the
Chief Counsel for Advocacy of the SBA for review under 5 U.S.C. 605(b).
Manufacturers of central air conditioners and heat pumps must certify to DOE that their
products comply with any applicable energy conservation standards. In certifying compliance,
manufacturers must test their products according to the DOE test procedures for central air
conditioners and heat pumps, including any amendments adopted for those test procedures.
DOE has established regulations for the certification and recordkeeping requirements for all
covered consumer products and commercial equipment, including central air conditioners and
heat pumps. 76 FR 12422 (March 7, 2011); 80 FR 5099 (Jan. 30, 2015). The collection-of-
information requirement for the certification and recordkeeping is subject to review and approval
by OMB under the Paperwork Reduction Act (PRA). This requirement has been approved by
OMB under OMB control number 1910-1400. Public reporting burden for the certification is
estimated to average 20 hours per response, including the time for reviewing instructions,
searching existing data sources, gathering and maintaining the data needed, and completing and
Notwithstanding any other provision of the law, no person is required to respond to, nor
shall any person be subject to a penalty for failure to comply with, a collection of information
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subject to the requirements of the PRA, unless that collection of information displays a currently
In this supplemental proposed rule, DOE proposes test procedure amendments that it
expects will be used to develop and implement future energy conservation standards for central
air conditioners and heat pumps. DOE has determined that this rule falls into a class of actions
that are categorically excluded from review under the National Environmental Policy Act of
1969 (42 U.S.C. 4321 et seq.) and DOE’s implementing regulations at 10 CFR Part 1021.
Specifically, this proposed rule would amend the existing test procedures without affecting the
amount, quality or distribution of energy usage, and, therefore, would not result in any
CFR Part 1021, Subpart D, which applies to any rulemaking that interprets or amends an existing
rule without changing the environmental effect of that rule. Accordingly, neither an
http://energy.gov/nepa/categorical-exclusion-cx-determinations-cx
State law or that have Federalism implications. The Executive Order requires agencies to
examine the constitutional and statutory authority supporting any action that would limit the
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policymaking discretion of the States and to carefully assess the necessity for such actions. The
Executive Order also requires agencies to have an accountable process to ensure meaningful and
timely input by State and local officials in the development of regulatory policies that have
Federalism implications. On March 14, 2000, DOE published a statement of policy describing
the intergovernmental consultation process it will follow in the development of such regulations.
65 FR 13735. DOE has examined this proposed rule and has determined that it would not have a
substantial direct effect on the States, on the relationship between the national government and
the States, or on the distribution of power and responsibilities among the various levels of
government. EPCA governs and prescribes Federal preemption of State regulations as to energy
conservation for the products that are the subject of this proposed rule. States can petition DOE
for exemption from such preemption to the extent, and based on criteria, set forth in EPCA. (42
Regarding the review of existing regulations and the promulgation of new regulations,
section 3(a) of Executive Order 12988, “Civil Justice Reform,” 61 FR 4729 (Feb. 7, 1996),
imposes on Federal agencies the general duty to adhere to the following requirements: (1)
eliminate drafting errors and ambiguity; (2) write regulations to minimize litigation; (3) provide
a clear legal standard for affected conduct rather than a general standard; and (4) promote
simplification and burden reduction. Section 3(b) of Executive Order 12988 specifically requires
that Executive agencies make every reasonable effort to ensure that the regulation: (1) clearly
specifies the preemptive effect, if any; (2) clearly specifies any effect on existing Federal law or
regulation; (3) provides a clear legal standard for affected conduct while promoting
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simplification and burden reduction; (4) specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting clarity and general
draftsmanship under any guidelines issued by the Attorney General. Section 3(c) of Executive
Order 12988 requires Executive agencies to review regulations in light of applicable standards in
sections 3(a) and 3(b) to determine whether they are met or it is unreasonable to meet one or
more of them. DOE has completed the required review and determined that, to the extent
permitted by law, the proposed rule meets the relevant standards of Executive Order 12988.
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) requires each Federal
agency to assess the effects of Federal regulatory actions on State, local, and Tribal governments
and the private sector. Pub. L. No. 104-4, sec. 201 (codified at 2 U.S.C. 1531). For a proposed
regulatory action likely to result in a rule that may cause the expenditure by State, local, and
Tribal governments, in the aggregate, or by the private sector of $100 million or more in any one
year (adjusted annually for inflation), section 202 of UMRA requires a Federal agency to publish
a written statement that estimates the resulting costs, benefits, and other effects on the national
economy. (2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to develop an
effective process to permit timely input by elected officers of State, local, and Tribal
plan for giving notice and opportunity for timely input to potentially affected small governments
before establishing any requirements that might significantly or uniquely affect small
governments. On March 18, 1997, DOE published a statement of policy on its process for
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http://energy.gov/gc/office-general-counsel. DOE examined this proposed rule according to
UMRA and its statement of policy and determined that the rule contains neither an
intergovernmental mandate, nor a mandate that may result in the expenditure of $100 million or
H. Review Under the Treasury and General Government Appropriations Act, 1999
Section 654 of the Treasury and General Government Appropriations Act, 1999 (Pub. L.
105-277) requires Federal agencies to issue a Family Policymaking Assessment for any rule that
may affect family well-being. This rule would not have any impact on the autonomy or integrity
of the family as an institution. Accordingly, DOE has concluded that it is not necessary to
DOE has determined, under Executive Order 12630, “Governmental Actions and
Interference with Constitutionally Protected Property Rights” 53 FR 8859 (March 18, 1988),
that this regulation would not result in any takings that might require compensation under the
J. Review Under the Treasury and General Government Appropriations Act, 2001
Section 515 of the Treasury and General Government Appropriations Act, 2001 (44
U.S.C. 3516 note) provides for agencies to review most disseminations of information to the
public under guidelines established by each agency pursuant to general guidelines issued by
OMB. OMB’s guidelines were published at 67 FR 8452 (Feb. 22, 2002), and DOE’s guidelines
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were published at 67 FR 62446 (Oct. 7, 2002). DOE has reviewed this proposed rule under the
OMB and DOE guidelines and has concluded that it is consistent with applicable policies in
those guidelines.
Energy Supply, Distribution, or Use,” 66 FR 28355 (May 22, 2001), requires Federal agencies to
prepare and submit to OMB, a Statement of Energy Effects for any proposed significant energy
action. A “significant energy action” is defined as any action by an agency that promulgated or
is expected to lead to promulgation of a final rule, and that: (1) is a significant regulatory action
under Executive Order 12866, or any successor order; and (2) is likely to have a significant
adverse effect on the supply, distribution, or use of energy; or (3) is designated by the
Administrator of OIRA as a significant energy action. For any proposed significant energy
action, the agency must give a detailed statement of any adverse effects on energy supply,
distribution, or use should the proposal be implemented, and of reasonable alternatives to the
action and their expected benefits on energy supply, distribution, and use.
The proposed regulatory action to amend the test procedure for measuring the energy
efficiency of central air conditioners and heat pumps is not a significant regulatory action under
Executive Order 12866. Moreover, it would not have a significant adverse effect on the supply,
distribution, or use of energy, nor has it been designated as a significant energy action by the
Administrator of OIRA. Therefore, it is not a significant energy action, and, accordingly, DOE
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L. Review Under Section 32 of the Federal Energy Administration Act of 1974
Under section 301 of the Department of Energy Organization Act (Pub. L. 95–91; 42
U.S.C. 7101), DOE must comply with section 32 of the Federal Energy Administration Act of
1974, as amended by the Federal Energy Administration Authorization Act of 1977. (15 U.S.C.
788; FEAA) Section 32 essentially provides in relevant part that, where a proposed rule
authorizes or requires use of commercial standards, the notice of proposed rulemaking must
inform the public of the use and background of such standards. In addition, section 32(c)
requires DOE to consult with the Attorney General and the Chairman of the Federal Trade
competition.
The proposed rule incorporates testing methods contained in the following commercial
standards: AHRI 210/240-2008 with Addendum 1 and 2, Performance Rating of Unitary Air-
Conditioning & Air-Source Heat Pump Equipment; and ANSI/AHRI 1230-2010 with Addendum
Pump Equipment. While the proposed test procedure is not exclusively based on AHRI
210/240-2008 or ANSI/AHRI 1230-2010, one component of the test procedure, namely test
setup requirements, adopts language from AHRI 210/240-2008 without amendment; and another
component of the test procedure, namely test setup and test performance requirements for multi-
Department has evaluated these standards and is unable to conclude whether they fully comply
with the requirements of section 32(b) of the FEAA, (i.e., that they were developed in a manner
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that fully provides for public participation, comment, and review). DOE will consult with the
Attorney General and the Chairman of the FTC concerning the impact of these test procedures
In this SNOPR, DOE proposes to incorporate by reference (IBR) the following two test
“Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment;” and
Flow (VRF) Multi-Split Air-Conditioning and Heat Pump Equipment.” DOE also proposes to
IBR a draft version of ASHRAE 210/240 which has not yet been published. DOE also proposes
to update its IBR to the most recent version of the following standards published by ASHRAE:
ASHRAE 23.1-2010 titled “Methods of Testing for Rating the Performance of Positive
Temperatures of the Refrigerant”, ASHRAE Standard 37-2009, Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, ASHRAE 41.1-2013
titled “Standard Method for Temperature Measurement”, ASHRAE 41.6-2014 titled “Standard
Method for Humidity Measurement”, and ASHRAE 41.9-2011titled “Standard Methods for
updates its IBR to the most recent version of the following test procedure from ASHRAE and
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ANSI/AHRI 210/240-2008 is an industry accepted test procedure that measures the
cooling and heating performance of central air conditioners and heat pumps and is applicable to
products sold in North America. The test procedure proposed in this SNOPR references various
sections of ANSI/AHRI 210/240-2008 that address test setup, test conditions, and rating
http://www.ahrinet.org/site/686/Standards/HVACR-Industry-Standards/Search-Standards.
AHRI Standard 210/240-Draft is a draft version of AHRI 210/240 that AHRI provided to DOE
in 2015. AHRI Standard 210/240-Draft will supersede the 2008 version once it is published.
0045).
ANSI/AHRI 1230-2010 is an industry accepted test procedure that measures the cooling
and heating performance of variable refrigerant flow (VRF) multi-split air conditioners and heat
pumps and is applicable to products sold in North America. The test procedure proposed in this
SNOPR for VRF multi-split systems references various sections of ANSI/AHRI 1230-2010 that
address test setup, test conditions, and rating requirements. ANSI/AHRI 1230-2010 is readily
Standards/Search-Standards.
ASHRAE 23.1-2010 is an industry accepted test procedure for rating the thermodynamic
performance of positive displacement refrigerant compressors and condensing units that operate
at subcritical temperatures. The test procedure proposed in this SNOPR references sections of
ASHRAE 23.1-2010 that address requirements, instruments, methods of testing, and testing
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procedure specific to compressor calibration. ASHRAE 23.1-2010 can be purchased from
ASHRAE Standard 37-2009 is an industry accepted standard that provides test methods
for determining the cooling capacity of unitary air-conditioning equipment and the cooling or
heating capacities, or both, of unitary heat pump equipment. The test procedure proposed in this
SNOPR references various sections of ASHRAE Standard 37-2009 that address test conditions
and test procedures. The current DOE test procedure references a previous version of this
standard, ASHRAE 37-2005. ASHRAE Standard 37-2009 can be purchased from ASHRAE’s
website at https://www.ashrae.org/resources--publications.
heating, refrigerating, and air-conditioning equipment. The test procedure proposed in this
SNOPR references sections of ASHRAE 41.1-2013 that address requirements, instruments, and
methods for measuring temperature. ASHRAE 41.1-2013 can be purchased from ASHRAE’s
website at https://www.ashrae.org/resources--publications.
ASHRAE 41.6-2014 is an industry accepted test method for measuring humidity of moist
air. The test procedure proposed in this SNOPR references sections of ASHRAE 41.6-2014 that
address requirements, instruments, and methods for measuring humidity. ASHRAE 41.6-2014
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ASHRAE 41.9-2011 is an industry accepted standard that provides recommended
practices for measuring the mass flow rate of volatile refrigerants using calorimeters. The test
procedure proposed in this SNOPR references sections of ASHRAE 41.9-2011 that address
requirements, instruments, and methods for measuring refrigerant flow during compressor
https://www.ashrae.org/resources--publications.
test methods for a laboratory test of a fan or other air moving device to determine its
aerodynamic performance in terms of air flow rate, pressure developed, power consumption, air
density, speed of rotation, and efficiency for rating or guarantee purposes. The test procedure in
this SNOPR references various sections of ASHRAE/AMCA 51-07/210-07 that address test
conditions. The current DOE test procedure references a previous version of this standard,
V. Public Participation
The time, date and location of the public meeting are listed in the DATES and
ADDRESSES sections at the beginning of this document. If you plan to attend the public
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Please note that foreign nationals visiting DOE Headquarters are subject to advance
security screening procedures which require advance notice prior to attendance at the public
meeting. If a foreign national wishes to participate in the public meeting, please inform DOE of
this fact as soon as possible by contacting Ms. Regina Washington at (202) 586-1214 or by e-
DOE requires visitors to have laptops and other devices, such as tablets, checked upon
entry into the building. Any person wishing to bring these devices into the Forrestal Building
will be required to obtain a property pass. Visitors should avoid bringing these devices, or allow
an extra 45 minutes to check in. Please report to the visitor's desk to have devices checked
Due to the REAL ID Act implemented by the Department of Homeland Security (DHS),
there have been recent changes regarding ID requirements for individuals wishing to enter
Federal buildings from specific states and U.S. territories. Driver's licenses from the following
states or territory will not be accepted for building entry and one of the alternate forms of ID
listed below will be required. DHS has determined that regular driver's licenses (and ID cards)
from the following jurisdictions are not acceptable for entry into DOE facilities: Alaska,
American Samoa, Arizona, Louisiana, Maine, Massachusetts, Minnesota, New York, Oklahoma,
and Washington. Acceptable alternate forms of Photo-ID include: U.S. Passport or Passport
Card; an Enhanced Driver's License or Enhanced ID-Card issued by the states of Minnesota,
New York or Washington (Enhanced licenses issued by these states are clearly marked Enhanced
or Enhanced Driver's License); a military ID or other Federal government issued Photo-ID card.
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In addition, you can attend the public meeting via webinar. Webinar registration
information, participant instructions, and information about the capabilities available to webinar
participants will be published on DOE’s website: [INSERT LINK]. Participants are responsible
for ensuring their systems are compatible with the webinar software.
Any person who has plans to present a prepared general statement may request that
copies of his or her statement be made available at the public meeting. Such persons may submit
requests, along with an advance electronic copy of their statement in PDF (preferred), Microsoft
Word or Excel, WordPerfect, or text (ASCII) file format, to the appropriate address shown in the
ADDRESSES section at the beginning of this notice. The request and advance copy of
statements must be received at least one week before the public meeting and may be emailed,
hand-delivered, or sent by mail. DOE prefers to receive requests and advance copies via email.
Please include a telephone number to enable DOE staff to make a follow-up contact, if needed.
DOE will designate a DOE official to preside at the public meeting and may also use a
professional facilitator to aid discussion. The meeting will not be a judicial or evidentiary-type
public hearing, but DOE will conduct it in accordance with section 336 of EPCA (42 U.S.C.
6306). A court reporter will be present to record the proceedings and prepare a transcript. DOE
reserves the right to schedule the order of presentations and to establish the procedures governing
the conduct of the public meeting. After the public meeting and until the end of the comment
220
period, interested parties may submit further comments on the proceedings and any aspect of the
rulemaking.
The public meeting will be conducted in an informal, conference style. DOE will present
summaries of comments received before the public meeting, allow time for prepared general
statements by participants, and encourage all interested parties to share their views on issues
affecting this rulemaking. Each participant will be allowed to make a general statement (within
time limits determined by DOE), before the discussion of specific topics. DOE will permit, as
At the end of all prepared statements on a topic, DOE will permit participants to clarify
their statements briefly and comment on statements made by others. Participants should be
prepared to answer questions by DOE and by other participants concerning these issues. DOE
representatives may also ask questions of participants concerning other matters relevant to this
rulemaking. The official conducting the public meeting will accept additional comments or
questions from those attending, as time permits. The presiding official will announce any further
procedural rules or modification of the above procedures that may be needed for the proper
A transcript of the public meeting will be included in the docket, which can be viewed as
described in the Docket section at the beginning of this notice. In addition, any person may buy
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D. Submission of Comments
DOE will accept comments, data, and information regarding this proposed rule before or
after the public meeting, but no later than the date provided in the DATES section at the
beginning of this proposed rule. Interested parties may submit comments using any of the
Submitting comments via regulations.gov. The regulations.gov web page will require
you to provide your name and contact information. Your contact information will be viewable to
DOE Building Technologies staff only. Your contact information will not be publicly viewable
except for your first and last names, organization name (if any), and submitter representative
name (if any). If your comment is not processed properly because of technical difficulties, DOE
will use this information to contact you. If DOE cannot read your comment due to technical
difficulties and cannot contact you for clarification, DOE may not be able to consider your
comment.
However, your contact information will be publicly viewable if you include it in the
comment or in any documents attached to your comment. Any information that you do not want
to be publicly viewable should not be included in your comment, nor in any document attached
to your comment. Persons viewing comments will see only first and last names, organization
names, correspondence containing comments, and any documents submitted with the comments.
222
Confidential Business Information (CBI)). Comments submitted through regulations.gov cannot
be claimed as CBI. Comments received through the website will waive any CBI claims for the
information submitted. For information on submitting CBI, see the Confidential Business
Information section.
comments will be posted within a few days of being submitted. However, if large volumes of
comments are being processed simultaneously, your comment may not be viewable for up to
several weeks. Please keep the comment tracking number that regulations.gov provides after
Submitting comments via email, hand delivery, or mail. Comments and documents
submitted via email, hand delivery, or mail also will be posted to regulations.gov. If you do not
want your personal contact information to be publicly viewable, do not include it in your
comment or any accompanying documents. Instead, provide your contact information on a cover
letter. Include your first and last names, email address, telephone number, and optional mailing
address. The cover letter will not be publicly viewable as long as it does not include any
comments
Include contact information each time you submit comments, data, documents, and other
information to DOE. If you submit via mail or hand delivery, please provide all items on a CD,
if feasible. It is not necessary to submit printed copies. No facsimiles (faxes) will be accepted.
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Comments, data, and other information submitted to DOE electronically should be
provided in PDF (preferred), Microsoft Word or Excel, WordPerfect, or text (ASCII) file format.
Provide documents that are not secured, written in English and free of any defects or viruses.
Documents should not contain special characters or any form of encryption and, if possible, they
Campaign form letters. Please submit campaign form letters by the originating
organization in batches of between 50 to 500 form letters per PDF or as one form letter with a
list of supporters’ names compiled into one or more PDFs. This reduces comment processing
submitting information that he or she believes to be confidential and exempt by law from public
disclosure should submit via email, postal mail, or hand delivery two well-marked copies: one
copy of the document marked confidential including all the information believed to be
confidential, and one copy of the document marked non-confidential with the information
believed to be confidential deleted. Submit these documents via email or on a CD, if feasible.
DOE will make its own determination about the confidential status of the information and treat it
confidential include: (1) A description of the items; (2) whether and why such items are
customarily treated as confidential within the industry; (3) whether the information is generally
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known by or available from other sources; (4) whether the information has previously been made
available to others without obligation concerning its confidentiality; (5) an explanation of the
competitive injury to the submitting person which would result from public disclosure; (6) when
such information might lose its confidential character due to the passage of time; and (7) why
It is DOE’s policy that all comments may be included in the public docket, without
change and as received, including any personal information provided in the comments (except
Although DOE welcomes comments on any aspect of this proposal, DOE is particularly
interested in receiving comments and views of interested parties concerning the following issues:
1. The details characterizing the same model of indoor unit, same model of outdoor unit, and
2. Its proposed changes to the determination of certified ratings for single-split-system air
conditioners, specifically in its proposed phased approach where in the first phase
manufacturers must certify all models of outdoor units with the model of coil-only indoor
unit that is likely to have the largest volume of retail sales with the particular model of
outdoor unit but may use the model of blower coil indoor unit likely to have the highest sales
if the model of outdoor unit is sold only with models of blower coil indoor units, and may
use testing or AEDMs to rate other combinations; and in the second phase manufacturers
must certify all models of outdoor units with the model of blower coil indoor unit that is
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likely to have the largest volume of retail sales with that model of outdoor unit but must rate
3. Its proposed definitions for blower coil and coil-only indoor units;
4. Whether additional testing and rating requirements are necessary for multi-split systems
paired with models of conventional ducted indoor units rather than short-duct units;
systems including models of both SDHV and non-ducted or short-ducted indoor units, and if
so, how they should be rated (i.e., by by taking the mean of a sample of tested non-ducted
units and a sample of tested SDHV units or by testing a combination on non-ducted and
SDHV units), and whether the SDHV or split-system standard would be most appropriate;
6. Whether manufacturers support having the ability to test mix-match systems using the test
procedure rather than rating them using an average of the other tested systems;
7. Whether manufacturers support the rating of mix-match systems using other than a straight
8. Whether the definition of “tested combination” is appropriate for rating specific individual
combinations, or whether manufacturers want more flexibility such as testing with more than
5 indoor units;
9. Information and data on manufacturing and testing variability associated with multi-split
systems that would allow it to understand how a single unit may be representative of the
population and what tolerances would need to be applied to ratings based on a single unit
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11. Its proposal for ICMs to test each model of indoor unit with the lowest-SEER model of
outdoor unit that is certified as a part of a basic model by an OUM as well as any test burden
12. The likelihood of multiple individual models of single-package units meeting the
requirements proposed in the basic model definition to be assigned to the same basic model;
13. Whether, if manufacturers are able to assign multiple individual single-package models to a
single basic model, whether manufacturers would want to use an AEDM to rate other
individual models within the same basic model other than the lowest SEER individual model;
14. Whether manufacturers would want to employ an AEDM to rate the off-mode power
consumption for other variations of off-mode associated with the single-package basic model
15. The reporting burden associated with the proposed certification reporting requirements
16. The additions to the represented value requirements for cooling capacity, heating capacity,
17. The proposal to not require additional testing to validate an AEDM beyond the testing
required under 429.16(a)(2)(ii) for split-system air conditioners and heat pumps where
manufacturers must test each basic model, being each model of outdoor unit, with at least
18. The proposal that ICMs must use the combinations they would be required to test, under
429.16, to validate an AEDM that is intended to be used for other individual combinations
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19. Whether the approach to not penalize manufacturers for applying conservative ratings to their
rating;
20. Whether manufacturers would typically apply more than one AEDM, and if they would, the
21. Its proposal for multi-circuit products to adopt the same common duct testing approach used
for testing multi-split products; and whether this method will yield accurate results that are
22. Its proposals for multi-blower products, including whether individual adjustments of each
blower are appropriate and whether external static pressures measured for individual tests
may be different;
23. Its proposal to require a test for off mode power consumption at 72±2 °F, a second test at the
temperature, and the proposal that manufacturers include in certification reports the
temperatures at which the crankcase heater is designed to turn on and turn off for the heating
season, if applicable;
24. The proposal to replace the off mode test at 57 °F with a test at a temperature which is 5±2
°F below a manufacturer-specified turn-on temperature to maintain the intent of the off mode
power consumption rating as a rating that measures the off mode power consumption for the
heating season, and allay the stakeholders’ concerns of a loophole at the 57 °F test point;
25. The proposal to use a per-compressor off mode power consumption metric so as to not
penalize manufacturers of products with multiple compressor systems, which are highly
efficient and require larger crankcase heaters for safe and reliable operation;
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26. The proposal on the multiplier of 1.5 for determining the shoulder season and heating season
modulated compressors, which require a larger crankcase heater to ensure safe and reliable
operation;
27. The proposal to more accurately reflect the off mode power consumption for coil-only and
blower coil split-system units by excluding the low-voltage power from the indoor unit when
measuring off mode power consumption for coil-only split-system air conditioners and
including the low-voltage power from the indoor unit when measuring off mode power
consumption for blower coil split-system air conditioning and heat pumps;
28. The proposal to incent manufacturers of products with time delays by adopting a credit to
shoulder season energy consumption that is proportional to the duration of the delay or a
default of 25% savings in shoulder season off mode energy consumption and the possibility
29. The proposal to add optional informational equations to determine the actual off mode
energy consumption, based on the hours of off mode operation and off mode power for the
30. Whether regulating crankcase heater energy consumption has a negative impact on product
31. The proposal to improve repeatability of testing central air conditioner and heat pump
products by requiring the lowest fan speed setting that meets minimum static pressure and
maximum air volume rate requirements for blower coil systems and requiring the lowest fan
speed settings that meets the maximum static pressure and maximum air volume rate
229
32. The proposal to mirror how insulation is installed in the field by requiring test laboratories
either install the insulation shipped with the unit or use insulation as specified in the
33. The proposal to clarify liquid refrigerant line insulation requirements by requiring such
34. The proposal to prevent thermal losses from the refrigerant mass flow meter to the floor by
requiring a thermal barrier if the meter is not mounted on a pedestal or is not elevated;
35. The proposal to require either an air sampling device used on all outdoor unit air-inlet
surfaces or demonstration of air temperature uniformity for the outdoor unit vis-a-vis 1.5 °F
36. The proposal to require that the dry bulb temperature and humidity measurements used to
verify that the required outdoor air conditions have been maintained be measured for the air
collected by the air sampling device (e.g., rather than being measured by temperature sensors
37. The proposal to limit thermal losses by preventing the air sampling device from nearing the
test chamber floor, insulating air sampling device surfaces, and requiring dry bulb and
humidity measurements be made at the same location in the air sampling device;
38. The proposal to fix maximum compressor speed when testing at each of the outdoor
temperature for those control systems that vary maximum compressor speed with outdoor
temperature;
39. The proposal to prevent improper refrigerant charging techniques by requiring charging of
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40. The proposal to require, for air conditioners and cooling-and-heating heat pumps refrigerant
charging at the A or A2 test condition, and for heating-only heat pumps refrigerant charging
units equipped with fixed orifice type metering devices and a 10 ± 2 oF subcooling
temperature requirement for units equipped with thermostatic expansion valve or electronic
41. The proposal to verify functionality of heat pumps at the H1 or H12 test condition after
charging at the A or A2 test condition, and if non-functional, the proposal to adjust refrigerant
charge to the requirements of the proposed standardized charging procedure at the H1 or H12
test condition;
42. The proposal to require refrigerant charging based on the outdoor installation instructions for
outdoor unit manufacturer products and refrigerant charging based on the indoor installation
instructions for independent coil manufacturer products, where both the indoor and outdoor
installation instructions are provided and advise differently, unless otherwise specified by
43. The proposal to require installation of pressure gauges and verification of refrigerant charge
amount and, if charging instructions are not available adjust charge based on the proposed
44. All aspects of its proposals to amend the refrigerant charging procedures;
45. The proposal to allow for cyclic tests of single-package ducted units an upturned duct as an
alternative arrangement to replace the currently-required damper in the inlet portion of the
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46. The proposal to further justify adequacy of the alternative arrangement in preventing thermal
losses during the OFF portion of the cyclic test by proposing installing a dry bulb
temperature sensor near the indoor inlet and requiring the maximum permissible range of the
recorded temperatures during the OFF period be no greater than 1.0 °F;
47. The proposed revisions to the cyclic test procedure for the determination of both the cooling
and heating coefficient of degradation, including additional test data that would support the
proposed specifications, or changes to, the number of warm-up cycles, the cycle time for
variable speed units, the number of cycles averaged to obtain the value, and the stability
criteria;
48. The proposal to allay stakeholder concerns regarding compressor break-in period by allowing
49. Its proposed limitation of incorporation by reference to industry standards to specific sections
necessary for the test procedure, including any specific sections stakeholders feel should be
50. The proposed sampling interval for dry-bulb temperatures, wet bulb temperature, dew point
51. The appropriate use of the target value and maximum tolerances for refrigerant charging, as
52. The proposal for damping pressure transducer signals including whether the proposed
53. Setting a definition for short duct systems to mean ducted systems whose indoor units can
deliver no more than 0.07 in. wc. ESP when delivering the full load air volume rate for
cooling operation, and requiring such systems meet the minimum ESP levels as proposed in
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the NOPR: 0.03 in. wc. for units less than 28,800 Btu/h; 0.05 in. wc. for units between
29,000 Btu/h and 42,500 Btu/h; and 0.07 in. wc. for units greater than 43,000 Btu/h;
54. The incorporation by reference of AHRI 1230-2010, and in particular the specific sections of
Appendix M and AHRI 1230-2010 that DOE proposes to apply to testing VRF systems;
55. The proposed change to the informative tables at the beginning of Section 2. Testing
Conditions and/or whether additional modifications to the new table could be implemented to
56. Its proposal to delete the definition of mini-split air conditioners and heat pumps, and define
unit and that has two or more coil-only or blower coil indoor units connected with a single
refrigeration circuit, where the indoor units operate in unison in response to a single indoor
thermostat; and (2) single-split-system to represent a split-system that has one outdoor unit
and that has one coil-only or blower coil indoor unit connected to its other component(s) with
57. Its proposal to include in the ESP requirement a pressure drop contribution associated with
average typical filter and indoor coil fouling levels and its use of residential-based indoor coil
and filter fouling pressure drop data to estimate the appropriate ESP contribution; DOE also
requests data that would validate the proposed ESP contributions or suggest adjustments that
58. Its proposals to set higher minimum ESP requirements for systems other than multi-split
systems and small-duct, high-velocity systems and report the external static pressure used
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59. Its proposal to implement an allowance in ESP for air-conditioning units tested in blower-
coil (or single-package) configuration in which a condensing furnace is in the air flow path
during the test. DOE seeks comment regarding the proposed 0.1 in. wc. ESP reduction for
such tests, including test data to support suggestions regarding different reductions.
60. Its proposal to revise the heating load line that shifts the heating balance point and zero load
point to lower ambient temperatures that better reflect field operations and energy use
characteristics, as well as its proposal to perform cyclic testing for variable speed heat pumps
at 47 °F instead of at 62 °F;
61. Whether, in the case that the proposed heating load line is not adopted, DOE should modify
the HSPF rating procedure for variable speed heat pumps at mid-range outdoor temperatures
using option 1: which entails basing performance on minimum speed tests at 47 °F and
intermediate speed test at 35 °F and is the less accurate option but has no additional test
burden; or option 2: which entails basing performance on minimum speed tests at 47 °F and
62. Test results and other data regarding whether HSPF results for other variable speed heat
pumps would be more significantly impacted by this change to the test procedure to test at
higher (in conjunction with the test at maximum speed at 17 °F outdoor temperature) as well
as whether the additional test burden would offset the advantages of the proposed
modification;
63. The estimate of the number of small entities that may be impacted by the proposed test
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For the reasons set forth in the preamble, DOE proposes to amend Part 429 of chapter II of Title
* * * * *
(8) The test sample size (i.e., number of units tested for the basic model, or in the case of single-
split-system central air conditioners and central air conditioning heat pumps, for each individual
* * * * *
(12) If the test sample size is listed as “0” to indicate the certification is based upon the use of an
alternate way of determining measures of energy conservation, identify the method used for
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commercial refrigeration equipment, and commercial HVAC equipment must provide the
* * * * *
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3. Amend section 429.16 to read as follows:
§ 429.16 Central Air Conditioners and Central Air Conditioning Heat Pumps
(a) Determination of Certified Rating. Determine the certified rating for each basic model
manufacturers must certify additional ratings for each individual combination within the same
basic model either based on testing or by using an AEDM subject to the limitations of paragraph
(a)(2) of this section. This includes blower coil and coil-only systems both before and after the
compliance date of any amended energy conservation standards. For multi-split, multi-circuit,
and single-zone-multiple-coil systems, each basic model must include a rating for a non-ducted
combination and may also include ratings for a ducted combination and a mixed non-
identical are offered with multiple options for off mode-related components, rate the individual
model/combination with the crankcase heater and controls that are the most consumptive. A
manufacturer may also certify less consumptive off mode options; however, the manufacturer
(i) The general requirements of §429.11 apply to central air conditioners and heat pumps; and
represented values for each basic model through testing of the following, specific, individual
model or combination:
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Category Equipment Type Must test each: With:
Single-Package AC
Single-Package HP
Space-Constrained Single-
Single-
Package Package AC Basic Model Lowest SEER individual model
Unit
Space-Constrained Single-
Package HP
Single-Split-System HP
The model of indoor unit that is
Space-Constrained Split-
likely to have the largest volume
System AC
Model of Outdoor
Unit of retail sales with the particular
Space-Constrained Split-
model of outdoor unit.
System HP
At a minimum, a “tested
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of SDHV units must be tested (in
short-ducted combination).
purposes.
represented values for each basic model through testing of the following, specific, individual
240
241
Date Equipment Type Must test each: With:
The model of coil-only indoor
outdoor unit
outdoor unit
On or after the
The model of blower coil indoor
compliance date
of any amended
unit that is likely to have the
energy
conservation
Model of Outdoor largest volume of retail sales
standards with Split-system AC
Unit
which
with the particular model of
compliance is
required on or
outdoor unit
after January 1,
2017
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(iii)(A) Each basic model (for single-package systems) or individual combination (for split–
systems) tested must have a sample of sufficient size tested in accordance with the applicable
provisions of this subpart. The represented values for any basic model or individual combination
(1) Any represented value of power consumption or other measure of energy consumption
for which consumers would favor lower values must be greater than or equal to the higher of:
𝑛𝑛
1
𝑥𝑥̅ = � 𝑥𝑥𝑖𝑖
𝑛𝑛
𝑖𝑖=1
and, 𝑥𝑥̅ is the sample mean; n is the number of samples; and xi is the ith sample;
Or,
(ii) The upper 90 percent confidence limit (UCL) of the true mean divided by 1.05,
where:
𝑠𝑠
𝑈𝑈𝑈𝑈𝑈𝑈 = 𝑥𝑥̅ + 𝑡𝑡.90 ( )
√𝑛𝑛
And 𝑥𝑥̅ is the sample mean; s is the sample standard deviation; n is the number of
samples; and t0.90 is the t statistic for a 90% one-tailed confidence interval with n-1
and
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(2) Any represented value of the energy efficiency or other measure of energy
consumption for which consumers would favor higher values shall be less than or equal
𝑛𝑛
1
𝑥𝑥̅ = � 𝑥𝑥𝑖𝑖
𝑛𝑛
𝑖𝑖=1
and, 𝑥𝑥̅ is the sample mean; n is the number of samples; and xi is the ith sample;
Or,
(ii) The lower 90 percent confidence limit (LCL) of the true mean divided by
0.95, where:
𝑠𝑠
𝐿𝐿𝐿𝐿𝐿𝐿 = 𝑥𝑥̅ − 𝑡𝑡.90 ( )
√𝑛𝑛
And 𝑥𝑥̅ is the sample mean; s is the sample standard deviation; n is the number of
samples; and t0.90 is the t statistic for a 90% one-tailed confidence interval with n-
(3) The represented value of cooling capacity is the mean of the capacities measured for
the sample, rounded: (i) to the nearest 100 Btu/h if cooling capacity is less than 20,000
Btu/h, (ii) to the nearest 200 Btu/h if cooling capacity is greater than or equal to 20,000
Btu/h but less than 38,000 Btu/h, and (iii) to the nearest 500 Btu/h if cooling capacity is
greater than or equal to 38,000 Btu/h and less than 65,000 Btu/h.
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(4) The represented value of heating capacity is the mean of the capacities measured for
the sample, rounded: (i) to the nearest 100 Btu/h if heating capacity is less than 20,000
Btu/h, (ii) to the nearest 200 Btu/h if heating capacity is greater than or equal to 20,000
Btu/h but less than 38,000 Btu/h, and (iii) to the nearest 500 Btu/h if heating capacity is
greater than or equal to 38,000 Btu/h and less than 65,000 Btu/h.
(5) The represented value of sensible heat ratio (SHR) is the mean of the SHR measured
(iii)(B) For heat pumps, all units of the sample population must be tested in both the cooling and
heating modes and the results used for determining all representations.
(iii)(C)(1) Determine the represented value of estimated annual operating cost for cooling-only
(i) For cooling-only units or the cooling portion of the estimated annual operating cost for
air-source heat pumps that provide both heating and cooling, the product of:
The quotient of the represented value of cooling capacity, in Btu's per hour as determined in
section (a)(1)(iii)(A)(3), divided by the represented value of SEER, in Btu's per watt-hour, as
determined in (a)(1)(iii)(A)(2);
The representative average use cycle for cooling of 1,000 hours per year;
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
estimated annual operating cost for air-source heat pumps that provide both heating and cooling:
(A) When using Appendix M to subpart B of Part 430, the product of:
The quotient of the mean of the standardized design heating requirement for the sample, in
Btu's per hour, nearest to the Region IV minimum design heating requirement, determined for
each unit in the sample in section 4.2 of appendix M to subpart B of Part 430, divided by the
represented value of heating seasonal performance factor (HSPF), in Btu's per watt-hour,
The representative average use cycle for heating of 2,080 hours per year;
The adjustment factor of 0.77, which serves to adjust the calculated design heating
requirement and heating load hours to the actual load experienced by a heating system;
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
(B) When using Appendix M1 to subpart B of Part 430, the product of:
The quotient of the represented value of cooling capacity (for air-source heat pumps that
provide both cooling and heating) in Btu's per hour, as determined in section (a)(1)(iii)(A)(3), or
the represented value of heating capacity (for air-source heat pumps that provide only heating),
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as determined in section (a)(1)(iii)(A)(4), divided by the represented value of heating seasonal
performance factor (HSPF), in Btu's per watt-hour, calculated for Region IV, as determined in
(a)(1)(iii)(A)(2);
The representative average use cycle for heating of 1,572 hours per year;
The adjustment factor of 1.30, which serves to adjust the calculated design heating
requirement and heating load hours to the actual load experienced by a heating system;
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
(iii) For air-source heat pumps that provide both heating and cooling, the estimated annual
operating cost is the sum of the quantity determined in paragraph (a)(1)(iii)(C)(1)(i) of this
(2) Determine the represented value of estimated regional annual operating cost for cooling-
(i) For cooling-only units or the cooling portion of the estimated regional annual operating
cost for air-source heat pumps that provide both heating and cooling, the product of:
The quotient of the represented value of cooling capacity, in Btu's per hour, determined in
(a)(1)(iii)(A)(3) divided by the represented value of SEER, in Btu's per watt-hour, determined in
(a)(1)(iii)(A)(2);
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The estimated number of regional cooling load hours per year determined from Figure 3 in
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
(ii) For air-source heat pumps that provide only heating or for the heating portion of the
estimated regional annual operating cost for air-source heat pumps that provide both heating and
cooling:
(A) When using Appendix M to subpart B of Part 430, the product of:
The estimated number of regional heating load hours per year determined from Figure 2 in
The quotient of the mean of the standardized design heating requirement for the sample, in
Btu's per hour, for the appropriate generalized climatic region of interest (i.e., corresponding to
the regional heating load hours from “A”) and determined for each unit in the sample in section
4.2 of appendix M to subpart B of Part 430, divided by the represented value of HSPF, in Btu's
per watt-hour, calculated for the appropriate generalized climatic region of interest and
in (a)(1)(iii)(A)(2);
The adjustment factor of 0.77; which serves to adjust the calculated design heating
requirement and heating load hours to the actual load experienced by a heating system;
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A conversion factor of 0.001 kilowatts per watt; and
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
(B) When using Appendix M1 to subpart B of Part 430, the product of:
The estimated number of regional heating load hours per year determined from Table 19 in
The quotient of the represented value of cooling capacity (for air-source heat pumps that
provide both cooling and heating) in Btu's per hour, as determined in section (a)(1)(iii)(A)(3), or
the represented value of heating capacity (for air-source heat pumps that provide only heating),
as determined in section (a)(1)(iii)(A)(4), divided by the represented value of HSPF, in Btu's per
watt-hour, calculated for the appropriate generalized climatic region of interest, and determined
in (a)(1)(iii)(A)(2);
The adjustment factor of 1.30, which serves to adjust the calculated design heating
requirement and heating load hours to the actual load experienced by a heating system;
The representative average unit cost of electricity in dollars per kilowatt-hour as provided
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(iii) For air-source heat pumps that provide both heating and cooling, the estimated regional
annual operating cost is the sum of the quantity determined in paragraph (a)(1)(iii)(C)(2)(i) of
this section added to the quantity determined in paragraph (a)(1)(iii)(C)(2)(ii) of this section.
(3)(i) The cooling mode efficiency measure for cooling-only units and for air-source heat
pumps that provide cooling is the represented value of the SEER, in Btu's per watt-hour,
(ii) The heating mode efficiency measure for air-source heat pumps is the represented value
of the HSPF, in Btu's per watt-hour for each applicable standardized design heating requirement
(iii)(D) Rounding requirements. Round represented values of estimated annual operating cost
to the nearest dollar per year. Round represented values of EER, SEER, HSPF, and APF to the
(i) For basic models rated by ICMs and for single-split-system air conditioners, split-system heat
conditioners, for every individual combination within a basic model other than the individual
production units, must be tested as complete systems with the resulting ratings for the
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combination obtained in accordance with paragraphs (a)(1)(i) and (a)(1)(iii) of this
section; or
(B) The representative values of the measures of energy efficiency must be assigned
through the application of an AEDM in accordance with paragraph (3) of this section
and §429.70. An AEDM may only be used to rate individual combinations in a basic
model other than the combination required for mandatory testing under
(A) For basic models composed of both non-ducted and short-ducted units, the
(B) All other individual combinations of models of indoor units for the same model of
outdoor unit for which the manufacturer chooses to make representations must be
the application of an AEDM pursuant to the requirements of §429.70 and the provisions of this
section, where:
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(i) Any represented value of the average off mode power consumption or other measure
lower values must be greater than or equal to the output of the AEDM; and
(ii) Any represented value of the SEER, EER, HSPF or other measure of energy
efficiency of an individual combination for which consumers would favor higher values
(b) Limitations. (1) Any model of outdoor unit that is certified in a combination that does not
meet all regional standards cannot also be certified in a combination that meets the regional
standard(s). Outdoor unit model numbers cannot span regions unless the model of outdoor unit
is compliant with all standards in all possible combinations. If a model of outdoor unit is
certified below a regional standard, then it must have a unique individual model number for
distribution in each region. (2) Models of outdoor units that are rated and distributed in
combinations that span multiple product classes must be tested and certified pursuant to
paragraph (a) as compliant with the applicable standard for each product class.
(1) The requirements of §429.12 apply to central air conditioners and heat pumps; and
(2) Pursuant to §429.12(b)(13), for each basic model (for single-package systems) or individual
combination (for split–systems), a certification report must include the following public product-
specific information: The seasonal energy efficiency ratio (SEER in British thermal units per
Watt-hour (Btu/W-h)); the average off mode power consumption (PW,OFF in Watts); the cooling
capacity in British thermal units per hour (Btu/h); the sensible heat ratio calculated based on full-
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load cooling conditions at the outdoor ambient conditions of 82 °F dry bulb and 65 °F wet bulb;
and
(i) for heat pumps, the heating seasonal performance factor (HSPF in British thermal
(ii) for air conditioners (excluding space constrained), the energy efficiency ratio (EER in
(iii) for single-split-system equipment, whether the rating is for a coil-only or blower coil
system; and
VRF), whether the rating is for a non-ducted, short-ducted, SDHV, or mixed non-ducted
(3) The basic model number and individual model number(s) required to be reported under
Type Number 1 2 3
Number unique
Single Package Package N/A N/A
to the basic
model
Air Mover (or
N/A if rating
Number unique
Split System coil-only system
to the basic Outdoor Unit Indoor Unit(s)
(rated by OUM) or fan is part of
model
indoor unit
model number)
Number unique
Outdoor Unit
to the basic Outdoor Unit N/A N/A
Only
model
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Split-System or Number unique
SDHV (rated by to the basic Outdoor Unit Indoor Unit(s) N/A
ICM) model
must include the following additional product-specific information: the cooling full load air
volume rate for the system or for each indoor unit as applicable (in cubic feet per minute (cfm));
the air volume rates for other test conditions including minimum cooling air volume rate,
intermediate cooling air volume rate, full load heating air volume rate, minimum heating air
volume rate, intermediate heating air volume rate, and nominal heating air volume rate (cfm) for
the system or for each indoor unit as applicable, if different from the cooling full load air volume
rate; whether the individual model uses a fixed orifice, thermostatic expansion valve, electronic
expansion valve, or other type of metering device; the duration of the compressor break-in
period, if used; the 𝐶𝐶𝐷𝐷𝑐𝑐 value used to represent cooling mode cycling losses; the temperatures at
which the crankcase heater with controls is designed to turn on and designed to turn off for the
heating season, if applicable; the duration of the crankcase heater time delay for the shoulder
season and heating season, if such time delay is employed; the maximum time between defrosts
as allowed by the controls (in hours); whether an inlet plenum was installed during testing; and
indoor units tested with the outdoor unit; the nominal cooling capacity of each indoor unit
and outdoor unit in the combination; and the indoor units that are not providing heating
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(iii) for ducted systems having multiple indoor fans within a single indoor unit, the
number of indoor fans; the nominal cooling capacity of the indoor unit and outdoor unit;
which fan(s) are operating to attain the full-load air volume rate when controls limit the
simultaneous operation of all fans within the single indoor unit; and the allocation of the
full-load air volume rate to each operational fan when different capacity blowers are
(iv) for models tested with an indoor blower installed, the airflow-control settings
associated with full load cooling operation; and the airflow-control settings or alternative
instructions for setting fan speed to the speed upon which the rating is based;
(v) for models with time-adaptive defrost control, the frosting interval to be used during
Frost Accumulation tests and the procedure for manually initiating the defrost at the
specified time;
(vi) for models of indoor units designed for both horizontal and vertical installation or for
both up-flow and down-flow vertical installations, the orientation used for testing;
(vii) for variable speed units, the compressor frequency set points, and the required dip
(viii) for variable speed heat pumps, whether the unit controls restrict use of minimum
compressor speed operation for some range of operating ambient conditions, whether the
unit controls restrict use of maximum compressor speed operation for any ambient
temperatures below 17°F, and whether the optional H42 low temperature test was used to
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(d) Alternative methods for determining efficiency or energy use for central air conditioners and
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4. Amend section 429.70 by revising paragraph (e) to read as follows:
* * * * *
(e) Alternate Efficiency Determination Method (AEDM) for central air conditioners and heat
pumps —
(1) Criteria an AEDM must satisfy. A manufacturer may not apply an AEDM to an individual
combination to determine its certified ratings (SEER, EER, HSPF, and/or PW,OFF) pursuant to this
(i) The AEDM is derived from a mathematical model that estimates the energy efficiency or
(ii) The manufacturer has validated the AEDM, in accordance with paragraph (e)(2) of this
section with individual combinations that meet the current Federal energy conservation
standards.
(2) Validation of an AEDM. Before using an AEDM, the manufacturer must validate the
(i) The manufacturer must complete testing of each basic model as required under
429.16(a)(1)(ii). Using the AEDM, calculate the energy use or efficiency for each of the
tested individual combinations within each basic model. Compare the rating based on testing
and the AEDM energy use or efficiency output according to paragraph (e)(2)(ii) of this
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section. The manufacturer is responsible for ensuring the accuracy and reliability of the
AEDM.
(A) For an energy-efficiency metric, the predicted efficiency for each individual
combination calculated by applying the AEDM may not be more than three percent
greater than the efficiency determined from the corresponding test of the combination.
(B) For an energy-consumption metric, the predicted energy consumption for each
individual combination, calculated by applying the AEDM, may not be more than three
percent less than the energy consumption determined from the corresponding test of the
combination.
(C) The predicted energy efficiency or consumption for each individual combination
calculated by applying the AEDM must meet or exceed the applicable federal energy
conservation standard.
Each test must have been performed in accordance with the DOE test procedure
applicable at the time the individual combination being rated with the AEDM is
distributed in commerce.
(3) AEDM records retention requirements. If a manufacturer has used an AEDM to determine
representative values pursuant to this section, the manufacturer must have available upon request
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(i) The AEDM, including the mathematical model, the engineering or statistical analysis,
(ii) Product information, complete test data, AEDM calculations, and the statistical
comparisons from the units tested that were used to validate the AEDM pursuant to
(iii) Product information and AEDM calculations for each individual combination certified
(4) Additional AEDM requirements. If requested by the Department and at DOE's discretion, the
(i) Conduct simulations before representatives of the Department to predict the performance
(5) AEDM verification testing. DOE may use the test data for a given individual combination
generated pursuant to §429.104 to verify the certified rating determined by an AEDM as long as
(i) Selection of units. DOE will obtain one or more units for test from retail, if available. If
units cannot be obtained from retail, DOE will request that a unit be provided by the
manufacturer;
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(ii) Lab requirements. DOE will conduct testing at an independent, third-party testing facility
of its choosing. In cases where no third-party laboratory is capable of testing the equipment,
(iii) Testing. At no time during verification testing may the lab and the manufacturer
communicate without DOE authorization. If during test set-up or testing, the lab indicates to
DOE that it needs additional information regarding a given individual combination in order
to test in accordance with the applicable DOE test procedure, DOE may organize a meeting
between DOE, the manufacturer and the lab to provide such information.
(iv) Failure to meet certified rating. If an individual combination tests worse than its certified
rating (i.e., lower than the certified efficiency rating or higher than the certified consumption
rating) by more than 5%, or the test results in a different cooling capacity than its certified
cooling capacity by more than 5%, DOE will notify the manufacturer. DOE will provide the
manufacturer with all documentation related to the test set up, test conditions, and test results
for the unit. Within the timeframe allotted by DOE, the manufacturer:
(A) May present any and all claims regarding testing validity; and
(B) If not on site for the initial test set-up, must test at least one additional unit of the
same combination obtained from a retail source at its own expense, following the test
(v) Tolerances.
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(A) For consumption metrics, the result from a DOE verification test must be less than or
(B) For efficiency metrics, the result from a DOE verification test must be greater than or
(vi) Invalid rating. If, following discussions with the manufacturer and a retest where
applicable, DOE determines that the verification testing was conducted appropriately in
accordance with the DOE test procedure, DOE will issue a determination that the ratings for
the basic model are invalid. The manufacturer must conduct additional testing and re-rate and
re-certify the individual combinations within the basic model that were rated using the
AEDM based on all test data collected, including DOE's test data.
(A) If DOE has determined that a manufacturer made invalid ratings on individual
combinations within two or more basic models rated using the manufacturer’s AEDM
within a 24 month period, the manufacturer must test the least efficient and most efficient
429.16(a)(1)(ii). The twenty-four month period begins with a DOE determination that a
(B) If DOE has determined that a manufacturer made invalid ratings on more than four
basic models rated using the manufacturer’s AEDM within a 24-month period, the
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(C) If a manufacturer has lost the privilege of using an AEDM, the manufacturer may
(3) Performing six new tests per basic model, a minimum of two of which must be
* * * * *
* * * * *
(1) Verification of cooling capacity. The cooling capacity of each tested unit of the basic model
(for single package systems) or individual combination (for split-systems) will be measured
pursuant to the test requirements of part 430. The results of the measurement(s) will be compared
(i) If the measurement(s) (either the measured cooling capacity for a single unit sample or the
average of the measured cooling capacities for a multiple unit sample) is less than or equal to
1.05 x the certified cooling capacity and greater than or equal to 0.95 x the certified cooling
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capacity, the certified cooling capacity will be used as the basis for determining SEER.
(ii) Otherwise, the measurement(s) (either the measured cooling capacity for a single unit
sample or the average of the measured cooling capacities for a multiple unit sample, as
(2) Verification of Cd value. (i) For central air conditioners and heat pumps other than models of
outdoor units with no match, the 𝐶𝐶𝐷𝐷𝑐𝑐 and/or 𝐶𝐶𝐷𝐷ℎ value of the basic model (for single package
to the test requirements of 10 CFR part 430 for each unit tested. The results of the
measurement(s) for each 𝐶𝐶𝐷𝐷𝑐𝑐 or 𝐶𝐶𝐷𝐷ℎ value will be compared to the 𝐶𝐶𝐷𝐷𝑐𝑐 or 𝐶𝐶𝐷𝐷ℎ value certified by the
manufacturer.
(A) If the results of the measurement(s) (either the measured value for a single unit sample or
the average of the measured values for a multiple unit sample) is 0.02 or more greater than
the certified 𝐶𝐶𝐷𝐷𝑐𝑐 or 𝐶𝐶𝐷𝐷ℎ value, the average measured 𝐶𝐶𝐷𝐷𝑐𝑐 or 𝐶𝐶𝐷𝐷ℎ value will serve as the basis for
(B) For all other cases, the certified 𝐶𝐶𝐷𝐷𝑐𝑐 or 𝐶𝐶𝐷𝐷ℎ value will be used as the basis for calculation of
(ii) For models of outdoor units with no match, or for tests in which the criteria for the cyclic test
in 10 CFR Part 30, Subpart B, Appendix M, section 3.5e, cannot be achieved, DOE will use the
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For the reasons set forth in the preamble, DOE proposes to amend Part 430 as follows:
pump,” “indoor unit,” “outdoor unit,” “small duct, high velocity system,” “tested
combination;”
§430.2 Definitions.
* * * * *
Basic model means all units of a given type of covered product (or class thereof) manufactured
by one manufacturer; having the same primary energy source; and, which have essentially
identical electrical, physical, and functional (or hydraulic) characteristics that affect energy
(1) With respect to general service fluorescent lamps, general service incandescent lamps,
and incandescent reflector lamps: Lamps that have essentially identical light output and
electrical characteristics—including lumens per watt (lm/W) and color rendering index
(CRI).
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(2) With respect to faucets and showerheads: Have the identical flow control mechanism
attached to or installed within the fixture fittings, or the identical water-passage design
features that use the same path of water in the highest flow mode.
(3) With respect to furnace fans: Are marketed and/or designed to be installed in the same
(4) With respect to central air conditioners and central air conditioning heat pumps: (a)
essentially identical electrical, physical, and functional (or hydraulic) characteristics means:
(i) for split-systems manufactured by independent coil manufacturers (ICMs) and for
small-duct, high velocity systems: all individual combinations having the same model of
indoor unit, which means the same or comparably performing indoor coil(s) [same face
area; fin material, depth, style (e.g., wavy, louvered), and density (fins per inch); tube
pattern, material, diameter, wall thickness, and internal enhancement], indoor blower(s)
[same air flow with the same indoor coil and external static pressure, same power input],
auxiliary refrigeration system components if present (e.g., expansion valve), and controls.
(ii) for split-systems manufactured by outdoor unit manufacturers (OUMs): all individual
combinations having the same model of outdoor unit, which means the same or
comparably performing compressor(s) [same displacement rate (volume per time) and
same capacity and power input when tested under the same operating conditions],
outdoor coil(s) [same face area; fin material, depth, style (e.g., wavy, louvered), and
density (fins per inch); tube pattern, material, diameter, wall thickness, and internal
enhancement], outdoor fan(s) [same air flow with the same outdoor coil, same power
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input], auxiliary refrigeration system components if present (e.g., suction accumulator,
(iii) for single-package models: all individual models having the same or comparably
performing compressor(s) [same displacement rate (volume per time) and same capacity
and power input when tested under the same operating conditions], outdoor coil(s) and
indoor coil(s) [same face area; fin material, depth, style (e.g., wavy, louvered), and
density (fins per inch); tube pattern, material, diameter, wall thickness, and internal
enhancement], outdoor fan(s) [same air flow with the same outdoor coil, same power
input], indoor blower(s) [same air flow with the same indoor coil and external static
pressure, same power input], auxiliary refrigeration system components if present (e.g.
(b) For single-split-system and single-package models, manufacturers may instead choose
to make each individual combination or model its own basic model provided the testing and
(c) For multi-split, multi-circuit, and single-zone-multiple-coil models, a basic model may
not include both individual SDHV combinations and non-SDHV combinations even when
they include the same model of outdoor unit. The manufacturer may choose to identify
* * * * *
Central air conditioner or central air conditioning heat pump means a product, other than a
packaged terminal air conditioner or packaged terminal heat pump, which is powered by single
phase electric current, air cooled, rated below 65,000 Btu per hour, not contained within the
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same cabinet as a furnace, the rated capacity of which is above 225,000 Btu per hour, and is a
heat pump or a cooling unit only. A central air conditioner or central air conditioning heat pump
may consist of: (1) a single-package unit, (2) an outdoor unit and one or more indoor units, (3) an
indoor unit only, or (4) an outdoor unit only. In the case of (3) and (4), the unit must be tested
and rated as a system (combination of both an indoor and an outdoor unit). For all central air
conditioner and central air conditioning heat pump-related definitions, see Appendix M or M1.
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3. Section 430.3 is amended by:
b. renumbering paragraphs (f)(6) through (f)(9) as (f)(7) through (f)(10) and revising said
paragraphs; and
* * * * *
(b) * * *
(1) AHRI 210/240-2008 with Addendums 1 and 2 (formerly ARI Standard 210/240),
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment, sections
6.1.3.2 , 6.1.3.4 , 6.1.3.5 and figures D1, D2, D4, approved by ANSI December, 2012, IBR
* * * * *
(3) ANSI/AHRI 1230-2010 with Addendum 2, Performance Rating of Variable Refrigerant Flow
Multi-Split Air-Conditioning and Heat Pump Equipment, sections 3 (except 3.8, 3.9, 3.13, 3.14,
3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31), 5.1.3, 5.1.4, , 6.1.5 (except Table
8), 6.1.6, and 6.2, approved August 2, 2010, Addendum 2 dated June 2014, IBR approved for
(4) AHRI 210/240-Draft, Performance Rating of Unitary Air-Conditioning & Air- Source Heat
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* * * * *
(f) * * *
* * * * *
(2) ASHRAE 23.1-2010, Methods of Testing for Rating the Performance of Positive
Temperatures of the Refrigerant, sections 5, 6, 7, and 8 only, approved January 28, 2010, IBR
(3) ASHRAE 37-2009, Methods of Testing for Rating Electrically Driven Unitary Air-
Conditioning and Heat Pump Equipment, sections 5.1.1, 5.2, 5.5.1, 6.1.1, 6.1.2, 6.1.4, 6.4, 6.5,
7.3, 7.4, 7.5, 7.7.2.1, 7.7.2.2, 8.1.2, 8.1.3, 8.2, 8.6.2; figures 1, 2, 4, 7a, 7b, 7c, 8; and table 3,
approved June 20, 2009, IBR approved for appendix M and M1 to subpart B.
* * * * *
(5) ASHRAE 41.1-1986 (Reaffirmed 2006), Standard Method for Temperature Measurement,
approved February 18, 1987, IBR approved for appendices E and AA to subpart B.
(6) ASHRAE 41.1-2013, Standard Method for Temperature Measurement, approved January 30,
2013, Sections 4, 5, 6, 7.2, and 7.3 only, IBR approved for appendices M and M1.
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(7) ASHRAE 41.2-1987 (Reaffirmed 1992), Standard Methods for Laboratory Airflow
Measurement, section 5.2.2 and figure 14, approved October 1, 1987, IBR approved for
(8) ASHRAE 41.6-2014, Standard Method for Humidity Measurement, sections 4, 5, 6, and 7.1,
approved July 3, 2014, sections 4, 5, 6, and 7 only IBR approved for appendix M and M1 to
subpart B.
(9) ASHRAE 41.9-2011, Standard Methods for Volatile-Refrigerant Mass Flow Measurements
Using Calorimeters, approved February 3, 2011, sections 5, 6, 7, 8, 9, and 11 only IBR approved
Aerodynamic Performance Rating, figures 2A and 12, approved August 17, 2007, IBR approved
* * * * *
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4. Section 430.23 is amended by revising section (m) to read as follows:
§ 430.23 Test procedures for the measurement of energy and water consumption.
* * * * *
(m) Central Air Conditioners and heat pumps. See the note at the beginning of appendix M/M1
to determine the appropriate test method. All values discussed in this section must be determined
(1) Cooling capacity must be determined from the steady-state wet-coil test (A or A2 Test), as
described in section 3.2 of appendix M or M1 to this subpart, and rounded off to the nearest (i) to
the nearest 50 Btu/h if cooling capacity is less than 20,000 Btu/h, (ii) to the nearest 100 Btu/h if
cooling capacity is greater than or equal to 20,000 Btu/h but less than 38,000 Btu/h, and (iii) to
the nearest 250 Btu/h if cooling capacity is greater than or equal to 38,000 Btu/h and less than
65,000 Btu/h.
(2) Seasonal energy efficiency ratio (SEER) must be determined from section 4.1 of appendix M
(3) When representations are made of energy efficiency ratio (EER), EER must be determined in
section 4.7 of appendix M or M1 to this subpart, and rounded off to the nearest 0.025 Btu/W-h.
(4) Heating seasonal performance factors (HSPF) must be determined in section 4.2 of appendix
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(5) Average off mode power consumption must be determined according to section 4.3 of
(6) Sensible heat ratio (SHR) must be determined according to section 4.6 of appendix M or M1
to this subpart, and rounded off to the nearest 0.5 percent (%).
(7) All other measures of energy efficiency or consumption or other useful measures of
* * * * *
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5. Revise Appendix M to Subpart B of Part 430 to read as follows:
Note: Prior to [DATE 180 DAYS AFTER PUBLICATION OF THE FINAL RULE IN
with respect to the energy use, power, or efficiency of central air conditioners and central air
conditioning heat pumps must be based on the results of testing pursuant to either this appendix
the 10 CFR parts 200 to 499 edition revised as of January 1, 2015. Any representations made
with respect to the energy use or efficiency of such central air conditioners and central air
On or after [DATE 180 DAYS AFTER PUBLICATION OF THE FINAL RULE IN THE
FEDERAL REGISTER] and prior to the compliance date for any amended energy conservation
standards, any representations, including compliance certifications, made with respect to the
energy use, power, or efficiency of central air conditioners and central air conditioning heat
On or after the compliance date for any amended energy conservation standards, any
representations, including compliance certifications, made with respect to the energy use, power,
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or efficiency of central air conditioners and central air conditioning heat pumps must be based on
1.1 Scope.
This test procedure provides a method of determining SEER, EER, HSPF and PW,OFF for
central air conditioners and central air conditioning heat pumps including the following
categories:
specific sections of several industry standards, as listed in § 430.3. In cases where there is a
conflict, the language of the test procedure in this appendix takes precedence over the
incorporated standards.
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1.2 Definitions
Airflow-control settings are programmed or wired control system configurations that control a fan
than interaction with a user-operable control (i.e., a thermostat) that meets the manufacturer
specifications for installed-use are those found in the product literature shipped with the unit.
Airflow prevention device denotes a device(s) that prevents airflow via natural convection by
mechanical means, such as an air damper box, or by means of changes in duct height, such as
an upturned duct.
Annual performance factor means the total heating and cooling done by a heat pump in a
particular region in one year divided by the total electric energy used in one year. The
Blower coil indoor unit means the indoor unit of a split-system central air conditioner or heat
pump that includes a refrigerant-to-air heat exchanger coil, may include a cooling-mode
expansion device, and includes either an indoor blower housed with the coil or a separate
designated air mover such as a furnace or a modular blower (as defined in Appendix AA).
Blower coil system refers to a split-system that includes one or more blower coil indoor units.
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Coil-only indoor unit means the indoor unit of a split-system central air conditioner or heat pump
that includes a refrigerant-to-air heat exchanger coil and may include a cooling-mode
expansion device, but does not include an indoor blower housed with the coil, and does not
include a separate designated air mover such as a furnace or a modular blower (as defined in
modular blower for indoor air movement. Coil-only system refers to a system that includes
Condensing unit removes the heat absorbed by the refrigerant to transfer it to the outside
environment, and which consists of an outdoor coil, compressor(s), and air moving device.
Constant-air-volume-rate indoor blower means a fan that varies its operating speed to provide a
Continuously recorded, when referring to a dry bulb measurement, dry bulb temperature used for
test room control, wet bulb temperature, dew point temperature, or relative humidity
measurements, means that the specified value must be sampled at regular intervals that are
Cooling load factor (CLF) means the ratio having as its numerator the total cooling delivered
during a cyclic operating interval consisting of one ON period and one OFF period. The
denominator is the total cooling that would be delivered, given the same ambient conditions,
had the unit operated continuously at its steady-state, space-cooling capacity for the same
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Coefficient of Performance (COP) means the ratio of the average rate of space heating delivered
to the average rate of electrical energy consumed by the heat pump. These rate quantities
must be determined from a single test or, if derived via interpolation, must be determined at a
single set of operating conditions. COP is a dimensionless quantity. When determined for a
ducted unit tested without an indoor blower installed, COP must include the section 3.7and
3.9.1 default values for the heat output and power input of a fan motor.
Crankcase heater means any electrically powered device or mechanism for intentionally
generating heat within and/or around the compressor sump volume often done to minimize
the dilution of the compressor’s refrigerant oil by condensed refrigerant. Crankcase heater
control may be achieved using a timer or may be based on a change in temperature or some
other measurable parameter, such that the crankcase heater is not required to operate
Cyclic Test means a test where the unit's compressor is cycled on and off for specific time
intervals. A cyclic test provides half the information needed to calculate a degradation
coefficient.
Damper box means a short section of duct having an air damper that meets the performance
Degradation coefficient (CD) means a parameter used in calculating the part load factor. The
degradation coefficient for cooling is denoted by CDc. The degradation coefficient for heating
is denoted by CDh.
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Demand-defrost control system means a system that defrosts the heat pump outdoor coil only
monitor one or more parameters that always vary with the amount of frost accumulated on
the outdoor coil (e.g., coil to air differential temperature, coil differential air pressure,
outdoor fan power or current, optical sensors) at least once for every ten minutes of
compressor ON-time when space heating. One acceptable alternative to the criterion given in
the prior sentence is a feedback system that measures the length of the defrost period and
adjusts defrost frequency accordingly. In all cases, when the frost parameter(s) reaches a
defrosts are terminated based on monitoring a parameter(s) that indicates that frost has been
eliminated from the coil. (Note: Systems that vary defrost intervals according to outdoor dry-
bulb temperature are not demand-defrost systems.) A demand-defrost control system, which
otherwise meets the above requirements, may allow time-initiated defrosts if, and only if,
Design heating requirement (DHR) predicts the space heating load of a residence when subjected
to outdoor design conditions. Estimates for the minimum and maximum DHR are provided
Dry-coil tests are cooling mode tests where the wet-bulb temperature of the air supplied to the
indoor coil is maintained low enough that no condensate forms on this coil.
Ducted system means an air conditioner or heat pump that is designed to be permanently
installed equipment and delivers conditioned air to the indoor space through a duct(s). The
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Energy efficiency ratio (EER) means the ratio of the average rate of space cooling delivered to
the average rate of electrical energy consumed by the air conditioner or heat pump. These
rate quantities must be determined from a single test or, if derived via interpolation, must be
𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
determined at a single set of operating conditions. EER is expressed in units of 𝑊𝑊
.
When determined for a ducted unit tested without an indoor blower installed, EER must
include the section 3.3 and 3.5.1 default values for the heat output and power input of a fan
motor.
Evaporator coil absorbs heat from an enclosed space and transfers the heat to a refrigerant.
Heat pump means a kind of central air conditioner, which consists of one or more assemblies,
exchanger to provide air heating, and may also provide air cooling, air dehumidifying, air
Heating load factor (HLF) means the ratio having as its numerator the total heating delivered
during a cyclic operating interval consisting of one ON period and one OFF period. The
denominator is the total heating that would be delivered, given the same ambient conditions,
if the unit operated continuously at its steady-state space heating capacity for the same total
Heating season means the months of the year that require heating, e.g., typically, and roughly,
Heating seasonal performance factor (HSPF) means the total space heating required during the
space heating season, expressed in Btu's, divided by the total electrical energy consumed by
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the heat pump system during the same season, expressed in watt-hours. The HSPF used to
evaluate compliance with the Energy Conservation Standards (see 10 CFR 430.32(c)) is
based on Region IV, the minimum standardized design heating requirement, and the
Heat pump having a heat comfort controller means equipment that regulates the operation of the
electric resistance elements to assure that the air temperature leaving the indoor section does
not fall below a specified temperature. This specified temperature is usually field adjustable.
Heat pumps that actively regulate the rate of electric resistance heating when operating below
the balance point (as the result of a second stage call from the thermostat) but do not operate
to maintain a minimum delivery temperature are not considered as having a heat comfort
controller.
Independent coil manufacturer (ICM) means a manufacturer that manufactures indoor units but
Indoor unit transfers heat between the refrigerant and the indoor air and consists of an indoor coil
and casing and may include a cooling mode expansion device and/or an air moving device.
Multiple-split (or multi-split) system means a split system that has one outdoor unit and two or
more indoor coil-only or indoor blower coil units connected to its other component(s) with a
single refrigerant circuit. The indoor units operate independently and can condition multiple
zones in response to at least two indoor thermostats or temperature sensors. The outdoor unit
operates in response to independent operation of the indoor units based on control input of
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multiple indoor thermostats or temperature sensors, and/or based on refrigeration circuit
Multiple-circuit (or multi-circuit) system means a split system that has one outdoor unit and that
has two or more indoor units installed on two or more refrigeration circuits such that each
refrigeration circuit serves a compressor and one and only one indoor unit, and refrigerant is
Nominal capacity means the capacity that is claimed by the manufacturer in the product name
plate. Nominal cooling capacity is approximate to the air conditioner cooling capacity tested
Non-ducted system means a split-system central air conditioner or heat pump that is designed to
be permanently installed and that directly heats or cools air within the conditioned space
using one or more indoor units that are mounted on room walls and/or ceilings. The system
may be of a modular design that allows for combining multiple outdoor coils and
Normalized Gross Indoor Fin Surface (NGIFS) means the gross fin surface area of the indoor
unit coil divided by the cooling capacity measured for the A or A2 Test whichever applies.
Off-mode power consumption means the power consumption when the unit is connected to its
main power source but is neither providing cooling nor heating to the building it serves.
Off-mode season means, for central air conditioners, the shoulder season and the entire heating
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Outdoor unit transfers heat between the refrigerant and the outdoor air, and consists of an
outdoor coil, compressor(s), an air moving device, and in addition for heat pumps, could
include a heating mode expansion device, reversing valve, and defrost controls.
Outdoor unit manufacturer (OUM) means a manufacturer of single-package units, outdoor units,
Part-load factor (PLF) means the ratio of the cyclic energy efficiency ratio (coefficient of
both energy efficiency ratios (coefficients of performance) are determined based on operation
Seasonal energy efficiency ratio (SEER) means the total heat removed from the conditioned
space during the annual cooling season, expressed in Btu's, divided by the total electrical
energy consumed by the central air conditioner or heat pump during the same season,
expressed in watt-hours.
Short ducted system means a ducted split system whose one or more indoor sections produce
greater than zero but no greater than 0.1 inches (of water) of external static pressure when
operated at the full-load air volume not exceeding 450 cfm per rated ton of cooling.
Shoulder season means the months of the year in between those months that require cooling and
those months that require heating, e.g., typically, and roughly, April through May, and
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Single-package unit means any central air conditioner or heat pump that has all major assemblies
Single-split-system means a split system that has one outdoor unit and that has one indoor coil-
only or indoor blower coil unit connected to its other component(s) with a single refrigeration
circuit.
Single-zone-multiple-coil split system means a split system that has one outdoor unit and that has
two or more indoor units connected with a single refrigeration circuit. The indoor units
Small-duct, high-velocity system means a system that contains a blower and indoor coil
combination that is designed for, and produces, at least 1.2 inches (of water) of external static
pressure when operated at the full-load air volume rate of 220-350 cfm per rated ton of
cooling. When applied in the field, uses high-velocity room outlets (i.e., generally greater
than 1000 fpm) having less than 6.0 square inches of free area.
Split system means any air conditioner or heat pump that has one or more of the major
assemblies separated from the others. Split-systems may be either blower coil systems or
coil-only systems.
Standard Air means dry air having a mass density of 0.075 lb/ft3.
Steady-state test means a test where the test conditions are regulated to remain as constant as
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Temperature bin means the 5 °F increments that are used to partition the outdoor dry-bulb
temperature ranges of the cooling (≥65 °F) and heating (<65 °F) seasons.
Test condition tolerance means the maximum permissible difference between the average value
Test operating tolerance means the maximum permissible range that a measurement may vary
over the specified test interval. The difference between the maximum and minimum sampled
values must be less than or equal to the specified test operating tolerance.
(1) The system consists of one outdoor unit with one or more compressors matched with
(i) Collectively, have a nominal cooling capacity greater than or equal to 95 percent and
less than or equal to 105 percent of the nominal cooling capacity of the outdoor unit;
(ii) Represent the highest sales volume model family that can meet the 95 percent
nominal cooling capacity of the outdoor unit [Note: another indoor model family may be
used if five indoor units from the highest sales volume model family do not provide
(iii) Individually not have a nominal cooling capacity greater than 50 percent of the
nominal cooling capacity of the outdoor unit, unless the nominal cooling capacity of the
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(iv) Operate at fan speeds consistent with manufacturer’s specifications; and
(v) All be subject to the same minimum external static pressure requirement while able to
produce the same external static pressure at the exit of each outlet plenum when
(vi) Where referenced, “nominal cooling capacity” is to be interpreted for indoor units as
the highest cooling capacity listed in published product literature for 95 °F outdoor dry
bulb temperature and 80 °F dry bulb, 67 °F wet bulb indoor conditions, and for outdoor
units as the lowest cooling capacity listed in published product literature for these
conditions. If incomplete or no operating conditions are reported, the highest (for indoor
units) or lowest (for outdoor units) such cooing capacity shall be used.
Time-adaptive defrost control system is a demand-defrost control system that measures the
length of the prior defrost period(s) and uses that information to automatically determine
Time-temperature defrost control systems initiate or evaluate initiating a defrost cycle only when
generally a fixed value (e.g., 30, 45, 90 minutes) although it may vary based on the measured
(e.g., outdoor temperature, evaporator temperature) indicate that frost formation conditions
are present, and it is reset/remains at zero at all other times. In one application of the control
scheme, a defrost is initiated whenever the counter time equals the predetermined ON-time.
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In a second application of the control scheme, one or more parameters are measured (e.g., air
defrost is initiated only if the measured parameter(s) falls within a predetermined range. The
ON-time counter is reset regardless of whether or not a defrost is initiated. If systems of this
second type use cumulative ON-time intervals of 10 minutes or less, then the heat pump may
Triple-capacity, northern heat pump means a heat pump that provides two stages of cooling and
three stages of heating. The two common stages for both the cooling and heating modes are
the low capacity stage and the high capacity stage. The additional heating mode stage is the
booster capacity stage, which offers the highest heating capacity output for a given set of
Triple-split system means a central air conditioner or heat pump that is composed of three
separate components: An outdoor fan coil section, an indoor blower coil section, and an
Two-capacity (or two-stage) compressor system means a central air conditioner or heat pump
that has a compressor or a group of compressors operating with only two stages of capacity.
For such systems, low capacity means the compressor(s) operating at low stage, or at low
load test conditions. The low compressor stage for heating mode tests may be the same or
For such systems, high capacity means the compressor(s) operating at low stage, or at full
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Two-capacity, northern heat pump means a heat pump that has a factory or field-selectable lock-
out feature to prevent space cooling at high-capacity. Two-capacity heat pumps having this
feature will typically have two sets of ratings, one with the feature disabled and one with the
feature enabled. The certified indoor coil model number should reflect whether the ratings
pertain to the lockout enabled option via the inclusion of an extra identifier, such as “+LO”.
When testing as a two-capacity, northern heat pump, the lockout feature must remain enabled
Variable refrigerant flow (VRF) system means a multi-split system with at least three compressor
capacity stages, distributing refrigerant through a piping network to multiple indoor blower
coil units each capable of individual zone temperature control, through proprietary zone
systems less than 65,000 Btu/h are a kind of central air conditioners and central air
Variable-speed compressor system means a central air conditioner or heat pump that has a
compressor that uses a variable-speed drive to vary the compressor speed to achieve variable
capacities.
For such a system, maximum speed means the maximum operating speed, measured by RPM
or frequency (Hz), that the unit is designed to operate in cooling mode or heating mode.
Maximum speed does not change with ambient temperature, and it can be different from
cooling mode to heating mode. Maximum speed does not necessarily mean maximum
capacity.
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For such systems, minimum speed means the minimum speed, measured by RPM or
frequency (Hz), that the unit is designed to operate in cooling mode or heating mode.
Minimum speed does not change with ambient temperature, and it can be different from
cooling mode to heating mode. Minimum speed does not necessarily mean minimum
capacity.
Wet-coil test means a test conducted at test conditions that typically cause water vapor to
(A) Test VRF systems using ANSI/AHRI Standard 1230-2010 sections 3 (except 3.8, 3.9, 3.13,
3.14, 3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31), 5.1.3, 5.1.4, , 6.1.5 (except
Table 8), 6.1.6, and 6.2 and Appendix M. Where ANSI/AHRI Standard 1230-2010 refers to the
Appendix C therein substitute the provisions of this appendix. In cases where there is a conflict,
the language of the test procedure in this appendix takes precedence over ANSI/AHRI Standard
1230-2010.
1230-2010, excluding sections 3.8, 3.9, 3.13, 3.14, 3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29,
3.30, and 3.31. For rounding requirements refer to §430.23 (m). For determination of certified
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For test room requirements, refer to section 2.1 from Appendix M. For test unit
installation requirements refer to sections 2.2.a, 2.2.b, 2.2.c, 2.2.1, 2.2.2, 2.2.3(a), 2.2.3(c) , 2.2.4,
2.2.5, and 2.4 to 2.12 from Appendix M, and sections 5.1.3 and 5.1.4 of ANSI/AHRI Standard
1230-2010.
For general requirements for the test procedure refer to section 3.1 of Appendix M,
except for sections 3.1.3 and 3.1.4, which are requirements for indoor air volume and outdoor air
volume. For indoor air volume and outdoor air volume requirements, refer instead to section
6.1.5 (except Table 8) and 6.1.6 of ANSI/AHRI Standard 1230-2010. For external static pressure
For the test procedure, refer to sections 3.3 to 3.5 and 3.7 to 3.13 in Appendix M. For
cooling mode and heating mode test conditions, refer to section 6.2 of ANSI/AHRI Standard
(B) For systems other than VRF, only a subset of the sections listed in this test procedure apply
when testing and rating a particular unit. Table 1 shows the sections of the test procedure that
apply to each system. This table is meant to assist manufacturers in finding the appropriate
sections of the test procedure; the appendix sections rather than the table provide the specific
requirements for testing, and given the varied nature of available units, manufacturers are
responsible for determining which sections apply to each unit tested. To use this table, first refer
to the sections listed under “all units”. Then refer to additional requirements based on: (1) system
configuration(s), (2) the compressor staging or modulation capability, and (3) any special
features.
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Testing requirements for space-constrained products do not differ from similar equipment
that is not space-constrained and thus are not listed separately in this table. Air conditioners and
heat pumps are not listed separately in this table, but heating procedures and calculations apply
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Testing conditions Testing procedures Calculations
3.1.4.4.1; 3.1.4.4.2;
3.1.4.1.1; 3.1.4.1.1a,b;
Single split-system – blower coil 2.2a(1) 3.1.4.4.3a-b; 3.1.4.5.1;
3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
3.1.4.4.1; 3.1.4.4.2;
Tri-split 2.2a(2)
System Configurations (more than one may apply)
3.1.4.4.1; 3.1.4.4.2;
3.1.4.1.1; 3.1.4.1.1a,b;
Single-package 2.2.4.1(2); 2.2.5.6b; 2.4.1; 2.4.2 3.1.4.4.3a-b; 3.1.4.5.1;
3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
3.1.4.4.2c;
Two-capacity northern heat pump 3.2.3c 3.6.3
3.1.4.5.2 c- d
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SDHV (non-VRF) 2.2b; 2.4.1c; 2.5.4.3
3.1.4.4.1; 3.1.4.4.2;
Single- zone-multi-coil split and non- 3.1.4.1.1; 3.1.4.1.1a-b;
2.2a(1),(3); 2.2.3; 2.4.1b 3.1.4.4.3a-b; 3.1.4.5.1;
VRF multiple-split with duct 3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
3.1.4.1.2; 3.1.4.2d;
Single-zone-multi-coil split and non- 3.1.4.4.4; 3.1.4.5.2e; 3.1.4.6c;
2.2.a(1),(3); 2.2.3 3.1.4.3c; 3.2.4c;
VRF multiple-split, ductless 3.6.4.c; 3.8c
3.5c,g,h; 3.5.2; 3.8c
2.1; 2.2.a; 2.2.b; 2.2.c; 2.2.1; 2.2.2; 3.1 (except 3.3-3.5 3.7–3.10 4.4;
†
VRF multiple-split and 2.2.3(a); 2.2.3(c);, 2.2.4; 2.2.5; 2.4- 3.1.3, 3.1.4) 4.5;
4.1 4.2
†
VRF SDHV 2.12 3.1.4.1.1c; 4.6
3.11-3.13
Single speed compressor, fixed speed fan 3.2.1 3.6.1 4.1.1 4.2.1
Single speed compressor, VAV fan 3.1.7 3.2.2 3.6.2 4.1.2 4.2.2
Modulation
Capability
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*Does not apply to heating-only heat pumps.
in the table to perform test setup, testing, and calculations for rating VRF multiple-split and VRF SDHV systems.
NOTE: For all units, use section 3.13 for off mode testing procedures and section 4.3 for off mode calculations. For all units subject to an EER standard, use
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2.1 Test room requirements.
a. Test using two side-by-side rooms, an indoor test room and an outdoor test room. For
however, use as many available indoor test rooms as needed to accommodate the total
number of indoor units. These rooms must comply with the requirements specified in
b. Inside these test rooms, use artificial loads during cyclic tests and Frost Accumulation
tests, if needed, to produce stabilized room air temperatures. For one room, select an electric
resistance heater(s) having a heating capacity that is approximately equal to the heating
capacity of the test unit's condenser. For the second room, select a heater(s) having a capacity
that is close to the sensible cooling capacity of the test unit's evaporator. When applied, cycle
the heater located in the same room as the test unit evaporator coil ON and OFF when the test
unit cycles ON and OFF. Cycle the heater located in the same room as the test unit
condensing coil ON and OFF when the test unit cycles OFF and ON.
a. Install the unit according to section 8.2 of ASHRAE Standard 37-2009, subject to the
1) When testing split systems, follow the requirements given in section 6.1.3.5 of AHRI
210/240-2008 with Addendum 1 and 2. For the vapor refrigerant line(s), use the
insulation included with the unit; if no insulation is provided, refer to the specifications
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for the insulation in the installation instructions included with the unit by the
manufacturer; if no insulation is included with the unit and the installation instructions do
not contain provisions for insulating the line(s), fully insulate the vapor refrigerant line(s)
with vapor proof insulation having an inside diameter that matches the refrigerant tubing
and a nominal thickness of at least 0.5 inches. For the liquid refrigerant line(s), use the
insulation included with the unit; if no insulation is provided, refer to the specifications
for the insulation in the installation instructions included with the unit by the
manufacturer; if no insulation is included with the unit and the installation instructions do
not contain provisions for insulating the line(s), leave the liquid refrigerant line(s)
exposed to the air for air conditioners and heat pumps that heat and cool; or, for heating-
only heat pumps, insulate the liquid refrigerant line(s) with insulation having an inside
diameter that matches the refrigerant tubing and a nominal thickness of at least 0.5
inches;
2) When testing split systems, if the indoor unit does not ship with a cooling mode
expansion device, test the system using the device as specified in the installation
instructions provided with the indoor unit. If none is specified, test the system using a
thermostatic expansion valve with internal pressure equalization that the valve
3) When testing triple-split systems (see section 1.2, Definitions), use the tubing length
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the outdoor coil, indoor compressor section, and indoor coil while still meeting the
4) When testing split systems having multiple indoor coils, connect each indoor blower-
coil to the outdoor unit using: (a) 25 feet of tubing, or (b) tubing furnished by the
2009. Refer to section 2.10 of this appendix to learn which secondary methods require
split system with insulation having an inside diameter that matches the refrigerant tubing
b. For units designed for both horizontal and vertical installation or for both up-flow and
down-flow vertical installations, the manufacturer must use the orientation for testing
specified in the certification report. Conduct testing with the following installed:
(2) supplementary heating coils; and(3) other equipment specified as part of the unit,
including all hardware used by a heat comfort controller if so equipped (see section 1,
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c. Testing a ducted unit without having an indoor air filter installed is permissible as long as
the minimum external static pressure requirement is adjusted as stated in Table 3, note 3 (see
section 3.1.4). Except as noted in section 3.1.10, prevent the indoor air supplementary
heating coils from operating during all tests. For coil-only indoor units that are supplied
without an enclosure, create an enclosure using 1 inch fiberglass ductboard having a nominal
density of 6 pounds per cubic foot. Or alternatively, use some other insulating material
having a thermal resistance (“R” value) between 4 and 6 hr·ft2· °F/Btu. For units where the
d. When testing coil-only central air conditioners and heat pumps, install a toroidal-type
transformer to power the system’s low-voltage components, complying with any additional
requirements for this transformer mentioned in the installation manuals included with the unit
by the manufacturer. If the installation manuals do not provide specifications for the
transformer, use a transformer having the following features: (1) a nominal volt-amp rating
that results in the transformer being loaded at a level that is between 25 and 90 percent based
on the highest power value expected and then confirmed during the off mode test; (2)
designed to operate with a primary input of 230 V, single phase, 60 Hz; and (3) that provides
an output voltage that is within the specified range for each low-voltage component. The
power consumption of the components connected to the transformer must be included as part
of the total system power consumption during the off mode tests, less if included the power
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e. An outdoor unit with no match (i.e., that is not sold with indoor units) shall be tested
without an indoor blower installed, with a single cooling air volume rate, using an indoor unit
whose coil has (1) round tubes of outer diameter no less than 0.375 inches, and (2) a
normalized gross indoor fin surface (NGIFS) no greater than 1.15 square inches per British
where,
Lf = Indoor coil fin length in inches, also height of the coil transverse to the tubes.
Nf = Number of fins.
𝑄𝑄̇𝑐𝑐 (95) = the measured space cooling capacity of the tested outdoor unit/indoor unit
Btu/h.http://www.ecfr.gov/graphics/pdfs/er11oc05.173.pdfhttp://www.ecfr.gov/graphics/
pdfs/er11oc05.173.pdf
Set heat pump defrost controls at the normal settings which most typify those encountered in
generalized climatic region IV. (Refer to Figure 1 and Table 19 of section 4.2 for information on
region IV.) For heat pumps that use a time-adaptive defrost control system (see section 1.2,
Definitions), the manufacturer must specify the frosting interval to be used during Frost
Accumulation tests and provide the procedure for manually initiating the defrost at the specified
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time. To ease testing of any unit, the manufacturer should provide information and any necessary
Configure the multiple-speed outdoor fan according to the installation manual included with
the unit by the manufacturer, and thereafter, leave it unchanged for all tests. The controls of the
unit must regulate the operation of the outdoor fan during all lab tests except dry coil cooling
mode tests. For dry coil cooling mode tests, the outdoor fan must operate at the same speed used
during the required wet coil test conducted at the same outdoor test conditions.
2.2.3 Special requirements for multi-split air conditioners and heat pumps, systems composed of
multiple single-zone-multiple-coil split-system units (having multiple outdoor units located side-
by-side), and ducted systems using a single indoor section containing multiple blowers that
Because these systems will have more than one indoor blower and possibly multiple outdoor
fans and compressor systems, references in this test procedure to a singular indoor blower,
outdoor fan, and compressor means all indoor blowers, all outdoor fans, and all compressor
a. Additional requirements for multi-split air conditioners and heat pumps and systems
composed of multiple single-zone-multiple-coil split-system units. For any test where the
system is operated at part load (i.e., one or more compressors “off”, operating at the
manufacturer shall designate the indoor coil(s) that are not providing heating or cooling
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during the test such that the sum of the nominal heating or cooling capacity of the operational
indoor units is within 5 percent of the intended part load heating or cooling capacity. For
variable-speed systems, the manufacturer must designate at least one indoor unit that is not
providing heating or cooling for all tests conducted at minimum compressor speed. For all
other part-load tests, the manufacturer shall choose to turn off zero, one, two, or more indoor
units. The chosen configuration shall remain unchanged for all tests conducted at the same
compressor speed/capacity. For any indoor coil that is not providing heating or cooling
during a test, cease forced airflow through this indoor coil and block its outlet duct.
b. Additional requirements for ducted systems with a single indoor section containing
multiple blowers where the blowers are designed to cycle on and off independently of one
another and are not controlled such that all blowers are modulated to always operate at the
same air volume rate or speed. This Appendix covers systems with a single-speed
compressor or systems offering two fixed stages of compressor capacity (e.g., a two-speed
compressor, two single-speed compressors). For any test where the system is operated at its
lowest capacity—i.e., the lowest total air volume rate allowed when operating the single-
least one-third of the full-load air volume rate must be turned off unless prevented by the
controls of the unit. In such cases, turn off as many blowers as permitted by the unit’s
controls. Where more than one option exists for meeting this “off” blower requirement, the
manufacturer shall include in its installation manuals included with the unit which blower(s)
are turned off. The chosen configuration shall remain unchanged for all tests conducted at the
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same lowest capacity configuration. For any indoor coil turned off during a test, cease forced
c. For test setups where it is physically impossible for the laboratory to use the required line
length listed in Table 3 of ANSI/AHRI Standard 1230-2010 with Addendum 2, then the
actual refrigerant line length used by the laboratory may exceed the required length and the
refrigerant line length correction factors in Table 4 of ANSI/AHRI Standard 1230-2010 with
2.2.4 Wet-bulb temperature requirements for the air entering the indoor and outdoor coils.
2.2.4.1 Cooling mode tests. For wet-coil cooling mode tests, regulate the water vapor content of
the air entering the indoor unit to the applicable wet-bulb temperature listed in Tables 4 to 7. As
noted in these same tables, achieve a wet-bulb temperature during dry-coil cooling mode tests
that results in no condensate forming on the indoor coil. Controlling the water vapor content of
the air entering the outdoor side of the unit is not required for cooling mode tests except when
testing:
(1) Units that reject condensate to the outdoor coil during wet coil tests. Tables 4-7 list the
(2) Single-package units where all or part of the indoor section is located in the outdoor test
room. The average dew point temperature of the air entering the outdoor coil during wet coil
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tests must be within ±3.0 °F of the average dew point temperature of the air entering the
indoor coil over the 30-minute data collection interval described in section 3.3. For dry coil
tests on such units, it may be necessary to limit the moisture content of the air entering the
For heating mode tests, regulate the water vapor content of the air entering the outdoor unit
to the applicable wet-bulb temperature listed in Tables 11 to 14. The wet-bulb temperature
entering the indoor side of the heat pump must not exceed 60 °F. Additionally, if the Outdoor Air
Enthalpy test method is used while testing a single-package heat pump where all or part of the
outdoor section is located in the indoor test room, adjust the wet-bulb temperature for the air
entering the indoor side to yield an indoor-side dew point temperature that is as close as
reasonably possible to the dew point temperature of the outdoor-side entering air.
mean the manufacturer's installation instructions that come packaged with or appear in the labels
applied to the unit. This does not include online manuals. Installation instructions that are
shipped with the unit shall take precedence over installation instructions that appear in the labels
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2.2.5.2 Instructions to Use for Charging
a. Where the manufacturer's installation instructions contain two sets of refrigerant charging
criteria, one for field installations and one for lab testing, use the field installation criteria.
b. For systems consisting of an outdoor unit manufacturer’s outdoor section and indoor section
with differing charging procedures the refrigerant charge shall be adjusted per the outdoor
installation instructions.
c. For systems consisting of an outdoor unit manufacturer’s outdoor section and an independent
coil manufacturer’s indoor section with differing charging procedures the refrigerant charge shall
a. Use the tests or operating conditions specified in the manufacturer’s installation instructions
for charging.
b. If the manufacturer’s installation instructions do not specify a test or operating conditions for
charging or there are no manufacturer’s instructions, use the following test(s): (1) for air
conditioners or cooling and heating heat pumps, use the A or A2 test. (2) for cooling and heating
heat pumps that do not function in the H1 or H12 test with the charge set for the A or A2 test and
a. Consult the manufacturer’s installation instructions regarding which parameters to set and
their target values. If the instructions provide ranges of values, select target values equal to the
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b. In the event of conflicting information between charging instructions (defined as multiple
conditions given for charge adjustment where all conditions specified cannot be met), follow the
following hierarchy.
1. Superheat
6. Charge weight
1. Subcooling
5. Charge weight
c. If there are no installation instructions and/or they do not provide parameters and target values,
set superheat to a target value of 12 ˚F for fixed orifice systems or set subcooling to a target
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a. If the manufacturer’s installation instructions specify tolerances on target values for the
b. Otherwise, use the following tolerances for the different charging parameters:
• High side pressure or corresponding saturation or dew point temperature: +/- 4.0 psi or
+/- 1.0 ˚F
• Low side pressure or corresponding saturation or dew point temperature: +/- 2.0 psi or
+/- 0.8 ˚F
If, using the initial charge set in the A or A2 test, the conditions are not within the range specified
in manufacturer’s instructions for the H1 or H12 test, make as small as possible an adjustment to
obtain conditions for this test in the specified range. After this adjustment, recheck conditions in
the A or A2 test to confirm that they are still within the specified range for this test.
b. Single-Package Systems
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Unless otherwise directed by the manufacturer’s installation instructions, install one or more
refrigerant line pressure gauges during the setup of the unit if setting of refrigerant charge is
based on certain operating parameters: (1) install a pressure gauge on the liquid line if charging
is on the basis of subcooling, or high side pressure or corresponding saturation or dew point
temperature; (2) install a pressure gauge on the suction line if charging is on the basis of
manufacturer’s installation instructions indicate that pressure gauges are not to be installed,
setting of charge shall not be based on any of the parameters listed in (1) and (2) above.
After charging the system as described in this test procedure, use the set refrigerant
charge for all tests used to determine performance. Do not adjust the refrigerant charge at any
If a unit's controls allow for overspeeding the indoor blower (usually on a temporary basis),
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a. Set indoor blower airflow-control settings (e.g., fan motor pin settings, fan motor speed)
according to the installation instructions that are provided with the equipment while meeting
the airflow requirements that are specified in section 3.1.4. If the manufacturer installation
instructions do not provide guidance on the airflow-control settings for a system tested with
the indoor blower installed, select the lowest speed that will satisfy the minimum external
static pressure specified in section 3.1.4.1.1 with an air volume rate at or higher than the rated
full-load cooling air volume rate while meeting the maximum air flow requirement.
b. Express the Cooling Full-load Air Volume Rate, the Cooling Minimum Air Volume Rate,
and the Cooling Intermediate Air Volume Rate in terms of standard air.
a. If needed, set the indoor blower airflow-control settings (e.g., fan motor pin settings, fan
motor speed) according to the installation instructions that are provided with the equipment.
Do this set-up while meeting all applicable airflow requirements specified in sections 3.1.4.
For a cooling and heating heat pump tested with an indoor blower installed, if the
settings, use the same airflow-control settings used for the cooling test. If the manufacturer
installation instructions do not provide guidance on the airflow-control settings for a heating-
only heat pump tested with the indoor blower installed, select the lowest speed that will
satisfy the minimum external static pressure specified in section 3.1.4.4.3 with an air volume
rate at or higher than the rated heating full-load air volume rate.
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b. Express the Heating Full-Load Air Volume Rate, the Heating Minimum Air Volume Rate,
the Heating Intermediate Air Volume Rate, and the Heating Nominal Air Volume Rate in
Insulate and/or construct the outlet plenum described in section 2.4.1 and, if installed, the
inlet plenum described in section 2.4.2 with thermal insulation having a nominal overall
a. Attach a plenum to the outlet of the indoor coil. (NOTE: for some packaged systems, the
b. For systems having multiple indoor coils, or multiple indoor blowers within a single
indoor section, attach a plenum to each indoor coil or blower outlet. Connect two or more
outlet plenums to a single common duct so that each indoor coil ultimately connects to an
airflow measuring apparatus (section 2.6). If using more than one indoor test room, do
likewise, creating one or more common ducts within each test room that contains multiple
indoor coils. At the plane where each plenum enters a common duct, install an adjustable
airflow damper and use it to equalize the static pressure in each plenum. Each outlet air
temperature grid (section 2.5.4) and airflow measuring apparatus are located downstream of
c. For small-duct, high-velocity systems, install an outlet plenum that has a diameter that is
equal to or less than the value listed below. The limit depends only on the Cooling Full-Load
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Air Volume Rate (see section 3.1.4.1.1) and is effective regardless of the flange dimensions
on the outlet of the unit (or an air supply plenum adapter accessory, if installed in accordance
d. Add a static pressure tap to each face of the (each) outlet plenum, if rectangular, or at four
evenly distributed locations along the circumference of an oval or round plenum. Create a
manifold that connects the four static pressure taps. Figures 7a, 7b, 7c of ASHRAE Standard
37-2009 shows two of the three options allowed for the manifold configuration; the third
ASHRAE Standard 37-2009. See Figures 7a, 7b, 7c, and 8 of ASHRAE Standard 37-2009
for the cross-sectional dimensions and minimum length of the (each) plenum and the
locations for adding the static pressure taps for units tested with and without an indoor
blower installed.
the cross-sectional area and P is the perimeter of the rectangular plenum, and compare it to the
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2.4.2 Inlet plenum for the indoor unit.
Install an inlet plenum when testing a coil-only indoor unit or a packaged system where the
indoor coil is located in the outdoor test room. Add static pressure taps at the center of each face
of this plenum, if rectangular, or at four evenly distributed locations along the circumference of
an oval or round plenum. Make a manifold that connects the four static-pressure taps using one
of the three configurations specified in section 2.4.1. See Figures 7b, 7c, and Figure 8 of
ASHRAE Standard 37-2009 for cross-sectional dimensions, the minimum length of the inlet
plenum, and the locations of the static-pressure taps. When testing a ducted unit having an indoor
blower (and the indoor coil is in the indoor test room), test with an inlet plenum installed unless
physically prohibited by space limitations within the test room. If used, construct the inlet
plenum and add the four static-pressure taps as shown in Figure 8 of ASHRAE Standard 37-
2009. If used, the inlet duct size shall equal the size of the inlet opening of the air-handling
(blower coil) unit or furnace, with a minimum length of 6 inches. Manifold the four static-
pressure taps using one of the three configurations specified in section 2.4.1.d. Never use an inlet
2.5 Indoor coil air property measurements and air damper box applications.
Follow instructions for indoor coil air property measurements as described in AHRI 210/240-
a. Measure the dry-bulb temperature and water vapor content of the air entering and
leaving the indoor coil. If needed, use an air sampling device to divert air to a sensor(s)
that measures the water vapor content of the air. See Section 5.3 of ASHRAE Standard
41.1-2013 for guidance on constructing an air sampling device. No part of the air
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sampling device or the tubing transferring the sampled air to the sensor shall be within
two inches of the test chamber floor, and the transfer tubing shall be insulated. The
sampling device may also divert air to a remotely located sensor(s) that measures dry
bulb temperature. The air sampling device and the remotely located temperature sensor(s)
may be used to determine the entering air dry bulb temperature during any test. The air
sampling device and the remotely located leaving air dry bulb temperature sensor(s) may
b. An acceptable alternative in all cases, including the two special cases noted above, is to
install a grid of dry bulb temperature sensors within the outlet and inlet ducts. Use a
temperature grid to get the average dry bulb temperature at one location, leaving or entering,
or when two grids are applied as a thermopile, to directly obtain the temperature difference.
A grid of temperature sensors (which may also be used for determining average leaving air
dry bulb temperature) is required to measure the temperature distribution within a cross-
c. Use an inlet and outlet air damper box, an inlet upturned duct, or any combination thereof
when conducting one or both of the cyclic tests listed in sections 3.2 and 3.6 on ducted
systems. Otherwise if not conducting one or both of said cyclic tests, install an outlet air
damper box when testing ducted and non-ducted heat pumps that cycle off the indoor blower
during defrost cycles if no other means is available for preventing natural or forced
convection through the indoor unit when the indoor blower is off. Never use an inlet damper
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box or an inlet upturned duct when testing a non-ducted system. An inlet upturned duct is a
length of ductwork so installed upstream from the inlet such that the indoor duct inlet
opening, facing upwards, is sufficiently high to prevent natural convection transfer out of the
duct. If an inlet upturned duct is used, install a dry bulb temperature sensor near the inlet
opening of the indoor duct at a centerline location not higher than the lowest elevation of the
duct edges at the inlet, and ensure that the variation of the dry bulb temperature at this
location, measured at least every minute during the compressor OFF period of the cyclic test,
2.5.1 Test set-up on the inlet side of the indoor coil: for cases where the inlet airflow prevention
device is installed.
applies.
b. For an inlet damper box, locate the grid of entering air dry-bulb temperature sensors, if
used, and the air sampling device, or the sensor used to measure the water vapor content of
the inlet air, at a location immediately upstream of the damper box inlet. For an inlet
upturned duct, locate the grid of entering air dry-bulb temperature sensors, if used, and the air
sampling device, or the sensor used to measure the water vapor content of the inlet air, at a
location at least one foot downstream from the beginning of the insulated portion of the duct
but before the static pressure measurement; install a dry-bulb temperature sensor at a
centerline location not higher than the lowest elevation of the duct edges at the device inlet.
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Construct the airflow prevention device having a cross-sectional flow area equal to or greater
than the flow area of the inlet plenum. Install the airflow prevention device upstream of the inlet
plenum and construct ductwork connecting it to the inlet plenum. If needed, use an adaptor plate
or a transition duct section to connect the airflow prevention device with the inlet plenum.
Insulate the ductwork and inlet plenum with thermal insulation that has a nominal overall
Construct the airflow prevention device having a cross-sectional flow area equal to or greater
than the flow area of the air inlet of the indoor unit. Install the airflow prevention device
immediately upstream of the inlet of the indoor unit. If needed, use an adaptor plate or a short
transition duct section to connect the airflow prevention device with the unit's air inlet. Add
static pressure taps at the center of each face of a rectangular airflow prevention device, or at
four evenly distributed locations along the circumference of an oval or round airflow prevention
device. Locate the pressure taps between the airflow prevention device and the inlet of the indoor
unit. Make a manifold that connects the four static pressure taps. Insulate the ductwork with
thermal insulation that has a nominal overall resistance (R-value) of at least 19 hr•ft2 • °F/Btu.
2.5.2 Test set-up on the inlet side of the indoor unit: for cases where no airflow prevention
device is installed.
If using the section 2.4.2 inlet plenum and a grid of dry bulb temperature sensors, mount the
grid at a location upstream of the static pressure taps described in section 2.4.2, preferably at the
entrance plane of the inlet plenum. If the section 2.4.2 inlet plenum is not used, but a grid of dry
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bulb temperature sensors is used, locate the grid approximately 6 inches upstream from the inlet
of the indoor coil. Or, in the case of non-ducted units having multiple indoor coils, locate a grid
approximately 6 inches upstream from the inlet of each indoor coil. Position an air sampling
device, or the sensor used to measure the water vapor content of the inlet air, immediately
upstream of the (each) entering air dry-bulb temperature sensor grid. If a grid of sensors is not
used, position the entering air sampling device (or the sensor used to measure the water vapor
Section 6.5.2 of ASHRAE Standard 37-2009 describes the method for fabricating static-
pressure taps. Also refer to Figure 2A of ASHRAE Standard 51-07/AMCA Standard 210-07.Use
a differential pressure measuring instrument that is accurate to within ±0.01 inches of water and
has a resolution of at least 0.01 inches of water to measure the static pressure difference between
the indoor coil air inlet and outlet. Connect one side of the differential pressure instrument to the
manifolded pressure taps installed in the outlet plenum. Connect the other side of the instrument
to the manifolded pressure taps located in either the inlet plenum or incorporated within the
airflow prevention device. If an inlet plenum or inlet airflow prevention device is not used, leave
the inlet side of the differential pressure instrument open to the surrounding atmosphere. For
non-ducted systems that are tested with multiple outlet plenums, measure the static pressure
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a. Install an interconnecting duct between the outlet plenum described in section 2.4.1 and
the airflow measuring apparatus described below in section 2.6. The cross-sectional flow area
of the interconnecting duct must be equal to or greater than the flow area of the outlet plenum
or the common duct used when testing non-ducted units having multiple indoor coils. If
needed, use adaptor plates or transition duct sections to allow the connections. To minimize
leakage, tape joints within the interconnecting duct (and the outlet plenum). Construct or
insulate the entire flow section with thermal insulation having a nominal overall resistance
b. Install a grid(s) of dry-bulb temperature sensors inside the interconnecting duct. Also,
install an air sampling device, or the sensor(s) used to measure the water vapor content of the
outlet air, inside the interconnecting duct. Locate the dry-bulb temperature grid(s) upstream
of the air sampling device (or the in-duct sensor(s) used to measure the water vapor content
of the outlet air). Air that circulates through an air sampling device and past a remote water-
If using an outlet air damper box (see section 2.5), install it within the interconnecting duct at
a location downstream of the location where air from the sampling device is reintroduced or
downstream of the in-duct sensor that measures water vapor content of the outlet air. The leakage
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rate from the combination of the outlet plenum, the closed damper, and the duct section that
connects these two components must not exceed 20 cubic feet per minute when a negative
device(s) upstream of the outlet air, dry-bulb temperature grid (but downstream of the outlet
plenum static pressure taps). Use a perforated screen located between the mixing device and the
dry-bulb temperature grid, with a maximum open area of 40 percent. One or both items should
help to meet the maximum outlet air temperature distribution specified in section 3.1.8. Mixing
devices are described in sections 5.3.2 and 5.3.3 of ASHRAE Standard 41.1-2013 and section
For small-duct, high-velocity systems, install an air damper near the end of the
interconnecting duct, just prior to the transition to the airflow measuring apparatus of section 2.6.
To minimize air leakage, adjust this damper such that the pressure in the receiving chamber of
the airflow measuring apparatus is no more than 0.5 inch of water higher than the surrounding
test room ambient. If applicable, in lieu of installing a separate damper, use the outlet air damper
box of sections 2.5 and 2.5.4.1 if it allows variable positioning. Also apply these steps to any
conventional indoor blower unit that creates a static pressure within the receiving chamber of the
airflow measuring apparatus that exceeds the test room ambient pressure by more than 0.5 inches
of water column.
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2.5.5 Dry bulb temperature measurement.
a. Measure dry bulb temperatures as specified in sections 4, 5.3, 6, 7.2, and 7.3 of ASHRAE
Standard 41.1-2013.
b. Distribute the sensors of a dry-bulb temperature grid over the entire flow area. The
Determine water vapor content by measuring dry-bulb temperature combined with the air
wet-bulb temperature, dew point temperature, or relative humidity. If used, construct and apply
wet-bulb temperature sensors as specified in sections 4, 5, 6, 7.2, 7.3, 7.4, and 7.5 of ASHRAE
Standard 41.6-2014. The temperature sensor (wick removed) must be accurate to within ±0.2 °F.
If used, apply dew point hygrometers as specified in sections 4, 5, 6, and 7.1 of ASHRAE
Standard 41.6-2014. The dew point hygrometers must be accurate to within ±0.4 °F when
operated at conditions that result in the evaluation of dew points above 35 °F. If used, a relative
humidity (RH) meter must be accurate to within ±0.7% RH. Other means to determine the
psychrometric state of air may be used as long as the measurement accuracy is equivalent to or
better than the accuracy achieved from using a wet-bulb temperature sensor that meets the above
specifications.
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If used (see section 2.5), the air damper box(es) must be capable of being completely opened
a. Fabricate and operate an Air Flow Measuring Apparatus as specified in section 6.2 and 6.3
Standard 210-07 or Figure 14 of ASHRAE Standard 41.2-87 (RA 92) for guidance on
placing the static pressure taps and positioning the diffusion baffle (settling means) relative
to the chamber inlet. When measuring the static pressure difference across nozzles and/or
velocity pressure at nozzle throats using electronic pressure transducers and a data
the test tolerance limits specified in section 9.2 and Table 2 of ASHRAE Standard 37-2009,
dampen the measurement system such that the time constant associated with response to a
step change in measurement (time for the response to change 63% of the way from the initial
b. Connect the airflow measuring apparatus to the interconnecting duct section described in
section 2.5.4. See sections 6.1.1, 6.1.2, and 6.1.4, and Figures 1, 2, and 4 of ASHRAE
Standard 37-2009; and Figures D1, D2, and D4 of AHRI 210/240-2008 with Addendum 1
and 2 for illustrative examples of how the test apparatus may be applied within a complete
laboratory set-up. Instead of following one of these examples, an alternative set-up may be
used to handle the air leaving the airflow measuring apparatus and to supply properly
conditioned air to the test unit's inlet. The alternative set-up, however, must not interfere with
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the prescribed means for measuring airflow rate, inlet and outlet air temperatures, inlet and
outlet water vapor contents, and external static pressures, nor create abnormal conditions
surrounding the test unit. (Note: Do not use an enclosure as described in section 6.1.3 of
Perform all tests at the voltage specified in section 6.1.3.2 of AHRI 210/240-2008 with
Addendum 1 and 2 for “Standard Rating Tests.” If the voltage on the nameplate of indoor and
outdoor units differs, the voltage supply on the outdoor unit shall be selected for testing. Measure
the supply voltage at the terminals on the test unit using a volt meter that provides a reading that
a. Use an integrating power (watt-hour) measuring system to determine the electrical energy
or average electrical power supplied to all components of the air conditioner or heat pump
condensate pump on non-ducted indoor units, etc.). The watt-hour measuring system must
give readings that are accurate to within ±0.5 percent. For cyclic tests, this accuracy is
required during both the ON and OFF cycles. Use either two different scales on the same
watt-hour meter or two separate watt-hour meters. Activate the scale or meter having the
lower power rating within 15 seconds after beginning an OFF cycle. Activate the scale or
meter having the higher power rating active within 15 seconds prior to beginning an ON
cycle. For ducted units tested with a fan installed, the ON cycle lasts from compressor ON to
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indoor blower OFF. For ducted units tested without an indoor blower installed, the ON cycle
lasts from compressor ON to compressor OFF. For non-ducted units, the ON cycle lasts from
indoor blower ON to indoor blower OFF. When testing air conditioners and heat pumps
b. When performing section 3.5 and/or 3.8 cyclic tests on non-ducted units, provide
instrumentation to determine the average electrical power consumption of the indoor blower
motor to within ±1.0 percent. If required according to sections 3.3, 3.4, 3.7, 3.9.1, and/or
3.10, this same instrumentation requirement applies when testing air conditioners and heat
Make elapsed time measurements using an instrument that yields readings accurate to within
±0.2 percent.
2.10 Test apparatus for the secondary space conditioning capacity measurement.
For all tests, use the Indoor Air Enthalpy Method to measure the unit's capacity. This method
uses the test set-up specified in sections 2.4 to 2.6. In addition, for all steady-state tests, conduct
a second, independent measurement of capacity as described in section 3.1.1. For split systems,
use one of the following secondary measurement methods: Outdoor Air Enthalpy Method,
Compressor Calibration Method, or Refrigerant Enthalpy Method. For single-package units, use
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either the Outdoor Air Enthalpy Method or the Compressor Calibration Method as the secondary
measurement.
b. The test apparatus required for the Outdoor Air Enthalpy Method is a subset of the
apparatus used for the Indoor Air Enthalpy Method. Required apparatus includes the
following:
(1) On the outlet side, an outlet plenum containing static pressure taps (sections 2.4,
(3) A duct section that connects these two components and itself contains the
instrumentation for measuring the dry-bulb temperature and water vapor content of the
air leaving the outdoor coil (sections 2.5.4, 2.5.5, and 2.5.6), and
(4) On the inlet side, a sampling device and temperature grid (section 2.11b.).
c. During the preliminary tests described in sections 3.11.1 and 3.11.1.1, measure the
evaporator and condenser temperatures or pressures. On both the outdoor coil and the indoor
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coil, solder a thermocouple onto a return bend located at or near the midpoint of each coil or
at points not affected by vapor superheat or liquid subcooling. Alternatively, if the test unit is
not sensitive to the refrigerant charge, install pressure gages to the access valves or to ports
created from tapping into the suction and discharge lines according to sections 7.4.2 and
8.2.5 of ASHRAE Standard 37–2009. Use this alternative approach when testing a unit
Measure refrigerant pressures and temperatures to determine the evaporator superheat and
the enthalpy of the refrigerant that enters and exits the indoor coil. Determine refrigerant flow
rate or, when the superheat of the refrigerant leaving the evaporator is less than 5 °F, total
capacity from separate calibration tests conducted under identical operating conditions. When
using this method, install instrumentation, measure refrigerant properties, and adjust the
refrigerant charge according to section 7.4.2 and 8.2.5 of ASHRAE Standard 37-2009. Use
refrigerant temperature and pressure measuring instruments that meet the specifications given in
For this method, calculate space conditioning capacity by determining the refrigerant
enthalpy change for the indoor coil and directly measuring the refrigerant flow rate. Use section
7.5.2 of ASHRAE Standard 37-2009 for the requirements for this method, including the
additional instrumentation requirements, and information on placing the flow meter and a sight
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glass. Use refrigerant temperature, pressure, and flow measuring instruments that meet the
specifications given in sections 5.1.1, 5.2, and 5.5.1 of ASHRAE Standard 37-2009. Refrigerant
flow measurement device(s), if used, must be elevated at least two feet from the test chamber
floor or placed upon insulating material having a total thermal resistance of at least R-12 and
extending at least one foot laterally beyond each side of the device(s)’ exposed surfaces, unless
the device(s) are elevated at least two feet from the floor.
Follow instructions for measurement of test room ambient conditions as described in AHRI
a. If using a test set-up where air is ducted directly from the conditioning apparatus to the
indoor coil inlet (see Figure 2, Loop Air-Enthalpy Test Method Arrangement, of ASHRAE
Standard 37-2009), add instrumentation to permit measurement of the indoor test room dry-
bulb temperature.
b. For the outdoor side, install a grid of evenly-distributed sensors on every air-permitting
face on the inlet of the outdoor unit, such that each measurement represents an air-inlet area
of no more than one square foot. This grid must be constructed and applied as per section 5.3
these sensors may differ by no more than 1.5 ˚F—otherwise adjustments to the test room
must be made to improve temperature uniformity. The outdoor conditions shall be verified
with the air collected by air sampling device. Air collected by an air sampling device at the
air inlet of the outdoor unit for transfer to sensors for measurement of temperature and/or
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humidity shall be protected from temperature change as follows: any surface of the air
conveying tubing in contact with surrounding air at a different temperature than the sampled
air shall be insulated with thermal insulation with a nominal thermal resistance (R-value) of
at least 19 hr • ft2 • °F/Btu, no part of the air sampling device or the tubing conducting the
sampled air to the sensors shall be within two inches of the test chamber floor, and pairs of
measurements (e.g. dry bulb temperature and wet bulb temperature) used to determine water
vapor content of sampled air shall be measured in the same location. Take steps (e.g., add or
re-position a lab circulating fan), as needed, to maximize temperature uniformity within the
outdoor test room. However, ensure that any fan used for this purpose does not cause air
velocities in the vicinity of the test unit to exceed 500 feet per minute.
c. Measure dry bulb temperatures as specified in sections 4, 5, 7.2, 6, and 7.3 of ASHRAE
Standard 41.1-2013. Measure water vapor content as stated above in section 2.5.6.
When required, measure fan speed using a revolution counter, tachometer, or stroboscope
Determine the average barometric pressure during each test. Use an instrument that meets the
3. Testing Procedures
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3.1 General Requirements.
If, during the testing process, an equipment set-up adjustment is made that would have
altered the performance of the unit during any already completed test, then repeat all tests
affected by the adjustment. For cyclic tests, instead of maintaining an air volume rate, for each
airflow nozzle, maintain the static pressure difference or velocity pressure during an ON period
at the same pressure difference or velocity pressure as measured during the steady-state test
Use the testing procedures in this section to collect the data used for calculating (1)
performance metrics for central air conditioners and heat pumps during the cooling season; (2)
performance metrics for heat pumps during the heating season; and (3) power consumption
metric(s) for central air conditioners and heat pumps during the off mode season(s).
For all tests, use the Indoor Air Enthalpy Method test apparatus to determine the unit's space
conditioning capacity. The procedure and data collected, however, differ slightly depending upon
whether the test is a steady-state test, a cyclic test, or a Frost Accumulation test. The following
sections described these differences. For all steady-state tests (i.e., the A, A2, A1, B, B2, B1, C,
C1, EV, F1, G1, H01, H1, H12, H11, HIN, H3, H32, and H31 Tests), in addition, use one of the
acceptable secondary methods specified in section 2.10 to determine indoor space conditioning
capacity. Calculate this secondary check of capacity according to section 3.11. The two
capacity measurements must agree to within 6 percent to constitute a valid test. For this capacity
comparison, use the Indoor Air Enthalpy Method capacity that is calculated in section 7.3 of
ASHRAE Standard 37-2009 (and, if testing a coil-only system, do not make the after-test fan
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heat adjustments described in section 3.3, 3.4, 3.7, and 3.10 of this appendix). However, include
the appropriate section 3.3 to 3.5 and 3.7 to 3.10 fan heat adjustments within the Indoor Air
Where needed, the manufacturer must provide a means for overriding the controls of the test
unit so that the compressor(s) operates at the specified speed or capacity and the indoor blower
operates at the specified speed or delivers the specified air volume rate.
For all tests, meet the requirements given in section 6.1.3.4 of AHRI 210/240-2008 with
Addendum 1 and 2 when obtaining the airflow through the outdoor coil.
3.1.3.1 Double-ducted. For products intended to be installed with the outdoor airflow ducted,
the unit shall be installed with outdoor coil ductwork installed per manufacturer installation
instructions and shall operate between 0.10 and 0.15 in H2O external static pressure.
External static pressure measurements shall be made in accordance with ASHRAE Standard
Airflow setting(s) shall be determined before testing begins. Unless otherwise specified
within this or its subsections, no changes shall be made to the airflow setting(s) after initiation of
testing.
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3.1.4.1.1 Cooling Full-Load Air Volume Rate for Ducted Units.
The manufacturer must specify the cooling full-load air volume rate and the instructions for
setting fan speed or controls. Adjust the cooling full-load air volume rate if needed to satisfy the
additional requirements of this section. First, when conducting the A or A2 Test (exclusively), the
measured air volume rate, when divided by the measured indoor air-side total cooling capacity
must not exceed 37.5 cubic feet per minute of standard air (scfm) per 1000 Btu/h. If this ratio is
exceeded, reduce the air volume rate until this ratio is equaled. Use this reduced air volume rate
for all tests that call for using the Cooling Full-load Air Volume Rate. Pressure requirements are
as follows:
a. For all ducted units tested with an indoor blower installed, except those having a constant-
1. Achieve the Cooling Full-load Air Volume Rate, determined in accordance with the
previous paragraph;
3. If this pressure is equal to or greater than the applicable minimum external static
pressure cited in Table 3, the pressure requirement is satisfied. Use the current air volume
rate for all tests that require the Cooling Full-load Air Volume Rate.
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable Table 3 minimum is
equaled or
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4b. until the measured air volume rate equals 90 percent of the air volume rate from
5. If the conditions of step 4a occur first, the pressure requirement is satisfied. Use the
step 4a reduced air volume rate for all tests that require the Cooling Full-load Air Volume
Rate.
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor blower (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor blower set-up
cannot be further changed, reduce the air volume rate and increase the external static
pressure by adjusting the exhaust fan of the airflow measuring apparatus until the
applicable Table 3 minimum is equaled. Use this reduced air volume rate for all tests that
b. For ducted units that are tested with a constant-air-volume-rate indoor blower installed.
For all tests that specify the Cooling Full-load Air Volume Rate, obtain an external static
pressure as close to (but not less than) the applicable Table 3 value that does not cause
automatic shutdown of the indoor blower or air volume rate variation QVar, defined as
𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚 − 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚
𝑄𝑄𝑉𝑉𝑉𝑉𝑉𝑉 = � 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚 + 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚
� ∗ 100
� �
2
Where:
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QVar = airflow variance, percent
Additional test steps as described in section 3.3.(e) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted units that are tested without an indoor fan installed. For the A or A2 Test,
(exclusively), the pressure drop across the indoor coil assembly must not exceed 0.30 inches
of water. If this pressure drop is exceeded, reduce the air volume rate until the measured
pressure drop equals the specified maximum. Use this reduced air volume rate for all tests
Table 3 Minimum External Static Pressure for Ducted Systems Tested With an Indoor
blower Installed
Minimum external resistance3 (Inches of water)
Short ducted Small-duct, high- All other
Rated Cooling1 or
Heating2 Capacity systems4 velocity systems4 5 systems
(Btu/h)
Up Thru 28,800 0.03 1.10 0.10
29,000 to 42,500 0.05 1.15 0.15
43,000 and Above 0.07 1.20 0.20
1
For air conditioners and heat pumps, the value cited by the manufacturer in published literature
for the unit's capacity when operated at the A or A2 Test conditions.
2
For heating-only heat pumps, the value the manufacturer cites in published literature for the
unit's capacity when operated at the H1 or H12 Test conditions.
3
For ducted units tested without an air filter installed, increase the applicable tabular value by
0.08 inches of water.
4
See section 1.2, Definitions, to determine if the equipment qualifies as a short-ducted or a small-
duct, high-velocity system.
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5
If a closed-loop, air-enthalpy test apparatus is used on the indoor side, limit the resistance to
airflow on the inlet side of the indoor blower coil to a maximum value of 0.1 inch of water.
Impose the balance of the airflow resistance on the outlet side of the indoor blower.
d. For ducted systems having multiple indoor blowers within a single indoor section, obtain
the full-load air volume rate with all blowers operating unless prevented by the controls of
the unit. In such cases, turn on the maximum number of blowers permitted by the unit’s
controls. Where more than one option exists for meeting this “on” blower requirement,
which blower(s) are turned on must match that specified by the manufacturer in the
installation manuals included with the unit. Conduct section 3.1.4.1.1 setup steps for each
blower separately. If two or more indoor blowers are connected to a common duct as per
section 2.4.1, either turn off the other indoor blowers connected to the same common duct or
temporarily divert their air volume to the test room when confirming or adjusting the setup
configuration of individual blowers. If the indoor blowers are all the same size or model, the
target air volume rate for each blower plenum equals the full-load air volume rate divided by
the number of “on” blowers. If different size blowers are used within the indoor section, the
allocation of the system’s full-load air volume rate assigned to each “on” blower must match
that specified by the manufacturer in the installation manuals included with the unit.
For non-ducted units, the Cooling Full-load Air Volume Rate is the air volume rate that
results during each test when the unit is operated at an external static pressure of zero inches of
water.
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The manufacturer must specify the cooling minimum air volume rate and the instructions for
setting fan speed or controls. The target external static pressure, ΔPst_i, for any test “i” with a
specified air volume rate not equal to the cooling full-load air volume rate is determined as
follows.
2
𝑄𝑄𝑖𝑖
∆𝑃𝑃𝑠𝑠𝑠𝑠_𝑖𝑖 = ∆𝑃𝑃𝑠𝑠𝑠𝑠_𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 � �
𝑄𝑄𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓
Where:
Qfull = cooling full-load air volume rate as measured after setting and/or adjustment as described
in section 3.1.4.1.1.
a. For ducted units tested with an indoor blower installed that is not a constant-air-volume
3. If this pressure is equal to or greater than the target minimum external static pressure
calculated as described above, use the current air volume rate for all tests that require the
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable target minimum is
equaled or
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4b. until the measured air volume rate equals 90 percent of the air volume rate from
5. If the conditions of step 4a occur first, use the step 4a reduced air volume rate for all
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor fan (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor fan set-up cannot
be further changed, reduce the air volume rate and increase the external static pressure by
adjusting the exhaust fan of the airflow measuring apparatus until the applicable target
minimum is equaled. Use this reduced air volume rate for all tests that require the
b. For ducted units with constant-air-volume indoor blowers, conduct all tests that specify the
cooling minimum air volume rate—(i.e., the A1, B1, C1, F1, and G1 Tests)—at an external
static pressure that does not cause an automatic shutdown of the indoor blower or air volume
rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10 percent, while being as
close to, but not less than the target minimum external static pressure. Additional test steps
as described in section 3.3(e) of this appendix are required if the measured external static
pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted two-capacity units that are tested without an indoor blower installed, the
Cooling Minimum Air Volume Rate is the higher of (1) the rate specified by the installation
instructions included with the unit by the manufacturer or (2) 75 percent of the Cooling Full-
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load Air Volume Rate. During the laboratory tests on a coil-only (fanless) unit, obtain this
Cooling Minimum Air Volume Rate regardless of the pressure drop across the indoor coil
assembly.
d. For non-ducted units, the Cooling Minimum Air Volume Rate is the air volume rate that
results during each test when the unit operates at an external static pressure of zero inches of
water and at the indoor fan setting used at low compressor capacity (two-capacity system) or
compressor and a variable-speed variable-air-volume-rate indoor fan, use the lowest fan
e. For ducted systems having multiple indoor blowers within a single indoor section, operate
the indoor blowers such that the lowest air volume rate allowed by the unit’s controls is
obtained when operating the lone single-speed compressor or when operating at low
compressor capacity while meeting the requirements of section 2.2.3.2 for the minimum
number of blowers that must be turned off. Adjust for external static pressure and if
necessary adjust air volume rates as described in section 3.1.4.2.a if the indoor fan is not a
constant-air-volume indoor fan. The sum of the individual “on” blowers’ air volume rates is
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The manufacturer must specify the cooling intermediate air volume rate and the instructions
for setting fan speed or controls. Calculate target minimum external static pressure as described
in section 3.1.4.2.
a. For ducted units tested with an indoor blower, installed that is not a constant-air-volume
indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for cooling
b. For ducted units tested with constant-air-volume indoor blowers installed, conduct the
EV Test at an external static pressure that does not cause an automatic shutdown of the indoor
blower or air volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10
percent, while being as close to, but not less than the target minimum external static pressure.
Additional test steps as described in section 3.3(e) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
c. For non-ducted units, the Cooling Intermediate Air Volume Rate is the air volume rate that
results when the unit operates at an external static pressure of zero inches of water and at the
fan speed selected by the controls of the unit for the EV Test conditions.
3.1.4.4.1 Ducted heat pumps where the Heating and Cooling Full-load Air Volume Rates are the
same.
a. Use the Cooling Full-load Air Volume Rate as the Heating Full-load Air Volume Rate for:
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1. Ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower that operates at the same airflow-control setting during both the A
2. Ducted heat pumps tested with constant-air-flow indoor blowers installed that provide
the same air flow for the A (or A2) and the H1 (or H12) Tests; and
3. Ducted heat pumps that are tested without an indoor blower installed (except two-
capacity northern heat pumps that are tested only at low capacity cooling—see 3.1.4.4.2).
b. For heat pumps that meet the above criteria “1” and “3,” no minimum requirements apply
to the measured external or internal, respectively, static pressure. For heat pumps that meet
the above criterion “2,” test at an external static pressure that does not cause an automatic
shutdown of the indoor blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than, the same Table
3 minimum external static pressure as was specified for the A (or A2) cooling mode test.
Additional test steps as described in section 3.9.1(c) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
3.1.4.4.2 Ducted heat pumps where the Heating and Cooling Full-load Air Volume Rates are
The manufacturer must specify the heating full-load air volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2.
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a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
b. For ducted heat pumps tested with constant-air-volume indoor blowers installed, conduct
all tests that specify the heating full-load air volume rate at an external static pressure that
does not cause an automatic shutdown of the indoor blower or air volume rate variation QVar,
defined in section 3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less
than the target minimum external static pressure. Additional test steps as described in section
3.9.1(c) of this appendix are required if the measured external static pressure exceeds the
c. When testing ducted, two-capacity northern heat pumps (see section 1.2, Definitions), use
the appropriate approach of the above two cases for units that are tested with an indoor
blower installed. For coil-only northern heat pumps, the Heating Full-load Air Volume Rate
is the lesser of the rate specified by the manufacturer in the installation instructions included
with the unit or 133 percent of the Cooling Full-load Air Volume Rate. For this latter case,
obtain the Heating Full-load Air Volume Rate regardless of the pressure drop across the
d. For ducted systems having multiple indoor blowers within a single indoor section, obtain
the heating full-load air volume rate using the same “on” blowers as used for the cooling full-
load air volume rate. For systems where individual blowers regulate the speed (as opposed to
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the cfm) of the indoor blower, use the first section 3.1.4.4.2 equation for each blower
individually. Sum the individual blower air volume rates to obtain the heating full-load air
The manufacturer must specify the Heating Full-load Air Volume Rate.
a. For all ducted heating-only heat pumps tested with an indoor blower installed, except those
having a constant-air-volume-rate indoor blower. Conduct the following steps only during
3. If this pressure is equal to or greater than the Table 3 minimum external static pressure
that applies given the heating-only heat pump's rated heating capacity, use the current air
volume rate for all tests that require the Heating Full-load Air Volume Rate.
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable Table 3 minimum is
equaled or
4b. until the measured air volume rate equals 90 percent of the manufacturer-
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5. If the conditions of step 4a occurs first, use the step 4a reduced air volume rate for all
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor blower (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor blower set-up
cannot be further changed, reduce the air volume rate until the applicable Table 3
minimum is equaled. Use this reduced air volume rate for all tests that require the
b. For ducted heating-only heat pumps that are tested with a constant-air-volume-rate indoor
blower installed. For all tests that specify the Heating Full-load Air Volume Rate, obtain an
external static pressure that does not cause an automatic shutdown of the indoor blower or air
volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10 percent, while
being as close to, but not less than, the applicable Table 3 minimum. Additional test steps as
described in section 3.9.1(c) of this appendix are required if the measured external static
pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted heating-only heat pumps that are tested without an indoor blower installed. For
the H1 or H12 Test, (exclusively), the pressure drop across the indoor coil assembly must not
exceed 0.30 inches of water. If this pressure drop is exceeded, reduce the air volume rate
until the measured pressure drop equals the specified maximum. Use this reduced air volume
rate for all tests that require the Heating Full-load Air Volume Rate.
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3.1.4.4.4 Non-ducted heat pumps, including non-ducted heating-only heat pumps.
For non-ducted heat pumps, the Heating Full-load Air Volume Rate is the air volume rate
that results during each test when the unit operates at an external static pressure of zero inches of
water.
3.1.4.5.1 Ducted heat pumps where the Heating and Cooling Minimum Air Volume Rates are the
same.
a. Use the Cooling Minimum Air Volume Rate as the Heating Minimum Air Volume Rate
for:
1. Ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower that operates at the same airflow-control setting during both the A1
and the H11 tests;2. Ducted heat pumps tested with constant-air-flow indoor blowers
installed that provide the same air flow for the A1 and the H11 Tests; and
3. Ducted heat pumps that are tested without an indoor blower installed (except two-
capacity northern heat pumps that are tested only at low capacity cooling—see 3.1.4.4.2).
b. For heat pumps that meet the above criteria “1” and “3,” no minimum requirements apply
to the measured external or internal, respectively, static pressure. For heat pumps that meet
the above criterion “2,” test at an external static pressure that does not cause an automatic
shutdown of the indoor blower or air volume rate variation QVar, defined in section
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3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than, the same target
minimum external static pressure as was specified for the A1 cooling mode test. Additional
test steps as described in section 3.9.1(c) of this appendix are required if the measured
external static pressure exceeds the target value by more than 0.03 inches of water.
3.1.4.5.2 Ducted heat pumps where the Heating and Cooling Minimum Air Volume Rates are
The manufacturer must specify the heating minimum volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2.
a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
b. For ducted heat pumps tested with constant-air-volume indoor blowers installed,
conduct all tests that specify the Heating Minimum Air Volume Rate—(i.e., the H01, H11, H21,
and H31 Tests)—at an external static pressure that does not cause an automatic shutdown of the
indoor blower while being as close to, but not less thanor air volume rate variation QVar, defined
in section 3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than the target
minimum external static pressure. Additional test steps as described in section 3.9.1(c) of this
appendix are required if the measured external static pressure exceeds the target value by more
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c. For ducted two-capacity northern heat pumps that are tested with an indoor blower
d. For ducted two-capacity heat pumps that are tested without an indoor blower installed, use
the Cooling Minimum Air Volume Rate as the Heating Minimum Air Volume Rate. For
ducted two-capacity northern heat pumps that are tested without an indoor blower installed,
use the Cooling Full-load Air Volume Rate as the Heating Minimum Air Volume Rate. For
ducted two-capacity heating-only heat pumps that are tested without an indoor blower
installed, the Heating Minimum Air Volume Rate is the higher of the rate specified by the
manufacturer in the test setup instructions included with the unit or 75 percent of the Heating
Full-load Air Volume Rate. During the laboratory tests on a coil-only system, obtain the
Heating Minimum Air Volume Rate without regard to the pressure drop across the indoor
coil assembly.
e. For non-ducted heat pumps, the Heating Minimum Air Volume Rate is the air volume rate
that results during each test when the unit operates at an external static pressure of zero
inches of water and at the indoor blower setting used at low compressor capacity (two-
capacity system) or minimum compressor speed (variable-speed system). For units having a
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f. For ducted systems with multiple indoor blowers within a single indoor section, obtain the
heating minimum air volume rate using the same “on” blowers as used for the cooling
minimum air volume rate. For systems where individual blowers regulate the speed (as
opposed to the cfm) of the indoor blower, use the first section 3.1.4.5 equation for each
blower individually. Sum the individual blower air volume rates to obtain the heating
The manufacturer must specify the heating intermediate air volume rate and the instructions
for setting fan speed or controls. Calculate target minimum external static pressure as described
in section 3.1.4.2.
a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
b. For ducted heat pumps tested with constant-air-volume indoor blowers installed, conduct
the H2V Test at an external static pressure that does not cause an automatic shutdown of the
indoor blower or air volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10
percent, while being as close to, but not less than the target minimum external static pressure.
Additional test steps as described in section 3.9.1(c) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
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c. For non-ducted heat pumps, the Heating Intermediate Air Volume Rate is the air volume
rate that results when the heat pump operates at an external static pressure of zero inches of
water and at the fan speed selected by the controls of the unit for the H2V Test conditions.
The manufacturer must specify the heating nominal air volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2. Make adjustments as described in section 3.14.6 for heating intermediate air
volume rate so that the target minimum external static pressure is met or exceeded.
3.1.5 Indoor test room requirement when the air surrounding the indoor unit is not supplied from
If using a test set-up where air is ducted directly from the air reconditioning apparatus to the
indoor coil inlet (see Figure 2, Loop Air-Enthalpy Test Method Arrangement, of ASHRAE
Standard 37-2009), maintain the dry bulb temperature within the test room within ±5.0 °F of the
applicable sections 3.2 and 3.6 dry bulb temperature test condition for the air entering the indoor
For all steady-state tests and for Frost Accumulation (H2, H21, H22, H2V) tests, calculate the
air volume rate through the indoor coil as specified in sections 7.7.2.1 and 7.7.2.2 of ASHRAE
Standard 37-2009. When using the Outdoor Air Enthalpy Method, follow sections 7.7.2.1 and
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7.7.2.2 to calculate the air volume rate through the outdoor coil. To express air volume rates in
������
̇
𝑉𝑉𝑚𝑚𝑚𝑚 ������
𝑉𝑉̇𝑚𝑚𝑚𝑚
Equation 3-1 𝑉𝑉𝑠𝑠̇ = 𝑙𝑙𝑙𝑙𝑙𝑙𝑑𝑑a ′ = 𝑙𝑙𝑙𝑙𝑙𝑙𝑑𝑑a
0.075 ∗𝑣𝑣𝑛𝑛 ∗[1+𝑊𝑊𝑛𝑛 ] 0.075 ∗𝑣𝑣𝑛𝑛
𝑓𝑓𝑓𝑓3 𝑓𝑓𝑓𝑓3
where,
vn′ = specific volume of air-water vapor mixture at the nozzle, ft3 per lbm of the air-water
vapor mixture
Wn = humidity ratio at the nozzle, lbm of water vapor per lbm of dry air
vn = specific volume of the dry air portion of the mixture evaluated at the dry-bulb
temperature, vapor content, and barometric pressure existing at the nozzle, ft3 per lbm of
dry air.
(Note: In the first printing of ASHRAE Standard 37-2009, the second IP equation for
Manufacturers may optionally operate the equipment under test for a “break-in” period, not
to exceed 20 hours, prior to conducting the test method specified in this section. A manufacturer
who elects to use this optional compressor break-in period in its certification testing should
344
record this information (including the duration) in the test data underlying the certified ratings
that are required to be maintained under 10 CFR 429.71. When testing a ducted unit (except if a
heating-only heat pump), conduct the A or A2 Test first to establish the Cooling Full-load Air
Volume Rate. For ducted heat pumps where the Heating and Cooling Full-load Air Volume
Rates are different, make the first heating mode test one that requires the Heating Full-load Air
Volume Rate. For ducted heating-only heat pumps, conduct the H1 or H12 Test first to establish
the Heating Full-load Air Volume Rate. When conducting an cyclic test, always conduct it
immediately after the steady-state test that requires the same test conditions. For variable-speed
systems, the first test using the Cooling Minimum Air Volume Rate should precede the EV Test,
and the first test using the Heating Minimum Air Volume Rate must precede the H2V Test. The
3.1.8 Requirement for the air temperature distribution leaving the indoor coil.
For at least the first cooling mode test and the first heating mode test, monitor the
temperature distribution of the air leaving the indoor coil using the grid of individual sensors
described in sections 2.5 and 2.5.4. For the 30-minute data collection interval used to determine
capacity, the maximum spread among the outlet dry bulb temperatures from any data sampling
must not exceed 1.5 °F. Install the mixing devices described in section 2.5.4.2 to minimize the
temperature spread.
3.1.9 Requirement for the air temperature distribution entering the outdoor coil.
Monitor the temperatures of the air entering the outdoor coil using the grid of temperature
sensors described in section 2.11. For the 30-minute data collection interval used to determine
345
capacity, the maximum difference between dry bulb temperatures measured at any of these
Except as noted, disable heat pump resistance elements used for heating indoor air at all
times, including during defrost cycles and if they are normally regulated by a heat comfort
controller. For heat pumps equipped with a heat comfort controller, enable the heat pump
resistance elements only during the below-described, short test. For single-speed heat pumps
covered under section 3.6.1, the short test follows the H1 or, if conducted, the H1C Test. For
two-capacity heat pumps and heat pumps covered under section 3.6.2, the short test follows the
H12 Test. Set the heat comfort controller to provide the maximum supply air temperature. With
the heat pump operating and while maintaining the Heating Full-load Air Volume Rate, measure
the temperature of the air leaving the indoor-side beginning 5 minutes after activating the heat
comfort controller. Sample the outlet dry-bulb temperature at regular intervals that span 5
minutes or less. Collect data for 10 minutes, obtaining at least 3 samples. Calculate the average
3.2 Cooling mode tests for different types of air conditioners and heat pumps.
3.2.1 Tests for a unit having a single-speed compressor, or a multi-circuit system, that is tested
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Conduct two steady-state wet coil tests, the A and B Tests. Use the two dry-coil tests, the
steady-state C Test and the cyclic D Test, to determine the cooling mode cyclic degradation
coefficient, CDc. If testing outdoor units of central air conditioners or heat pumps that are not sold
with indoor units, assign CDc the default value of 0.2. Table 4 specifies test conditions for these
four tests.
Table 4 Cooling Mode Test Conditions for Units Having a Single-Speed Compressor and a
Fixed-Speed Indoor blower, a Constant Air Volume Rate Indoor blower, or No Indoor
blower
3.2.2 Tests for a unit having a single-speed compressor where the indoor section uses a
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3.2.2.1 Indoor blower capacity modulation that correlates with the outdoor dry bulb temperature
Conduct four steady-state wet coil tests: The A2, A1, B2, and B1 Tests. Use the two dry-coil
tests, the steady-state C1 Test and the d D1 Test, to determine the cooling mode cyclic
3.2.2.2 Indoor blower capacity modulation based on adjusting the sensible to total (S/T) cooling
capacity ratio.
The testing requirements are the same as specified in section 3.2.1 and Table 4. Use a
Cooling Full-load Air Volume Rate that represents a normal installation. If performed, conduct
the steady-state C Test and the cyclic D Test with the unit operating in the same S/T capacity
Table 5 Cooling Mode Test Conditions for Units with a Single-Speed Compressor That
Meet the Section 3.2.2.1 Indoor Unit Requirements
348
D1 Test4—required 80 (4) 82 (5)
(cyclic, dry coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
3
Defined in section 3.1.4.2.
4
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. (It is recommended that an indoor wet-bulb temperature of 57 °F or less be used.)
5
Maintain the airflow nozzles static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the C1 Test.
3.2.3 Tests for a unit having a two-capacity compressor. (see section 1.2, Definitions)
a. Conduct four steady-state wet coil tests: the A2, B2, B1, and F1 Tests. Use the two dry-coil
tests, the steady-state C1 Test and the cyclic D1 Test, to determine the cooling-mode cyclic-
degradation coefficient, CDc. Table 6 specifies test conditions for these six tests.
b. For units having a variable speed indoor blower that is modulated to adjust the sensible to
total (S/T) cooling capacity ratio, use Cooling Full-load and Cooling Minimum Air Volume
Rates that represent a normal installation. Additionally, if conducting the dry-coil tests,
operate the unit in the same S/T capacity control mode as used for the B1 Test.
c. Test two-capacity, northern heat pumps (see section 1.2, Definitions) in the same way as a
single speed heat pump with the unit operating exclusively at low compressor capacity (see
d. If a two-capacity air conditioner or heat pump locks out low-capacity operation at higher
outdoor temperatures, then use the two dry-coil tests, the steady-state C2 Test and the cyclic
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D2 Test, to determine the cooling-mode cyclic-degradation coefficient that only applies to
on/off cycling from high capacity, CDc(k=2). The default CDc(k=2) is the same value as
equivalently, CDc(k=1)].
Table 6 Cooling Mode Test Conditions for Units Having a Two-Capacity Compressor
1
A2 Test— 80 67 95 75 High Cooling Full-
required Load.2
(steady, wet
coil)
1
B2 Test— 80 67 82 65 High Cooling Full-
required Load.2
(steady, wet
coil)
1
B1 Test— 80 67 82 65 Low Cooling
required Minimum.3
(steady, wet
coil)
350
C1 Test— 80 (4) 82 Low Cooling
required Minimum.3
(steady, dry-
coil)
1
F1 Test— 80 67 67 53.5 Low Cooling
required Minimum.3
(steady, wet
coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
3
Defined in section 3.1.4.2.
4
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet-bulb temperature of 57 °F or less.
5
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the C2 Test.
6
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the C1 Test.
a. Conduct five steady-state wet coil tests: The A2, EV, B2, B1, and F1 Tests. Use the two dry-
coil tests, the steady-state G1 Test and the cyclic I1 Test, to determine the cooling mode
cyclic degradation coefficient, CDc. Table 7 specifies test conditions for these seven tests.
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where a tolerance of plus 5 percent or the next higher inverter frequency step from that
calculated is allowed.
b. For units that modulate the indoor blower speed to adjust the sensible to total (S/T) cooling
capacity ratio, use Cooling Full-load, Cooling Intermediate, and Cooling Minimum Air
Volume Rates that represent a normal installation. Additionally, if conducting the dry-coil
tests, operate the unit in the same S/T capacity control mode as used for the F1 Test.
c. For multiple-split air conditioners and heat pumps (except where noted), the following
procedures supersede the above requirements: For all Table 7 tests specified for a minimum
compressor speed, at least one indoor unit must be turned off. The manufacturer shall
designate the particular indoor unit(s) that is turned off. The manufacturer must also specify
the compressor speed used for the Table 7 EV Test, a cooling-mode intermediate compressor
speed that falls within 1⁄4 and 3⁄4 of the difference between the maximum and minimum
expected to yield the highest EER for the given EV Test conditions and bracketed compressor
speed range. The manufacturer can designate that one or more indoor units are turned off for
the EV Test.
Table 7 Cooling Mode Test Condition for Units Having a Variable-Speed Compressor
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1
A2 Test— 80 67 95 75 Maximum Cooling Full-
required Load2
(steady, wet
coil)
1
B2 Test— 80 67 82 65 Maximum Cooling Full-
required Load2
(steady, wet
coil)
1
EV Test— 80 67 87 69 Intermediate Cooling
required Intermediate3
(steady, wet
coil)
1
B1 Test— 80 67 82 65 Minimum Cooling
required Minimum4
(steady, wet
coil)
1
F1 Test— 80 67 67 53.5 Minimum Cooling
required Minimum4
(steady, wet
coil)
G1 Test5— 80 (6) 67 Minimum Cooling
required Minimum4
(steady, dry-
coil)
I1 Test5— 80 (6) 67 Minimum (6)
required
(cyclic, dry-
coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
3
Defined in section 3.1.4.3.
4
Defined in section 3.1.4.2.
5
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet bulb temperature of 57 °F or less.
6
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the G1 Test.
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3.2.5 Cooling mode tests for northern heat pumps with triple-capacity compressors.
Test triple-capacity, northern heat pumps for the cooling mode in the same way as specified
3.2.6 Tests for an air conditioner or heat pump having a single indoor unit having multiple
3.3 Test procedures for steady-state wet coil cooling mode tests (the A, A2, A1, B, B2, B1, EV,
and F1 Tests).
a. For the pretest interval, operate the test room reconditioning apparatus and the unit to be
tested until maintaining equilibrium conditions for at least 30 minutes at the specified section
3.2 test conditions. Use the exhaust fan of the airflow measuring apparatus and, if installed,
the indoor blower of the test unit to obtain and then maintain the indoor air volume rate
and/or external static pressure specified for the particular test. Continuously record (see
(1) The dry-bulb temperature of the air entering the indoor coil,
(2) The water vapor content of the air entering the indoor coil,
(3) The dry-bulb temperature of the air entering the outdoor coil, and
(4) For the section 2.2.4 cases where its control is required, the water vapor content of the
354
Refer to section 3.11 for additional requirements that depend on the selected secondary
test method.
b. After satisfying the pretest equilibrium requirements, make the measurements specified in
Table 3 of ASHRAE Standard 37-2009 for the Indoor Air Enthalpy method and the user-
selected secondary method. Make said Table 3 measurements at equal intervals that span 5
minutes or less. Continue data sampling until reaching a 30-minute period (e.g., four
consecutive 10-minute samples) where the test tolerances specified in Table 8 are satisfied.
For those continuously recorded parameters, use the entire data set from the 30-minute
interval to evaluate Table 8 compliance. Determine the average electrical power consumption
of the air conditioner or heat pump over the same 30-minute interval.
c. Calculate indoor-side total cooling capacity and sensible cooling capacity as specified in
sections 7.3.3.1 and 7.3.3.3 of ASHRAE Standard 37-2009. Do not adjust the parameters
used in calculating capacity for the permitted variations in test conditions. Evaluate air
enthalpies based on the measured barometric pressure. Use the values of the specific heat of
air given in section 7.3.3.1 for calculation of the sensible cooling capacities. Assign the
average total space cooling capacity, average sensible cooling capacity, and electrical power
consumption over the 30-minute data collection interval to the variables Q̇ck(T), Q̇sck(T) and
Ėck(T), respectively. For these three variables, replace the “T” with the nominal outdoor
temperature at which the test was conducted. The superscript k is used only when testing
multi-capacity units. Use the superscript k=2 to denote a test with the unit operating at high
355
capacity or maximum speed, k=1 to denote low capacity or minimum speed, and k=v to
1250 𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
∗ 𝑉𝑉̇𝑠𝑠
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
365 𝑊𝑊
∗ 𝑉𝑉̇𝑠𝑠
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
where V̇̅s is the average measured indoor air volume rate expressed in units of cubic feet per
Table 8 Test Operating and Test Condition Tolerances for Section 3.3 Steady-State Wet
Coil Cooling Mode Tests and Section 3.4 Dry Coil Cooling Mode Tests
356
3
Leaving temperature 1.0
5
External resistance to airflow, inches 0.12 0.02
of water
Electrical voltage, % of rdg. 2.0 1.5
Nozzle pressure drop, % of rdg. 8.0
1
See section 1.2, Definitions.
2
Only applies during wet coil tests; does not apply during steady-state, dry coil cooling mode
tests.
3
Only applies when using the Outdoor Air Enthalpy Method.
4
Only applies during wet coil cooling mode tests where the unit rejects condensate to the outdoor
coil.
5
Only applies when testing non-ducted units.
e. For air conditioners and heat pumps having a constant-air-volume-rate indoor blower, the
five additional steps listed below are required if the average of the measured external static
pressures exceeds the applicable sections 3.1.4 minimum (or target) external static pressure
1. Measure the average power consumption of the indoor blower motor (Ėfan,1) and record
the corresponding external static pressure (ΔP1) during or immediately following the 30-
2. After completing the 30-minute interval and while maintaining the same test
conditions, adjust the exhaust fan of the airflow measuring apparatus until the external
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3. After re-establishing steady readings of the fan motor power and external static
pressure, determine average values for the indoor blower power (Ėfan,2) and the external
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑛𝑛,2 − 𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,1
𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,min = ̇
(Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
5. Increase the total space cooling capacity, Q̇ck(T), by the quantity (Ėfan,1 − Ėfan,min),
when expressed on a Btu/h basis. Decrease the total electrical power, Ėck(T), by the same
3.4 Test procedures for the steady-state dry-coil cooling-mode tests (the C, C1, C2, and G1 Tests).
a. Except for the modifications noted in this section, conduct the steady-state dry coil cooling
mode tests as specified in section 3.3 for wet coil tests. Prior to recording data during the
steady-state dry coil test, operate the unit at least one hour after achieving dry coil conditions.
Drain the drain pan and plug the drain opening. Thereafter, the drain pan should remain
completely dry.
b. Denote the resulting total space cooling capacity and electrical power derived from the test
as Q̇ss,dry and Ėss,dry.With regard to a section 3.3 deviation, do not adjust Q̇ss,dry for duct losses
(i.e., do not apply section 7.3.3.3 of ASHRAE Standard 37-2009). In preparing for the
section 3.5 cyclic tests, record the average indoor-side air volume rate, V̇̅, specific heat of the
358
air, Cp,a (expressed on dry air basis), specific volume of the air at the nozzles, v′n, humidity
ratio at the nozzles, Wn, and either pressure difference or velocity pressure for the flow
nozzles. For units having a variable-speed indoor fan (that provides either a constant or
variable air volume rate) that will or may be tested during the cyclic dry coil cooling mode
test with the indoor fan turned off (see section 3.5), include the electrical power used by the
indoor fan motor among the recorded parameters from the 30-minute test.
c. If the temperature sensors used to provide the primary measurement of the indoor-side dry
bulb temperature difference during the steady-state dry-coil test and the subsequent cyclic
dry- coil test are different, include measurements of the latter sensors among the regularly
sampled data. Beginning at the start of the 30-minute data collection period, measure and
compute the indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally spaced data sample. If
using a consistent data sampling rate that is less than 1 minute, calculate and record minutely
averages for the two temperature differences. If using a consistent sampling rate of one
minute or more, calculate and record the two temperature differences from each data sample.
After having recorded the seventh (i=7) set of temperature differences, calculate the
𝑖𝑖
1 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝑆𝑆𝑆𝑆)
𝐹𝐹𝐶𝐶𝐶𝐶 = �
7 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝐶𝐶𝐶𝐶𝐶𝐶)
𝑖𝑖−6
Each time a subsequent set of temperature differences is recorded (if sampling more frequently
than every 5 minutes), calculate FCD using the most recent seven sets of values. Continue these
calculations until the 30-minute period is completed or until a value for FCD is calculated that
359
falls outside the allowable range of 0.94–1.06. If the latter occurs, immediately suspend the test
and identify the cause for the disparity in the two temperature difference measurements.
Recalibration of one or both sets of instrumentation may be required. If all the values for FCD are
within the allowable range, save the final value of the ratio from the 30-minute test as FCD*. If
the temperature sensors used to provide the primary measurement of the indoor-side dry bulb
temperature difference during the steady-state dry- coil test and the subsequent cyclic dry-coil
3.5 Test procedures for the cyclic dry-coil cooling-mode tests (the D, D1, D2, and I1 Tests).
a. After completing the steady-state dry-coil test, remove the Outdoor Air Enthalpy method
test apparatus, if connected, and begin manual OFF/ON cycling of the unit's compressor. The
test set-up should otherwise be identical to the set-up used during the steady-state dry coil
test. When testing heat pumps, leave the reversing valve during the compressor OFF cycles
in the same position as used for the compressor ON cycles, unless automatically changed by
the controls of the unit. For units having a variable-speed indoor blower, the manufacturer
has the option of electing at the outset whether to conduct the cyclic test with the indoor
blower enabled or disabled. Always revert to testing with the indoor blower disabled if cyclic
b. For units having a single-speed or two-capacity compressor, cycle the compressor OFF for
24 minutes and then ON for 6 minutes (Δτcyc,dry = 0.5 hours). For units having a variable-
speed compressor, cycle the compressor OFF for 48 minutes and then ON for 12 minutes
(Δτcyc,dry = 1.0 hours). Repeat the OFF/ON compressor cycling pattern until the test is
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completed. Allow the controls of the unit to regulate cycling of the outdoor fan. If an
upturned duct is used, measure the dry-bulb temperature at the inlet of the device at least
once every minute and ensure that its test operating tolerance is within 1.0 °F for each
c. Sections 3.5.1 and 3.5.2 specify airflow requirements through the indoor coil of ducted and
non-ducted systems, respectively. In all cases, use the exhaust fan of the airflow measuring
apparatus (covered under section 2.6) along with the indoor blower of the unit, if installed
and operating, to approximate a step response in the indoor coil airflow. Regulate the exhaust
fan to quickly obtain and then maintain the flow nozzle static pressure difference or velocity
pressure at the same value as was measured during the steady-state dry coil test. The pressure
difference or velocity pressure should be within 2 percent of the value from the steady-state
dry coil test within 15 seconds after airflow initiation. For units having a variable-speed
indoor blower that ramps when cycling on and/or off, use the exhaust fan of the airflow
measuring apparatus to impose a step response that begins at the initiation of ramp up and
d. For units having a variable-speed indoor blower, conduct the cyclic dry coil test using the
pull-thru approach described below if any of the following occur when testing with the fan
operating:
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(3) The unit operates for more than 30 seconds at an external static pressure that is 0.1
inches of water or more higher than the value measured during the prior steady-state test.
For the pull-thru approach, disable the indoor blower and use the exhaust fan of the airflow
measuring apparatus to generate the specified flow nozzles static pressure difference or
velocity pressure. If the exhaust fan cannot deliver the required pressure difference because
e. Conduct a minimum of six complete compressor OFF/ON cycles for a unit with a single-
cycles for a unit with a variable speed compressor. The first three cycles for a unit with a
single-speed compressor or two-speed compressor and the first two cycles for a unit with a
unit with a variable speed compressor are the warm-up period—the later cycles are called the
active cycles. Calculate the degradation coefficient CD for each complete active cycle if the
test tolerances given in Table 9 are satisfied. If the average CD for the first three active cycles
is within 0.02 of the average CD for the first two active cycles, use the average CD of the
three active cycles as the final result. If these averages differ by more than 0.02, continue the
test to get CD for the fourth cycle. If the average CD of the last three cycles is lower than or
no more than 0.02 greater than the average CD of the first three cycles, use the average CD of
all four active cycles as the final result. Otherwise, continue the test with a fifth cycle. If the
average CD of the last three cycles is 0.02 higher than the average for the previous three
cycles, use the default CD, otherwise use the average CD of all five active cycles. If the test
tolerances given in Table 9 are not satisfied, use default CD value. The default CD value for
cooling is 0.2.
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f. With regard to the Table 9 parameters, continuously record the dry-bulb temperature of the
air entering the indoor and outdoor coils during periods when air flows through the respective
coils. Sample the water vapor content of the indoor coil inlet air at least every 2 minutes
during periods when air flows through the coil. Record external static pressure and the air
volume rate indicator (either nozzle pressure difference or velocity pressure) at least every
minute during the interval that air flows through the indoor coil. (These regular
measurements of the airflow rate indicator are in addition to the required measurement at 15
seconds after flow initiation.) Sample the electrical voltage at least every 2 minutes
beginning 30 seconds after compressor start-up. Continue until the compressor, the outdoor
fan, and the indoor blower (if it is installed and operating) cycle off.
g. For ducted units, continuously record the dry-bulb temperature of the air entering (as noted
above) and leaving the indoor coil. Or if using a thermopile, continuously record the
difference between these two temperatures during the interval that air flows through the
indoor coil. For non-ducted units, make the same dry-bulb temperature measurements
beginning when the compressor cycles on and ending when indoor coil airflow ceases.
h. Integrate the electrical power over complete cycles of length Δτcyc,dry. For ducted units
tested with an indoor blower installed and operating, integrate electrical power from indoor
blower OFF to indoor blower OFF. For all other ducted units and for non-ducted units,
integrate electrical power from compressor OFF to compressor OFF. (Some cyclic tests will
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use the same data collection intervals to determine the electrical energy and the total space
cooling. For other units, terminate data collection used to determine the electrical energy
Table 9 Test Operating and Test Condition Tolerances for Cyclic Dry Coil Cooling Mode
Tests
Test Test
Operating Condition
Tolerance1 Tolerance1
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i. If the Table 9 tolerances are satisfied over the complete cycle, record the measured
electrical energy consumption as ecyc,dry and express it in units of watt-hours. Calculate the
60∗𝑉𝑉̇∗𝐶𝐶𝑝𝑝,𝑎𝑎 ∗Γ 60∗𝑉𝑉̇∗𝐶𝐶𝑝𝑝,𝑎𝑎 ∗Γ ∗ 𝜏𝜏
2
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑 = ′ ∗(1+𝑊𝑊 )]
[𝑣𝑣𝑛𝑛
=
𝑣𝑣𝑛𝑛
and Γ = 𝐹𝐹𝐶𝐶𝐶𝐶 ∫𝜏𝜏 [𝑇𝑇𝑎𝑎1 (𝜏𝜏) − 𝑇𝑇𝑎𝑎2 (𝜏𝜏)]𝛿𝛿𝛿𝛿, ℎ𝑟𝑟 ∗ ℉
𝑛𝑛 1
where V̇̅, Cp,a, vn′ (or vn), Wn, and FCD* are the values recorded during the section 3.4 dry
Tal(τ) = dry bulb temperature of the air entering the indoor coil at time τ, °F.
Ta2(τ) = dry bulb temperature of the air leaving the indoor coil at time τ, °F.
τ1 = for ducted units, the elapsed time when airflow is initiated through the indoor
coil; for non-ducted units, the elapsed time when the compressor is cycled on, hr.
The automatic controls that are normally installed with the test unit must govern the OFF/ON
cycling of the air moving equipment on the indoor side (exhaust fan of the airflow measuring
apparatus and, if installed, the indoor blower of the test unit). For example, for ducted units
tested without an indoor blower installed but rated based on using a fan time delay relay, control
the indoor coil airflow according to the rated ON and/or OFF delays provided by the relay. For
ducted units having a variable-speed indoor blower that has been disabled (and possibly
removed), start and stop the indoor airflow at the same instances as if the fan were enabled. For
all other ducted units tested without an indoor blower installed, cycle the indoor coil airflow in
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unison with the cycling of the compressor. If air damper boxes are used, close them on the inlet
and outlet side during the OFF period. Airflow through the indoor coil should stop within 3
seconds after the automatic controls of the test unit (act to) de-energize the indoor blower. For
ducted units tested without an indoor blower installed (excluding the special case where a
365 𝑊𝑊
Equation 3.5-2. 1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
∗ 𝑉𝑉̇𝑠𝑠 ∗ [𝜏𝜏2 − 𝜏𝜏1 ]
1250 𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
Equation 3.5-3. 1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
∗ 𝑉𝑉̇𝑠𝑠 ∗ [𝜏𝜏2 − 𝜏𝜏1 ]
where V̇̅s is the average indoor air volume rate from the section 3.4 dry coil steady-state test and
is expressed in units of cubic feet per minute of standard air (scfm). For units having a variable-
speed indoor blower that is disabled during the cyclic test, increase ecyc,dry and decrease
a. The product of [τ2 − τ1] and the indoor blower power measured during or following the dry
b. The following algorithm if the indoor blower ramps its speed when cycling.
pressure that was measured during the steady-state test, at operating conditions associated
with the midpoint of the ramp-up interval, and at conditions associated with the midpoint
of the ramp-down interval. For these measurements, the tolerances on the airflow volume
or the external static pressure are the same as required for the section 3.4 steady-state test.
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2. For each case, determine the fan power from measurements made over a minimum of 5
minutes.
3. Approximate the electrical energy consumption of the indoor blower if it had operated
during the cyclic test using all three power measurements. Assume a linear profile during
the ramp intervals. The manufacturer must provide the durations of the ramp-up and
ramp-down intervals. If the test setup instructions included with the unit by the
manufacturer specifies a ramp interval that exceeds 45 seconds, use a 45-second ramp
Do not use airflow prevention devices when conducting cyclic tests on non-ducted units.
Until the last OFF/ON compressor cycle, airflow through the indoor coil must cycle off and on in
unison with the compressor. For the last OFF/ON compressor cycle—the one used to determine
ecyc,dry and qcyc,dry—use the exhaust fan of the airflow measuring apparatus and the indoor blower
of the test unit to have indoor airflow start 3 minutes prior to compressor cut-on and end three
minutes after compressor cutoff. Subtract the electrical energy used by the indoor blower during
the 3 minutes prior to compressor cut-on from the integrated electrical energy, ecyc,dry. Add the
electrical energy used by the indoor blower during the 3 minutes after compressor cutoff to the
integrated cooling capacity, qcyc,dry. For the case where the non-ducted unit uses a variable-speed
indoor blower which is disabled during the cyclic test, correct ecyc,dry and qcyc,dry using the same
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approach as prescribed in section 3.5.1 for ducted units having a disabled variable-speed indoor
blower.
Use the two dry-coil tests to determine the cooling-mode cyclic-degradation coefficient, CDc.
capacity. The default value for two-capacity units cycling at high capacity, however, is the low-
capacity coefficient, i.e., CDc(k=2) = CDc. Evaluate CDc using the above results and those from
where,
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
𝐸𝐸𝐸𝐸𝐸𝐸𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑 =
𝑒𝑒𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
the average energy efficiency ratio during the cyclic dry coil cooling mode test, Btu/W·h
𝑄𝑄̇𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑
𝐸𝐸𝐸𝐸𝐸𝐸𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑 =
𝐸𝐸̇𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑
the average energy efficiency ratio during the steady-state dry coil cooling mode test, Btu/W·h
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
𝐶𝐶𝐶𝐶𝐶𝐶 =
𝑄𝑄𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑 ∗ Δ𝜏𝜏𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
Round the calculated value for CDc to the nearest 0.01. If CDc is negative, then set it equal to
zero.
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3.6 Heating mode tests for different types of heat pumps, including heating-only heat
pumps.
3.6.1 Tests for a heat pump having a single-speed compressor that is tested with a fixed
speed indoor blower installed, with a constant-air-volume-rate indoor blower installed, or with
no indoor blower installed. Conduct the High Temperature Cyclic (H1C) Test to determine the
heating mode cyclic-degradation coefficient, CDh. Test conditions for the four tests are specified
in Table 10.
Table 10 Heating Mode Test Conditions for Units Having a Single-Speed Compressor and
a Fixed-Speed Indoor blower, a Constant Air Volume Rate Indoor blower, or No Indoor
blower
3.6.2 Tests for a heat pump having a single-speed compressor and a single indoor unit
having either (1) a variable speed, variable-air-rate indoor blower whose capacity modulation
correlates with outdoor dry bulb temperature or (2) multiple blowers. Conduct five tests: two
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High Temperature Tests (H12 and H11), one Frost Accumulation Test (H22), and two Low
Temperature Tests (H32 and H31). Conducting an additional Frost Accumulation Test (H21) is
optional. Conduct the High Temperature Cyclic (H1C1) Test to determine the heating mode
cyclic-degradation coefficient, CDh. Test conditions for the seven tests are specified in Table 11.
If the optional H21 Test is not performed, use the following equations to approximate the
capacity and electrical power of the heat pump at the H21 test conditions:
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
where,
𝑄𝑄̇ℎ𝑘𝑘=2 (35)
𝑄𝑄̇ 𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝑄𝑄̇𝑘𝑘=2 (17) + 0.6 ∗ [𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)]
𝐸𝐸̇ℎ𝑘𝑘=2 (35)
𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝐸𝐸̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)�
The quantities Q̇hk=2(47), Ėhk=2(47), Q̇hk=1(47), and Ėhk=1(47) are determined from the H12 and
H11 Tests and evaluated as specified in section 3.7; the quantities Q̇hk=2(35) and Ėhk=2(35) are
determined from the H22 Test and evaluated as specified in section 3.9; and the quantities
Q̇hk=2(17), Ėhk=2(17), Q̇hk=1(17), and Ėhk=1(17), are determined from the H32 and H31 Tests
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Table 11 Heating Mode Test Conditions for Units with a Single-Speed Compressor That
Meet the Section 3.6.2 Indoor Unit Requirements
3.6.3 Tests for a heat pump having a two-capacity compressor (see section 1.2, Definitions),
a. Conduct one Maximum Temperature Test (H01), two High Temperature Tests (H12and
H11), one Frost Accumulation Test (H22), and one Low Temperature Test (H32). Conduct an
additional Frost Accumulation Test (H21) and Low Temperature Test (H31) if both of the
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1. Knowledge of the heat pump's capacity and electrical power at low compressor
capacity for outdoor temperatures of 37 °F and less is needed to complete the section
and less.
If the above two conditions are met, an alternative to conducting the H21 Frost Accumulation
is to use the following equations to approximate the capacity and electrical power:
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
Determine the quantities Q̇hk=1 (47) and Ėhk=1 (47) from the H11 Test and evaluate them
according to Section 3.7. Determine the quantities Q̇hk=1 (17) and Ėhk=1 (17) from the
b. Conduct the High Temperature Cyclic Test (H1C1) to determine the heating mode cyclic-
degradation coefficient, CDh. If a two-capacity heat pump locks out low capacity operation at
lower outdoor temperatures, conduct the High Temperature Cyclic Test (H1C2) to determine
the high-capacity heating mode cyclic-degradation coefficient, CDh (k=2). The default
CDh (k=2) is the same value as determined or assigned for the low-capacity cyclic-
degradation coefficient, CDh [or equivalently, CDh (k=1)]. Table 12 specifies test conditions
Table 12 Heating Mode Test Conditions for Units Having a Two-Capacity Compressor
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Air entering indoor unit Air entering outdoor
temperature (°F) unit temperature (°F)
Test Dry bulb Wet bulb Dry bulb Wet bulb Compressor Heating air
description capacity volume rate
H01 Test 70 60(max) 62 56.5 Low Heating
(required, Minimum.1
steady)
H12 Test 70 60(max) 47 43 High Heating Full-
(required, Load.2
steady)
H1C2 Test 70 60(max) 47 43 High (3)
(required7,
cyclic)
H11 Test 70 60(max) 47 43 Low Heating
(required) Minimum.1
H1C1 Test 70 60(max) 47 43 Low (4)
(required,
cyclic)
H22 Test 70 60(max) 35 33 High Heating Full-
(required) Load.2
H21 Test5 6 70 60(max) 35 33 Low Heating
(required) Minimum.1
H32 Test 70 60(max) 17 15 High Heating Full-
(required, Load.2
steady)
H31 Test5 70 60(max) 17 15 Low Heating
(required, Minimum.1
steady)
1
Defined in section 3.1.4.5.
2
Defined in section 3.1.4.4.
3
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same
pressure or velocity as measured during the H12 Test.
4
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same
pressure or velocity as measured during the H11 Test.
5
Required only if the heat pump's performance when operating at low compressor capacity and outdoor temperatures
less than 37 °F is needed to complete the section 4.2.3 HSPF calculations.
6
If table note #5 applies, the section 3.6.3 equations for Q̇hk=1 (35) and Ėhk=1 (17) may be used in lieu of conducting
the H21 Test.
7
Required only if the heat pump locks out low capacity operation at lower outdoor temperatures.
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3.6.4 Tests for a heat pump having a variable-speed compressor.
a. Conduct one Maximum Temperature Test (H01), two High Temperature Tests (H12 and
H11), one Frost Accumulation Test (H2V), and one Low Temperature Test (H32). Conducting
one or both of the following tests is optional: An additional High Temperature Test (H1N)
and an additional Frost Accumulation Test (H22). Conduct the Maximum Temperature
Cyclic (H0C1) Test to determine the heating mode cyclic-degradation coefficient, CDh. Test
conditions for the eight tests are specified in Table 13. Determine the intermediate
compressor speed cited in Table 13 using the heating mode maximum and minimum
Where a tolerance of plus 5 percent or the next higher inverter frequency step from that
calculated is allowed. If the H22Test is not done, use the following equations to approximate
𝑄𝑄̇ℎ𝑘𝑘=2 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)��
𝐸𝐸̇ℎ𝑘𝑘=2 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)��
b. Determine the quantities Q̇hk=2(47) and from Ėhk=2(47) from the H12 Test and evaluate
them according to section 3.7. Determine the quantities Q̇hk=2(17) and Ėhk=2(17) from the
H32 Test and evaluate them according to section 3.10. For heat pumps where the heating
mode maximum compressor speed exceeds its cooling mode maximum compressor speed,
conduct the H1N Test if the manufacturer requests it. If the H1N Test is done, operate the heat
pump's compressor at the same speed as the speed used for the cooling mode A2 Test. Refer
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to the last sentence of section 4.2 to see how the results of the H1N Test may be used in
Table 13 Heating Mode Test Conditions for Units Having a Variable-Speed Compressor
375
c. For multiple-split heat pumps (only), the following procedures supersede the above
requirements. For all Table 13 tests specified for a minimum compressor speed, at least one
indoor unit must be turned off. The manufacturer shall designate the particular indoor unit(s)
that is turned off. The manufacturer must also specify the compressor speed used for the
Table 13 H2V Test, a heating mode intermediate compressor speed that falls
within 1⁄4 and 3⁄4 of the difference between the maximum and minimum heating mode speeds.
The manufacturer should prescribe an intermediate speed that is expected to yield the highest
COP for the given H2V Test conditions and bracketed compressor speed range. The
manufacturer can designate that one or more specific indoor units are turned off for the
H2V Test.
3.6.5 Additional test for a heat pump having a heat comfort controller.
Test any heat pump that has a heat comfort controller (see section 1.2, Definitions) according
to section 3.6.1, 3.6.2, or 3.6.3, whichever applies, with the heat comfort controller disabled.
Additionally, conduct the abbreviated test described in section 3.1.9 with the heat comfort
controller active to determine the system's maximum supply air temperature. (Note: heat pumps
having a variable speed compressor and a heat comfort controller are not covered in the test
3.6.6 Heating mode tests for northern heat pumps with triple-capacity compressors.
Test triple-capacity, northern heat pumps for the heating mode as follows:
(a) Conduct one maximum-temperature test (H01), two high-temperature tests (H12 and H11),
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one Frost Accumulation test (H22), two low-temperature tests (H32, H33), and one minimum-
temperature test (H43). Conduct an additional Frost Accumulation test (H21) and low-
temperature test (H31) if both of the following conditions exist: (1) Knowledge of the heat
pump’s capacity and electrical power at low compressor capacity for outdoor temperatures of
37°F and less is needed to complete the section 4.2.6 seasonal performance calculations; and
(2) the heat pump’s controls allow low-capacity operation at outdoor temperatures of 37°F
and less. If the above two conditions are met, an alternative to conducting the H21 Frost
Accumulation Test to determine Q̇hk=1(35) and Ėhk=1(35) is to use the following equations to
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
In evaluating the above equations, determine the quantities Q̇hk=1(47) from the H11 Test and
evaluate them according to section 3.7. Determine the quantities Q̇hk=1(17) and Ėhk=1(17)
from the H31 Test and evaluate them according to section 3.10. Use the paired values of
Q̇hk=1(35) and Ėhk=1(35) derived from conducting the H21 Frost Accumulation Test and
evaluated as specified in section 3.9.1 or use the paired values calculated using the above
default equations, whichever contribute to a higher Region IV HSPF based on the DHRmin.
(b) Conducting a Frost Accumulation Test (H23) with the heat pump operating at its booster
capacity is optional. If this optional test is not conducted, determine Q̇hk=3(35) and Ėhk=3(35)
using the following equations to approximate this capacity and electrical power:
𝑄𝑄̇ℎ𝑘𝑘=3 (35) = 𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝑄𝑄̇ℎ𝑘𝑘=3 (17) + 1.20 ∗ �𝑄𝑄̇ℎ𝑘𝑘=3 (17) − 𝑄𝑄̇ℎ𝑘𝑘=3 (2)��
𝐸𝐸̇ℎ𝑘𝑘=3 (35) = 𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) + 1.20 ∗ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) − 𝐸𝐸̇ℎ𝑘𝑘=3 (2)��
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where:
𝑄𝑄̇ℎ𝑘𝑘=2 (35)
𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝑄𝑄̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)�
𝐸𝐸̇ℎ𝑘𝑘=2 (35)
𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) = 𝑘𝑘=2
𝐸𝐸̇ℎ (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)�
Determine the quantities Q̇hk=2(47) and Ėhk=2(47) from the H12 Test and evaluate them
according to section 3.7. Determine the quantities Q̇hk=2(35) and Ėhk=2(35) from the H22Test
and evaluate them according to section 3.9.1. Determine the quantities Q̇hk=2(17) and
Ėhk=2(17) from the H32Test, determine the quantities Q̇hk=3(17) and Ėhk=3(17) from the
H33Test, and determine the quantities Q̇hk=3(2) and Ėhk=3(2) from the H43Test. Evaluate all
six quantities according to section 3.10. Use the paired values of Q̇hk=3(35) and Ėhk=3(35)
derived from conducting the H23Frost Accumulation Test and calculated as specified in
section 3.9.1 or use the paired values calculated using the above default equations, whichever
(c) Conduct the high-temperature cyclic test (H1C1) to determine the heating mode cyclic-
degradation coefficient, CDh. If a triple-capacity heat pump locks out low capacity operation
at lower outdoor temperatures, conduct the high-temperature cyclic test (H1C2) to determine
the high-capacity heating mode cyclic-degradation coefficient, CDh (k=2). The default CDh
(k=2) is the same value as determined or assigned for the low-capacity cyclic-degradation
coefficient, CDh [or equivalently, CDh (k=1)]. Finally, if a triple-capacity heat pump locks out
both low and high capacity operation at the lowest outdoor temperatures, conduct the low-
temperature cyclic test (H3C3) to determine the booster-capacity heating mode cyclic-
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degradation coefficient, CDh (k=3). The default CDh (k=3) is the same value as determined or
assigned for the high-capacity cyclic-degradation coefficient, CDh [or equivalently, CDh
Table 14 Heating Mode Test Conditions for Units with a Triple-Capacity Compressor
Test description Air entering indoor Air entering outdoor unit Compressor Heating air
unit temperature temperature capacity volume rate
°F °F
Dry bulb Wet Dry bulb Wet bulb
bulb
Load2
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3.6.7 Tests for a heat pump having a single indoor unit having multiple blowers and offering two
stages of compressor modulation. Conduct the heating mode tests specified in section 3.6.3.
3.7 Test procedures for steady-state Maximum Temperature and High Temperature heating mode
a. For the pretest interval, operate the test room reconditioning apparatus and the heat pump until
equilibrium conditions are maintained for at least 30 minutes at the specified section 3.6 test
conditions. Use the exhaust fan of the airflow measuring apparatus and, if installed, the indoor
blower of the heat pump to obtain and then maintain the indoor air volume rate and/or the
external static pressure specified for the particular test. Continuously record the dry-bulb
temperature of the air entering the indoor coil, and the dry-bulb temperature and water vapor
content of the air entering the outdoor coil. Refer to section 3.11 for additional requirements that
depend on the selected secondary test method. After satisfying the pretest equilibrium
requirements, make the measurements specified in Table 3 of ASHRAE Standard 37-2009 for
the Indoor Air Enthalpy method and the user-selected secondary method. Make said Table 3
measurements at equal intervals that span 5 minutes or less. Continue data sampling until a 30-
minute period (e.g., four consecutive 10-minute samples) is reached where the test tolerances
specified in Table 15 are satisfied. For those continuously recorded parameters, use the entire
data set for the 30-minute interval when evaluating Table 15 compliance. Determine the average
electrical power consumption of the heat pump over the same 30-minute interval.
Table 15 Test Operating and Test Condition Tolerances for Section 3.7 and Section 3.10
Steady-State Heating Mode Tests
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Test Test
operating tolerance1 condition tolerance1
Indoor dry-bulb, °F:
Entering temperature 2.0 0.5
Leaving temperature 2.0
Indoor wet-bulb, °F:
Entering temperature 1.0
Leaving temperature 1.0
Outdoor dry-bulb, °F:
Entering temperature 2.0 0.5
2
Leaving temperature 2.0
Outdoor wet-bulb, °F:
Entering temperature 1.0 0.3
2
Leaving temperature 1.0
3
External resistance to airflow, inches of water 0.12 0.02
Electrical voltage, % of rdg 2.0 1.5
Nozzle pressure drop, % of rdg 8.0
1
See section 1.2, Definitions.
2
Only applies when the Outdoor Air Enthalpy Method is used.
3
Only applies when testing non-ducted units.
b. Calculate indoor-side total heating capacity as specified in sections 7.3.4.1 and 7.3.4.3 of
ASHRAE Standard 37-2009. Do not adjust the parameters used in calculating capacity for
the permitted variations in test conditions. Assign the average space heating capacity and
electrical power over the 30-minute data collection interval to the variables Q̇hk and Ėhk(T)
respectively. The “T” and superscripted “k” are the same as described in section 3.3.
Additionally, for the heating mode, use the superscript to denote results from the optional
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c. For heat pumps tested without an indoor blower installed, increase Q̇hk(T) by
1250 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ �
∗ 𝑉𝑉𝑠𝑠̇
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
365 𝑊𝑊 �̇
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠
where V̇̅s is the average measured indoor air volume rate expressed in units of cubic feet per
minute of standard air (scfm). During the 30-minute data collection interval of a High
Temperature Test, pay attention to preventing a defrost cycle. Prior to this time, allow the
heat pump to perform a defrost cycle if automatically initiated by its own controls. As in all
cases, wait for the heat pump's defrost controls to automatically terminate the defrost cycle.
Heat pumps that undergo a defrost should operate in the heating mode for at least 10 minutes
after defrost termination prior to beginning the 30-minute data collection interval. For some
heat pumps, frost may accumulate on the outdoor coil during a High Temperature test. If the
indoor coil leaving air temperature or the difference between the leaving and entering air
temperatures decreases by more than 1.5 °F over the 30-minute data collection interval, then
do not use the collected data to determine capacity. Instead, initiate a defrost cycle. Begin
collecting data no sooner than 10 minutes after defrost termination. Collect 30 minutes of
new data during which the Table 15 test tolerances are satisfied. In this case, use only the
results from the second 30-minute data collection interval to evaluate Q̇hk(47) and Ėhk(47).
d. If conducting the cyclic heating mode test, which is described in section 3.8, record the
average indoor-side air volume rate, V̇̅, specific heat of the air, Cp,a (expressed on dry air
basis), specific volume of the air at the nozzles, vn′ (or vn), humidity ratio at the nozzles, Wn,
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and either pressure difference or velocity pressure for the flow nozzles. If either or both of
the below criteria apply, determine the average, steady-state, electrical power consumption of
1. The section 3.8 cyclic test will be conducted and the heat pump has a variable-speed
2. The heat pump has a (variable-speed) constant-air volume-rate indoor blower and
during the steady-state test the average external static pressure (ΔP1) exceeds the
applicable section 3.1.4.4 minimum (or targeted) external static pressure (ΔPmin) by 0.03
Determine Ėfan,1 by making measurements during the 30-minute data collection interval, or
immediately following the test and prior to changing the test conditions. When the above “2”
criteria applies, conduct the following four steps after determining Ėfan,1 (which corresponds
to ΔP1):
i. While maintaining the same test conditions, adjust the exhaust fan of the airflow measuring
apparatus until the external static pressure increases to approximately ΔP1 + (ΔP1 − ΔPmin).
ii. After re-establishing steady readings for fan motor power and external static pressure,
determine average values for the indoor blower power (Ėfan,2) and the external static pressure
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iii. Approximate the average power consumption of the indoor blower motor if the 30-minute
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,2 ̇
− 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,min = (Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
iv. Decrease the total space heating capacity, Q̇hk(T), by the quantity (Ėfan,1 − Ėfan,min), when
expressed on a Btu/h basis. Decrease the total electrical power, Ėhk(T) by the same fan power
e. If the temperature sensors used to provide the primary measurement of the indoor-side dry
bulb temperature difference during the steady-state dry-coil test and the subsequent cyclic
dry-coil test are different, include measurements of the latter sensors among the regularly
sampled data. Beginning at the start of the 30-minute data collection period, measure and
compute the indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally spaced data sample. If
using a consistent data sampling rate that is less than 1 minute, calculate and record minutely
averages for the two temperature differences. If using a consistent sampling rate of one
minute or more, calculate and record the two temperature differences from each data sample.
After having recorded the seventh (i=7) set of temperature differences, calculate the
𝑖𝑖
1 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝑆𝑆𝑆𝑆)
𝐹𝐹𝐶𝐶𝐶𝐶 = �
7 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝐶𝐶𝐶𝐶𝐶𝐶)
𝑖𝑖−6
Each time a subsequent set of temperature differences is recorded (if sampling more
frequently than every 5 minutes), calculate FCD using the most recent seven sets of values.
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Continue these calculations until the 30-minute period is completed or until a value for FCD is
calculated that falls outside the allowable range of 0.94–1.06. If the latter occurs,
immediately suspend the test and identify the cause for the disparity in the two temperature
required. If all the values for FCD are within the allowable range, save the final value of the
ratio from the 30-minute test as FCD*. If the temperature sensors used to provide the primary
measurement of the indoor-side dry bulb temperature difference during the steady-state dry-
coil test and the subsequent cyclic dry-coil test are the same, set FCD*= 1.
3.8 Test procedures for the cyclic heating mode tests (the H0C1, H1C, H1C1 and H1C2 Tests).
a. Except as noted below, conduct the cyclic heating mode test as specified in section 3.5. As
adapted to the heating mode, replace section 3.5 references to “the steady-state dry coil test”
with “the heating mode steady-state test conducted at the same test conditions as the cyclic
heating mode test.” Use the test tolerances in Table 16 rather than Table 9. Record the
outdoor coil entering wet-bulb temperature according to the requirements given in section 3.5
for the outdoor coil entering dry-bulb temperature. Drop the subscript “dry” used in variables
cited in section 3.5 when referring to quantities from the cyclic heating mode test. , The
default CD value for heating is 0.25. If available, use electric resistance heaters (see section
2.1) to minimize the variation in the inlet air temperature. Determine the total space heating
delivered during the cyclic heating test, qcyc, as specified in section 3.5 except for making the
following changes:
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(1) When evaluating Equation 3.5-1, use the values of V̇̅, Cp,a,vn′, (or vn), and Wn that
were recorded during the section 3.7 steady-state test conducted at the same test
conditions.
∗ 𝜏𝜏
∫𝜏𝜏 [𝑇𝑇𝑎𝑎1 (𝜏𝜏) − 𝑇𝑇𝑎𝑎2 (𝜏𝜏)]𝛿𝛿𝛿𝛿, ℎ𝑟𝑟 × ∘ 𝐹𝐹,
2
(2) Calculate Γ using, Γ = 𝐹𝐹𝐶𝐶𝐶𝐶
1
where FCD* is the value recorded during the section 3.7 steady-state test conducted at the
b. For ducted heat pumps tested without an indoor blower installed (excluding the special
case where a variable-speed fan is temporarily removed), increase qcyc by the amount
calculated using Equation 3.5-3. Additionally, increase ecyc by the amount calculated using
Equation 3.5-2. In making these calculations, use the average indoor air volume rate (V̇̅s)
determined from the section 3.7 steady-state heating mode test conducted at the same test
conditions.
c. For non-ducted heat pumps, subtract the electrical energy used by the indoor blower during
the 3 minutes after compressor cutoff from the non-ducted heat pump's integrated heating
capacity, qcyc.
during the OFF/ON cycling, operate the heat pump continuously until 10 minutes after
defrost termination. After that, begin cycling the heat pump immediately or delay until the
specified test conditions have been re-established. Pay attention to preventing defrosts after
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beginning the cycling process. For heat pumps that cycle off the indoor blower during a
defrost cycle, make no effort here to restrict the air movement through the indoor coil while
the fan is off. Resume the OFF/ON cycling while conducting a minimum of two complete
Use the results from the required cyclic test and the required steady-state test that were
conducted at the same test conditions to determine the heating mode cyclic-degradation
coefficient CDh. Add “(k=2)” to the coefficient if it corresponds to a two-capacity unit cycling at
high capacity. For the below calculation of the heating mode cyclic degradation coefficient, do
not include the duct loss correction from section 7.3.3.3 of ASHRAE Standard 37-2009 in
determining Q̇hk(Tcyc) (or qcyc). The default value for two-capacity units cycling at high capacity,
however, is the low-capacity coefficient, i.e., CDh (k=2) = CDh. The tested CDh is calculated as
follows:
𝐶𝐶𝐶𝐶𝑃𝑃𝑐𝑐𝑐𝑐𝑐𝑐
1 − 𝐶𝐶𝐶𝐶𝑃𝑃
𝑠𝑠𝑠𝑠 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
𝐶𝐶𝐷𝐷ℎ =
1 − 𝐻𝐻𝐻𝐻𝐻𝐻
where,
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐
𝐶𝐶𝐶𝐶𝑃𝑃𝑐𝑐𝑐𝑐𝑐𝑐 = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝑒𝑒𝑐𝑐𝑐𝑐𝑐𝑐
the average coefficient of performance during the cyclic heating mode test,
dimensionless.
𝑄𝑄̇ℎ𝑘𝑘 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
𝐶𝐶𝐶𝐶𝑃𝑃𝑠𝑠𝑠𝑠 (𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 ) = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝐸𝐸̇ℎ𝑘𝑘 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
387
the average coefficient of performance during the steady-state heating mode test
conducted at the same test conditions—i.e., same outdoor dry bulb temperature,
Tcyc, and speed/capacity, k, if applicable—as specified for the cyclic heating mode
test, dimensionless.
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐
𝐻𝐻𝐻𝐻𝐻𝐻 =
𝑄𝑄̇ℎ �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 � ∗
𝑘𝑘
Δ𝜏𝜏𝑐𝑐𝑐𝑐𝑐𝑐
Tcyc = the nominal outdoor temperature at which the cyclic heating mode test is
conducted, 62 or 47 °F.
Δτcyc = the duration of the OFF/ON intervals; 0.5 hours when testing a heat pump
having a single-speed or two-capacity compressor and 1.0 hour when testing a heat
Round the calculated value for CDh to the nearest 0.01. If CDh is negative, then set it equal to
zero.
Table 16 Test operating and test condition tolerances for cyclic heating mode tests.
Test Test
operating condition
tolerance1 tolerance1
Indoor entering dry-bulb temperature,2 °F 2.0 0.5
Indoor entering wet-bulb temperature,2 °F 1.0
Outdoor entering dry-bulb temperature,2 °F 2.0 0.5
Outdoor entering wet-bulb temperature,2 °F 2.0 1.0
External resistance to air-flow,2 inches of water 0.12
Airflow nozzle pressure difference or velocity pressure,2 % 2.0 3
2.0
of reading
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Electrical voltage,4 % of rdg 8.0 1.5
1
See section 1.2, Definitions.
2
Applies during the interval that air flows through the indoor (outdoor) coil except for the first 30 seconds after flow
initiation. For units having a variable-speed indoor blower that ramps, the tolerances listed for the external resistance
to airflow shall apply from 30 seconds after achieving full speed until ramp down begins.
3
The test condition shall be the average nozzle pressure difference or velocity pressure measured during the steady-
state test conducted at the same test conditions.
4
Applies during the interval that at least one of the following—the compressor, the outdoor fan, or, if applicable, the
indoor blower—are operating, except for the first 30 seconds after compressor start-up.
3.9 Test procedures for Frost Accumulation heating mode tests (the H2, H22, H2V, and
H21 Tests). a. Confirm that the defrost controls of the heat pump are set as specified in section
2.2.1. Operate the test room reconditioning apparatus and the heat pump for at least 30 minutes
at the specified section 3.6 test conditions before starting the “preliminary” test period. The
preliminary test period must immediately precede the “official” test period, which is the heating
and defrost interval over which data are collected for evaluating average space heating capacity
b. For heat pumps containing defrost controls which are likely to cause defrosts at
intervals less than one hour, the preliminary test period starts at the termination of an automatic
defrost cycle and ends at the termination of the next occurring automatic defrost cycle. For heat
pumps containing defrost controls which are likely to cause defrosts at intervals exceeding one
hour, the preliminary test period must consist of a heating interval lasting at least one hour
followed by a defrost cycle that is either manually or automatically initiated. In all cases, the heat
c. The official test period begins when the preliminary test period ends, at defrost
termination. The official test period ends at the termination of the next occurring automatic
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defrost cycle. When testing a heat pump that uses a time-adaptive defrost control system (see
section 1.2, Definitions), however, manually initiate the defrost cycle that ends the official test
period at the instant indicated by instructions provided by the manufacturer. If the heat pump has
not undergone a defrost after 6 hours, immediately conclude the test and use the results from the
full 6-hour period to calculate the average space heating capacity and average electrical power
consumption.
For heat pumps that turn the indoor blower off during the defrost cycle, take steps to
cease forced airflow through the indoor coil and block the outlet duct whenever the heat pump's
controls cycle off the indoor blower. If it is installed, use the outlet damper box described in
d. Defrost termination occurs when the controls of the heat pump actuate the first change
in converting from defrost operation to normal heating operation. Defrost initiation occurs when
the controls of the heat pump first alter its normal heating operation in order to eliminate possible
e. To constitute a valid Frost Accumulation test, satisfy the test tolerances specified in
Table 17 during both the preliminary and official test periods. As noted in Table 17, test
operating tolerances are specified for two sub-intervals: (1) When heating, except for the first 10
minutes after the termination of a defrost cycle (Sub-interval H, as described in Table 17) and (2)
when defrosting, plus these same first 10 minutes after defrost termination (Sub-interval D, as
described in Table 17). Evaluate compliance with Table 17 test condition tolerances and the
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majority of the test operating tolerances using the averages from measurements recorded only
during Sub-interval H. Continuously record the dry bulb temperature of the air entering the
indoor coil, and the dry bulb temperature and water vapor content of the air entering the outdoor
coil. Sample the remaining parameters listed in Table 17 at equal intervals that span 5 minutes or
less.
f. For the official test period, collect and use the following data to calculate average space
heating capacity and electrical power. During heating and defrosting intervals when the controls
of the heat pump have the indoor blower on, continuously record the dry-bulb temperature of the
air entering (as noted above) and leaving the indoor coil. If using a thermopile, continuously
record the difference between the leaving and entering dry-bulb temperatures during the
interval(s) that air flows through the indoor coil. For heat pumps tested without an indoor blower
installed, determine the corresponding cumulative time (in hours) of indoor coil airflow,
Δτa. Sample measurements used in calculating the air volume rate (refer to sections 7.7.2.1 and
7.7.2.2 of ASHRAE Standard 37-2009) at equal intervals that span 10 minutes or less. (Note: In
the first printing of ASHRAE Standard 37-2009, the second IP equation for Qmi should read: .)
Record the electrical energy consumed, expressed in watt-hours, from defrost termination to
defrost termination, eDEFk(35), as well as the corresponding elapsed time in hours, ΔτFR.
Table 17 Test Operating and Test Condition Tolerances for Frost Accumulation Heating
Mode Tests.
Sub-interval H2
4
Indoor entering dry-bulb temperature, °F 2.0 4.0 0.5
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Indoor entering wet-bulb temperature, °F 1.0
Outdoor entering dry-bulb temperature, °F 2.0 10.0 1.0
Outdoor entering wet-bulb temperature, °F 1.5 0.5
External resistance to airflow, inches of water 0.12 0.025
Electrical voltage, % of rdg 2.0 1.5
1See section 1.2, Definitions.
2Applies when the heat pump is in the heating mode, except for the first 10 minutes after termination of a defrost
cycle.
3Applies during a defrost cycle and during the first 10 minutes after the termination of a defrost cycle when the heat
pump is operating in the heating mode.
4For heat pumps that turn off the indoor blower during the defrost cycle, the noted tolerance only applies during the
10 minute interval that follows defrost termination.
5Only applies when testing non-ducted heat pumps.
a. Evaluate average space heating capacity, Q̇hk(35), when expressed in units of Btu per
hour, using:
where,
V̇̅ = the average indoor air volume rate measured during Sub-interval H, cfm.
Cp,a = 0.24 + 0.444 · Wn, the constant pressure specific heat of the air-water vapor
mixture that flows through the indoor coil and is expressed on a dry air basis, Btu /
lbmda · °F.
vn′ = specific volume of the air-water vapor mixture at the nozzle, ft3 / lbmmx.
Wn = humidity ratio of the air-water vapor mixture at the nozzle, lbm of water vapor per
ΔτFR = τ2 − τ1, the elapsed time from defrost termination to defrost termination, hr.
𝜏𝜏
Γ = ∫𝜏𝜏 2[𝑇𝑇𝑎𝑎2 (𝜏𝜏) − 𝑇𝑇𝑎𝑎1 (𝜏𝜏)]𝑑𝑑𝑑𝑑, ℎ𝑟𝑟 ∗ ∘ 𝐹𝐹
1
392
Tal(τ) = dry bulb temperature of the air entering the indoor coil at elapsed time τ, °F; only
recorded when indoor coil airflow occurs; assigned the value of zero during periods (if
Ta2(τ) = dry bulb temperature of the air leaving the indoor coil at elapsed time τ, °F; only
recorded when indoor coil airflow occurs; assigned the value of zero during periods (if
τ1 = the elapsed time when the defrost termination occurs that begins the official test
period, hr.
τ2 = the elapsed time when the next automatically occurring defrost termination occurs,
vn = specific volume of the dry air portion of the mixture evaluated at the dry-bulb
temperature, vapor content, and barometric pressure existing at the nozzle, ft3 per lbm of
dry air.
To account for the effect of duct losses between the outlet of the indoor unit and the section
2.5.4 dry-bulb temperature grid, adjust Q̇hk(35) in accordance with section 7.3.4.3 of
b. Evaluate average electrical power, Ėhk(35), when expressed in units of watts, using:
𝑒𝑒𝑑𝑑𝑑𝑑𝑑𝑑 (35)
𝐸𝐸̇ℎ𝑘𝑘 (35) =
Δ𝜏𝜏𝐹𝐹𝐹𝐹
For heat pumps tested without an indoor blower installed, increase Q̇hk(35) by,
393
and increase Ėhk(35) by,
365 𝑊𝑊 �̇ ∗ Δ𝜏𝜏𝑎𝑎
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠 Δ𝜏𝜏𝐹𝐹𝐹𝐹
where V̇̅s is the average indoor air volume rate measured during the Frost Accumulation
heating mode test and is expressed in units of cubic feet per minute of standard air
(scfm).
c. For heat pumps having a constant-air-volume-rate indoor blower, the five additional steps
listed below are required if the average of the external static pressures measured during sub-
Interval H exceeds the applicable section 3.1.4.4, 3.1.4.5, or 3.1.4.6 minimum (or targeted)
1. Measure the average power consumption of the indoor blower motor (Ėfan,1) and record
the corresponding external static pressure (ΔP1) during or immediately following the
Frost Accumulation heating mode test. Make the measurement at a time when the heat
pump is heating, except for the first 10 minutes after the termination of a defrost cycle.
2. After the Frost Accumulation heating mode test is completed and while maintaining
the same test conditions, adjust the exhaust fan of the airflow measuring apparatus until
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3. After re-establishing steady readings for the fan motor power and external static
pressure, determine average values for the indoor blower power (Ėfan,2) and the external
4. Approximate the average power consumption of the indoor blower motor had the Frost
Accumulation heating mode test been conducted at ΔPmin using linear extrapolation:
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,2 ̇
− 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,min = (Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
5. Decrease the total heating capacity, Q̇hk(35), by the quantity [(Ėfan,1 − Ėfan,min)·
(Δτ a/Δτ FR], when expressed on a Btu/h basis. Decrease the total electrical power,
a. Assign the demand defrost credit, Fdef, that is used in section 4.2 to the value of 1 in all
cases except for heat pumps having a demand-defrost control system (see section 1.2,
Δ𝜏𝜏𝑑𝑑𝑑𝑑𝑑𝑑 − 1.5
𝐹𝐹𝑑𝑑𝑑𝑑𝑑𝑑 = 1 + 0.03 ∗ �1 − �
Δ𝜏𝜏max − 1.5
where,
Δτdef = the time between defrost terminations (in hours) or 1.5, whichever is greater.
Accumulation test and the heat pump has not completed a defrost cycle.
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Δτmax = maximum time between defrosts as allowed by the controls (in hours) or 12,
whichever is less, as provided in the installation manuals included with the unit by the
manufacturer.
b. For two-capacity heat pumps and for section 3.6.2 units, evaluate the above equation using
the Δτdef that applies based on the Frost Accumulation Test conducted at high capacity and/or
at the Heating Full-load Air Volume Rate. For variable-speed heat pumps, evaluate
Δτdef based on the required Frost Accumulation Test conducted at the intermediate
compressor speed.
3.10 Test procedures for steady-state Low Temperature heating mode tests (the H3, H32, and
H31 Tests).
Except for the modifications noted in this section, conduct the Low Temperature heating
mode test using the same approach as specified in section 3.7 for the Maximum and High
Temperature tests. After satisfying the section 3.7 requirements for the pretest interval but before
beginning to collect data to determine Q̇hk(17) and Ėhk(17), conduct a defrost cycle. This defrost
cycle may be manually or automatically initiated. The defrost sequence must be terminated by
the action of the heat pump's defrost controls. Begin the 30-minute data collection interval
described in section 3.7, from which Q̇hk(17) and Ėhk(17) are determined, no sooner than 10
minutes after defrost termination. Defrosts should be prevented over the 30-minute data
collection interval.
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3.11.1 If using the Outdoor Air Enthalpy Method as the secondary test method.
During the “official” test, the outdoor air-side test apparatus described in section 2.10.1 is
connected to the outdoor unit. To help compensate for any effect that the addition of this test
apparatus may have on the unit's performance, conduct a “preliminary” test where the outdoor
air-side test apparatus is disconnected. Conduct a preliminary test prior to the first section 3.2
steady-state cooling mode test and prior to the first section 3.6 steady-state heating mode test. No
other preliminary tests are required so long as the unit operates the outdoor fan during all cooling
mode steady-state tests at the same speed and all heating mode steady-state tests at the same
speed. If using more than one outdoor fan speed for the cooling mode steady-state tests,
however, conduct a preliminary test prior to each cooling mode test where a different fan speed
is first used. This same requirement applies for the heating mode tests.
a. The test conditions for the preliminary test are the same as specified for the official test.
Connect the indoor air-side test apparatus to the indoor coil; disconnect the outdoor air-side
test apparatus. Allow the test room reconditioning apparatus and the unit being tested to
operate for at least one hour. After attaining equilibrium conditions, measure the following
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Continue these measurements until a 30-minute period (e.g., four consecutive 10-minute
samples) is obtained where the Table 8 or Table 15, whichever applies, test tolerances are
satisfied.
b. After collecting 30 minutes of steady-state data, reconnect the outdoor air-side test
apparatus to the unit. Adjust the exhaust fan of the outdoor airflow measuring apparatus until
averages for the evaporator and condenser temperatures, or the saturated temperatures
corresponding to the measured pressures, agree within ±0.5 °F of the averages achieved
when the outdoor air-side test apparatus was disconnected. Calculate the averages for the
reconnected case using five or more consecutive readings taken at one minute intervals.
Make these consecutive readings after re-establishing equilibrium conditions and before
Connect the outdoor-side test apparatus to the unit. Adjust the exhaust fan of the outdoor
airflow measuring apparatus to achieve the same external static pressure as measured during the
prior preliminary test conducted with the unit operating in the same cooling or heating mode at
a. Continue (preliminary test was conducted) or begin (no preliminary test) the official test
by making measurements for both the Indoor and Outdoor Air Enthalpy Methods at equal
intervals that span 5 minutes or less. Discontinue these measurements only after obtaining a
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30-minute period where the specified test condition and test operating tolerances are
(2) For cases where a preliminary test is conducted, the capacities determined using the
Indoor Air Enthalpy Method from the official and preliminary test periods must agree
b. For space cooling tests, calculate capacity from the outdoor air-enthalpy measurements as
specified in sections 7.3.3.2 and 7.3.3.3 of ASHRAE Standard 37-2009. Calculate heating
7.3.3.4.3 of the same ASHRAE Standard. Adjust the outdoor-side capacity according to
section 7.3.3.4 of ASHRAE Standard 37-2009 to account for line losses when testing split
systems. Use the outdoor unit fan power as measured during the official test and not the
value measured during the preliminary test, as described in section 8.6.2 of ASHRAE
3.11.2 If using the Compressor Calibration Method as the secondary test method.
a. Conduct separate calibration tests using a calorimeter to determine the refrigerant flow
rate. Or for cases where the superheat of the refrigerant leaving the evaporator is less than 5
°F, use the calorimeter to measure total capacity rather than refrigerant flow rate. Conduct
these calibration tests at the same test conditions as specified for the tests in this appendix.
Operate the unit for at least one hour or until obtaining equilibrium conditions before
collecting data that will be used in determining the average refrigerant flow rate or total
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capacity. Sample the data at equal intervals that span 5 minutes or less. Determine average
flow rate or average capacity from data sampled over a 30-minute period where the Table 8
(cooling) or the Table 15 (heating) tolerances are satisfied. Otherwise, conduct the calibration
9, and 11 of ASHRAE Standard 41.9-2011; and section 7.4 of ASHRAE Standard 37-2009.
b. Calculate space cooling and space heating capacities using the compressor calibration
Standard 37-2009.
Conduct this secondary method according to section 7.5 of ASHRAE Standard 37-2009.
Calculate space cooling and heating capacities using the refrigerant-enthalpy method
measurements as specified in sections 7.5.4 and 7.5.5, respectively, of the same ASHRAE
Standard.
a. When reporting rated capacities, round them off as specified in 10 CFR Part 430.23 (for a
b. For the capacities used to perform the section 4 calculations, however, round only to
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Conduct one of the following tests after the completion of the B, B1, or B2 Test, whichever
comes last: if the central air conditioner or heat pump lacks a compressor crankcase heater,
perform the test in Section 3.13.1; if the central air conditioner or heat pump has compressor
crankcase heater that lacks controls, perform the test in Section 3.13.1; if the central air
conditioner or heat pump has a compressor crankcase heater equipped with controls, perform the
3.13.1 This test determines the off mode average power rating for central air conditioners and
heat pumps that lack a compressor crankcase heater, or have a compressor crankcase heater that
lacks controls.
a. Configure Controls: Configure the controls of the central air conditioner or heat pump so
that it operates as if connected to a building thermostat that is set to the OFF position. This
particular test contains no requirements as to ambient conditions within the test rooms, and
room conditions are allowed to change during the test. Ensure that the low-voltage
b. Measure 𝑃𝑃1𝑥𝑥 : Determine the average power from non-zero value data measured over a 5-
minute interval of the non-operating central air conditioner or heat pump and designate the
average power as 𝑃𝑃1𝑥𝑥 , the shoulder season total off mode power.
c. Measure 𝑃𝑃𝑥𝑥 for coil-only split systems (that would be installed in the field with a furnace
having a dedicated board for indoor controls) and for blower-coil split systems for which a
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furnace is the designated air mover: Disconnect all low-voltage wiring for the outdoor
components and outdoor controls from the low-voltage transformer. Determine the average
power from non-zero value data measured over a 5-minute interval of the power supplied to
the (remaining) low-voltage components of the central air conditioner or heat pump, or low-
d. Calculate P1:
Single-package systems and blower coil split systems for which the designated air mover is
not a furnace: Divide the shoulder season total off mode power (𝑃𝑃1𝑥𝑥 ) by the number of
compressors to calculate P1, the shoulder season per-compressor off mode power. If the
compressor is a modulating-type, assign a value of 1.5 for the number of compressors. Round
P1 to the nearest watt and record as both P1 and P2, the latter of which is the heating season
Coil-only split systems (that would be installed in the field with a furnace having a dedicated
board for indoor controls) and blower-coil split systems for which a furnace is the designated
air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the shoulder season total off mode
power (𝑃𝑃1𝑥𝑥 ) and divide by the number of compressors to calculate P1, the shoulder season
1.5 for the number of compressors. Round P1 to the nearest watt and record as both P1 and
P2, the latter of which is the heating season per-compressor off mode power. The expression
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𝑃𝑃1 −𝑃𝑃
𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
3.13.2 This test determines the off mode average power rating for central air conditioners and
heat pumps that have a compressor crankcase heater equipped with controls.
temperature in the air between 2 and 6 inches from the crankcase heater temperature sensor
or, if no such temperature sensor exists, position it in the air between 2 and 6 inches from the
crankcase heater. Utilize the temperature measurements from this sensor for this portion of
the test procedure. Configure the controls of the central air conditioner or heat pump so that it
operates as if connected to a building thermostat that is set to the OFF position. Ensure that
the low-voltage transformer and low-voltage components are connected. Adjust the outdoor
temperature at a rate of change of no more than 20 °F per hour and achieve an outdoor dry-
bulb temperature of 72 °F. Maintain this temperature within +/-2 °F for at least 5 minutes,
b. Measure 𝑃𝑃1𝑥𝑥 : Determine the average power from non-zero value data measured over a 5-
minute interval of the non-operating central air conditioner or heat pump and designate the
average power as 𝑃𝑃1𝑥𝑥 , the shoulder season total off mode power.
c. Reconfigure Controls: In the process of reaching the target outdoor dry-bulb temperature,
adjust the outdoor temperature at a rate of change of no more than 20 °F per hour. This target
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Certification Database at which the crankcase heater turns on, minus five degrees Fahrenheit.
Maintain this temperature within +/-2 °F for at least 5 minutes, while maintaining an indoor
d. Measure 𝑃𝑃2𝑥𝑥 : Determine the average non-zero power of the non-operating central air
conditioner or heat pump over a 5-minute interval and designate it as 𝑃𝑃2𝑥𝑥 , the heating season
e. Measure 𝑃𝑃𝑥𝑥 for coil-only split systems (that would be installed in the field with a furnace
having a dedicated board for indoor controls) and for blower-coil split systems for which a
furnace is the designated air mover: Disconnect all low-voltage wiring for the outdoor
components and outdoor controls from the low-voltage transformer. Determine the average
power from non-zero value data measured over a 5-minute interval of the power supplied to
the (remaining) low-voltage components of the central air conditioner or heat pump, or low-
f. Calculate P1:
Single-package systems and blower coil split systems for which the air mover is not a
furnace: Divide the shoulder season total off mode power (𝑃𝑃1𝑥𝑥 ) by the number of compressors to
calculate P1, the shoulder season per-compressor off mode power. Round to the nearest watt. If
the compressor is a modulating-type, assign a value of 1.5 for the number of compressors. The
𝑥𝑥 𝑃𝑃1
expression for calculating P1 is as follows:𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐.
404
Coil-only split systems (that would be installed in the field with a furnace having a
dedicated board for indoor controls) and blower-coil split systems for which a furnace is the
designated air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the shoulder season total off
mode power (𝑃𝑃1𝑥𝑥 ) and divide by the number of compressors to calculate P1, the shoulder season
per-compressor off mode power. Round to the nearest watt. If the compressor is a modulating-
type, assign a value of 1.5 for the number of compressors. The expression for calculating P1 is as
follows:
𝑃𝑃1 −𝑃𝑃
𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
h. Calculate P2:
Single-package systems and blower coil split systems for which the air mover is not a
furnace: Divide the heating season total off mode power (𝑃𝑃2𝑥𝑥 ) by the number of compressors
to calculate P2, the heating season per-compressor off mode power. Round to the nearest
watt. If the compressor is a modulating-type, assign a value of 1.5 for the number of
𝑃𝑃2
𝑥𝑥
𝑃𝑃2 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐.
Coil-only split systems (that would be installed in the field with a furnace having a dedicated
board for indoor controls) and blower-coil split systems for which a furnace is the designated
air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the heating season total off mode power
(𝑃𝑃2𝑥𝑥 ) and divide by the number of compressors to calculate P2, the heating season per-
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compressor off mode power. Round to the nearest watt. If the compressor is a modulating-
type, assign a value of 1.5 for the number of compressors. The expression for calculating P2
is as follows:
𝑃𝑃2 −𝑃𝑃
𝑃𝑃2 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
4.1 Seasonal Energy Efficiency Ratio (SEER) Calculations. SEER must be calculated as follows:
For equipment covered under sections 4.1.2, 4.1.3, and 4.1.4, evaluate the seasonal energy
efficiency ratio,
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗)
∑8𝑗𝑗=1 𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗) ∑8𝑗𝑗=1
Equation 4.1-1 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 = ∑8𝑗𝑗=1 𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
= 𝑁𝑁
𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
8
∑𝑗𝑗=1
𝑁𝑁
where,
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗)
= the ratio of the total space cooling provided during periods of the space cooling
𝑁𝑁
season when the outdoor temperature fell within the range represented by bin temperature
𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
= the electrical energy consumed by the test unit during periods of the space cooling
𝑁𝑁
season when the outdoor temperature fell within the range represented by bin temperature
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Tj = the outdoor bin temperature, °F. Outdoor temperatures are grouped or “binned.” Use
bins of 5 °F with the 8 cooling season bin temperatures being 67, 72, 77, 82, 87, 92, 97,
Additionally, for sections 4.1.2, 4.1.3, and 4.1.4, use a building cooling load, BL(Tj). When
where,
Q̇ck=2(95) = the space cooling capacity determined from the A2 Test and calculated as
The temperatures 95 °F and 65 °F in the building load equation represent the selected
4.1.1 SEER calculations for an air conditioner or heat pump having a single-speed compressor
that was tested with a fixed-speed indoor blower installed, a constant-air-volume-rate indoor
a. Evaluate the seasonal energy efficiency ratio, expressed in units of Btu/watt-hour, using:
where,
407
𝑄𝑄̇𝑐𝑐 (82)
𝐸𝐸𝐸𝐸𝐸𝐸𝐵𝐵 = 𝐸𝐸̇𝑐𝑐 (82)
= the energy efficiency ratio determined from the B Test described in
PLF(0.5) = 1 − 0.5 · CDc, the part-load performance factor evaluated at a cooling load
b. Refer to section 3.3 regarding the definition and calculation of Q̇c(82) and Ėc(82).
4.1.2 SEER calculations for an air conditioner or heat pump having a single-speed compressor
4.1.2.1 Units covered by section 3.2.2.1 where indoor blower capacity modulation correlates
with the outdoor dry bulb temperature. The manufacturer must provide information on how the
indoor air volume rate or the indoor blower speed varies over the outdoor temperature range of
67 °F to 102 °F. Calculate SEER using Equation 4.1-1. Evaluate the quantity qc(Tj)/N in
where,
408
Q̇c(Tj) = the space cooling capacity of the test unit when operating at outdoor
nj/N = fractional bin hours for the cooling season; the ratio of the number of hours during
the cooling season when the outdoor temperature fell within the range represented by bin
a. For the space cooling season, assign nj/N as specified in Table 18. Use Equation 4.1-2 to
where,
the space cooling capacity of the test unit at outdoor temperature Tj if operated at the
the space cooling capacity of the test unit at outdoor temperature Tj if operated at the
b. For units where indoor blower speed is the primary control variable, FPck=1 denotes the fan
speed used during the required A1 and B1 Tests (see section 3.2.2.1), FPck=2 denotes the fan
speed used during the required A2 and B2 Tests, and FPc(Tj) denotes the fan speed used by
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the unit when the outdoor temperature equals Tj. For units where indoor air volume rate is the
primary control variable, the three FPc's are similarly defined only now being expressed in
terms of air volume rates rather than fan speeds. Refer to sections 3.2.2.1, 3.1.4 to 3.1.4.2,
and 3.3 regarding the definitions and calculations of Q̇ck=1(82), Q̇ck=1(95),Q̇c k=2(82), and
Q̇ck=2(95).
where,
Ėc(Tj) = the electrical power consumption of the test unit when operating at outdoor
temperature Tj, W.
c. The quantities X(Tj) and nj /N are the same quantities as used in Equation 4.1.2-1.
the electrical power consumption of the test unit at outdoor temperature Tj if operated at
consumption of the test unit at outdoor temperature Tj if operated at the Cooling Full-load Air
Volume Rate, W.
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e. The parameters FPck=1, and FPck=2, and FPc(Tj) are the same quantities that are used when
evaluating Equation 4.1.2-2. Refer to sections 3.2.2.1, 3.1.4 to 3.1.4.2, and 3.3 regarding the
4.1.2.2 Units covered by section 3.2.2.2 where indoor blower capacity modulation is used to
adjust the sensible to total cooling capacity ratio. Calculate SEER as specified in section 4.1.1.
4.1.3 SEER calculations for an air conditioner or heat pump having a two-capacity compressor.
Calculate SEER using Equation 4.1-1. Evaluate the space cooling capacity, Q̇ck=1 (Tj), and
electrical power consumption, Ėck=1 (Tj), of the test unit when operating at low compressor
where Q̇ck=1 (82) and Ėck=1 (82) are determined from the B1 Test, Q̇ck=1 (67) and Ėck=1 (67) are
determined from the F1Test, and all four quantities are calculated as specified in section 3.3.
Evaluate the space cooling capacity, Q̇ck=2 (Tj), and electrical power consumption, Ėck=2 (Tj), of
the test unit when operating at high compressor capacity and outdoor temperature Tj using,
411
where Q̇ck=2(95) and Ėck=2(95) are determined from the A2 Test, Q̇ck=2(82), and Ėck=2(82), are
determined from the B2Test, and all are calculated as specified in section 3.3.
The calculation of Equation 4.1-1 quantities qc(Tj)/N and ec(Tj)/N differs depending on
whether the test unit would operate at low capacity (section 4.1.3.1), cycle between low and
high capacity (section 4.1.3.2), or operate at high capacity (sections 4.1.3.3 and 4.1.3.4) in
responding to the building load. For units that lock out low capacity operation at higher
outdoor temperatures, the manufacturer must supply information regarding this temperature
so that the appropriate equations are used. Use Equation 4.1-2 to calculate the building load,
4.1.3.1 Steady-state space cooling capacity at low compressor capacity is greater than or equal to
where,
Xk=1(Tj) = BL(Tj)/Q̇ck=1(Tj), the cooling mode low capacity load factor for temperature
bin j, dimensionless.
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fractional bin hours for the cooling season; the ratio of the number of hours during
the cooling season when the outdoor temperature fell within the range represented by bin
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use
4.1.3.2 Unit alternates between high (k=2) and low (k=1) compressor capacity to satisfy the
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where,
bin j, dimensionless.
Xk=2(Tj) = 1 − Xk=1(Tj), the cooling mode, high capacity load factor for temperature bin j,
dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations
4.1.3-1 and 4.1.3-2, respectively, to evaluate Q̇ck=1(Tj) and Ėck=1(Tj). Use Equations 4.1.3-3
4.1.3.3 Unit only operates at high (k=2) compressor capacity at temperature Tj and its capacity is
greater than the building cooling load, BL(Tj) <Q̇ck=2(Tj). This section applies to units that lock
where,
Xk=2(Tj) = BL(Tj)/Q̇ck=2(Tj), the cooling mode high capacity load factor for temperature
bin j, dimensionless.
𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 = 1 − 𝐶𝐶𝐷𝐷𝑐𝑐 (𝑘𝑘 = 2) ∗ [1 − 𝑋𝑋 𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ) the part load factor, dimensionless.
Obtain the fraction bin hours for the cooling season, from Table 18. Use Equations 4.1.3-
3 and 4.1.3-4, respectively, to evaluate Q̇ck=2 (Tj) and Ėck=2 (Tj). If the C2 and D2 Tests
414
described in section 3.2.3 and Table 6 are not conducted, set CDc (k=2) equal to the default
4.1.3.4 Unit must operate continuously at high (k=2) compressor capacity at temperature Tj,
BL(Tj) ≥Q̇ck=2(Tj).
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations 4.1.3-
4.1.4 SEER calculations for an air conditioner or heat pump having a variable-speed compressor.
Calculate SEER using Equation 4.1-1. Evaluate the space cooling capacity, Q̇ck=1(Tj), and
electrical power consumption, Ėck=1(Tj), of the test unit when operating at minimum compressor
𝐸𝐸 ̇ 𝑘𝑘=1
(82)−𝐸𝐸𝑐𝑐 (67) ̇ 𝑘𝑘=1
Equation 4.1.4-2 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (67) + 𝑐𝑐 ∗ (𝑇𝑇𝑗𝑗 − 67)
82−67
where Qc (82) and Ėc (82) are determined from the B1 Test, Q̇ck=1(67) and Ėck=1(67)
̇ k=1 k=1
are determined from the F1 Test, and all four quantities are calculated as specified in section 3.3.
Evaluate the space cooling capacity, Q̇ck=2(Tj), and electrical power consumption, Ėck=2(Tj), of
the test unit when operating at maximum compressor speed and outdoor temperature Tj. Use
Equations 4.1.3-3 and 4.1.3-4, respectively, where Q̇ck=2(95) and Ėck=2(95) are determined from
the A2 Test, Q̇ck=2(82) and Ėck=2(82) are determined from the B2 Test, and all four quantities are
calculated as specified in section 3.3. Calculate the space cooling capacity, Q̇ck=v(Tj), and
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electrical power consumption, Ėck=v(Tj), of the test unit when operating at outdoor temperature
Tj and the intermediate compressor speed used during the section 3.2.4 (and Table 7) EV Test
using,
4.1.4.1 Steady-state space cooling capacity when operating at minimum compressor speed is
greater than or equal to the building cooling load at temperature Tj, Q̇ck=1(Tj) ≥BL(Tj).
where,
Xk=1(Tj) = BL(Tj) / Q̇ck=1(Tj), the cooling mode minimum speed load factor for
nj/N = fractional bin hours for the cooling season; the ratio of the number of hours during
the cooling season when the outdoor temperature fell within the range represented by bin
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations
4.1.3-1 and 4.1.3-2, respectively, to evaluate Q̇ck=l (Tj) and Ėck=l (Tj).
4.1.4.2 Unit operates at an intermediate compressor speed (k=i) in order to match the building
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𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗 ) 𝑛𝑛𝑗𝑗 𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗 ) 𝑛𝑛𝑗𝑗
= 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗ = 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗
𝑁𝑁 𝑁𝑁 𝑁𝑁 𝑁𝑁
where,
Q̇ck=i(Tj) = BL(Tj), the space cooling capacity delivered by the unit in matching the
building load at temperature Tj, Btu/h. The matching occurs with the unit operating at
compressor speed k = i.
𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = the electrical power input required by the test unit when
𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
EERk=i(Tj) = the steady-state energy efficiency ratio of the test unit when operating at a
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. For each
temperature bin where the unit operates at an intermediate compressor speed, determine the
EERk=i(Tj) = A + B · Tj + C · Tj2.
For each unit, determine the coefficients A, B, and C by conducting the following
calculations once:
𝑇𝑇 2 −𝑇𝑇 2 𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 (𝑇𝑇1 )−𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=2 (𝑇𝑇2 )−𝐷𝐷∗[𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 (𝑇𝑇1 )−𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=𝑣𝑣 (𝑇𝑇𝑣𝑣 )]
𝐷𝐷 = 𝑇𝑇22 −𝑇𝑇12 𝐵𝐵 = 𝑇𝑇1 −𝑇𝑇2 −𝐷𝐷∗(𝑇𝑇1 −𝑇𝑇𝑣𝑣 )
𝑣𝑣 1
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where,
T1 = the outdoor temperature at which the unit, when operating at minimum compressor
speed, provides a space cooling capacity that is equal to the building load (Q̇ck=l (Tl) =
BL(T1)), °F. Determine T1 by equating Equations 4.1.3-1 and 4.1-2 and solving for
outdoor temperature.
Tv = the outdoor temperature at which the unit, when operating at the intermediate
compressor speed used during the section 3.2.4 EV Test, provides a space cooling
capacity that is equal to the building load (Q̇ck=v (Tv) = BL(Tv)), °F. Determine Tv by
equating Equations 4.1.4-1 and 4.1-2 and solving for outdoor temperature.
T2 = the outdoor temperature at which the unit, when operating at maximum compressor
speed, provides a space cooling capacity that is equal to the building load (Q̇ck=2 (T2) =
BL(T2)), °F. Determine T2 by equating Equations 4.1.3-3 and 4.1-2 and solving for
outdoor temperature.
4.1.4.3 Unit must operate continuously at maximum (k=2) compressor speed at temperature Tj,
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as specified in section 4.1.3.4 with the understanding that Q̇ck=2(Tj) and Ėck=2(Tj) correspond to
maximum compressor speed operation and are derived from the results of the tests specified in
section 3.2.4.
4.1.5 SEER calculations for an air conditioner or heat pump having a single indoor unit with
multiple blowers. Calculate SEER using Eq. 4.1– 1, where qc(Tj)/N and ec(Tj)/N are evaluated as
4.1.5.1 For multiple blower systems that are connected to a lone, single-speed outdoor unit. a.
Calculate the space cooling capacity, 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), and electrical power consumption, 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), of
the test unit when operating at the cooling minimum air volume rate and outdoor temperature Tj
using the equations given in section 4.1.2.1. Calculate the space cooling capacity, 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), and
electrical power consumption, 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), of the test unit when operating at the cooling full-load
air volume rate and outdoor temperature Tj using the equations given in section 4.1.2.1. In
evaluating the section 4.1.2.1 equations, determine the quantities 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (82) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (82) from
the B1 Test, 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (95) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (95) from the Al Test, 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (82) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (82) from the B2
Test, and 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (95) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (95) from the A2 Test. Evaluate all eight quantities as specified in
section 3.3. Refer to section 3.2.2.1 and Table 5 for additional information on the four referenced
laboratory tests. b. Determine the cooling mode cyclic degradation coefficient, CDc, as per
sections 3.2.2.1 and 3.5 to 3.5.3. Assign this same value to CDc(K=2). c. Except for using the
above values of 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), CDc, and CDc (K=2), calculate the
quantities qc(Tj)/N and ec(Tj)/N as specified in section 4.1.3.1 for cases where 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ) ≥
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BL(Tj). For all other outdoor bin temperatures, Tj, calculate qc(Tj)/N and ec(Tj)/N as specified in
section 4.1.3.3 if 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ) > BL (Tj) or as specified in section 4.1.3.4 if 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ) ≤ BL(Tj).
4.1.5.2 For multiple blower systems that are connected to either a lone outdoor unit having a
two-capacity compressor or to two separate but identical model single-speed outdoor units.
4.2 Heating Seasonal Performance Factor (HSPF) Calculations. Unless an approved alternative
efficiency determination method is used, as set forth in 10 CFR 429.70(e), HSPF must be
calculated as follows: Six generalized climatic regions are depicted in Figure 1 and otherwise
defined in Table 19. For each of these regions and for each applicable standardized design
where,
eh(Tj) / N = The ratio of the electrical energy consumed by the heat pump during periods
of the space heating season when the outdoor temperature fell within the range
represented by bin temperature Tj to the total number of hours in the heating season (N),
W. For heat pumps having a heat comfort controller, this ratio may also include electrical
energy used by resistive elements to maintain a minimum air delivery temperature (see
4.2.5).
RH(Tj) / N= The ratio of the electrical energy used for resistive space heating during
periods when the outdoor temperature fell within the range represented by bin
temperature Tj to the total number of hours in the heating season (N), W. Except as noted
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in section 4.2.5, resistive space heating is modeled as being used to meet that portion of
the building load that the heat pump does not meet because of insufficient capacity or
because the heat pump automatically turns off at the lowest outdoor temperatures. For
heat pumps having a heat comfort controller, all or part of the electrical energy used by
resistive heaters at a particular bin temperature may be reflected in eh(Tj) / N (see 4.2.5).
Tj = the outdoor bin temperature, °F. Outdoor temperatures are “binned” such that
calculations are only performed based one temperature within the bin. Bins of 5 °F are
used.
nj / N= Fractional bin hours for the heating season; the ratio of the number of hours
during the heating season when the outdoor temperature fell within the range represented
by bin temperature Tj to the total number of hours in the heating season, dimensionless.
J = for each generalized climatic region, the total number of temperature bins,
dimensionless. Referring to Table 19, J is the highest bin number (j) having a nonzero
entry for the fractional bin hours for the generalized climatic region of interest.
of Tj; the heating season building load also depends on the generalized climatic region's
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Region Number I II III IV V VI
Heating Load Hours, HLH 750 1250 1750 2250 2750 *2750
Outdoor Design Temperature, TOD 37 27 17 5 −10 30
j Tj (°F) Fractional Bin Hours, nj/N
1 62 .291 .215 .153 .132 .106 .113
2 57 .239 .189 .142 .111 .092 .206
3 52 .194 .163 .138 .103 .086 .215
4 47 .129 .143 .137 .093 .076 .204
5 42 .081 .112 .135 .100 .078 .141
6 37 .041 .088 .118 .109 .087 .076
7 32 .019 .056 .092 .126 .102 .034
8 27 .005 .024 .047 .087 .094 .008
9 22 .001 .008 .021 .055 .074 .003
10 17 0 .002 .009 .036 .055 0
11 12 0 0 .005 .026 .047 0
12 7 0 0 .002 .013 .038 0
13 2 0 0 .001 .006 .029 0
14 −3 0 0 0 .002 .018 0
15 −8 0 0 0 .001 .010 0
16 −13 0 0 0 0 .005 0
17 −18 0 0 0 0 .002 0
18 −23 0 0 0 0 .001 0
(65−𝑇𝑇𝑗𝑗 )
Equation 4.2-2 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 � = ∗ 𝐶𝐶 ∗ 𝐷𝐷𝐷𝐷𝐷𝐷
65−𝑇𝑇𝑂𝑂𝑂𝑂
where,
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TOD = the outdoor design temperature, °F. An outdoor design temperature is specified for
C = 0.77, a correction factor which tends to improve the agreement between calculated
DHR = the design heating requirement (see section 1.2, Definitions), Btu/h.
Calculate the minimum and maximum design heating requirements for each generalized
65−𝑇𝑇
𝑄𝑄̇ℎ𝑘𝑘 (47) ∗ � 60𝑂𝑂𝑂𝑂 � , 𝑓𝑓𝑓𝑓𝑓𝑓 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝐼𝐼, 𝐼𝐼𝐼𝐼, 𝐼𝐼𝐼𝐼𝐼𝐼, 𝐼𝐼𝐼𝐼, & 𝑉𝑉𝑉𝑉
𝐷𝐷𝐷𝐷𝐷𝐷𝑚𝑚𝑚𝑚𝑚𝑚 = � �
𝑄𝑄̇ℎ𝑘𝑘 (47), 𝑓𝑓𝑓𝑓𝑓𝑓 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑉𝑉
and
65−𝑇𝑇𝑂𝑂𝑂𝑂
2 ∗ 𝑄𝑄̇ℎ𝑘𝑘 (47) ∗ � � , 𝑓𝑓𝑓𝑓𝑓𝑓 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝐼𝐼, 𝐼𝐼𝐼𝐼, 𝐼𝐼𝐼𝐼𝐼𝐼, 𝐼𝐼𝐼𝐼, & 𝑉𝑉𝑉𝑉
𝐷𝐷𝐷𝐷𝐷𝐷𝑚𝑚𝑚𝑚𝑚𝑚 = � 60 �
2.2 ∗ 𝑄𝑄̇ℎ𝑘𝑘 (47), 𝑓𝑓𝑓𝑓𝑓𝑓 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑉𝑉
1. For a single-speed heat pump tested as per section 3.6.1, Q̇hk(47) = Q̇h(47), the
2. For a variable-speed heat pump, a section 3.6.2 single-speed heat pump, or a two-
capacity heat pump not covered by item 3, Q̇nk(47) = Q̇nk=2(47), the space heating
3. For two-capacity, northern heat pumps (see section 1.2, Definitions), Q̇kh(47) =
Q̇k=1h(47), the space heating capacity determined from the H11 Test.
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If the optional H1N Test is conducted on a variable-speed heat pump, the manufacturer
has the option of defining Q̇kh(47) as specified above in item 2 or as Q̇kh(47)=Q̇k=Nh(47), the
For all heat pumps, HSPF accounts for the heating delivered and the energy consumed by
auxiliary resistive elements when operating below the balance point. This condition occurs when
the building load exceeds the space heating capacity of the heat pump condenser. For HSPF
calculations for all heat pumps, see either section 4.2.1, 4.2.2, 4.2.3, or 4.2.4, whichever applies.
For heat pumps with heat comfort controllers (see section 1.2, Definitions), HSPF also
accounts for resistive heating contributed when operating above the heat-pump-plus-comfort-
controller balance point as a result of maintaining a minimum supply temperature. For heat
pumps having a heat comfort controller, see section 4.2.5 for the additional steps required for
4.2.1 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor
that was tested with a fixed-speed indoor blower installed, a constant-air-volume-rate indoor
424
𝑒𝑒ℎ (𝑇𝑇𝑗𝑗 ) 𝑋𝑋�𝑇𝑇𝑗𝑗 �∗𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 �∗𝛿𝛿�𝑇𝑇𝑗𝑗 � 𝑛𝑛𝑗𝑗
Equation 4.2.1-1 = ∗
𝑁𝑁 𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 𝑁𝑁
𝑅𝑅𝑅𝑅(𝑇𝑇𝑗𝑗 ) 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 �−[𝑋𝑋�𝑇𝑇𝑗𝑗 �∗𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 �∗𝛿𝛿�𝑇𝑇𝑗𝑗 �] 𝑛𝑛𝑗𝑗
Equation 4.2.1-2 = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ ∗
𝑁𝑁 3.413 𝑁𝑁
𝑊𝑊
where,
whichever is less; the heating mode load factor for temperature bin j, dimensionless.
Q̇h(Tj) = the space heating capacity of the heat pump when operating at outdoor
Ėh(Tj) = the electrical power consumption of the heat pump when operating at outdoor
temperature Tj, W.
Use Equation 4.2-2 to determine BL(Tj). Obtain fractional bin hours for the heating season,
𝑗𝑗 𝑄𝑄̇ℎ �𝑇𝑇 �
⎧ 0, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 <1 ⎫
3.413∗𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 �
⎪ ⎪
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 �
Equation 4.2.1-3 𝛿𝛿�𝑇𝑇𝑗𝑗 � = 1⁄2 , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 < 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 3.413∗𝐸𝐸̇ �𝑇𝑇 � ≥ 1
⎨ ℎ 𝑗𝑗 ⎬
⎪ 𝑄𝑄̇ ℎ �𝑇𝑇 𝑗𝑗 � ⎪
1, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 > 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎩ 3.413∗𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � ⎭
where,
425
Toff = the outdoor temperature when the compressor is automatically shut off, °F. (If no
Ton = the outdoor temperature when the compressor is automatically turned back on, if
Equation 4.2.1-4
[𝑄𝑄̇ℎ (47)−𝑄𝑄̇ℎ (17)]∗(𝑇𝑇𝑗𝑗 −17)
𝑄𝑄̇ℎ (17) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � = � 47−17
[𝑄𝑄̇ℎ (35)−𝑄𝑄̇ℎ (17)]∗(𝑇𝑇𝑗𝑗 −17)
𝑄𝑄̇ℎ (17) + , 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
35−17
Equation 4.2.1-5
𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 �
⎧ ̇ �𝐸𝐸̇ℎ (47) − 𝐸𝐸̇ℎ (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
⎪𝐸𝐸ℎ (17) + 47 − 17
, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
=
⎨ �𝐸𝐸̇ℎ (35) − 𝐸𝐸̇ℎ (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
⎪ 𝐸𝐸̇ℎ (17) + , 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
⎩ 35 − 17
where Q̇h(47) and Ėh(47) are determined from the H1 Test and calculated as specified in
section 3.7; Q̇h(35) and Ėh(35) are determined from the H2 Test and calculated as specified in
section 3.9.1; and Q̇h(17) and Ėh(17) are determined from the H3 Test and calculated as
4.2.2 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor
426
information about how the indoor air volume rate or the indoor blower speed varies over the
in Equation 4.2-1 as specified in section 4.2.1 with the exception of replacing references to the
H1C Test and section 3.6.1 with the H1C1 Test and section 3.6.2. In addition, evaluate the space
heating capacity and electrical power consumption of the heat pump Q̇h(Tj) and Ėh(Tj) using
where the space heating capacity and electrical power consumption at both low capacity
(k=1) and high capacity (k=2) at outdoor temperature Tj are determined using
Equation 4.2.2-3
�𝑄𝑄̇ 𝑘𝑘 (47)−𝑄𝑄̇ 𝑘𝑘 (17)�∗(𝑇𝑇 −17)
𝑗𝑗
𝑄𝑄̇ℎ𝑘𝑘 (17) +
ℎ ℎ
, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
𝑄𝑄ℎ𝑘𝑘̇ �𝑇𝑇𝑗𝑗 � = � 47−17
�𝑄𝑄̇ℎ𝑘𝑘 (35)−𝑄𝑄̇ℎ𝑘𝑘 (17)�∗(𝑇𝑇𝑗𝑗 −17)
𝑄𝑄̇ℎ𝑘𝑘 (17) + , 𝑖𝑖𝑓𝑓 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
35−17
Equation 4.2.2-4
̇ 𝑘𝑘 ̇ 𝑘𝑘
⎧𝐸𝐸̇ 𝑘𝑘 (17) + �𝐸𝐸ℎ (47) − 𝐸𝐸ℎ (17)� ∗ (𝑇𝑇𝑗𝑗 − 17) , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
⎪ ℎ 47 − 17
̇ 𝑘𝑘
𝐸𝐸ℎ �𝑇𝑇𝑗𝑗 � =
⎨ �𝐸𝐸ℎ𝑘𝑘̇ (35) − 𝐸𝐸̇ℎ𝑘𝑘 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
̇
⎪ 𝐸𝐸ℎ (17) +𝑘𝑘
, 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
⎩ 35 − 17
For units where indoor blower speed is the primary control variable, FPhk=1 denotes the fan
speed used during the required H11 and H31 Tests (see Table 11), FPhk=2 denotes the fan
427
speed used during the required H12, H22, and H32 Tests, and FPh(Tj) denotes the fan speed
used by the unit when the outdoor temperature equals Tj. For units where indoor air volume
rate is the primary control variable, the three FPh's are similarly defined only now being
expressed in terms of air volume rates rather than fan speeds. Determine Q̇hk=1(47) and
Ėhk=1(47) from the H11 Test, and Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all
four quantities as specified in section 3.7. Determine Q̇hk=1(35) and Ėhk=1(35) as specified in
section 3.6.2; determine Q̇hk=2(35) and Ėhk=2(35) and from the H22 Test and the calculation
specified in section 3.9. Determine Q̇hk=1(17) and Ėhk=1(17 from the H31 Test, and Q̇hk=2(17)
and Ėhk=2(17) from the H32 Test. Calculate all four quantities as specified in section 3.10.
4.2.3 Additional steps for calculating the HSPF of a heat pump having a two-capacity
differ depending upon whether the heat pump would operate at low capacity (section 4.2.3.1),
cycle between low and high capacity (Section 4.2.3.2), or operate at high capacity (sections
4.2.3.3 and 4.2.3.4) in responding to the building load. For heat pumps that lock out low capacity
operation at low outdoor temperatures, the manufacturer must supply information regarding the
a. Evaluate the space heating capacity and electrical power consumption of the heat pump
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�𝑄𝑄̇ℎ𝑘𝑘=1 (62) − 𝑄𝑄̇ℎ𝑘𝑘=1 (47)� ∗ (𝑇𝑇𝑗𝑗 − 47)
⎧ 𝑄𝑄̇ℎ𝑘𝑘=1 (47) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 40 ℉
⎪ 62 − 47
⎪
�𝑄𝑄̇ 𝑘𝑘=1 (35) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
𝑄𝑄̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑘𝑘=1 (17) + ℎ , 𝑖𝑖𝑖𝑖 17 ℉ ≤ 𝑇𝑇𝑗𝑗 < 40 ℉
⎨ 35 − 17
⎪
⎪ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
̇ 𝑘𝑘=1
𝑄𝑄ℎ (17) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 < 17 ℉
⎩ 47 − 17
�𝐸𝐸̇ 𝑘𝑘=1 (62)−𝐸𝐸̇ 𝑘𝑘=1 (47)�∗(𝑇𝑇 −47)
𝑗𝑗
𝐸𝐸̇ℎ𝑘𝑘=1 (47) +
ℎ ℎ
⎧ , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 40 ℉
62−47
⎪
�𝐸𝐸̇ 𝑘𝑘=1 (35)−𝐸𝐸̇ℎ𝑘𝑘=1 (17)�∗(𝑇𝑇𝑗𝑗 −17)
𝐸𝐸̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑘𝑘=1 (17) + ℎ , 𝑖𝑖𝑖𝑖 17 ℉ ≤ 𝑇𝑇𝑗𝑗 < 40 ℉
⎨ 35−17
⎪ �𝐸𝐸̇ℎ𝑘𝑘=1 (47)−𝐸𝐸̇ℎ𝑘𝑘=1 (17)�∗(𝑇𝑇𝑗𝑗 −17)
⎩ 𝐸𝐸 ̇ 𝑘𝑘=1
ℎ (17) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 < 17 ℉
47−17
b. Evaluate the space heating capacity and electrical power consumption (Q̇hk=2(Tj) and
Ėhk=2 (Tj)) of the heat pump when operating at high compressor capacity and outdoor
temperature Tj by solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. Determine
Q̇hk=1(62) and Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test, and
Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all six quantities as specified in section
3.7. Determine Q̇hk=2(35) and Ėhk=2(35) from the H22 Test and, if required as described in
section 3.6.3, determine Q̇hk=1(35) and Ėhk=1(35) from the H21 Test. Calculate the required 35
°F quantities as specified in section 3.9. Determine Q̇hk=2(17) and Ėhk=2(17) from the H32 Test
and, if required as described in section 3.6.3, determine Q̇hk=1(17) and Ėhk=1(17) from the
4.2.3.1 Steady-state space heating capacity when operating at low compressor capacity is
greater than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj) ≥BL(Tj).
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𝑅𝑅𝑅𝑅(𝑇𝑇𝑗𝑗 ) 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 �∗[1−𝛿𝛿�𝑇𝑇𝑗𝑗 �] 𝑛𝑛𝑗𝑗
Equation 4.2.3-2 = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ ∗
𝑁𝑁 3.413 𝑁𝑁
𝑊𝑊
where,
Xk=1(Tj) = BL(Tj) / Q̇hk=1(Tj), the heating mode low capacity load factor for temperature
bin j, dimensionless.
where Toff and Ton are defined in section 4.2.1. Use the calculations given in section
(a) The heat pump locks out low capacity operation at low outdoor temperatures and
4.2.3.2 Heat pump alternates between high (k=2) and low (k=1) compressor capacity to satisfy
𝑒𝑒ℎ (𝑇𝑇𝑗𝑗 ) 𝑛𝑛
=[𝑋𝑋 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗ 𝐸𝐸̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � + 𝑋𝑋 𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �] ∗ 𝛿𝛿�𝑇𝑇𝑗𝑗 � ∗ 𝑁𝑁𝑗𝑗
𝑁𝑁
430
where,
𝑘𝑘=1
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � − 𝐵𝐵𝐵𝐵(𝑇𝑇𝑗𝑗 )
𝑋𝑋 �𝑇𝑇𝑗𝑗 � = 𝑘𝑘=2
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � − 𝑄𝑄̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
Xk=2(Tj) = 1 − Xk=1(Tj) the heating mode, high capacity load factor for temperature bin j,
dimensionless.
Determine the low temperature cut-out factor, δ′(Tj), using Equation 4.2.3-3.
4.2.3.3 Heat pump only operates at high (k=2) compressor capacity at temperature Tj and its
capacity is greater than the building heating load, BL(Tj) <Q̇hk=2(Tj). This section applies to units
that lock out low compressor capacity operation at low outdoor temperatures.
where,
If the H1C2 Test described in section 3.6.3 and Table 12 is not conducted, set CDh (k=2)
Determine the low temperature cut-out factor, δ(Tj), using Equation 4.2.3-3.
4.2.3.4 Heat pump must operate continuously at high (k=2) compressor capacity at temperature
Where
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎧ 0, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 𝑜𝑜𝑜𝑜 <1
⎪ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
𝛿𝛿′�𝑇𝑇𝑗𝑗 � = 1⁄2 , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 < 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎨ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪ 𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪ 1, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 > 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎩ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
4.2.4 Additional steps for calculating the HSPF of a heat pump having a variable-speed
compressor. Calculate HSPF using Equation 4.2-1. Evaluate the space heating capacity,
Q̇hk=1(Tj), and electrical power consumption, Ėhk=1(Tj), of the heat pump when operating at
where Q̇hk=1(62) and Ėhk=1(62) are determined from the H01 Test, Q̇hk=1(47) and Ėhk=1(47)
are determined from the H11Test, and all four quantities are calculated as specified in
section 3.7. Evaluate the space heating capacity, Q̇hk=2(Tj), and electrical power
consumption, Ėhk=2(Tj), of the heat pump when operating at maximum compressor speed
and outdoor temperature Tj by solving Equations 4.2.2-3 and 4.2.2-4, respectively, for
k=2. Determine the Equation 4.2.2-3 and 4.2.2-4 quantities Q̇hk=2(47) and Ėhk=2(47) from
the H12 Test and the calculations specified in section 3.7. Determine Q̇hk=2(35) and
Ėhk=2(35) from the H22 Test and the calculations specified in section 3.9 or, if the
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H22 Test is not conducted, by conducting the calculations specified in section 3.6.4.
Determine Q̇hk=2(17) and Ėhk=2(17) from the H32 Test and the calculations specified in
section 3.10. Calculate the space heating capacity, Q̇hk=v(Tj), and electrical power
consumption, Ėhk=v(Tj), of the heat pump when operating at outdoor temperature Tj and
the intermediate compressor speed used during the section 3.6.4 H2V Test using
where Q̇hk=v(35) and Ėhk=v(35) are determined from the H2V Test and calculated as
specified in section 3.9. Approximate the slopes of the k=v intermediate speed heating
where,
Use Equations 4.2.4-1 and 4.2.4-2, respectively, to calculate Q̇hk=1(35) and Ėhk=1(35).
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4.2.4.1 Steady-state space heating capacity when operating at minimum compressor speed is
greater than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj ≥BL(Tj). Evaluate
as specified in section 4.2.3.1. Except now use Equations 4.2.4-1 and 4.2.4-2 to evaluate
Q̇hk=1(Tj) and Ėhk=1(Tj), respectively, and replace section 4.2.3.1 references to “low
capacity” and section 3.6.3 with “minimum speed” and section 3.6.4. Also, the last
4.2.4.2 Heat pump operates at an intermediate compressor speed (k=i) in order to match the
where,
𝑄𝑄̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
𝐸𝐸̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
Q̇hk=i(Tj) = BL(Tj), the space heating capacity delivered by the unit in matching the
building load at temperature (Tj), Btu/h. The matching occurs with the heat pump
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COPk=i(Tj) = the steady-state coefficient of performance of the heat pump when operating
For each temperature bin where the heat pump operates at an intermediate compressor speed,
COPk=i(Tj) = A + B . Tj + C . Tj2.
For each heat pump, determine the coefficients A, B, and C by conducting the following
calculations once:
𝑇𝑇 2 −𝑇𝑇 2 𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=2 (𝑇𝑇4 )−𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=1 (𝑇𝑇3 )−𝐷𝐷∗[𝐶𝐶𝐶𝐶𝐶𝐶 𝑘𝑘=2 (𝑇𝑇4 )−𝐶𝐶𝐶𝐶𝐶𝐶 𝑘𝑘=𝑣𝑣 (𝑇𝑇𝑣𝑣ℎ )]
𝐷𝐷 = 𝑇𝑇 23 −𝑇𝑇42 𝐵𝐵 = 𝑇𝑇4 −𝑇𝑇3 −𝐷𝐷∗(𝑇𝑇4 −𝑇𝑇𝑣𝑣ℎ )
𝑣𝑣ℎ 4
where,
T3 = the outdoor temperature at which the heat pump, when operating at minimum
compressor speed, provides a space heating capacity that is equal to the building load
(Q̇hk=1(T3) = BL(T3)), °F. Determine T3 by equating Equations 4.2.4-1 and 4.2-2 and
solving for:
outdoor temperature.
Tvh = the outdoor temperature at which the heat pump, when operating at the intermediate
compressor speed used during the section 3.6.4 H2V Test, provides a space heating
capacity that is equal to the building load (Q̇hk=v(Tvh) = BL(Tvh)), °F. Determine Tvh by
equating Equations 4.2.4-3 and 4.2-2 and solving for outdoor temperature.
435
T4 = the outdoor temperature at which the heat pump, when operating at maximum
compressor speed, provides a space heating capacity that is equal to the building load
(Q̇hk=2(T4) = BL(T4)), °F. Determine T4 by equating Equations 4.2.2-3 (k=2) and 4.2-2
For multiple-split heat pumps (only), the following procedures supersede the above
requirements for calculating COPhk=i(Tj). For each temperature bin where T3 >Tj >Tvh,
4.2.4.3 Heat pump must operate continuously at maximum (k=2) compressor speed at
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as specified in section 4.2.3.4 with the understanding that Q̇hk=2(Tj) and Ėhk=2(Tj)
correspond to maximum compressor speed operation and are derived from the results of
4.2.5 Heat pumps having a heat comfort controller. Heat pumps having heat comfort
controllers, when set to maintain a typical minimum air delivery temperature, will cause the heat
pump condenser to operate less because of a greater contribution from the resistive elements.
With a conventional heat pump, resistive heating is only initiated if the heat pump condenser
cannot meet the building load (i.e., is delayed until a second stage call from the indoor
thermostat). With a heat comfort controller, resistive heating can occur even though the heat
pump condenser has adequate capacity to meet the building load (i.e., both on during a first stage
call from the indoor thermostat). As a result, the outdoor temperature where the heat pump
compressor no longer cycles (i.e., starts to run continuously), will be lower than if the heat pump
4.2.5.1 Heat pump having a heat comfort controller: additional steps for calculating the HSPF
of a heat pump having a single-speed compressor that was tested with a fixed-speed indoor
installed. Calculate the space heating capacity and electrical power of the heat pump without the
heat comfort controller being active as specified in section 4.2.1 (Equations 4.2.1-4 and 4.2.1-5)
for each outdoor bin temperature, Tj, that is listed in Table 19. Denote these capacities and
electrical powers by using the subscript “hp” instead of “h.” Calculate the mass flow rate
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(expressed in pounds-mass of dry air per hour) and the specific heat of the indoor air (expressed
where V̇̅s, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0 �𝑇𝑇𝑗𝑗 � = 70℉ +
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj/N), RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified in section 4.2.1. For each
bin calculation, use the space heating capacity and electrical power from Case 1 or Case
2, whichever applies.
Case 1. For outdoor bin temperatures where To(Tj) is equal to or greater than TCC (the
maximum supply temperature determined according to section 3.1.9), determine Q̇h(Tj) and
Ėh(Tj) as specified in section 4.2.1 (i.e., Q̇h(Tj) = Q̇hp(Tj) and Ėhp(Tj) = Ėhp(Tj)). Note: Even
though To(Tj) ≥Tcc, resistive heating may be required; evaluate Equation 4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) >Tcc, determine Q̇h(Tj) and Ėh(Tj) using,
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
where,
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
438
NOTE: Even though To(Tj) <Tcc, additional resistive heating may be required; evaluate
4.2.5.2 Heat pump having a heat comfort controller: additional steps for calculating the HSPF
indoor blower. Calculate the space heating capacity and electrical power of the heat pump
without the heat comfort controller being active as specified in section 4.2.2 (Equations 4.2.2-1
and 4.2.2-2) for each outdoor bin temperature, Tj, that is listed in Table 19. Denote these
capacities and electrical powers by using the subscript “hp” instead of “h.” Calculate the mass
flow rate (expressed in pounds-mass of dry air per hour) and the specific heat of the indoor air
(expressed in Btu/lbmda · °F) from the results of the H12 Test using:
where V̇̅S, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0 �𝑇𝑇𝑗𝑗 � = 70℉ +
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj)/N , RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified in section 4.2.1 with the
exception of replacing references to the H1C Test and section 3.6.1 with the H1C1 Test
and section 3.6.2. For each bin calculation, use the space heating capacity and electrical
439
Case 1. For outdoor bin temperatures where To(Tj) is equal to or greater than TCC (the
maximum supply temperature determined according to section 3.1.9), determine Q̇h(Tj) and
Ėh(Tj) as specified in section 4.2.2 (i.e. Q̇h(Tj) = Q̇hp(Tj) and Ėh(Tj) = Ėhp(Tj)). Note: Even
though To(Tj) ≥TCC, resistive heating may be required; evaluate Equation 4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) <TCC, determine Q̇h(Tj) and Ėh(Tj) using,
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
where,
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though To(Tj) <Tcc, additional resistive heating may be required; evaluate
4.2.5.3 Heat pumps having a heat comfort controller: additional steps for calculating the HSPF of
a heat pump having a two-capacity compressor. Calculate the space heating capacity and
electrical power of the heat pump without the heat comfort controller being active as specified in
section 4.2.3 for both high and low capacity and at each outdoor bin temperature, Tj, that is listed
in Table 19. Denote these capacities and electrical powers by using the subscript “hp” instead of
“h.” For the low capacity case, calculate the mass flow rate (expressed in pounds-mass of dry air
per hour) and the specific heat of the indoor air (expressed in Btu/lbmda · °F) from the results of
440
where V̇̅s, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
the heat pump condenser coil when operating at low capacity using,
𝑄𝑄̇ℎ𝑝𝑝
𝑘𝑘=1
�𝑇𝑇𝑗𝑗 �
𝑇𝑇0𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 70℉ + 𝑘𝑘=1 𝑘𝑘=1
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Repeat the above calculations to determine the mass flow rate (ṁdak=2) and the specific heat
of the indoor air (Cp,dak=2) when operating at high capacity by using the results of the
H12 Test. For each outdoor bin temperature listed in Table 19, calculate the nominal
temperature of the air leaving the heat pump condenser coil when operating at high capacity
using,
𝑘𝑘=2
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 70℉ + 𝑘𝑘=2 𝑘𝑘=2
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj)/N, RH(Tj)/N, Xk=1(Tj), and/or Xk=2(Tj), PLFj, and δ′(Tj) or δ″(Tj) as
specified in section 4.2.3.1. 4.2.3.2, 4.2.3.3, or 4.2.3.4, whichever applies, for each
temperature bin. To evaluate these quantities, use the low-capacity space heating capacity
and the low-capacity electrical power from Case 1 or Case 2, whichever applies; use the
high-capacity space heating capacity and the high-capacity electrical power from Case 3
Case 1. For outdoor bin temperatures where Tok=1(Tj) is equal to or greater than TCC (the
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and Ėhk=1(Tj) as specified in section 4.2.3 (i.e., Q̇hk=1(Tj) = Q̇hpk=1(Tj) and Ėhk=1(Tj) =
Ėhpk=1(Tj).
NOTE: Even though Tok=1(Tj) ≥TCC, resistive heating may be required; evaluate RH(Tj)/N for
all bins.
Case 2. For outdoor bin temperatures where Tok=1(Tj) <TCC, determine Q̇hk=1(Tj) and Ėhk=1(Tj)
using,
where,
𝑘𝑘=1
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=1 𝑘𝑘=1
�𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 𝑘𝑘=1
∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=1
�𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though Tok=1(Tj) ≥Tcc, additional resistive heating may be required; evaluate
Case 3. For outdoor bin temperatures where Tok=2(Tj) is equal to or greater than TCC,
determine Q̇hk=2(Tj) and Ėhk=2(Tj) as specified in section 4.2.3 (i.e., Q̇hk=2(Tj) = Q̇hpk=2(Tj) and
Ėhk=2(Tj) = Ėhpk=2(Tj)).
NOTE: Even though Tok=2(Tj) <TCC, resistive heating may be required; evaluate RH(Tj)/N for
all bins.
Case 4. For outdoor bin temperatures where Tok=2(Tj) <TCC, determine Q̇hk=2(Tj) and Ėhk=2(Tj)
using,
442
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 �
where,
𝑘𝑘=2
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=2 𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 𝑘𝑘=2
∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though Tok=2(Tj) <Tcc, additional resistive heating may be required; evaluate
4.2.5.4 Heat pumps having a heat comfort controller: additional steps for calculating the HSPF of
4.2.6 Additional steps for calculating the HSPF of a heat pump having a triple-capacity
compressor. The only triple-capacity heat pumps covered are triple-capacity, northern heat
pumps.
For such heat pumps, the calculation of the Eq. 4.2–1 quantities
differ depending on whether the heat pump would cycle on and off at low capacity (section
4.2.6.1), cycle on and off at high capacity (section 4.2.6.2), cycle on and off at booster capacity
(4.2.6.3), cycle between low and high capacity (section 4.2.6.4), cycle between high and booster
capacity (section 4.2.6.5), operate continuously at low capacity (4.2.6.6), operate continuously at
high capacity (section 4.2.6.7), operate continuously at booster capacity (4.2.6.8), or heat solely
using resistive heating (also section 4.2.6.8) in responding to the building load. As applicable,
the manufacturer must supply information regarding the outdoor temperature range at which
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each stage of compressor capacity is active. As an informative example, data may be submitted
in this manner: At the low (k=1) compressor capacity, the outdoor temperature range of
operation is 40 °F ≤ T ≤ 65 °F; At the high (k=2) compressor capacity, the outdoor temperature
range of operation is 20 °F ≤ T ≤ 50 °F; At the booster (k=3) compressor capacity, the outdoor
a. Evaluate the space heating capacity and electrical power consumption of the heat pump
when operating at low compressor capacity and outdoor temperature Tj using the equations
given in section 4.2.3 for Q̇hk=1(Tj) and Ėhk=1 (Tj)) In evaluating the section 4.2.3 equations,
Determine Q̇hk=1(62) and Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test,
and Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all four quantities as specified in
section 3.7. If, in accordance with section 3.6.6, the H31 Test is conducted, calculate Q̇hk=1(17)
and Ėhk=1(17) as specified in section 3.10 and determine Q̇hk=1(35) and Ėhk=1(35) as specified in
section 3.6.6.
b. Evaluate the space heating capacity and electrical power consumption (Q̇hk=2(Tj) and
Ėhk=2 (Tj)) of the heat pump when operating at high compressor capacity and outdoor temperature
Tj by solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. Determine Q̇hk=1(62) and
Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test, and Q̇hk=2(47) and
Ėhk=2(47) from the H12 Test, evaluated as specified in section 3.7. Determine the equation input
for Q̇hk=2(35) and Ėhk=2(35) from the H22, evaluated as specified in section 3.9.1. Also, determine
Q̇hk=2(17) and Ėhk=2(17) from the H32 Test, evaluated as specified in section 3.10.
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c. Evaluate the space heating capacity and electrical power consumption of the heat pump
𝐸𝐸̇ℎ𝑘𝑘=3 �𝑇𝑇𝑗𝑗 �
⎧ ̇ 𝑘𝑘=3 �𝐸𝐸̇ℎ 𝑘𝑘=3
(35) − 𝐸𝐸̇ℎ𝑘𝑘=3 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
⎪𝐸𝐸ℎ (17) + , 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 ≤ 45 ℉
= 35 − 17
⎨ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) − 𝐸𝐸̇ℎ𝑘𝑘=3 (2)� ∗ (𝑇𝑇𝑗𝑗 − 2)
⎪ 𝐸𝐸̇ℎ𝑘𝑘=3 (2) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 17 ℉
⎩ 17 − 2
Determine Q̇hk=3(17) and Ėhk=3(17) from the H33 Test and determine Q̇hk=2(2) and Ėhk=3(2) from
the H43 Test. Calculate all four quantities as specified in section 3.10. Determine the equation
4.2.6.1 Steady-state space heating capacity when operating at low compressor capacity is greater
than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj) ≥BL(Tj)., and the heat
using Eqs. 4.2.3-1 and 4.2.3-2, respectively. Determine the equation inputs Xk=1(Tj), PLFj, and
δ′(Tj) as specified in section 4.2.3.1. In calculating the part load factor, PLFj , use the low-
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4.2.6.2 Heat pump only operates at high (k=2) compressor capacity at temperature Tj and its
capacity is greater than or equal to the building heating load, BL(Tj) <Q̇hk=2(Tj). Evaluate the
quantities
as specified in section 4.2.3.3. Determine the equation inputs Xk=2(Tj), PLFj , and δ′(Tj) as
specified in section 4.2.3.3. In calculating the part load factor, PLFj , use the high-capacity
4.2.6.3 Heat pump only operates at high (k=3) compressor capacity at temperature Tj and its
capacity is greater than or equal to the building heating load, BL(Tj) ≤Q̇hk=3(Tj).
where
𝑋𝑋 𝑘𝑘=3 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 ��𝑄𝑄̇ℎ𝑘𝑘=3 �𝑇𝑇𝑗𝑗 � and 𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 = 1 − 𝐶𝐶𝐷𝐷ℎ (𝑘𝑘 = 3) ∗ [1 − 𝑋𝑋 𝑘𝑘=3 (𝑇𝑇𝑗𝑗 )
Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3-3. Use the booster-capacity
4.2.6.4 Heat pump alternates between high (k=2) and low (k=1) compressor capacity to satisfy
the building heating load at a temperature Tj, Q̇hk=1(Tj) <BL(Tj) <Q̇hk=2(Tj). Evaluate the
quantities
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as specified in section 4.2.3.2. Determine the equation inputs Xk=1(Tj), Xk=2(Tj), and δ′(Tj) as
4.2.6.5 Heat pump alternates between high (k=2) and booster (k=3) compressor capacity to
satisfy the building heating load at a temperature Tj, Q̇hk=2(Tj) <BL(Tj) <Q̇hk=3(Tj).
where:
and Xk=3(Tj) = Xk=2(Tj) = the heating mode, booster capacity load factor for temperature bin j,
dimensionless. Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3-3.
4.2.6.6 Heat pump only operates at low (k=1) capacity at temperature Tj and its capacity is less
Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3.4 if the heat pump is
operating at its booster compressor capacity. If the heat pump system converts to using only
4.2.7 Additional steps for calculating the HSPF of a heat pump having a single indoor unit with
multiple blowers. The calculation of the Eq. 4.2–1 quantities eh(Tj)/N and RH(Tj)/N are
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4.2.7.1 For multiple blower heat pumps that are connected to a singular, single-speed outdoor
unit.
a. Calculate the space heating capacity, 𝑄𝑄̇ℎ𝑘𝑘=1 (Tj), and electrical power consumption,
𝐸𝐸̇ℎ𝑘𝑘=1 (Tj), of the heat pump when operating at the heating minimum air volume rate and
outdoor temperature Tj using Eqs. 4.2.2–3 and 4.2.2–4, respectively. Use these same
equations to calculate the space heating capacity, 𝑄𝑄̇ℎ𝑘𝑘=2 (Tj) and electrical power
consumption, 𝐸𝐸̇ℎ𝑘𝑘=2 (Tj), of the test unit when operating at the heating full-load air volume
rate and outdoor temperature Tj. In evaluating Eqs. 4.2.2–3 and 4.2.2– 4, determine the
quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (47) and 𝐸𝐸̇ℎ𝑘𝑘=1 (47) from the H11 Test; determine 𝑄𝑄̇ℎ𝑘𝑘=2 (47) and 𝐸𝐸̇ℎ𝑘𝑘=2 (47)
from the H12 Test. Evaluate all four quantities according to section 3.7. Determine the
quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (35) and 𝐸𝐸̇ℎ𝑘𝑘=1 (35) as specified in section 3.6.2. Determine 𝑄𝑄̇ℎ𝑘𝑘=2 (35) and
𝐸𝐸̇ℎ𝑘𝑘=2 (35) from the H22 Frost Accumulation Test as calculated according to section 3.9.1.
Determine the quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (17) and 𝐸𝐸̇ℎ𝑘𝑘=1 (17) from the H31 Test, and 𝑄𝑄̇ℎ𝑘𝑘=2(17) and
𝐸𝐸̇ℎ𝑘𝑘=2 (17) from the H32 Test. Evaluate all four quantities according to section 3.10. Refer to
section 3.6.2 and Table 11 for additional information on the referenced laboratory tests.
b. Determine the heating mode cyclic degradation coefficient, CDh, as per sections 3.6.2 and
c. Except for using the above values of 𝑄𝑄̇ℎ𝑘𝑘=1(Tj), 𝐸𝐸̇ℎ𝑘𝑘=1 (Tj), 𝑄𝑄̇ℎ𝑘𝑘=2 (Tj), 𝐸𝐸̇ℎ𝑘𝑘=2 (Tj), CDh, and
CDh(k = 2), calculate the quantities eh(Tj)/N as specified in section 4.2.3.1 for cases where
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𝑄𝑄̇ℎ𝑘𝑘=1 (Tj) ≥ BL(Tj). For all other outdoor bin temperatures, Tj, calculate eh(Tj)/N and
4.2.7.2 For multiple blower heat pumps connected to either a lone outdoor unit with a two-
capacity compressor or to two separate but identical model single-speed outdoor units. Calculate
4.3.1 For central air conditioners and heat pumps with a cooling capacity of:
less than 36,000 Btu/h, determine the off mode rating, 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 , with the following
equation:
greater than or equal to 36,000 Btu/h, calculate the capacity scaling factor according to:
𝑄𝑄̇𝐶𝐶 (95)
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 = ,
36,000
where, 𝑄𝑄̇𝐶𝐶 (95) is the total cooling capacity at the A or A2 Test condition, and determine
𝑃𝑃1
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
𝑖𝑖𝑖𝑖 𝑃𝑃2 = 0
the off mode rating, 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 , with the following equation: 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 = �(𝑃𝑃1+𝑃𝑃2)� ;
2
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
𝑜𝑜𝑜𝑜ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒
449
4.3.2 Calculate the off mode energy consumption for both central air conditioner and heat
pumps for the shoulder season, E1, using:𝐸𝐸1 = 𝑃𝑃1 · 𝑆𝑆𝑆𝑆𝑆𝑆; and the off mode energy
consumption of a CAC, only, for the heating season, E2, using: 𝐸𝐸2 = 𝑃𝑃2 · 𝐻𝐻𝐻𝐻𝐻𝐻; where P1
and P2 is determined in Section 3.13. HSH can be determined by multiplying the heating
season-hours from Table 21 with the fractional Bin-hours, from Table 19, that pertain to the
range of temperatures at which the crankcase heater operates. If the crankcase heater is
controlled to disable for the heating season, the temperature range at which the crankcase
the crankcase heater is operated during the heating season, the temperature range at which
the crankcase heater operates is defined to be from 72 °F to -23 °F, the latter of which is a
temperature that sets the range of Bin-hours to encompass all outside air temperatures in the
heating season.
SSH can be determined by multiplying the shoulder season-hours from Table 21 with the
Table 21 Representative Cooling and Heating Load Hours and the Corresponding Set of
Seasonal Hours for Each Generalized Climatic Region
450
I 2400 750 6731 1826 203
𝐻𝐻𝐻𝐻𝐻𝐻∙(65−𝑇𝑇𝑂𝑂𝑂𝑂 )
HSH is evaluated as: 𝐻𝐻𝐻𝐻𝐻𝐻 = 𝑛𝑛𝑗𝑗 ,
∑𝐽𝐽𝑗𝑗=1�65−𝑇𝑇𝑗𝑗 �∙
𝑁𝑁
𝑛𝑛𝑗𝑗
where 𝑇𝑇𝑂𝑂𝑂𝑂 and are listed in Table 18 and depend on the location of interest relative to
𝑁𝑁
Figure 1. For the six generalized climatic regions, this equation simplifies to the
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Region V: 𝐻𝐻𝐻𝐻𝐻𝐻 = 2.5295𝐻𝐻𝐻𝐻𝐻𝐻;
SSH is evaluated: 𝑆𝑆𝑆𝑆𝑆𝑆 = 8760 − (𝐶𝐶𝐶𝐶𝐶𝐶 + 𝐻𝐻𝐻𝐻𝐻𝐻), where CSH = the cooling season hours
calculated using CSH = 2.8045 · CLH.
Table 22 Fractional Bin Hours for the Shoulder Season Hours for All Regions
72 0.333 0.167
67 0.667 0.333
62 0 0.333
57 0 0.167
4.3.3 If a shoulder season crankcase heater time delay and/or a heating season crankcase heater
𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,𝑖𝑖
time delay is specified by the manufacturer, multiply E1 and/or E2, by �1 − �, where
60
𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,1 is the time delay for operation during the shoulder season and 𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,2 is the time delay
for operation during the heating season, in minutes. If a time delay is not specified, 𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,𝑖𝑖 is 15
minutes.
4.3.4 For air conditioners, the annual off mode energy consumption, ETOTAL, is:𝐸𝐸𝑇𝑇𝑇𝑇𝑇𝑇𝐴𝐴𝐿𝐿 =
𝐸𝐸1 + 𝐸𝐸2.
4.3.5 For heat pumps, the annual off mode energy consumption, ETOTAL, is E1.
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4.4 Calculations of the Actual and Representative Regional Annual Performance Factors for
Heat Pumps.
4.4.1 Calculation of actual regional annual performance factors (APFA) for a particular location
𝐴𝐴𝐴𝐴𝐹𝐹𝐴𝐴 =
where,
CLHA = the actual cooling hours for a particular location as determined using the map
Q̇ck(95) = the space cooling capacity of the unit as determined from the A or A2 Test,
HLHA = the actual heating hours for a particular location as determined using the map
DHR = the design heating requirement used in determining the HSPF; refer to section 4.2
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SEER = the seasonal energy efficiency ratio calculated as specified in section 4.1,
Btu/W·h.
HSPF = the heating seasonal performance factor calculated as specified in section 4.2 for
the generalized climatic region that includes the particular location of interest (see Figure
1), Btu/W·h. The HSPF should correspond to the actual design heating requirement
(DHR), if known. If it does not, it may correspond to one of the standardized design
P1 is the shoulder season per-compressor off mode power, as determined in section 3.13,
W.
P2 is the heating season per-compressor off mode power, as determined in section 3.13,
W.
4.4.2 Calculation of representative regional annual performance factors (APFR) for each
generalized climatic region and for each standardized design heating requirement.
where,
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CLHR = the representative cooling hours for each generalized climatic region, Table 23,
hr.
HLHR = the representative heating hours for each generalized climatic region, Table 23,
hr.
HSPF = the heating seasonal performance factor calculated as specified in section 4.2 for
the each generalized climatic region and for each standardized design heating requirement within
The SEER, Q̇ck(95), DHR, and C are the same quantities as defined in section 4.3.1.
Figure 1 shows the generalized climatic regions. Table 20 lists standardized design heating
requirements.
Table 23—Representative Cooling and Heating Load Hours for Each Generalized Climatic
Region
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4.5. Rounding of SEER, HSPF, and APF for reporting purposes. After calculating SEER
according to section 4.1, HSPF according to section 4.2, and APF according to section 4.3, round
the values off as specified in subpart B 430.23(m) of Title 10 of the Code of Federal Regulations.
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Figure 2—Cooling Load Hours (CLHA) for the United States
4.6 Calculations of the SHR, which should be computed for different equipment
Table 24—Applicable Test Conditions For Calculation of the Sensible Heat Ratio
Reference SHR computation
Appendix M from
blower
Requirements
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The SHR is defined and calculated as follows:
𝑄𝑄̇𝑠𝑠𝑠𝑠
𝑘𝑘
(𝑇𝑇)
= 𝑘𝑘
𝑄𝑄̇𝑐𝑐 (𝑇𝑇)
Where both the total and sensible cooling capacities are determined from the same
cooling mode test and calculated from data collected over the same 30-minute data collection
interval.
4.7 Calculations of the Energy Efficiency Ratio (EER). Calculate the energy efficiency
ratio using,
𝑄𝑄̇𝑐𝑐𝑘𝑘 (𝑇𝑇)
= 𝑘𝑘
𝐸𝐸̇𝑐𝑐 (𝑇𝑇)
where 𝑄𝑄̇𝑐𝑐𝑘𝑘 (𝑇𝑇) and 𝐸𝐸̇𝑐𝑐𝑘𝑘 (𝑇𝑇) are the space cooling capacity and electrical power consumption
determined from the 30-minute data collection interval of the same steady-state wet coil cooling
mode test and calculated as specified in section 3.3. Add the letter identification for each steady-
state test as a subscript (e.g., 𝐸𝐸𝐸𝐸𝑅𝑅𝐴𝐴2 ) to differentiate among the resulting EER values.
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6. Adding Appendix M1 to Subpart B of Part 430 to read as follows:
Note: Prior to [DATE 180 DAYS AFTER PUBLICATION OF THE FINAL RULE IN
with respect to the energy use, power, or efficiency of central air conditioners and central air
conditioning heat pumps must be based on the results of testing pursuant to either Appendix M
the 10 CFR parts 200 to 499 edition revised as of January 1, 2015. Any representations made
with respect to the energy use or efficiency of such central air conditioners and central air
On or after [DATE 180 DAYS AFTER PUBLICATION OF THE FINAL RULE IN THE
FEDERAL REGISTER] and prior to the compliance date for any amended energy conservation
standards, any representations, including compliance certifications, made with respect to the
energy use, power, or efficiency of central air conditioners and central air conditioning heat
On or after the compliance date for any amended energy conservation standards, any
representations, including compliance certifications, made with respect to the energy use, power,
or efficiency of central air conditioners and central air conditioning heat pumps must be based on
This test procedure provides a method of determining SEER, EER, HSPF and PW,OFF for
central air conditioners and central air conditioning heat pumps including the following
categories:
For purposes of this appendix, the Department of Energy incorporates by reference specific
sections of several industry standards, as listed in § 430.3. In cases where there is a conflict, the
language of the test procedure in this appendix takes precedence over the incorporated standards.
1.2. Definitions
Airflow-control settings are programmed or wired control system configurations that control a fan
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function (e.g., cooling, heating, or constant circulation)—without manual adjustment other
than interaction with a user-operable control (i.e., a thermostat) that meets the manufacturer
specifications for installed-use are those found in the product literature shipped with the unit.
Airflow prevention device denotes a device(s) that prevents airflow via natural convection by
mechanical means, such as an air damper box, or by means of changes in duct height, such as
an upturned duct.
Annual performance factor means the total heating and cooling done by a heat pump in a
particular region in one year divided by the total electric energy used in one year. The
Blower coil indoor unit means the indoor unit of a split-system central air conditioner or heat
pump that includes a refrigerant-to-air heat exchanger coil, may include a cooling-mode
expansion device, and includes either an indoor blower housed with the coil or a separate
designated air mover such as a furnace or a modular blower (as defined in Appendix AA).
Blower coil system refers to a split-system that includes one or more blower coil indoor units.
Coil-only indoor unit means the indoor unit of a split-system central air conditioner or heat pump
that includes a refrigerant-to-air heat exchanger coil and may include a cooling-mode
expansion device, but does not include an indoor blower housed with the coil, and does not
include a separate designated air mover such as a furnace or a modular blower (as defined in
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modular blower for indoor air movement. Coil-only system refers to a system that includes
Condensing unit removes the heat absorbed by the refrigerant to transfer it to the outside
environment, and which consists of an outdoor coil, compressor(s), and air moving device.
Constant-air-volume-rate indoor blower means a fan that varies its operating speed to provide a
Continuously recorded, when referring to a dry bulb measurement, dry bulb temperature used for
test room control, wet bulb temperature, dew point temperature, or relative humidity
measurements, means that the specified value must be sampled at regular intervals that are
Cooling load factor (CLF) means the ratio having as its numerator the total cooling delivered
during a cyclic operating interval consisting of one ON period and one OFF period. The
denominator is the total cooling that would be delivered, given the same ambient conditions,
had the unit operated continuously at its steady-state, space-cooling capacity for the same
Coefficient of Performance (COP) means the ratio of the average rate of space heating delivered
to the average rate of electrical energy consumed by the heat pump. These rate quantities
must be determined from a single test or, if derived via interpolation, must be determined at a
single set of operating conditions. COP is a dimensionless quantity. When determined for a
ducted unit tested without an indoor blower installed, COP must include the section 3.7and
3.9.1 default values for the heat output and power input of a fan motor.
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Crankcase heater means any electrically powered device or mechanism for intentionally
generating heat within and/or around the compressor sump volume often done to minimize
the dilution of the compressor’s refrigerant oil by condensed refrigerant. Crankcase heater
control may be achieved using a timer or may be based on a change in temperature or some
other measurable parameter, such that the crankcase heater is not required to operate
Cyclic Test means a test where the unit's compressor is cycled on and off for specific time
intervals. A cyclic test provides half the information needed to calculate a degradation
coefficient.
Damper box means a short section of duct having an air damper that meets the performance
Degradation coefficient (CD) means a parameter used in calculating the part load factor. The
degradation coefficient for cooling is denoted by CDc. The degradation coefficient for heating
is denoted by CDh.
Demand-defrost control system means a system that defrosts the heat pump outdoor coil only
monitor one or more parameters that always vary with the amount of frost accumulated on
the outdoor coil (e.g., coil to air differential temperature, coil differential air pressure,
outdoor fan power or current, optical sensors) at least once for every ten minutes of
compressor ON-time when space heating. One acceptable alternative to the criterion given in
the prior sentence is a feedback system that measures the length of the defrost period and
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adjusts defrost frequency accordingly. In all cases, when the frost parameter(s) reaches a
defrosts are terminated based on monitoring a parameter(s) that indicates that frost has been
eliminated from the coil. (Note: Systems that vary defrost intervals according to outdoor dry-
bulb temperature are not demand-defrost systems.) A demand-defrost control system, which
otherwise meets the above requirements, may allow time-initiated defrosts if, and only if,
Design heating requirement (DHR) predicts the space heating load of a residence when subjected
to outdoor design conditions. Estimates for the DHR are provided for six generalized U.S.
Dry-coil tests are cooling mode tests where the wet-bulb temperature of the air supplied to the
indoor coil is maintained low enough that no condensate forms on this coil.
Ducted system means an air conditioner or heat pump that is designed to be permanently
installed equipment and delivers conditioned air to the indoor space through a duct(s). The
Energy efficiency ratio (EER) means the ratio of the average rate of space cooling delivered to
the average rate of electrical energy consumed by the air conditioner or heat pump. These
rate quantities must be determined from a single test or, if derived via interpolation, must be
𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
determined at a single set of operating conditions. EER is expressed in units of 𝑊𝑊
.
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When determined for a ducted unit tested without an indoor blower installed, EER must
include the section 3.3 and 3.5.1 default values for the heat output and power input of a fan
motor.
Evaporator coil absorbs heat from an enclosed space and transfers the heat to a refrigerant.
Heat pump means a kind of central air conditioner, which consists of one or more assemblies,
exchanger to provide air heating, and may also provide air cooling, air dehumidifying, air
Heating load factor (HLF) means the ratio having as its numerator the total heating delivered
during a cyclic operating interval consisting of one ON period and one OFF period. The
denominator is the total heating that would be delivered, given the same ambient conditions,
if the unit operated continuously at its steady-state space heating capacity for the same total
Heating season means the months of the year that require heating, e.g., typically, and roughly,
Heating seasonal performance factor (HSPF) means the total space heating required during the
space heating season, expressed in Btu's, divided by the total electrical energy consumed by
the heat pump system during the same season, expressed in watt-hours. The HSPF used to
evaluate compliance with the Energy Conservation Standards (see 10 CFR 430.32(c)) is
based on Region IV, the design heating requirement, and the sampling plan stated in 10 CFR
429.16(a).
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Heat pump having a heat comfort controller means equipment that regulates the operation of the
electric resistance elements to assure that the air temperature leaving the indoor section does
not fall below a specified temperature. This specified temperature is usually field adjustable.
Heat pumps that actively regulate the rate of electric resistance heating when operating below
the balance point (as the result of a second stage call from the thermostat) but do not operate
to maintain a minimum delivery temperature are not considered as having a heat comfort
controller.
Independent coil manufacturer (ICM) means a manufacturer that manufactures indoor units but
Indoor unit transfers heat between the refrigerant and the indoor air and consists of an indoor coil
and casing and may include a cooling mode expansion device and/or an air moving device.
Multiple-split (or multi-split) system means a split system that has one outdoor unit and two or
more indoor coil-only or indoor blower coil units connected to its other component(s) with a
single refrigerant circuit. The indoor units operate independently and can condition multiple
zones in response to at least two indoor thermostats or temperature sensors. The outdoor unit
operates in response to independent operation of the indoor units based on control input of
Multiple-circuit (or multi-circuit) system means a split system that has one outdoor unit and that
has two or more indoor units installed on two or more refrigeration circuits such that each
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refrigeration circuit serves a compressor and one and only one indoor unit, and refrigerant is
Nominal capacity means the capacity that is claimed by the manufacturer in the product name
plate. Nominal cooling capacity is approximate to the air conditioner cooling capacity tested
Non-ducted system means a split-system central air conditioner or heat pump that is designed to
be permanently installed and that directly heats or cools air within the conditioned space
using one or more indoor units that are mounted on room walls and/or ceilings. The system
may be of a modular design that allows for combining multiple outdoor coils and
Normalized Gross Indoor Fin Surface (NGIFS) means the gross fin surface area of the indoor
unit coil divided by the cooling capacity measured for the A or A2 Test whichever applies.
Off-mode power consumption means the power consumption when the unit is connected to its
main power source but is neither providing cooling nor heating to the building it serves.
Off-mode season means, for central air conditioners, the shoulder season and the entire heating
Outdoor unit transfers heat between the refrigerant and the outdoor air, and consists of an
outdoor coil, compressor(s), an air moving device, and in addition for heat pumps, could
include a heating mode expansion device, reversing valve, and defrost controls.
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Outdoor unit manufacturer (OUM) means a manufacturer of single-package units, outdoor units,
Part-load factor (PLF) means the ratio of the cyclic energy efficiency ratio (coefficient of
both energy efficiency ratios (coefficients of performance) are determined based on operation
Seasonal energy efficiency ratio (SEER) means the total heat removed from the conditioned
space during the annual cooling season, expressed in Btu's, divided by the total electrical
energy consumed by the central air conditioner or heat pump during the same season,
expressed in watt-hours.
Short ducted system means a ducted split system whose one or more indoor sections produce
greater than zero but no greater than 0.1 inches (of water) of external static pressure when
operated at the full-load air volume not exceeding 450 cfm per rated ton of cooling.
Shoulder season means the months of the year in between those months that require cooling and
those months that require heating, e.g., typically, and roughly, April through May, and
Single-package unit means any central air conditioner or heat pump that has all major assemblies
Single-split-system means a split system that has one outdoor unit and that has one indoor coil-
only or indoor blower coil unit connected to its other component(s) with a single refrigeration
circuit.
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Single-zone-multiple-coil split system means a split system that has one outdoor unit and that has
two or more indoor units connected with a single refrigeration circuit. The indoor units
Small-duct, high-velocity system means a system that contains a blower and indoor coil
combination that is designed for, and produces, at least 1.2 inches (of water) of external static
pressure when operated at the full-load air volume rate of 220-350 cfm per rated ton of
cooling. When applied in the field, uses high-velocity room outlets (i.e., generally greater
than 1000 fpm) having less than 6.0 square inches of free area.
Split system means any air conditioner or heat pump that has one or more of the major
assemblies separated from the others. Split-systems may be either blower coil systems or
coil-only systems.
Standard Air means dry air having a mass density of 0.075 lb/ft3.
Steady-state test means a test where the test conditions are regulated to remain as constant as
Temperature bin means the 5 °F increments that are used to partition the outdoor dry-bulb
temperature ranges of the cooling (≥65 °F) and heating (<65 °F) seasons.
Test condition tolerance means the maximum permissible difference between the average value
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Test operating tolerance means the maximum permissible range that a measurement may vary
over the specified test interval. The difference between the maximum and minimum sampled
values must be less than or equal to the specified test operating tolerance.
(1) The system consists of one outdoor unit with one or more compressors matched with
(i) Collectively, have a nominal cooling capacity greater than or equal to 95 percent and
less than or equal to 105 percent of the nominal cooling capacity of the outdoor unit;
(ii) Represent the highest sales volume model family that can meet the 95 percent
nominal cooling capacity of the outdoor unit [Note: another indoor model family may be
used if five indoor units from the highest sales volume model family do not provide
(iii) Individually not have a nominal cooling capacity greater than 50 percent of the
nominal cooling capacity of the outdoor unit, unless the nominal cooling capacity of the
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(v) All be subject to the same minimum external static pressure requirement while able to
produce the same external static pressure at the exit of each outlet plenum when
(vi) Where referenced, “nominal cooling capacity” is to be interpreted for indoor units as
the highest cooling capacity listed in published product literature for 95 °F outdoor dry
bulb temperature and 80 °F dry bulb, 67 °F wet bulb indoor conditions, and for outdoor
units as the lowest cooling capacity listed in published product literature for these
conditions. If incomplete or no operating conditions are reported, the highest (for indoor
units) or lowest (for outdoor units) such cooing capacity shall be used.
Time-adaptive defrost control system is a demand-defrost control system that measures the
length of the prior defrost period(s) and uses that information to automatically determine
Time-temperature defrost control systems initiate or evaluate initiating a defrost cycle only when
generally a fixed value (e.g., 30, 45, 90 minutes) although it may vary based on the measured
(e.g., outdoor temperature, evaporator temperature) indicate that frost formation conditions
are present, and it is reset/remains at zero at all other times. In one application of the control
scheme, a defrost is initiated whenever the counter time equals the predetermined ON-time.
In a second application of the control scheme, one or more parameters are measured (e.g., air
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defrost is initiated only if the measured parameter(s) falls within a predetermined range. The
ON-time counter is reset regardless of whether or not a defrost is initiated. If systems of this
second type use cumulative ON-time intervals of 10 minutes or less, then the heat pump may
Triple-capacity, northern heat pump means a heat pump that provides two stages of cooling and
three stages of heating. The two common stages for both the cooling and heating modes are
the low capacity stage and the high capacity stage. The additional heating mode stage is the
booster capacity stage, which offers the highest heating capacity output for a given set of
Triple-split system means a central air conditioner or heat pump that is composed of three
separate components: An outdoor fan coil section, an indoor blower coil section, and an
Two-capacity (or two-stage) compressor system means a central air conditioner or heat pump
that has a compressor or a group of compressors operating with only two stages of capacity.
For such systems, low capacity means the compressor(s) operating at low stage, or at low
load test conditions. The low compressor stage for heating mode tests may be the same or
For such systems, high capacity means the compressor(s) operating at low stage, or at full
Two-capacity, northern heat pump means a heat pump that has a factory or field-selectable lock-
out feature to prevent space cooling at high-capacity. Two-capacity heat pumps having this
feature will typically have two sets of ratings, one with the feature disabled and one with the
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feature enabled. The certified indoor coil model number should reflect whether the ratings
pertain to the lockout enabled option via the inclusion of an extra identifier, such as “+LO”.
When testing as a two-capacity, northern heat pump, the lockout feature must remain enabled
Variable refrigerant flow (VRF) system means a multi-split system with at least three compressor
capacity stages, distributing refrigerant through a piping network to multiple indoor blower
coil units each capable of individual zone temperature control, through proprietary zone
systems less than 65,000 Btu/h are a kind of central air conditioners and central air
Variable-speed compressor system means a central air conditioner or heat pump that has a
compressor that uses a variable-speed drive to vary the compressor speed to achieve variable
capacities.
For such a system, maximum speed means the maximum operating speed, measured by RPM
or frequency (Hz), that the unit is designed to operate in cooling mode or heating mode.
Maximum speed does not change with ambient temperature, and it can be different from
cooling mode to heating mode. Maximum speed does not necessarily mean maximum
capacity.
For such systems, minimum speed means the minimum speed, measured by RPM or
frequency (Hz), that the unit is designed to operate in cooling mode or heating mode.
Minimum speed does not change with ambient temperature, and it can be different from
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cooling mode to heating mode. Minimum speed does not necessarily mean minimum
capacity.
Wet-coil test means a test conducted at test conditions that typically cause water vapor to
(A) Test VRF systems using ANSI/AHRI Standard 1230-2010 sections 3 (except 3.8, 3.9, 3.13,
3.14, 3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31), 5.1.3, 5.1.4, , 6.1.5 (except
Table 8), 6.1.6, and 6.2 and Appendix M. Where ANSI/AHRI Standard 1230-2010 refers to the
Appendix C therein substitute the provisions of this appendix. In cases where there is a conflict,
the language of the test procedure in this appendix takes precedence over ANSI/AHRI Standard
1230-2010.
1230-2010, excluding sections 3.8, 3.9, 3.13, 3.14, 3.15, 3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29,
3.30, and 3.31. For rounding requirements refer to §430.23 (m). For determination of certified
For test room requirements, refer to section 2.1 from Appendix M. For test unit
installation requirements refer to sections 2.2.a, 2.2.b, 2.2.c, 2.2.1, 2.2.2, 2.2.3(a), 2.2.3(c) , 2.2.4,
2.2.5, and 2.4 to 2.12 from Appendix M, and sections 5.1.3 and 5.1.4 of ANSI/AHRI Standard
1230-2010.
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For general requirements for the test procedure refer to section 3.1 of Appendix M,
except for sections 3.1.3 and 3.1.4, which are requirements for indoor air volume and outdoor air
volume. For indoor air volume and outdoor air volume requirements, refer instead to section
6.1.5 (except Table 8) and 6.1.6 of ANSI/AHRI Standard 1230-2010. For external static pressure
For the test procedure, refer to sections 3.3 to 3.5 and 3.7 to 3.13 in Appendix M. For
cooling mode and heating mode test conditions, refer to section 6.2 of ANSI/AHRI Standard
(B) For systems other than VRF, only a subset of the sections listed in this test procedure apply
when testing and rating a particular unit. Table 1 shows the sections of the test procedure that
apply to each system. This table is meant to assist manufacturers in finding the appropriate
sections of the test procedure; the appendix sections rather than the table provide the specific
requirements for testing, and given the varied nature of available units, manufacturers are
responsible for determining which sections apply to each unit tested. To use this table, first refer
to the sections listed under “all units”. Then refer to additional requirements based on: (1) system
configuration(s), (2) the compressor staging or modulation capability, and (3) any special
features.
Testing requirements for space-constrained products do not differ from similar equipment
that is not space-constrained and thus are not listed separately in this table. Air conditioners and
heat pumps are not listed separately in this table, but heating procedures and calculations apply
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Table 1 Informative Guidance for Using A 1
Testing conditions Testing procedures Calculations
3.1.4.4.1; 3.1.4.4.2;
3.1.4.1.1; 3.1.4.1.1a,b;
Single split-system – blower coil 2.2a(1) 3.1.4.4.3a-b; 3.1.4.5.1;
3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
3.1.4.4.1; 3.1.4.4.2;
Tri-split 2.2a(2)
3.1.4.4.1; 3.1.4.4.2;
3.1.4.1.1; 3.1.4.1.1a,b;
Single-package 2.2.4.1(2); 2.2.5.6b; 2.4.1; 2.4.2 3.1.4.4.3a-b; 3.1.4.5.1;
3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
Additional Requirements
3.1.4.4.2c;
Two-capacity northern heat pump 3.2.3c 3.6.3
3.1.4.5.2 c- d
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Triple-capacity northern heat pump 3.2.5 3.6.6 4.2.6
3.1.4.4.1; 3.1.4.4.2;
Single- zone-multi-coil split and non- 3.1.4.1.1; 3.1.4.1.1a-b;
2.2a(1),(3); 2.2.3; 2.4.1b 3.1.4.4.3a-b; 3.1.4.5.1;
VRF multiple-split with duct 3.1.4.2a-b; 3.1.4.3a-b
3.1.4.5.2a-c; 3.1.4.6a-b
3.1.4.1.2; 3.1.4.2d;
Single-zone-multi-coil split and non- 3.1.4.4.4; 3.1.4.5.2e; 3.1.4.6c;
2.2.a(1),(3); 2.2.3 3.1.4.3c; 3.2.4c;
VRF multiple-split, ductless 3.6.4.c; 3.8c
3.5c,g,h; 3.5.2; 3.8c
2.1; 2.2.a; 2.2.b; 2.2.c; 2.2.1; 2.2.2; 3.1 (except 3.3-3.5 3.7–3.10 4.4;
†
VRF multiple-split and 2.2.3(a); 2.2.3(c);, 2.2.4; 2.2.5; 2.4- 3.1.3, 3.1.4) 4.5;
4.1 4.2
†
VRF SDHV 2.12 3.1.4.1.1c; 4.6
3.11-3.13
Single speed compressor, fixed speed fan 3.2.1 3.6.1 4.1.1 4.2.1
Single speed compressor, VAV fan 3.1.7 3.2.2 3.6.2 4.1.2 4.2.2
Modulation
Capability
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*Does not apply to heating-only heat pumps.
in the table to perform test setup, testing, and calculations for rating VRF multiple-split and VRF SDHV systems.
NOTE: For all units, use section 3.13 for off mode testing procedures and section 4.3 for off mode calculations. For all units subject to an EER standard, use
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2.1 Test room requirements.
a. Test using two side-by-side rooms, an indoor test room and an outdoor test room. For
however, use as many available indoor test rooms as needed to accommodate the total
number of indoor units. These rooms must comply with the requirements specified in
b. Inside these test rooms, use artificial loads during cyclic tests and Frost Accumulation
tests, if needed, to produce stabilized room air temperatures. For one room, select an electric
resistance heater(s) having a heating capacity that is approximately equal to the heating
capacity of the test unit's condenser. For the second room, select a heater(s) having a capacity
that is close to the sensible cooling capacity of the test unit's evaporator. When applied, cycle
the heater located in the same room as the test unit evaporator coil ON and OFF when the test
unit cycles ON and OFF. Cycle the heater located in the same room as the test unit
condensing coil ON and OFF when the test unit cycles OFF and ON.
a. Install the unit according to section 8.2 of ASHRAE Standard 37-2009, subject to the
1) When testing split systems, follow the requirements given in section 6.1.3.5 of AHRI
210/240-2008 with Addendum 1 and 2. For the vapor refrigerant line(s), use the
insulation included with the unit; if no insulation is provided, refer to the specifications
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for the insulation in the installation instructions included with the unit by the
manufacturer; if no insulation is included with the unit and the installation instructions do
not contain provisions for insulating the line(s), fully insulate the vapor refrigerant line(s)
with vapor proof insulation having an inside diameter that matches the refrigerant tubing
and a nominal thickness of at least 0.5 inches. For the liquid refrigerant line(s), use the
insulation included with the unit; if no insulation is provided, refer to the specifications
for the insulation in the installation instructions included with the unit by the
manufacturer; if no insulation is included with the unit and the installation instructions do
not contain provisions for insulating the line(s), leave the liquid refrigerant line(s)
exposed to the air for air conditioners and heat pumps that heat and cool; or, for heating-
only heat pumps, insulate the liquid refrigerant line(s) with insulation having an inside
diameter that matches the refrigerant tubing and a nominal thickness of at least 0.5
inches;
2) When testing split systems, if the indoor unit does not ship with a cooling mode
expansion device, test the system using the device as specified in the installation
instructions provided with the indoor unit. If none is specified, test the system using a
thermostatic expansion valve with internal pressure equalization that the valve
3) When testing triple-split systems (see section 1.2, Definitions), use the tubing length
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the outdoor coil, indoor compressor section, and indoor coil while still meeting the
4) When testing split systems having multiple indoor coils, connect each indoor blower-
coil to the outdoor unit using: (a) 25 feet of tubing, or (b) tubing furnished by the
2009. Refer to section 2.10 of this appendix to learn which secondary methods require
split system with insulation having an inside diameter that matches the refrigerant tubing
b. For units designed for both horizontal and vertical installation or for both up-flow and
down-flow vertical installations, the manufacturer must use the orientation for testing
specified in the certification report. Conduct testing with the following installed:
(2) supplementary heating coils; and(3) other equipment specified as part of the unit,
including all hardware used by a heat comfort controller if so equipped (see section 1,
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c. Testing a ducted unit without having an indoor air filter installed is permissible as long as
the minimum external static pressure requirement is adjusted as stated in Table 3, note 3 (see
section 3.1.4). Except as noted in section 3.1.10, prevent the indoor air supplementary
heating coils from operating during all tests. For coil-only indoor units that are supplied
without an enclosure, create an enclosure using 1 inch fiberglass ductboard having a nominal
density of 6 pounds per cubic foot. Or alternatively, use some other insulating material
having a thermal resistance (“R” value) between 4 and 6 hr·ft2· °F/Btu. For units where the
d. When testing coil-only central air conditioners and heat pumps, install a toroidal-type
transformer to power the system’s low-voltage components, complying with any additional
requirements for this transformer mentioned in the installation manuals included with the unit
by the manufacturer. If the installation manuals do not provide specifications for the
transformer, use a transformer having the following features: (1) a nominal volt-amp rating
that results in the transformer being loaded at a level that is between 25 and 90 percent based
on the highest power value expected and then confirmed during the off mode test; (2)
designed to operate with a primary input of 230 V, single phase, 60 Hz; and (3) that provides
an output voltage that is within the specified range for each low-voltage component. The
power consumption of the components connected to the transformer must be included as part
of the total system power consumption during the off mode tests, less if included the power
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e. An outdoor unit with no match (i.e., that is not sold with indoor units) shall be tested
without an indoor blower installed, with a single cooling air volume rate, using an indoor unit
whose coil has (1) round tubes of outer diameter no less than 0.375 inches, and (2) a
normalized gross indoor fin surface (NGIFS) no greater than 1.15 square inches per British
where,
Lf = Indoor coil fin length in inches, also height of the coil transverse to the tubes.
Nf = Number of fins.
𝑄𝑄̇𝑐𝑐 (95) = the measured space cooling capacity of the tested outdoor unit/indoor unit
Btu/h.http://www.ecfr.gov/graphics/pdfs/er11oc05.173.pdfhttp://www.ecfr.gov/graphics/
pdfs/er11oc05.173.pdf
Set heat pump defrost controls at the normal settings which most typify those encountered in
generalized climatic region IV. (Refer to Figure 1 and Table 19 of section 4.2 for information on
region IV.) For heat pumps that use a time-adaptive defrost control system (see section 1.2,
Definitions), the manufacturer must specify the frosting interval to be used during Frost
Accumulation tests and provide the procedure for manually initiating the defrost at the specified
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time. To ease testing of any unit, the manufacturer should provide information and any necessary
Configure the multiple-speed outdoor fan according to the installation manual included with
the unit by the manufacturer, and thereafter, leave it unchanged for all tests. The controls of the
unit must regulate the operation of the outdoor fan during all lab tests except dry coil cooling
mode tests. For dry coil cooling mode tests, the outdoor fan must operate at the same speed used
during the required wet coil test conducted at the same outdoor test conditions.
2.2.3 Special requirements for multi-split air conditioners and heat pumps, systems composed of
multiple single-zone-multiple-coil split-system units (having multiple outdoor units located side-
by-side), and ducted systems using a single indoor section containing multiple blowers that
Because these systems will have more than one indoor blower and possibly multiple outdoor
fans and compressor systems, references in this test procedure to a singular indoor blower,
outdoor fan, and compressor means all indoor blowers, all outdoor fans, and all compressor
a. Additional requirements for multi-split air conditioners and heat pumps and systems
composed of multiple single-zone-multiple-coil split-system units. For any test where the
system is operated at part load (i.e., one or more compressors “off”, operating at the
manufacturer shall designate the indoor coil(s) that are not providing heating or cooling
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during the test such that the sum of the nominal heating or cooling capacity of the operational
indoor units is within 5 percent of the intended part load heating or cooling capacity. For
variable-speed systems, the manufacturer must designate at least one indoor unit that is not
providing heating or cooling for all tests conducted at minimum compressor speed. For all
other part-load tests, the manufacturer shall choose to turn off zero, one, two, or more indoor
units. The chosen configuration shall remain unchanged for all tests conducted at the same
compressor speed/capacity. For any indoor coil that is not providing heating or cooling
during a test, cease forced airflow through this indoor coil and block its outlet duct.
b. Additional requirements for ducted systems with a single indoor section containing
multiple blowers where the blowers are designed to cycle on and off independently of one
another and are not controlled such that all blowers are modulated to always operate at the
same air volume rate or speed. This Appendix covers systems with a single-speed
compressor or systems offering two fixed stages of compressor capacity (e.g., a two-speed
compressor, two single-speed compressors). For any test where the system is operated at its
lowest capacity—i.e., the lowest total air volume rate allowed when operating the single-
least one-third of the full-load air volume rate must be turned off unless prevented by the
controls of the unit. In such cases, turn off as many blowers as permitted by the unit’s
controls. Where more than one option exists for meeting this “off” blower requirement, the
manufacturer shall include in its installation manuals included with the unit which blower(s)
are turned off. The chosen configuration shall remain unchanged for all tests conducted at the
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same lowest capacity configuration. For any indoor coil turned off during a test, cease forced
c. For test setups where it is physically impossible for the laboratory to use the required line
length listed in Table 3 of ANSI/AHRI Standard 1230-2010 with Addendum 2, then the
actual refrigerant line length used by the laboratory may exceed the required length and the
refrigerant line length correction factors in Table 4 of ANSI/AHRI Standard 1230-2010 with
2.2.4 Wet-bulb temperature requirements for the air entering the indoor and outdoor coils.
For wet-coil cooling mode tests, regulate the water vapor content of the air entering the
indoor unit to the applicable wet-bulb temperature listed in Tables 4 to 7. As noted in these same
tables, achieve a wet-bulb temperature during dry-coil cooling mode tests that results in no
condensate forming on the indoor coil. Controlling the water vapor content of the air entering the
outdoor side of the unit is not required for cooling mode tests except when testing:
(1) Units that reject condensate to the outdoor coil during wet coil tests. Tables 4-7 list the
(2) Single-package units where all or part of the indoor section is located in the outdoor test
room. The average dew point temperature of the air entering the outdoor coil during wet coil
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tests must be within ±3.0 °F of the average dew point temperature of the air entering the
indoor coil over the 30-minute data collection interval described in section 3.3. For dry coil
tests on such units, it may be necessary to limit the moisture content of the air entering the
For heating mode tests, regulate the water vapor content of the air entering the outdoor unit
to the applicable wet-bulb temperature listed in Tables 11 to 14. The wet-bulb temperature
entering the indoor side of the heat pump must not exceed 60 °F. Additionally, if the Outdoor Air
Enthalpy test method is used while testing a single-package heat pump where all or part of the
outdoor section is located in the indoor test room, adjust the wet-bulb temperature for the air
entering the indoor side to yield an indoor-side dew point temperature that is as close as
reasonably possible to the dew point temperature of the outdoor-side entering air.
mean the manufacturer's installation instructions that come packaged with or appear in the labels
applied to the unit. This does not include online manuals. Installation instructions that are
shipped with the unit shall take precedence over installation instructions that appear in the labels
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2.2.5.2 Instructions to Use for Charging
a. Where the manufacturer's installation instructions contain two sets of refrigerant charging
criteria, one for field installations and one for lab testing, use the field installation criteria.
b. For systems consisting of an outdoor unit manufacturer’s outdoor section and indoor
section with differing charging procedures the refrigerant charge shall be adjusted per the
independent coil manufacturer’s indoor section with differing charging procedures the
for charging or there are no manufacturer’s instructions, use the following test(s): (1) for air
conditioners or cooling and heating heat pumps, use the A or A2 test. (2) for cooling and
heating heat pumps that do not function in the H1 or H12 test with the charge set for the A or
A2 test and for heating-only heat pumps, use the H1 or H12 test.
a. Consult the manufacturer’s installation instructions regarding which parameters to set and
their target values. If the instructions provide ranges of values, select target values equal to
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b. In the event of conflicting information between charging instructions (defined as multiple
conditions given for charge adjustment where all conditions specified cannot be met), follow
1. Superheat
6. Charge weight
1. Subcooling
5. Charge weight
c. If there are no installation instructions and/or they do not provide parameters and target
values, set superheat to a target value of 12 ˚F for fixed orifice systems or set subcooling to a
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a. If the manufacturer’s installation instructions specify tolerances on target values for the
b. Otherwise, use the following tolerances for the different charging parameters:
• High side pressure or corresponding saturation or dew point temperature: +/- 4.0 psi or
+/- 1.0 ˚F
• Low side pressure or corresponding saturation or dew point temperature: +/- 2.0 psi or
+/- 0.8 ˚F
If, using the initial charge set in the A or A2 test, the conditions are not within the range
specified in manufacturer’s instructions for the H1 or H12 test, make as small as possible an
adjustment to obtain conditions for this test in the specified range. After this adjustment,
recheck conditions in the A or A2 test to confirm that they are still within the specified range
b. Single-Package Systems
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Unless otherwise directed by the manufacturer’s installation instructions, install one or more
refrigerant line pressure gauges during the setup of the unit if setting of refrigerant charge is
based on certain operating parameters: (1) install a pressure gauge on the liquid line if
dew point temperature; (2) install a pressure gauge on the suction line if charging is on the
temperature. If manufacturer’s installation instructions indicate that pressure gauges are not
to be installed, setting of charge shall not be based on any of the parameters listed in (1) and
(2) above.
After charging the system as described in this test procedure, use the set refrigerant
charge for all tests used to determine performance. Do not adjust the refrigerant charge at any
If a unit's controls allow for overspeeding the indoor blower (usually on a temporary basis),
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2.3.1 Cooling tests.
a. Set indoor blower airflow-control settings (e.g., fan motor pin settings, fan motor speed)
according to the installation instructions that are provided with the equipment while meeting
the airflow requirements that are specified in section 3.1.4. If the manufacturer installation
instructions do not provide guidance on the airflow-control settings for a system tested with
the indoor blower installed, select the lowest speed that will satisfy the minimum external
static pressure specified in section 3.1.4.1.1 with an air volume rate at or higher than the rated
full-load cooling air volume rate while meeting the maximum air flow requirement.
b. Express the Cooling Full-load Air Volume Rate, the Cooling Minimum Air Volume Rate,
and the Cooling Intermediate Air Volume Rate in terms of standard air.
a. If needed, set the indoor blower airflow-control settings (e.g., fan motor pin settings, fan
motor speed) according to the installation instructions that are provided with the equipment.
Do this set-up while meeting all applicable airflow requirements specified in sections 3.1.4.
For a cooling and heating heat pump tested with an indoor blower installed, if the
settings, use the same airflow-control settings used for the cooling test. If the manufacturer
installation instructions do not provide guidance on the airflow-control settings for a heating-
only heat pump tested with the indoor blower installed, select the lowest speed that will
satisfy the minimum external static pressure specified in section 3.1.4.4.3 with an air volume
rate at or higher than the rated heating full-load air volume rate.
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b. Express the Heating Full-Load Air Volume Rate, the Heating Minimum Air Volume Rate,
the Heating Intermediate Air Volume Rate, and the Heating Nominal Air Volume Rate in
Insulate and/or construct the outlet plenum described in section 2.4.1 and, if installed, the
inlet plenum described in section 2.4.2 with thermal insulation having a nominal overall
a. Attach a plenum to the outlet of the indoor coil. (NOTE: for some packaged systems, the
b. For systems having multiple indoor coils, or multiple indoor blowers within a single
indoor section, attach a plenum to each indoor coil or blower outlet. Connect two or more
outlet plenums to a single common duct so that each indoor coil ultimately connects to an
airflow measuring apparatus (section 2.6). If using more than one indoor test room, do
likewise, creating one or more common ducts within each test room that contains multiple
indoor coils. At the plane where each plenum enters a common duct, install an adjustable
airflow damper and use it to equalize the static pressure in each plenum. Each outlet air
temperature grid (section 2.5.4) and airflow measuring apparatus are located downstream of
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c. For small-duct, high-velocity systems, install an outlet plenum that has a diameter that is
equal to or less than the value listed below. The limit depends only on the Cooling Full-Load
Air Volume Rate (see section 3.1.4.1.1) and is effective regardless of the flange dimensions
on the outlet of the unit (or an air supply plenum adapter accessory, if installed in accordance
d. Add a static pressure tap to each face of the (each) outlet plenum, if rectangular, or at four
evenly distributed locations along the circumference of an oval or round plenum. Create a
manifold that connects the four static pressure taps. Figures 7a, 7b, 7c of ASHRAE Standard
37-2009 shows two of the three options allowed for the manifold configuration; the third
ASHRAE Standard 37-2009. See Figures 7a, 7b, 7c, and 8 of ASHRAE Standard 37-2009
for the cross-sectional dimensions and minimum length of the (each) plenum and the
locations for adding the static pressure taps for units tested with and without an indoor
blower installed.
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*If the outlet plenum is rectangular, calculate its equivalent diameter using (4A/P,) where A is
the cross-sectional area and P is the perimeter of the rectangular plenum, and compare it to the
Install an inlet plenum when testing a coil-only indoor unit or a packaged system where the
indoor coil is located in the outdoor test room. Add static pressure taps at the center of each face
of this plenum, if rectangular, or at four evenly distributed locations along the circumference of
an oval or round plenum. Make a manifold that connects the four static-pressure taps using one
of the three configurations specified in section 2.4.1. See Figures 7b, 7c, and Figure 8 of
ASHRAE Standard 37-2009 for cross-sectional dimensions, the minimum length of the inlet
plenum, and the locations of the static-pressure taps. When testing a ducted unit having an indoor
blower (and the indoor coil is in the indoor test room), test with an inlet plenum installed unless
physically prohibited by space limitations within the test room. If used, construct the inlet
plenum and add the four static-pressure taps as shown in Figure 8 of ASHRAE Standard 37-
2009. If used, the inlet duct size shall equal the size of the inlet opening of the air-handling
(blower coil) unit or furnace, with a minimum length of 6 inches. Manifold the four static-
pressure taps using one of the three configurations specified in section 2.4.1.d. Never use an inlet
2.5 Indoor coil air property measurements and air damper box applications.
Follow instructions for indoor coil air property measurements as described in AHRI 210/240-
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a. Measure the dry-bulb temperature and water vapor content of the air entering and leaving
the indoor coil. If needed, use an air sampling device to divert air to a sensor(s) that measures
the water vapor content of the air. See Section 5.3 of ASHRAE Standard 41.1-2013 for
guidance on constructing an air sampling device. No part of the air sampling device or the
tubing transferring the sampled air to the sensor shall be within two inches of the test
chamber floor, and the transfer tubing shall be insulated. The sampling device may also
divert air to a remotely located sensor(s) that measures dry bulb temperature. The air
sampling device and the remotely located temperature sensor(s) may be used to determine
the entering air dry bulb temperature during any test. The air sampling device and the
remotely located leaving air dry bulb temperature sensor(s) may be used for all tests except:
b. An acceptable alternative in all cases, including the two special cases noted above, is to
install a grid of dry bulb temperature sensors within the outlet and inlet ducts. Use a
temperature grid to get the average dry bulb temperature at one location, leaving or entering,
or when two grids are applied as a thermopile, to directly obtain the temperature difference.
A grid of temperature sensors (which may also be used for determining average leaving air
dry bulb temperature) is required to measure the temperature distribution within a cross-
c. Use an inlet and outlet air damper box, an inlet upturned duct, or any combination thereof
when conducting one or both of the cyclic tests listed in sections 3.2 and 3.6 on ducted
systems. Otherwise if not conducting one or both of said cyclic tests, install an outlet air
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damper box when testing ducted and non-ducted heat pumps that cycle off the indoor blower
during defrost cycles if no other means is available for preventing natural or forced
convection through the indoor unit when the indoor blower is off. Never use an inlet damper
box or an inlet upturned duct when testing a non-ducted system. An inlet upturned duct is a
length of ductwork so installed upstream from the inlet such that the indoor duct inlet
opening, facing upwards, is sufficiently high to prevent natural convection transfer out of the
duct. If an inlet upturned duct is used, install a dry bulb temperature sensor near the inlet
opening of the indoor duct at a centerline location not higher than the lowest elevation of the
duct edges at the inlet, and ensure that the variation of the dry bulb temperature at this
location, measured at least every minute during the compressor OFF period of the cyclic test,
2.5.1 Test set-up on the inlet side of the indoor coil: for cases where the inlet airflow prevention
device is installed.
applies.
b. For an inlet damper box, locate the grid of entering air dry-bulb temperature sensors, if
used, and the air sampling device, or the sensor used to measure the water vapor content of
the inlet air, at a location immediately upstream of the damper box inlet. For an inlet
upturned duct, locate the grid of entering air dry-bulb temperature sensors, if used, and the air
sampling device, or the sensor used to measure the water vapor content of the inlet air, at a
location at least one foot downstream from the beginning of the insulated portion of the duct
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but before the static pressure measurement; install a dry-bulb temperature sensor at a
centerline location not higher than the lowest elevation of the duct edges at the device inlet.
Construct the airflow prevention device having a cross-sectional flow area equal to or greater
than the flow area of the inlet plenum. Install the airflow prevention device upstream of the inlet
plenum and construct ductwork connecting it to the inlet plenum. If needed, use an adaptor plate
or a transition duct section to connect the airflow prevention device with the inlet plenum.
Insulate the ductwork and inlet plenum with thermal insulation that has a nominal overall
Construct the airflow prevention device having a cross-sectional flow area equal to or greater
than the flow area of the air inlet of the indoor unit. Install the airflow prevention device
immediately upstream of the inlet of the indoor unit. If needed, use an adaptor plate or a short
transition duct section to connect the airflow prevention device with the unit's air inlet. Add
static pressure taps at the center of each face of a rectangular airflow prevention device, or at
four evenly distributed locations along the circumference of an oval or round airflow prevention
device. Locate the pressure taps between the airflow prevention device and the inlet of the indoor
unit. Make a manifold that connects the four static pressure taps. Insulate the ductwork with
thermal insulation that has a nominal overall resistance (R-value) of at least 19 hr•ft2 • °F/Btu.
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2.5.2 Test set-up on the inlet side of the indoor unit: for cases where no airflow prevention
device is installed.
If using the section 2.4.2 inlet plenum and a grid of dry bulb temperature sensors, mount the
grid at a location upstream of the static pressure taps described in section 2.4.2, preferably at the
entrance plane of the inlet plenum. If the section 2.4.2 inlet plenum is not used, but a grid of dry
bulb temperature sensors is used, locate the grid approximately 6 inches upstream from the inlet
of the indoor coil. Or, in the case of non-ducted units having multiple indoor coils, locate a grid
approximately 6 inches upstream from the inlet of each indoor coil. Position an air sampling
device, or the sensor used to measure the water vapor content of the inlet air, immediately
upstream of the (each) entering air dry-bulb temperature sensor grid. If a grid of sensors is not
used, position the entering air sampling device (or the sensor used to measure the water vapor
Section 6.5.2 of ASHRAE Standard 37-2009 describes the method for fabricating static-
pressure taps. Also refer to Figure 2A of ASHRAE Standard 51-07/AMCA Standard 210-07.Use
a differential pressure measuring instrument that is accurate to within ±0.01 inches of water and
has a resolution of at least 0.01 inches of water to measure the static pressure difference between
the indoor coil air inlet and outlet. Connect one side of the differential pressure instrument to the
manifolded pressure taps installed in the outlet plenum. Connect the other side of the instrument
to the manifolded pressure taps located in either the inlet plenum or incorporated within the
airflow prevention device. If an inlet plenum or inlet airflow prevention device is not used, leave
the inlet side of the differential pressure instrument open to the surrounding atmosphere. For
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non-ducted systems that are tested with multiple outlet plenums, measure the static pressure
a. Install an interconnecting duct between the outlet plenum described in section 2.4.1 and
the airflow measuring apparatus described below in section 2.6. The cross-sectional flow area
of the interconnecting duct must be equal to or greater than the flow area of the outlet plenum
or the common duct used when testing non-ducted units having multiple indoor coils. If
needed, use adaptor plates or transition duct sections to allow the connections. To minimize
leakage, tape joints within the interconnecting duct (and the outlet plenum). Construct or
insulate the entire flow section with thermal insulation having a nominal overall resistance
b. Install a grid(s) of dry-bulb temperature sensors inside the interconnecting duct. Also,
install an air sampling device, or the sensor(s) used to measure the water vapor content of the
outlet air, inside the interconnecting duct. Locate the dry-bulb temperature grid(s) upstream
of the air sampling device (or the in-duct sensor(s) used to measure the water vapor content
of the outlet air). Air that circulates through an air sampling device and past a remote water-
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2.5.4.1 Outlet air damper box placement and requirements.
If using an outlet air damper box (see section 2.5), install it within the interconnecting duct at
a location downstream of the location where air from the sampling device is reintroduced or
downstream of the in-duct sensor that measures water vapor content of the outlet air. The leakage
rate from the combination of the outlet plenum, the closed damper, and the duct section that
connects these two components must not exceed 20 cubic feet per minute when a negative
device(s) upstream of the outlet air, dry-bulb temperature grid (but downstream of the outlet
plenum static pressure taps). Use a perforated screen located between the mixing device and the
dry-bulb temperature grid, with a maximum open area of 40 percent. One or both items should
help to meet the maximum outlet air temperature distribution specified in section 3.1.8. Mixing
devices are described in sections 5.3.2 and 5.3.3 of ASHRAE Standard 41.1-2013 and section
For small-duct, high-velocity systems, install an air damper near the end of the
interconnecting duct, just prior to the transition to the airflow measuring apparatus of section 2.6.
To minimize air leakage, adjust this damper such that the pressure in the receiving chamber of
the airflow measuring apparatus is no more than 0.5 inch of water higher than the surrounding
test room ambient. If applicable, in lieu of installing a separate damper, use the outlet air damper
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box of sections 2.5 and 2.5.4.1 if it allows variable positioning. Also apply these steps to any
conventional indoor blower unit that creates a static pressure within the receiving chamber of the
airflow measuring apparatus that exceeds the test room ambient pressure by more than 0.5 inches
of water column.
a. Measure dry bulb temperatures as specified in sections 4, 5.3, 6, 7.2, and 7.3 of ASHRAE
Standard 41.1-2013.
b. Distribute the sensors of a dry-bulb temperature grid over the entire flow area. The
Determine water vapor content by measuring dry-bulb temperature combined with the air
wet-bulb temperature, dew point temperature, or relative humidity. If used, construct and apply
wet-bulb temperature sensors as specified in sections 4, 5, 6, 7.2, 7.3, 7.4, and 7.5 of ASHRAE
Standard 41.6-2014. The temperature sensor (wick removed) must be accurate to within ±0.2 °F.
If used, apply dew point hygrometers as specified in sections 4, 5, 6, and 7.1 of ASHRAE
Standard 41.6-2014. The dew point hygrometers must be accurate to within ±0.4 °F when
operated at conditions that result in the evaluation of dew points above 35 °F. If used, a relative
humidity (RH) meter must be accurate to within ±0.7% RH. Other means to determine the
psychrometric state of air may be used as long as the measurement accuracy is equivalent to or
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better than the accuracy achieved from using a wet-bulb temperature sensor that meets the above
specifications.
If used (see section 2.5), the air damper box(es) must be capable of being completely opened
a. Fabricate and operate an Air Flow Measuring Apparatus as specified in section 6.2 and 6.3
Standard 210-07 or Figure 14 of ASHRAE Standard 41.2-87 (RA 92) for guidance on
placing the static pressure taps and positioning the diffusion baffle (settling means) relative
to the chamber inlet. When measuring the static pressure difference across nozzles and/or
velocity pressure at nozzle throats using electronic pressure transducers and a data
the test tolerance limits specified in section 9.2 and Table 2 of ASHRAE Standard 37-2009,
dampen the measurement system such that the time constant associated with response to a
step change in measurement (time for the response to change 63% of the way from the initial
b. Connect the airflow measuring apparatus to the interconnecting duct section described in
section 2.5.4. See sections 6.1.1, 6.1.2, and 6.1.4, and Figures 1, 2, and 4 of ASHRAE
Standard 37-2009; and Figures D1, D2, and D4 of AHRI 210/240-2008 with Addendum 1
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and 2 for illustrative examples of how the test apparatus may be applied within a complete
laboratory set-up. Instead of following one of these examples, an alternative set-up may be
used to handle the air leaving the airflow measuring apparatus and to supply properly
conditioned air to the test unit's inlet. The alternative set-up, however, must not interfere with
the prescribed means for measuring airflow rate, inlet and outlet air temperatures, inlet and
outlet water vapor contents, and external static pressures, nor create abnormal conditions
surrounding the test unit. (Note: Do not use an enclosure as described in section 6.1.3 of
Perform all tests at the voltage specified in section 6.1.3.2 of AHRI 210/240-2008 with
Addendum 1 and 2 for “Standard Rating Tests.” If the voltage on the nameplate of indoor and
outdoor units differs, the voltage supply on the outdoor unit shall be selected for testing. Measure
the supply voltage at the terminals on the test unit using a volt meter that provides a reading that
a. Use an integrating power (watt-hour) measuring system to determine the electrical energy
or average electrical power supplied to all components of the air conditioner or heat pump
condensate pump on non-ducted indoor units, etc.). The watt-hour measuring system must
give readings that are accurate to within ±0.5 percent. For cyclic tests, this accuracy is
required during both the ON and OFF cycles. Use either two different scales on the same
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watt-hour meter or two separate watt-hour meters. Activate the scale or meter having the
lower power rating within 15 seconds after beginning an OFF cycle. Activate the scale or
meter having the higher power rating active within 15 seconds prior to beginning an ON
cycle. For ducted units tested with a fan installed, the ON cycle lasts from compressor ON to
indoor blower OFF. For ducted units tested without an indoor blower installed, the ON cycle
lasts from compressor ON to compressor OFF. For non-ducted units, the ON cycle lasts from
indoor blower ON to indoor blower OFF. When testing air conditioners and heat pumps
b. When performing section 3.5 and/or 3.8 cyclic tests on non-ducted units, provide
instrumentation to determine the average electrical power consumption of the indoor blower
motor to within ±1.0 percent. If required according to sections 3.3, 3.4, 3.7, 3.9.1, and/or
3.10, this same instrumentation requirement applies when testing air conditioners and heat
Make elapsed time measurements using an instrument that yields readings accurate to within
±0.2 percent.
2.10 Test apparatus for the secondary space conditioning capacity measurement.
For all tests, use the Indoor Air Enthalpy Method to measure the unit's capacity. This method
uses the test set-up specified in sections 2.4 to 2.6. In addition, for all steady-state tests, conduct
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a second, independent measurement of capacity as described in section 3.1.1. For split systems,
use one of the following secondary measurement methods: Outdoor Air Enthalpy Method,
Compressor Calibration Method, or Refrigerant Enthalpy Method. For single-package units, use
either the Outdoor Air Enthalpy Method or the Compressor Calibration Method as the secondary
measurement.
b. The test apparatus required for the Outdoor Air Enthalpy Method is a subset of the
apparatus used for the Indoor Air Enthalpy Method. Required apparatus includes the
following:
(1) On the outlet side, an outlet plenum containing static pressure taps (sections 2.4,
(3) A duct section that connects these two components and itself contains the
instrumentation for measuring the dry-bulb temperature and water vapor content of the
air leaving the outdoor coil (sections 2.5.4, 2.5.5, and 2.5.6), and
(4) On the inlet side, a sampling device and temperature grid (section 2.11b.).
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c. During the preliminary tests described in sections 3.11.1 and 3.11.1.1, measure the
evaporator and condenser temperatures or pressures. On both the outdoor coil and the indoor
coil, solder a thermocouple onto a return bend located at or near the midpoint of each coil or
at points not affected by vapor superheat or liquid subcooling. Alternatively, if the test unit is
not sensitive to the refrigerant charge, install pressure gages to the access valves or to ports
created from tapping into the suction and discharge lines according to sections 7.4.2 and
8.2.5 of ASHRAE Standard 37–2009. Use this alternative approach when testing a unit
Measure refrigerant pressures and temperatures to determine the evaporator superheat and
the enthalpy of the refrigerant that enters and exits the indoor coil. Determine refrigerant flow
rate or, when the superheat of the refrigerant leaving the evaporator is less than 5 °F, total
capacity from separate calibration tests conducted under identical operating conditions. When
using this method, install instrumentation, measure refrigerant properties, and adjust the
refrigerant charge according to section 7.4.2 and 8.2.5 of ASHRAE Standard 37-2009. Use
refrigerant temperature and pressure measuring instruments that meet the specifications given in
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For this method, calculate space conditioning capacity by determining the refrigerant
enthalpy change for the indoor coil and directly measuring the refrigerant flow rate. Use section
7.5.2 of ASHRAE Standard 37-2009 for the requirements for this method, including the
additional instrumentation requirements, and information on placing the flow meter and a sight
glass. Use refrigerant temperature, pressure, and flow measuring instruments that meet the
specifications given in sections 5.1.1, 5.2, and 5.5.1 of ASHRAE Standard 37-2009. Refrigerant
flow measurement device(s), if used, must be elevated at least two feet from the test chamber
floor or placed upon insulating material having a total thermal resistance of at least R-12 and
extending at least one foot laterally beyond each side of the device(s)’ exposed surfaces, unless
the device(s) are elevated at least two feet from the floor.
Follow instructions for measurement of test room ambient conditions as described in AHRI
a. If using a test set-up where air is ducted directly from the conditioning apparatus to the
indoor coil inlet (see Figure 2, Loop Air-Enthalpy Test Method Arrangement, of ASHRAE
Standard 37-2009), add instrumentation to permit measurement of the indoor test room dry-
bulb temperature.
b. For the outdoor side, install a grid of evenly-distributed sensors on every air-permitting
face on the inlet of the outdoor unit, such that each measurement represents an air-inlet area
of no more than one square foot. This grid must be constructed and applied as per section 5.3
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these sensors may differ by no more than 1.5 ˚F—otherwise adjustments to the test room
must be made to improve temperature uniformity. The outdoor conditions shall be verified
with the air collected by air sampling device. Air collected by an air sampling device at the
air inlet of the outdoor unit for transfer to sensors for measurement of temperature and/or
humidity shall be protected from temperature change as follows: any surface of the air
conveying tubing in contact with surrounding air at a different temperature than the sampled
air shall be insulated with thermal insulation with a nominal thermal resistance (R-value) of
at least 19 hr • ft2 • °F/Btu, no part of the air sampling device or the tubing conducting the
sampled air to the sensors shall be within two inches of the test chamber floor, and pairs of
measurements (e.g. dry bulb temperature and wet bulb temperature) used to determine water
vapor content of sampled air shall be measured in the same location. Take steps (e.g., add or
re-position a lab circulating fan), as needed, to maximize temperature uniformity within the
outdoor test room. However, ensure that any fan used for this purpose does not cause air
velocities in the vicinity of the test unit to exceed 500 feet per minute.
c. Measure dry bulb temperatures as specified in sections 4, 5, 7.2, 6, and 7.3 of ASHRAE
Standard 41.1-2013. Measure water vapor content as stated above in section 2.5.6.
When required, measure fan speed using a revolution counter, tachometer, or stroboscope
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Determine the average barometric pressure during each test. Use an instrument that meets the
3. Testing Procedures.
If, during the testing process, an equipment set-up adjustment is made that would have
altered the performance of the unit during any already completed test, then repeat all tests
affected by the adjustment. For cyclic tests, instead of maintaining an air volume rate, for each
airflow nozzle, maintain the static pressure difference or velocity pressure during an ON period
at the same pressure difference or velocity pressure as measured during the steady-state test
Use the testing procedures in this section to collect the data used for calculating (1)
performance metrics for central air conditioners and heat pumps during the cooling season; (2)
performance metrics for heat pumps during the heating season; and (3) power consumption
metric(s) for central air conditioners and heat pumps during the off mode season(s).
For all tests, use the Indoor Air Enthalpy Method test apparatus to determine the unit's space
conditioning capacity. The procedure and data collected, however, differ slightly depending upon
whether the test is a steady-state test, a cyclic test, or a Frost Accumulation test. The following
sections described these differences. For all steady-state tests (i.e., the A, A2, A1, B, B2, B1, C,
C1, EV, F1, G1, H01, H1, H12, H11, HIN, H3, H32, and H31 Tests), in addition, use one of the
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acceptable secondary methods specified in section 2.10 to determine indoor space conditioning
capacity. Calculate this secondary check of capacity according to section 3.11. The two capacity
measurements must agree to within 6 percent to constitute a valid test. For this capacity
comparison, use the Indoor Air Enthalpy Method capacity that is calculated in section 7.3 of
ASHRAE Standard 37-2009 (and, if testing a coil-only system, do not make the after-test fan
heat adjustments described in section 3.3, 3.4, 3.7, and 3.10 of this appendix). However, include
the appropriate section 3.3 to 3.5 and 3.7 to 3.10 fan heat adjustments within the Indoor Air
Where needed, the manufacturer must provide a means for overriding the controls of the test
unit so that the compressor(s) operates at the specified speed or capacity and the indoor
blower operates at the specified speed or delivers the specified air volume rate.
For all tests, meet the requirements given in section 6.1.3.4 of AHRI 210/240-2008 with
Addendum 1 and 2 when obtaining the airflow through the outdoor coil.
3.1.3.1 Double-ducted.
For products intended to be installed with the outdoor airflow ducted, the unit shall be
installed with outdoor coil ductwork installed per manufacturer installation instructions and
shall operate between 0.10 and 0.15 in H2O external static pressure. External static pressure
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measurements shall be made in accordance with ASHRAE Standard 37-2009 Section 6.4 and
6.5.
Airflow setting(s) shall be determined before testing begins. Unless otherwise specified
within this or its subsections, no changes shall be made to the airflow setting(s) after
initiation of testing.
The manufacturer must specify the cooling full-load air volume rate and the instructions for
setting fan speed or controls. Adjust the cooling full-load air volume rate if needed to satisfy the
additional requirements of this section. First, when conducting the A or A2 Test (exclusively), the
measured air volume rate, when divided by the measured indoor air-side total cooling capacity
must not exceed 37.5 cubic feet per minute of standard air (scfm) per 1000 Btu/h. If this ratio is
exceeded, reduce the air volume rate until this ratio is equaled. Use this reduced air volume rate
for all tests that call for using the Cooling Full-load Air Volume Rate. Pressure requirements are
as follows:
a. For all ducted units tested with an indoor blower installed, except those having a constant-
1. Achieve the Cooling Full-load Air Volume Rate, determined in accordance with the
previous paragraph;
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3. If this pressure is equal to or greater than the applicable minimum external static
pressure cited in Table 3, the pressure requirement is satisfied. Use the current air volume
rate for all tests that require the Cooling Full-load Air Volume Rate.
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable Table 3 minimum is
equaled or
4b. until the measured air volume rate equals 90 percent of the air volume rate from
5. If the conditions of step 4a occur first, the pressure requirement is satisfied. Use the
step 4a reduced air volume rate for all tests that require the Cooling Full-load Air Volume
Rate.
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor blower (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor blower set-up
cannot be further changed, reduce the air volume rate and increase the external static
pressure by adjusting the exhaust fan of the airflow measuring apparatus until the
applicable Table 3 minimum is equaled. Use this reduced air volume rate for all tests that
b. For ducted units that are tested with a constant-air-volume-rate indoor blower installed.
For all tests that specify the Cooling Full-load Air Volume Rate, obtain an external static
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pressure as close to (but not less than) the applicable Table 3 value that does not cause
automatic shutdown of the indoor blower or air volume rate variation QVar, defined as
𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚 − 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚
𝑄𝑄𝑉𝑉𝑎𝑎𝑎𝑎 = � 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚 + 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚
� ∗ 100
� �
2
where,
Additional test steps as described in section 3.3.(e) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted units that are tested without an indoor blower installed. For the A or A2 Test,
(exclusively), the pressure drop across the indoor coil assembly must not exceed 0.30 inches
of water. If this pressure drop is exceeded, reduce the air volume rate until the measured
pressure drop equals the specified maximum. Use this reduced air volume rate for all tests
Table 3—Minimum External Static Pressure for Ducted Systems Tested With an Indoor
blower Installed
Minimum external static pressure3 (Inches of water)
Short ducted Small-duct, high- All other
Rated Cooling1 or
Heating2 Capacity systems6 velocity systems4 5 systems
(Btu/h)
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≤28,800 0.03 1.10 0.45
≥29,000 and ≤42,500 0.05 1.15 0.50
≥43,000 0.07 1.20 0.55
1
For air conditioners and heat pumps, the value cited by the manufacturer in published literature
for the unit's capacity when operated at the A or A2 Test conditions.
2
For heating-only heat pumps, the value the manufacturer cites in published literature for the
unit's capacity when operated at the H1 or H12 Test conditions.
3
For ducted units tested without an air filter installed, increase the applicable tabular value by
0.08 inches of water. For ducted units for which the indoor blower installed for testing is the fan
of a condensing gas furnace, decrease the applicable tabular value by 0.10 inches of water (make
both adjustments if they both apply). If the adjusted value is less than zero, readjust it to zero.
4
See section 1.2, Definitions, to determine if the equipment qualifies as a small-duct, high-
velocity system.
5
If a closed-loop, air-enthalpy test apparatus is used on the indoor side, limit the resistance to
airflow on the inlet side of the indoor blower coil to a maximum value of 0.1 inch of water.
Impose the balance of the airflow resistance on the outlet side of the indoor blower.
6
See section 1.2. Definitions.
d. For ducted systems having multiple indoor blowers within a single indoor section, obtain
the full-load air volume rate with all blowers operating unless prevented by the controls of
the unit. In such cases, turn on the maximum number of blowers permitted by the unit’s
controls. Where more than one option exists for meeting this “on” blower requirement,
which blower(s) are turned on must match that specified by the manufacturer in the
installation manuals included with the unit. Conduct section 3.1.4.1.1 setup steps for each
blower separately. If two or more indoor blowers are connected to a common duct as per
section 2.4.1, either turn off the other indoor blowers connected to the same common duct or
temporarily divert their air volume to the test room when confirming or adjusting the setup
configuration of individual blowers. If the indoor blowers are all the same size or model, the
target air volume rate for each blower plenum equals the full-load air volume rate divided by
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the number of “on” blowers. If different size blowers are used within the indoor section, the
allocation of the system’s full-load air volume rate assigned to each “on” blower must match
that specified by the manufacturer in the installation manuals included with the unit.
For non-ducted units, the Cooling Full-load Air Volume Rate is the air volume rate that
results during each test when the unit is operated at an external static pressure of zero inches of
water.
The manufacturer must specify the cooling minimum air volume rate and the instructions for
setting fan speed or controls. The target external static pressure, ΔPst_i, for any test “i” with a
specified air volume rate not equal to the cooling full-load air volume rate is determined as
follows.
2
𝑄𝑄𝑖𝑖
∆𝑃𝑃𝑠𝑠𝑠𝑠_𝑖𝑖 = ∆𝑃𝑃𝑠𝑠𝑠𝑠_𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 � �
𝑄𝑄𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓
Where:
Qfull = cooling full-load air volume rate as measured after setting and/or adjustment as described
in section 3.1.4.1.1.
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a. For ducted units tested with an indoor blower installed that is not a constant-air-volume
3. If this pressure is equal to or greater than the target minimum external static pressure
calculated as described above, use the current air volume rate for all tests that require the
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable target minimum is
equaled or
4b. until the measured air volume rate equals 90 percent of the air volume rate from
5. If the conditions of step 4a occur first, use the step 4a reduced air volume rate for all
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor fan (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor fan set-up cannot
be further changed, reduce the air volume rate and increase the external static pressure by
adjusting the exhaust fan of the airflow measuring apparatus until the applicable target
minimum is equaled. Use this reduced air volume rate for all tests that require the
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b. For ducted units with constant-air-volume indoor blowers, conduct all tests that specify the
cooling minimum air volume rate—(i.e., the A1, B1, C1, F1, and G1 Tests)—at an external
static pressure that does not cause an automatic shutdown of the indoor blower or air volume
rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10 percent, while being as
close to, but not less than the target minimum external static pressure. Additional test steps
as described in section 3.3(e) of this appendix are required if the measured external static
pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted two-capacity units that are tested without an indoor blower installed, the
Cooling Minimum Air Volume Rate is the higher of (1) the rate specified by the installation
instructions included with the unit by the manufacturer or (2) 75 percent of the Cooling Full-
load Air Volume Rate. During the laboratory tests on a coil-only (fanless) unit, obtain this
Cooling Minimum Air Volume Rate regardless of the pressure drop across the indoor coil
assembly.
d. For non-ducted units, the Cooling Minimum Air Volume Rate is the air volume rate that
results during each test when the unit operates at an external static pressure of zero inches of
water and at the indoor fan setting used at low compressor capacity (two-capacity system) or
compressor and a variable-speed variable-air-volume-rate indoor fan, use the lowest fan
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e. For ducted systems having multiple indoor blowers within a single indoor section, operate
the indoor blowers such that the lowest air volume rate allowed by the unit’s controls is
obtained when operating the lone single-speed compressor or when operating at low
compressor capacity while meeting the requirements of section 2.2.3.2 for the minimum
number of blowers that must be turned off. Adjust for external static pressure and if
necessary adjust air volume rates as described in section 3.1.4.2.a if the indoor fan is not a
constant-air-volume indoor fan. The sum of the individual “on” blowers’ air volume rates is
The manufacturer must specify the cooling intermediate air volume rate and the instructions
for setting fan speed or controls. Calculate target minimum external static pressure as described
in section 3.1.4.2.
a. For ducted units tested with an indoor blower, installed that is not a constant-air-volume
indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for cooling
b. For ducted units tested with constant-air-volume indoor blowers installed, conduct the
EV Test at an external static pressure that does not cause an automatic shutdown of the indoor
blower or air volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10
percent, while being as close to, but not less than the target minimum external static pressure.
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Additional test steps as described in section 3.3(e) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
c. For non-ducted units, the Cooling Intermediate Air Volume Rate is the air volume rate that
results when the unit operates at an external static pressure of zero inches of water and at the
fan speed selected by the controls of the unit for the EV Test conditions.
3.1.4.4.1 Ducted heat pumps where the Heating and Cooling Full-load Air Volume Rates are the
same.
a. Use the Cooling Full-load Air Volume Rate as the Heating Full-load Air Volume Rate for:
1. Ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower that operates at the same airflow-control setting during both the A
2. Ducted heat pumps tested with constant-air-flow indoor blowers installed that provide
the same air flow for the A (or A2) and the H1 (or H12) Tests; and
3. Ducted heat pumps that are tested without an indoor blower installed (except two-
capacity northern heat pumps that are tested only at low capacity cooling—see 3.1.4.4.2).
b. For heat pumps that meet the above criteria “1” and “3,” no minimum requirements apply
to the measured external or internal, respectively, static pressure. For heat pumps that meet
the above criterion “2,” test at an external static pressure that does not cause an automatic
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shutdown of the indoor blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than, the same Table
3 minimum external static pressure as was specified for the A (or A2) cooling mode test.
Additional test steps as described in section 3.9.1(c) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
3.1.4.4.2 Ducted heat pumps where the Heating and Cooling Full-load Air Volume Rates are
The manufacturer must specify the heating full-load air volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2.
a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
b. For ducted heat pumps tested with constant-air-volume indoor blowers installed, conduct
all tests that specify the heating full-load air volume rate at an external static pressure that
does not cause an automatic shutdown of the indoor blower or air volume rate variation QVar,
defined in section 3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less
than the target minimum external static pressure. Additional test steps as described in section
3.9.1(c) of this appendix are required if the measured external static pressure exceeds the
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c. When testing ducted, two-capacity northern heat pumps (see section 1.2, Definitions), use
the appropriate approach of the above two cases for units that are tested with an indoor
blower installed. For coil-only northern heat pumps, the Heating Full-load Air Volume Rate
is the lesser of the rate specified by the manufacturer in the installation instructions included
with the unit or 133 percent of the Cooling Full-load Air Volume Rate. For this latter case,
obtain the Heating Full-load Air Volume Rate regardless of the pressure drop across the
d. For ducted systems having multiple indoor blowers within a single indoor section, obtain
the heating full-load air volume rate using the same “on” blowers as used for the cooling full-
load air volume rate. For systems where individual blowers regulate the speed (as opposed to
the cfm) of the indoor blower, use the first section 3.1.4.4.2 equation for each blower
individually. Sum the individual blower air volume rates to obtain the heating full-load air
The manufacturer must specify the Heating Full-load Air Volume Rate.
a. For all ducted heating-only heat pumps tested with an indoor blower installed, except those
having a constant-air-volume-rate indoor blower. Conduct the following steps only during
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3. If this pressure is equal to or greater than the Table 3 minimum external static pressure
that applies given the heating-only heat pump's rated heating capacity, use the current air
volume rate for all tests that require the Heating Full-load Air Volume Rate.
4a. reduce the air volume rate and increase the external static pressure by adjusting
the exhaust fan of the airflow measuring apparatus until the applicable Table 3 minimum is
equaled or
4b. until the measured air volume rate equals 90 percent of the manufacturer-
5. If the conditions of step 4a occurs first, use the step 4a reduced air volume rate for all
6. If the conditions of step 4b occur first, make an incremental change to the set-up of the
indoor blower (e.g., next highest fan motor pin setting, next highest fan motor speed) and
repeat the evaluation process beginning at above step 1. If the indoor blower set-up
cannot be further changed, reduce the air volume rate until the applicable Table 3
minimum is equaled. Use this reduced air volume rate for all tests that require the
b. For ducted heating-only heat pumps that are tested with a constant-air-volume-rate indoor
blower installed. For all tests that specify the Heating Full-load Air Volume Rate, obtain an
external static pressure that does not cause an automatic shutdown of the indoor blower or air
volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10 percent, while
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being as close to, but not less than, the applicable Table 3 minimum. Additional test steps as
described in section 3.9.1(c) of this appendix are required if the measured external static
pressure exceeds the target value by more than 0.03 inches of water.
c. For ducted heating-only heat pumps that are tested without an indoor blower installed. For
the H1 or H12 Test, (exclusively), the pressure drop across the indoor coil assembly must not
exceed 0.30 inches of water. If this pressure drop is exceeded, reduce the air volume rate
until the measured pressure drop equals the specified maximum. Use this reduced air volume
rate for all tests that require the Heating Full-load Air Volume Rate.
For non-ducted heat pumps, the Heating Full-load Air Volume Rate is the air volume rate
that results during each test when the unit operates at an external static pressure of zero inches of
water.
3.1.4.5.1 Ducted heat pumps where the Heating and Cooling Minimum Air Volume Rates are the
same.
a. Use the Cooling Minimum Air Volume Rate as the Heating Minimum Air Volume Rate
for:
1. Ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower that operates at the same airflow-control setting during both the A1
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and the H11 tests;2. Ducted heat pumps tested with constant-air-flow indoor blowers
installed that provide the same air flow for the A1 and the H11 Tests; and
3. Ducted heat pumps that are tested without an indoor blower installed (except two-
capacity northern heat pumps that are tested only at low capacity cooling—see 3.1.4.4.2).
b. For heat pumps that meet the above criteria “1” and “3,” no minimum requirements apply
to the measured external or internal, respectively, static pressure. For heat pumps that meet
the above criterion “2,” test at an external static pressure that does not cause an automatic
shutdown of the indoor blower or air volume rate variation QVar, defined in section
3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than, the same target
minimum external static pressure as was specified for the A1 cooling mode test. Additional
test steps as described in section 3.9.1(c) of this appendix are required if the measured
external static pressure exceeds the target value by more than 0.03 inches of water.
3.1.4.5.2 Ducted heat pumps where the Heating and Cooling Minimum Air Volume Rates are
The manufacturer must specify the heating minimum volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2.
a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
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b. For ducted heat pumps tested with constant-air-volume indoor blowers installed,
conduct all tests that specify the Heating Minimum Air Volume Rate—(i.e., the H01, H11, H21,
and H31 Tests)—at an external static pressure that does not cause an automatic shutdown of the
indoor blower while being as close to, but not less thanor air volume rate variation QVar, defined
in section 3.1.4.1.1.b, greater than 10 percent, while being as close to, but not less than the target
minimum external static pressure. Additional test steps as described in section 3.9.1(c) of this
appendix are required if the measured external static pressure exceeds the target value by more
c. For ducted two-capacity northern heat pumps that are tested with an indoor blower
d. For ducted two-capacity heat pumps that are tested without an indoor blower installed, use
the Cooling Minimum Air Volume Rate as the Heating Minimum Air Volume Rate. For
ducted two-capacity northern heat pumps that are tested without an indoor blower installed,
use the Cooling Full-load Air Volume Rate as the Heating Minimum Air Volume Rate. For
ducted two-capacity heating-only heat pumps that are tested without an indoor blower
installed, the Heating Minimum Air Volume Rate is the higher of the rate specified by the
manufacturer in the test setup instructions included with the unit or 75 percent of the Heating
Full-load Air Volume Rate. During the laboratory tests on a coil-only system, obtain the
Heating Minimum Air Volume Rate without regard to the pressure drop across the indoor
coil assembly.
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e. For non-ducted heat pumps, the Heating Minimum Air Volume Rate is the air volume rate
that results during each test when the unit operates at an external static pressure of zero
inches of water and at the indoor blower setting used at low compressor capacity (two-
capacity system) or minimum compressor speed (variable-speed system). For units having a
f. For ducted systems with multiple indoor blowers within a single indoor section, obtain the
heating minimum air volume rate using the same “on” blowers as used for the cooling
minimum air volume rate. For systems where individual blowers regulate the speed (as
opposed to the cfm) of the indoor blower, use the first section 3.1.4.5 equation for each
blower individually. Sum the individual blower air volume rates to obtain the heating
The manufacturer must specify the heating intermediate air volume rate and the instructions
for setting fan speed or controls. Calculate target minimum external static pressure as described
in section 3.1.4.2.
a. For ducted heat pumps tested with an indoor blower installed that is not a constant-air-
volume indoor blower, adjust for external static pressure as described in section 3.1.4.2.a for
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b. For ducted heat pumps tested with constant-air-volume indoor blowers installed, conduct
the H2V Test at an external static pressure that does not cause an automatic shutdown of the
indoor blower or air volume rate variation QVar, defined in section 3.1.4.1.1.b, greater than 10
percent, while being as close to, but not less than the target minimum external static pressure.
Additional test steps as described in section 3.9.1(c) of this appendix are required if the
measured external static pressure exceeds the target value by more than 0.03 inches of water.
c. For non-ducted heat pumps, the Heating Intermediate Air Volume Rate is the air volume
rate that results when the heat pump operates at an external static pressure of zero inches of
water and at the fan speed selected by the controls of the unit for the H2V Test conditions.
The manufacturer must specify the heating nominal air volume rate and the instructions for
setting fan speed or controls. Calculate target minimum external static pressure as described in
section 3.1.4.2. Make adjustments as described in section 3.14.6 for heating intermediate air
volume rate so that the target minimum external static pressure is met or exceeded.
3.1.5 Indoor test room requirement when the air surrounding the indoor unit is not supplied from
If using a test set-up where air is ducted directly from the air reconditioning apparatus to the
indoor coil inlet (see Figure 2, Loop Air-Enthalpy Test Method Arrangement, of ASHRAE
Standard 37-2009), maintain the dry bulb temperature within the test room within ±5.0 °F of the
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applicable sections 3.2 and 3.6 dry bulb temperature test condition for the air entering the indoor
For all steady-state tests and for Frost Accumulation (H2, H21, H22, H2V) tests, calculate the
air volume rate through the indoor coil as specified in sections 7.7.2.1 and 7.7.2.2 of ASHRAE
Standard 37-2009. When using the Outdoor Air Enthalpy Method, follow sections 7.7.2.1 and
7.7.2.2 to calculate the air volume rate through the outdoor coil. To express air volume rates in
������
̇
𝑉𝑉𝑚𝑚𝑚𝑚 ������
𝑉𝑉̇𝑚𝑚𝑚𝑚
Equation 3-1 𝑉𝑉𝑠𝑠̇ = 𝑙𝑙𝑙𝑙𝑙𝑙𝑑𝑑a ′ = 𝑙𝑙𝑙𝑙𝑙𝑙𝑑𝑑a
0.075 ∗𝑣𝑣𝑛𝑛 ∗[1+𝑊𝑊𝑛𝑛 ] 0.075 ∗𝑣𝑣𝑛𝑛
𝑓𝑓𝑓𝑓3 𝑓𝑓𝑓𝑓3
where,
vn′ = specific volume of air-water vapor mixture at the nozzle, ft3 per lbm of the air-water
vapor mixture
Wn = humidity ratio at the nozzle, lbm of water vapor per lbm of dry air
vn = specific volume of the dry air portion of the mixture evaluated at the dry-bulb
temperature, vapor content, and barometric pressure existing at the nozzle, ft3 per lbm of
dry air.
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(Note: In the first printing of ASHRAE Standard 37-2009, the second IP equation for
Manufacturers may optionally operate the equipment under test for a “break-in” period, not
to exceed 20 hours, prior to conducting the test method specified in this section. A manufacturer
who elects to use this optional compressor break-in period in its certification testing should
record this information (including the duration) in the test data underlying the certified ratings
that are required to be maintained under 10 CFR 429.71. When testing a ducted unit (except if a
heating-only heat pump), conduct the A or A2 Test first to establish the Cooling Full-load Air
Volume Rate. For ducted heat pumps where the Heating and Cooling Full-load Air Volume
Rates are different, make the first heating mode test one that requires the Heating Full-load Air
Volume Rate. For ducted heating-only heat pumps, conduct the H1 or H12 Test first to establish
the Heating Full-load Air Volume Rate. When conducting an cyclic test, always conduct it
immediately after the steady-state test that requires the same test conditions. For variable-speed
systems, the first test using the Cooling Minimum Air Volume Rate should precede the EV Test,
and the first test using the Heating Minimum Air Volume Rate must precede the H2V Test. The
3.1.8 Requirement for the air temperature distribution leaving the indoor coil.
For at least the first cooling mode test and the first heating mode test, monitor the
temperature distribution of the air leaving the indoor coil using the grid of individual sensors
described in sections 2.5 and 2.5.4. For the 30-minute data collection interval used to determine
530
capacity, the maximum spread among the outlet dry bulb temperatures from any data sampling
must not exceed 1.5 °F. Install the mixing devices described in section 2.5.4.2 to minimize the
temperature spread.
3.1.9 Requirement for the air temperature distribution entering the outdoor coil.
Monitor the temperatures of the air entering the outdoor coil using the grid of temperature
sensors described in section 2.11. For the 30-minute data collection interval used to determine
capacity, the maximum difference between dry bulb temperatures measured at any of these
Except as noted, disable heat pump resistance elements used for heating indoor air at all
times, including during defrost cycles and if they are normally regulated by a heat comfort
controller. For heat pumps equipped with a heat comfort controller, enable the heat pump
resistance elements only during the below-described, short test. For single-speed heat pumps
covered under section 3.6.1, the short test follows the H1 or, if conducted, the H1C Test. For
two-capacity heat pumps and heat pumps covered under section 3.6.2, the short test follows the
H12 Test. Set the heat comfort controller to provide the maximum supply air temperature. With
the heat pump operating and while maintaining the Heating Full-load Air Volume Rate, measure
the temperature of the air leaving the indoor-side beginning 5 minutes after activating the heat
comfort controller. Sample the outlet dry-bulb temperature at regular intervals that span 5
minutes or less. Collect data for 10 minutes, obtaining at least 3 samples. Calculate the average
531
3.2 Cooling mode tests for different types of air conditioners and heat pumps.
3.2.1 Tests for a unit having a single-speed compressor, or a system comprised of independently
circuited single-speed compressors, that is tested with a fixed-speed indoor blower installed, with
Conduct two steady-state wet coil tests, the A and B Tests. Use the two dry-coil tests, the
steady-state C Test and the cyclic D Test, to determine the cooling mode cyclic degradation
coefficient, CDc. If testing outdoor units of central air conditioners or heat pumps that are not sold
with indoor units, assign CDc the default value of 0.2. Table 4 specifies test conditions for these
four tests.
Table 4 Cooling Mode Test Conditions for Units Having a Single-Speed Compressor and a
Fixed-Speed Indoor blower, a Constant Air Volume Rate Indoor blower, or No Indoor
blower
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2
Defined in section 3.1.4.1.
3
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. (It is recommended that an indoor wet-bulb temperature of 57 °F or less be used.)
4
Maintain the airflow nozzles static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the C Test.
3.2.2 Tests for a unit having a single-speed compressor where the indoor section uses a single
3.2.2.1 Indoor blower capacity modulation that correlates with the outdoor dry bulb temperature
Conduct four steady-state wet coil tests: The A2, A1, B2, and B1 Tests. Use the two dry-coil
tests, the steady-state C1 Test and the cyclic D1 Test, to determine the cooling mode cyclic
3.2.2.2 Indoor blower capacity modulation based on adjusting the sensible to total (S/T) cooling
capacity ratio.
The testing requirements are the same as specified in section 3.2.1 and Table 4. Use a
Cooling Full-load Air Volume Rate that represents a normal installation. If performed, conduct
the steady-state C Test and the cyclic D Test with the unit operating in the same S/T capacity
Table 5 Cooling Mode Test Conditions for Units with a Single-Speed Compressor That
Meet the Section 3.2.2.1 Indoor Unit Requirements
Air entering indoor unit Air entering outdoor unit
temperature (°F) temperature (°F)
Dry bulb Wet bulb Dry bulb Wet bulb Cooling air
Test description volume rate
533
1
A2 Test—required 80 67 95 75 Cooling full-
(steady, wet coil) load2
1
A1 Test—required 80 67 95 75 Cooling
(steady, wet coil) minimum3
1
B2 Test—required 80 67 82 65 Cooling full-
(steady, wet coil) load2
1
B1 Test—required 80 67 82 65 Cooling
(steady, wet coil) minimum3
C1 Test4—required 80 (4) 82 Cooling
(steady, dry coil) minimum3
D1 Test4—required 80 (4) 82 (5)
(cyclic, dry coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
3
Defined in section 3.1.4.2.
4
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. (It is recommended that an indoor wet-bulb temperature of 57 °F or less be used.)
5
Maintain the airflow nozzles static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the C1 Test.
3.2.3 Tests for a unit having a two-capacity compressor. (see section 1.2, Definitions)
a. Conduct four steady-state wet coil tests: the A2, B2, B1, and F1 Tests. Use the two dry-coil
tests, the steady-state C1 Test and the cyclic D1 Test, to determine the cooling-mode cyclic-
degradation coefficient, CDc. Table 6 specifies test conditions for these six tests.
b. For units having a variable speed indoor blower that is modulated to adjust the sensible to
total (S/T) cooling capacity ratio, use Cooling Full-load and Cooling Minimum Air Volume
Rates that represent a normal installation. Additionally, if conducting the dry-coil tests,
operate the unit in the same S/T capacity control mode as used for the B1 Test.
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c. Test two-capacity, northern heat pumps (see section 1.2, Definitions) in the same way as a
single speed heat pump with the unit operating exclusively at low compressor capacity (see
d. If a two-capacity air conditioner or heat pump locks out low-capacity operation at higher
outdoor temperatures, then use the two dry-coil tests, the steady-state C2 Test and the cyclic
on/off cycling from high capacity, CDc(k=2). The default CDc(k=2) is the same value as
equivalently, CDc(k=1)].
Table 6 Cooling Mode Test Conditions for Units Having a Two-Capacity Compressor
1
A2 Test— 80 67 95 75 High Cooling Full-
required Load.2
(steady, wet
coil)
1
B2 Test— 80 67 82 65 High Cooling Full-
required Load.2
(steady, wet
coil)
1
B1 Test— 80 67 82 65 Low Cooling
required Minimum.3
(steady, wet
coil)
535
C2 Test— 80 (4) 82 High Cooling Full-
required Load.2
(steady, dry-
coil)
1
F1 Test— 80 67 67 53.5 Low Cooling
required Minimum.3
(steady, wet
coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
3
Defined in section 3.1.4.2.
4
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet-bulb temperature of 57 °F or less.
5
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
period at the same pressure or velocity as measured during the C2 Test.
6
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
536
a. Conduct five steady-state wet coil tests: The A2, EV, B2, B1, and F1 Tests. Use the two dry-
coil tests, the steady-state G1 Test and the cyclic I1 Test, to determine the cooling mode
cyclic degradation coefficient, CDc.. Table 7 specifies test conditions for these seven tests.
where a tolerance of plus 5 percent or the next higher inverter frequency step from that
calculated is allowed.
b. For units that modulate the indoor blower speed to adjust the sensible to total (S/T) cooling
capacity ratio, use Cooling Full-load, Cooling Intermediate, and Cooling Minimum Air
Volume Rates that represent a normal installation. Additionally, if conducting the dry-coil
tests, operate the unit in the same S/T capacity control mode as used for the F1 Test.
c. For multiple-split air conditioners and heat pumps (except where noted), the following
procedures supersede the above requirements: For all Table 7 tests specified for a minimum
compressor speed, at least one indoor unit must be turned off. The manufacturer shall
designate the particular indoor unit(s) that is turned off. The manufacturer must also specify
the compressor speed used for the Table 7 EV Test, a cooling-mode intermediate compressor
speed that falls within 1⁄4 and 3⁄4 of the difference between the maximum and minimum
expected to yield the highest EER for the given EV Test conditions and bracketed compressor
537
speed range. The manufacturer can designate that one or more indoor units are turned off for
the EV Test.
Table 7 Cooling Mode Test Condition for Units Having a Variable-Speed Compressor
Air entering indoor unit Air entering outdoor unit
temperature (°F) temperature (°F)
Test Compressor Cooling air
description Dry bulb Wet bulb Dry bulb Wet bulb speed volume rate
1
A2 Test— 80 67 95 75 Maximum Cooling Full-
required Load2
(steady, wet
coil)
1
B2 Test— 80 67 82 65 Maximum Cooling Full-
required Load2
(steady, wet
coil)
1
EV Test— 80 67 87 69 Intermediate Cooling
required Intermediate3
(steady, wet
coil)
1
B1 Test— 80 67 82 65 Minimum Cooling
required Minimum4
(steady, wet
coil)
1
F1 Test— 80 67 67 53.5 Minimum Cooling
required Minimum4
(steady, wet
coil)
G1 Test5— 80 (6) 67 Minimum Cooling
required Minimum4
(steady, dry-
coil)
I1 Test5— 80 (6) 67 Minimum (6)
required
(cyclic, dry-
coil)
1
The specified test condition only applies if the unit rejects condensate to the outdoor coil.
2
Defined in section 3.1.4.1.
538
3
Defined in section 3.1.4.3.
4
Defined in section 3.1.4.2.
5
The entering air must have a low enough moisture content so no condensate forms on the indoor
coil. DOE recommends using an indoor air wet bulb temperature of 57 °F or less.
6
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the G1 Test.
3.2.5 Cooling mode tests for northern heat pumps with triple-capacity compressors.
Test triple-capacity, northern heat pumps for the cooling mode in the same way as specified
3.2.6 Tests for an air conditioner or heat pump having a single indoor unit having multiple
3.3 Test procedures for steady-state wet coil cooling mode tests (the A, A2, A1, B, B2, B1, EV,
and F1 Tests).
a. For the pretest interval, operate the test room reconditioning apparatus and the unit to be
tested until maintaining equilibrium conditions for at least 30 minutes at the specified section
3.2 test conditions. Use the exhaust fan of the airflow measuring apparatus and, if installed,
the indoor blower of the test unit to obtain and then maintain the indoor air volume rate
and/or external static pressure specified for the particular test. Continuously record (see
(1) The dry-bulb temperature of the air entering the indoor coil,
(2) The water vapor content of the air entering the indoor coil,
539
(3) The dry-bulb temperature of the air entering the outdoor coil, and
(4) For the section 2.2.4 cases where its control is required, the water vapor content of the
Refer to section 3.11 for additional requirements that depend on the selected secondary
test method.
b. After satisfying the pretest equilibrium requirements, make the measurements specified in
Table 3 of ASHRAE Standard 37-2009 for the Indoor Air Enthalpy method and the user-
selected secondary method. Make said Table 3 measurements at equal intervals that span 5
minutes or less. Continue data sampling until reaching a 30-minute period (e.g., four
consecutive 10-minute samples) where the test tolerances specified in Table 8 are satisfied.
For those continuously recorded parameters, use the entire data set from the 30-minute
interval to evaluate Table 8 compliance. Determine the average electrical power consumption
of the air conditioner or heat pump over the same 30-minute interval.
c. Calculate indoor-side total cooling capacity and sensible cooling capacity as specified in
sections 7.3.3.1 and 7.3.3.3 of ASHRAE Standard 37-2009. Do not adjust the parameters
used in calculating capacity for the permitted variations in test conditions. Evaluate air
enthalpies based on the measured barometric pressure. Use the values of the specific heat of
air given in section 7.3.3.1 for calculation of the sensible cooling capacities. Assign the
average total space cooling capacity, average sensible cooling capacity, and electrical power
consumption over the 30-minute data collection interval to the variables Q̇ck(T), Q̇sck(T) and
540
Ėck(T), respectively. For these three variables, replace the “T” with the nominal outdoor
temperature at which the test was conducted. The superscript k is used only when testing
multi-capacity units. Use the superscript k=2 to denote a test with the unit operating at high
capacity or maximum speed, k=1 to denote low capacity or minimum speed, and k=v to
1505 𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
∗ 𝑉𝑉̇𝑠𝑠
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
441 𝑊𝑊 �̇
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠
where V̇̅s is the average measured indoor air volume rate expressed in units of cubic feet
Table 8—Test Operating and Test Condition Tolerances for Section 3.3 Steady-State Wet
Coil Cooling Mode Tests and Section 3.4 Dry Coil Cooling Mode Tests
Test operating tolerance1 Test condition tolerance1
Indoor dry-bulb, °F
Entering temperature 2.0 0.5
Leaving temperature 2.0
Indoor wet-bulb, °F
2
Entering temperature 1.0 0.3
2
Leaving temperature 1.0
Outdoor dry-bulb, °F
Entering temperature 2.0 0.5
3
Leaving temperature 2.0
541
Outdoor wet-bulb, °F
4
Entering temperature 1.0 0.3
3
Leaving temperature 1.0
5
External resistance to airflow, inches of water 0.12 0.02
tests.
3
Only applies when using the Outdoor Air Enthalpy Method.
4
Only applies during wet coil cooling mode tests where the unit rejects condensate to the outdoor
coil.
5
Only applies when testing non-ducted units.
e. For air conditioners and heat pumps having a constant-air-volume-rate indoor blower, the
five additional steps listed below are required if the average of the measured external static
pressures exceeds the applicable sections 3.1.4 minimum (or target) external static pressure
1. Measure the average power consumption of the indoor blower motor (Ėfan,1) and record
the corresponding external static pressure (ΔP1) during or immediately following the 30-
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2. After completing the 30-minute interval and while maintaining the same test
conditions, adjust the exhaust fan of the airflow measuring apparatus until the external
3. After re-establishing steady readings of the fan motor power and external static
pressure, determine average values for the indoor blower power (Ėfan,2) and the external
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,2 ̇
− 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,min = ̇
(Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
5. Increase the total space cooling capacity, Q̇ck(T), by the quantity (Ėfan,1 − Ėfan,min),
when expressed on a Btu/h basis. Decrease the total electrical power, Ėck(T), by the same
3.4 Test procedures for the steady-state dry-coil cooling-mode tests (the C, C1, C2, and G1 Tests).
a. Except for the modifications noted in this section, conduct the steady-state dry coil cooling
mode tests as specified in section 3.3 for wet coil tests. Prior to recording data during the
steady-state dry coil test, operate the unit at least one hour after achieving dry coil conditions.
Drain the drain pan and plug the drain opening. Thereafter, the drain pan should remain
completely dry.
543
b. Denote the resulting total space cooling capacity and electrical power derived from the test
as Q̇ss,dry and Ėss,dry.With regard to a section 3.3 deviation, do not adjust Q̇ss,dry for duct losses
(i.e., do not apply section 7.3.3.3 of ASHRAE Standard 37-2009). In preparing for the
section 3.5 cyclic tests, record the average indoor-side air volume rate, V̇̅, specific heat of the
air, Cp,a (expressed on dry air basis), specific volume of the air at the nozzles, v′n, humidity
ratio at the nozzles, Wn, and either pressure difference or velocity pressure for the flow
nozzles. For units having a variable-speed indoor fan (that provides either a constant or
variable air volume rate) that will or may be tested during the cyclic dry coil cooling mode
test with the indoor fan turned off (see section 3.5), include the electrical power used by the
indoor fan motor among the recorded parameters from the 30-minute test.
c. If the temperature sensors used to provide the primary measurement of the indoor-side dry
bulb temperature difference during the steady-state dry-coil test and the subsequent cyclic
dry- coil test are different, include measurements of the latter sensors among the regularly
sampled data. Beginning at the start of the 30-minute data collection period, measure and
compute the indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally spaced data sample. If
using a consistent data sampling rate that is less than 1 minute, calculate and record minutely
averages for the two temperature differences. If using a consistent sampling rate of one
minute or more, calculate and record the two temperature differences from each data sample.
After having recorded the seventh (i=7) set of temperature differences, calculate the
544
𝑖𝑖
1 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝑆𝑆𝑆𝑆)
𝐹𝐹𝐶𝐶𝐶𝐶 = �
7 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝐶𝐶𝐶𝐶𝐶𝐶)
𝑖𝑖−6
Each time a subsequent set of temperature differences is recorded (if sampling more frequently
than every 5 minutes), calculate FCD using the most recent seven sets of values. Continue these
calculations until the 30-minute period is completed or until a value for FCD is calculated that
falls outside the allowable range of 0.94–1.06. If the latter occurs, immediately suspend the test
and identify the cause for the disparity in the two temperature difference measurements.
Recalibration of one or both sets of instrumentation may be required. If all the values for FCD are
within the allowable range, save the final value of the ratio from the 30-minute test as FCD*. If
the temperature sensors used to provide the primary measurement of the indoor-side dry bulb
temperature difference during the steady-state dry- coil test and the subsequent cyclic dry-coil
3.5 Test procedures for the cyclic dry-coil cooling-mode tests (the D, D1, D2, and I1 Tests).
a. After completing the steady-state dry-coil test, remove the Outdoor Air Enthalpy method
test apparatus, if connected, and begin manual OFF/ON cycling of the unit's compressor. The
test set-up should otherwise be identical to the set-up used during the steady-state dry coil
test. When testing heat pumps, leave the reversing valve during the compressor OFF cycles
in the same position as used for the compressor ON cycles, unless automatically changed by
the controls of the unit. For units having a variable-speed indoor blower, the manufacturer
has the option of electing at the outset whether to conduct the cyclic test with the indoor
blower enabled or disabled. Always revert to testing with the indoor blower disabled if cyclic
545
b. For units having a single-speed or two-capacity compressor, cycle the compressor OFF for
24 minutes and then ON for 6 minutes (Δτcyc,dry = 0.5 hours). For units having a variable-
speed compressor, cycle the compressor OFF for 48 minutes and then ON for 12 minutes
(Δτcyc,dry = 1.0 hours). Repeat the OFF/ON compressor cycling pattern until the test is
completed. Allow the controls of the unit to regulate cycling of the outdoor fan. If an
upturned duct is used, measure the dry-bulb temperature at the inlet of the device at least
once every minute and ensure that its test operating tolerance is within 1.0 °F for each
c. Sections 3.5.1 and 3.5.2 specify airflow requirements through the indoor coil of ducted and
non-ducted systems, respectively. In all cases, use the exhaust fan of the airflow measuring
apparatus (covered under section 2.6) along with the indoor blower of the unit, if installed
and operating, to approximate a step response in the indoor coil airflow. Regulate the exhaust
fan to quickly obtain and then maintain the flow nozzle static pressure difference or velocity
pressure at the same value as was measured during the steady-state dry coil test. The pressure
difference or velocity pressure should be within 2 percent of the value from the steady-state
dry coil test within 15 seconds after airflow initiation. For units having a variable-speed
indoor blower that ramps when cycling on and/or off, use the exhaust fan of the airflow
measuring apparatus to impose a step response that begins at the initiation of ramp up and
546
d. For units having a variable-speed indoor blower, conduct the cyclic dry coil test using the
pull-thru approach described below if any of the following occur when testing with the fan
operating:
(3) The unit operates for more than 30 seconds at an external static pressure that is 0.1
inches of water or more higher than the value measured during the prior steady-state test.
For the pull-thru approach, disable the indoor blower and use the exhaust fan of the airflow
measuring apparatus to generate the specified flow nozzles static pressure difference or
velocity pressure. If the exhaust fan cannot deliver the required pressure difference because
e. Conduct a minimum of six complete compressor OFF/ON cycles for a unit with a single-
cycles for a unit with a variable speed compressor. The first three cycles for a unit with a
single-speed compressor or two-speed compressor and the first two cycles for a unit with a
unit with a variable speed compressor are the warm-up period—the later cycles are called the
active cycles. Calculate the degradation coefficient CD for each complete active cycle if the
test tolerances given in Table 9 are satisfied. If the average CD for the first three active cycles
is within 0.02 of the average CD for the first two active cycles, use the average CD of the
three active cycles as the final result. If these averages differ by more than 0.02, continue the
test to get CD for the fourth cycle. If the average CD of the last three cycles is lower than or
no more than 0.02 greater than the average CD of the first three cycles, use the average CD of
547
all four active cycles as the final result. Otherwise, continue the test with a fifth cycle. If the
average CD of the last three cycles is 0.02 higher than the average for the previous three
cycles, use the default CD, otherwise use the average CD of all five active cycles. If the test
tolerances given in Table 9 are not satisfied, use default CD value. The default CD value for
cooling is 0.2.
f. With regard to the Table 9 parameters, continuously record the dry-bulb temperature of the
air entering the indoor and outdoor coils during periods when air flows through the respective
coils. Sample the water vapor content of the indoor coil inlet air at least every 2 minutes
during periods when air flows through the coil. Record external static pressure and the air
volume rate indicator (either nozzle pressure difference or velocity pressure) at least every
minute during the interval that air flows through the indoor coil. (These regular
measurements of the airflow rate indicator are in addition to the required measurement at 15
seconds after flow initiation.) Sample the electrical voltage at least every 2 minutes
beginning 30 seconds after compressor start-up. Continue until the compressor, the outdoor
fan, and the indoor blower (if it is installed and operating) cycle off.
g. For ducted units, continuously record the dry-bulb temperature of the air entering (as noted
above) and leaving the indoor coil. Or if using a thermopile, continuously record the
difference between these two temperatures during the interval that air flows through the
indoor coil. For non-ducted units, make the same dry-bulb temperature measurements
beginning when the compressor cycles on and ending when indoor coil airflow ceases.
548
h. Integrate the electrical power over complete cycles of length Δτcyc,dry. For ducted units
tested with an indoor blower installed and operating, integrate electrical power from indoor
blower OFF to indoor blower OFF. For all other ducted units and for non-ducted units,
integrate electrical power from compressor OFF to compressor OFF. (Some cyclic tests will
use the same data collection intervals to determine the electrical energy and the total space
cooling. For other units, terminate data collection used to determine the electrical energy
Table 9 Test Operating and Test Condition Tolerances for Cyclic Dry Coil Cooling Mode
Tests
Test Test
Operating Condition
Tolerance1 Tolerance1
549
5
Applies during the interval when at least one of the following—the compressor, the outdoor fan,
or, if applicable, the indoor blower—are operating except for the first 30 seconds after
compressor start-up.
i. If the Table 9 tolerances are satisfied over the complete cycle, record the measured
electrical energy consumption as ecyc,dry and express it in units of watt-hours. Calculate the
60∗𝑉𝑉̇∗𝐶𝐶𝑝𝑝,𝑎𝑎 ∗Γ 60∗𝑉𝑉̇∗𝐶𝐶𝑝𝑝,𝑎𝑎 ∗Γ ∗ 𝜏𝜏
2
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑 = ′ ∗(1+𝑊𝑊 )]
[𝑣𝑣𝑛𝑛
=
𝑣𝑣𝑛𝑛
and Γ = 𝐹𝐹𝐶𝐶𝐶𝐶 ∫𝜏𝜏 [𝑇𝑇𝑎𝑎1 (𝜏𝜏) − 𝑇𝑇𝑎𝑎2 (𝜏𝜏)]𝛿𝛿𝛿𝛿, ℎ𝑟𝑟 ∗ ℉
𝑛𝑛 1
where V̇̅, Cp,a, vn′ (or vn), Wn, and FCD* are the values recorded during the section 3.4 dry
Tal(τ) = dry bulb temperature of the air entering the indoor coil at time τ, °F.
Ta2(τ) = dry bulb temperature of the air leaving the indoor coil at time τ, °F.
τ1 = for ducted units, the elapsed time when airflow is initiated through the indoor
coil; for non-ducted units, the elapsed time when the compressor is cycled on, hr.
The automatic controls that are normally installed with the test unit must govern the OFF/ON
cycling of the air moving equipment on the indoor side (exhaust fan of the airflow measuring
apparatus and, if installed, the indoor blower of the test unit). For example, for ducted units
tested without an indoor blower installed but rated based on using a fan time delay relay, control
the indoor coil airflow according to the rated ON and/or OFF delays provided by the relay. For
ducted units having a variable-speed indoor blower that has been disabled (and possibly
removed), start and stop the indoor airflow at the same instances as if the fan were enabled. For
550
all other ducted units tested without an indoor blower installed, cycle the indoor coil airflow in
unison with the cycling of the compressor. If air damper boxes are used, close them on the inlet
and outlet side during the OFF period. Airflow through the indoor coil should stop within 3
seconds after the automatic controls of the test unit (act to) de-energize the indoor blower. For
ducted units tested without an indoor blower installed (excluding the special case where a
441 𝑊𝑊 �̇ ∗ [𝜏𝜏 − 𝜏𝜏 ]
Equation 3.5-2 1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 ∗ 𝑉𝑉
𝑠𝑠 2 1
1505 𝐵𝐵𝐵𝐵𝐵𝐵/ℎ
Equation 3.5-3 1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
∗ 𝑉𝑉̇𝑠𝑠 ∗ [𝜏𝜏2 − 𝜏𝜏1 ]
where V̇̅s is the average indoor air volume rate from the section 3.4 dry coil steady-state
test and is expressed in units of cubic feet per minute of standard air (scfm). For units
having a variable-speed indoor blower that is disabled during the cyclic test, increase
a. The product of [τ2 − τ1] and the indoor blower power measured during or following the dry
b. The following algorithm if the indoor blower ramps its speed when cycling.
pressure that was measured during the steady-state test, at operating conditions associated
with the midpoint of the ramp-up interval, and at conditions associated with the midpoint
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of the ramp-down interval. For these measurements, the tolerances on the airflow volume
or the external static pressure are the same as required for the section 3.4 steady-state test.
2. For each case, determine the fan power from measurements made over a minimum of 5
minutes.
3. Approximate the electrical energy consumption of the indoor blower if it had operated
during the cyclic test using all three power measurements. Assume a linear profile during
the ramp intervals. The manufacturer must provide the durations of the ramp-up and
ramp-down intervals. If the test setup instructions included with the unit by the
manufacturer specifies a ramp interval that exceeds 45 seconds, use a 45-second ramp
Do not use airflow prevention devices when conducting cyclic tests on non-ducted
units. Until the last OFF/ON compressor cycle, airflow through the indoor coil must cycle off
and on in unison with the compressor. For the last OFF/ON compressor cycle—the one used to
determine ecyc,dry and qcyc,dry—use the exhaust fan of the airflow measuring apparatus and the
indoor blower of the test unit to have indoor airflow start 3 minutes prior to compressor cut-on
and end three minutes after compressor cutoff. Subtract the electrical energy used by the indoor
blower during the 3 minutes prior to compressor cut-on from the integrated electrical energy,
ecyc,dry. Add the electrical energy used by the indoor blower during the 3 minutes after
compressor cutoff to the integrated cooling capacity, qcyc,dry. For the case where the non-ducted
552
unit uses a variable-speed indoor blower which is disabled during the cyclic test, correct
ecyc,dry and qcyc,dry using the same approach as prescribed in section 3.5.1 for ducted units having
Use the two dry-coil tests to determine the cooling-mode cyclic-degradation coefficient, CDc.
capacity. Evaluate CDc using the above results and those from the section 3.4 dry-coil steady-
state test.
𝐸𝐸𝐸𝐸𝐸𝐸𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
1− 𝐸𝐸𝐸𝐸𝐸𝐸𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑
𝐶𝐶𝐷𝐷𝑐𝑐 =
1 − 𝐶𝐶𝐶𝐶𝐶𝐶
where,
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
𝐸𝐸𝐸𝐸𝐸𝐸𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑 =
𝑒𝑒𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
the average energy efficiency ratio during the cyclic dry coil cooling mode test, Btu/W·h
𝑄𝑄̇𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑
𝐸𝐸𝐸𝐸𝐸𝐸𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑 =
𝐸𝐸̇𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑
the average energy efficiency ratio during the steady-state dry coil cooling mode test, Btu/W·h
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
𝐶𝐶𝐶𝐶𝐶𝐶 =
𝑄𝑄𝑠𝑠𝑠𝑠,𝑑𝑑𝑑𝑑𝑑𝑑 ∗ Δ𝜏𝜏𝑐𝑐𝑐𝑐𝑐𝑐,𝑑𝑑𝑑𝑑𝑑𝑑
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Round the calculated value for CDc to the nearest 0.01. If CDc is negative, then set it equal to
zero.
3.6 Heating mode tests for different types of heat pumps, including heating-only heat pumps.
3.6.1 Tests for a heat pump having a single-speed compressor that is tested with a fixed speed
Conduct the High Temperature Cyclic (H1C) Test to determine the heating mode cyclic-
degradation coefficient, CDh. Test conditions for the four tests are specified in Table 10.
Table 10 Heating Mode Test Conditions for Units Having a Single-Speed Compressor and
a Fixed-Speed Indoor blower, a Constant Air Volume Rate Indoor blower, or No Indoor
blower
Air entering indoor Air entering outdoor
unit unit
Temperature (°F) Temperature (°F)
Dry bulb Wet bulb Dry bulb Wet bulb Heating air volume
Test description rate
H1 Test (required, steady) 70 60(max) 47 43 Heating Full-load1
H1C Test (required, 70 60(max) 47 43 (2)
cyclic)
H2 Test (required) 70 60(max) 35 33 Heating Full-load1
H3 Test (required, steady) 70 60(max) 17 15 Heating Full-load1
1
Defined in section 3.1.4.4.
2
Maintain the airflow nozzles static pressure difference or velocity pressure during the ON
period at the same pressure difference or velocity pressure as measured during the H1 Test.
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3.6.2 Tests for a heat pump having a single-speed compressor and a single indoor unit
having either (1) a variable speed, variable-air-rate indoor blower whose capacity modulation
Conduct five tests: two High Temperature Tests (H12 and H11), one Frost Accumulation
Test (H22), and two Low Temperature Tests (H32 and H31). Conducting an additional Frost
Accumulation Test (H21) is optional. Conduct the High Temperature Cyclic (H1C1) Test to
determine the heating mode cyclic-degradation coefficient, CDh. Test conditions for the seven
tests are specified in Table 11. If the optional H21 Test is not performed, use the following
equations to approximate the capacity and electrical power of the heat pump at the H21 test
conditions:
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
where,
𝑄𝑄̇ℎ𝑘𝑘=2 (35)
𝑄𝑄̇ 𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝑄𝑄̇𝑘𝑘=2 (17) + 0.6 ∗ [𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)]
𝐸𝐸̇ℎ𝑘𝑘=2 (35)
𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝐸𝐸̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)�
The quantities Q̇hk=2(47), Ėhk=2(47), Q̇hk=1(47), and Ėhk=1(47) are determined from the H12 and
H11 Tests and evaluated as specified in section 3.7; the quantities Q̇hk=2(35) and Ėhk=2(35) are
determined from the H22 Test and evaluated as specified in section 3.9; and the quantities
Q̇hk=2(17), Ėhk=2(17), Q̇hk=1(17), and Ėhk=1(17), are determined from the H32 and H31 Tests
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Table 11 Heating Mode Test Conditions for Units with a Single-Speed Compressor That
Meet the Section 3.6.2 Indoor Unit Requirements
Air entering indoor Air entering outdoor
unit unit
temperature (°F) temperature (°F)
Dry bulb Wet bulb Dry bulb Wet bulb Heating air volume
Test description rate
H12 Test (required, 70 60(max) 47 43 Heating Full-load.1
steady)
H11 Test (required, 70 60(max) 47 43 Heating Minimum.2
steady)
H1C1 Test (required, 70 60(max) 47 43 (3)
cyclic)
H22 Test (required) 70 60(max) 35 33 Heating Full-load.1
H21 Test (optional) 70 60(max) 35 33 Heating Minimum.2
H32 Test (required, 70 60(max) 17 15 Heating Full-load.1
steady)
H31 Test (required, 70 60(max) 17 15 Heating Minimum.2
steady)
1
Defined in section 3.1.4.4.
2
Defined in section 3.1.4.5.
3
Maintain the airflow nozzles static pressure difference or velocity pressure during the ON period at the same
pressure difference or velocity pressure as measured during the H11 Test.
3.6.3 Tests for a heat pump having a two-capacity compressor (see section 1.2, Definitions),
a. Conduct one Maximum Temperature Test (H01), two High Temperature Tests (H12and
H11), one Frost Accumulation Test (H22), and one Low Temperature Test (H32). Conduct an
additional Frost Accumulation Test (H21) and Low Temperature Test (H31) if both of the
1. Knowledge of the heat pump's capacity and electrical power at low compressor
capacity for outdoor temperatures of 37 °F and less is needed to complete the section
556
2. The heat pump's controls allow low-capacity operation at outdoor temperatures of 37
°F and less.
If the above two conditions are met, an alternative to conducting the H21 Frost Accumulation
is to use the following equations to approximate the capacity and electrical power:
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
Determine the quantities Q̇hk=1 (47) and Ėhk=1 (47) from the H11 Test and evaluate them
according to Section 3.7. Determine the quantities Q̇hk=1 (17) and Ėhk=1 (17) from the
b. Conduct the High Temperature Cyclic Test (H1C1) to determine the heating mode cyclic-
degradation coefficient, CDh. If a two-capacity heat pump locks out low capacity operation at
lower outdoor temperatures, conduct the High Temperature Cyclic Test (H1C2) to determine
the high-capacity heating mode cyclic-degradation coefficient, CDh (k=2). Table 12 specifies
Table 12 Heating Mode Test Conditions for Units Having a Two-Capacity Compressor
Air entering indoor unit Air entering outdoor
temperature (°F) unit temperature (°F)
Test Dry bulb Wet bulb Dry bulb Wet bulb Compressor Heating air
description capacity volume rate
H01 Test 70 60(max) 62 56.5 Low Heating
(required, Minimum.1
steady)
H12 Test 70 60(max) 47 43 High Heating Full-
(required, Load.2
steady)
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H1C2 Test 70 60(max) 47 43 High (3)
(required7,
cyclic)
H11 Test 70 60(max) 47 43 Low Heating
(required) Minimum.1
H1C1 Test 70 60(max) 47 43 Low (4)
(required,
cyclic)
H22 Test 70 60(max) 35 33 High Heating Full-
(required) Load.2
H21 Test5 6 70 60(max) 35 33 Low Heating
(required) Minimum.1
H32 Test 70 60(max) 17 15 High Heating Full-
(required, Load.2
steady)
H31 Test5 70 60(max) 17 15 Low Heating
(required, Minimum.1
steady)
1
Defined in section 3.1.4.5.
2
Defined in section 3.1.4.4.
3
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same
pressure or velocity as measured during the H12 Test.
4
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same
pressure or velocity as measured during the H11 Test.
5
Required only if the heat pump's performance when operating at low compressor capacity and outdoor temperatures
less than 37 °F is needed to complete the section 4.2.3 HSPF calculations.
6
If table note #5 applies, the section 3.6.3 equations for Q̇hk=1 (35) and Ėhk=1 (17) may be used in lieu of conducting
the H21 Test.
7
Required only if the heat pump locks out low capacity operation at lower outdoor temperatures.
a. (1) Conduct one Maximum Temperature Test (H01), two High Temperature Tests (H12 and
H11), one Frost Accumulation Test (H2V), and one Low Temperature Test (H32). Conducting
one or all of the following tests is optional: An additional High Temperature Test (H1N), an
additional Frost Accumulation Test (H22), and an additional Low Temperature Test (H42).
Conduct the High Temperature Cyclic (H1C1) Test to determine the heating mode cyclic-
558
degradation coefficient, CDh. (2) The optional low ambient temperature test (H42) may be
ambient temperature using the results of H42 and H32 rather than the results of H32 and H12.
This option may not be used for units which have a cutoff temperature preventing
compressor operation below 12 °F. If H42 is conducted, it is optional to conduct the H12 test
for heating capacity rating purposes--H1N can be conducted for heating capacity rating
Test conditions for the nine tests are specified in Table 13. Determine the intermediate
compressor speed cited in Table 13 using the heating mode maximum and minimum
calculated is allowed. If the H22Test is not done, use the following equations to
approximate the capacity and electrical power at the H22 test conditions:
𝑄𝑄̇ℎ𝑘𝑘=2 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)��
𝐸𝐸̇ℎ𝑘𝑘=2 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)��
b. Determine the quantities Q̇hk=2(47) and from Ėhk=2(47) from the H12 Test and evaluate
them according to section 3.7. Determine the quantities Q̇hk=2(17) and Ėhk=2(17) from the
H32 Test and evaluate them according to section 3.10. Determine the quantities Q̇hk=2(TL) and
Ėhk=2(TL ) from the H42 Test and evaluate them according to section 3.10. For heat pumps
where the heating mode maximum compressor speed exceeds its cooling mode maximum
compressor speed, conduct the H1N Test if the manufacturer requests it. If the H1N Test is
559
done, operate the heat pump's compressor at the same speed as the speed used for the cooling
mode A2 Test.
Table 13—Heating Mode Test Conditions for Units Having a Variable-Speed Compressor
description Dry bulb Wet bulb Dry bulb Wet bulb speed volume rate
(required, Minimum.1
steady)
560
(optional, Load.3
steady)6
1
Defined in section 3.1.4.5.
2
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON
period at the same pressure or velocity as measured during the H01 Test.
3
Defined in section 3.1.4.4.
4
Defined in section 3.1.4.7.
5
Defined in section 3.1.4.6.
6
If the maximum speed is limited below 17°F, this test becomes required.
7
If the cutoff temperature is higher than 2°F, run at the cutoff temperature.
8
If maximum speed is limited by unit control, this test should run at the maximum speed allowed
by the control, in such case, the speed is different from the maximum speed defined in the
definition section.
c. For multiple-split heat pumps (only), the following procedures supersede the above
requirements. For all Table 13 tests specified for a minimum compressor speed, at least one
indoor unit must be turned off. The manufacturer shall designate the particular indoor unit(s)
that is turned off. The manufacturer must also specify the compressor speed used for the
Table 13 H2V Test, a heating mode intermediate compressor speed that falls
within 1⁄4 and 3⁄4 of the difference between the maximum and minimum heating mode speeds.
The manufacturer should prescribe an intermediate speed that is expected to yield the highest
COP for the given H2V Test conditions and bracketed compressor speed range. The
manufacturer can designate that one or more specific indoor units are turned off for the
H2V Test.
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3.6.5 Additional test for a heat pump having a heat comfort controller.
Test any heat pump that has a heat comfort controller (see section 1.2, Definitions) according
to section 3.6.1, 3.6.2, or 3.6.3, whichever applies, with the heat comfort controller disabled.
Additionally, conduct the abbreviated test described in section 3.1.9 with the heat comfort
controller active to determine the system's maximum supply air temperature. (Note: heat pumps
having a variable speed compressor and a heat comfort controller are not covered in the test
3.6.6 Heating mode tests northern heat pumps with triple-capacity compressors.
Test triple-capacity, northern heat pumps for the heating mode as follows:
a. Conduct one maximum-temperature test (H01), two high-temperature tests (H12 and H11),
one Frost Accumulation test (H22), two low-temperature tests (H32, H33), and one minimum-
temperature test (H43). Conduct an additional Frost Accumulation test (H21) and low-
temperature test (H31) if both of the following conditions exist: (1) Knowledge of the heat
pump’s capacity and electrical power at low compressor capacity for outdoor temperatures of
37°F and less is needed to complete the section 4.2.6 seasonal performance calculations; and
(2) the heat pump’s controls allow low-capacity operation at outdoor temperatures of 37°F
and less. If the above two conditions are met, an alternative to conducting the H21 Frost
Accumulation Test to determine Q̇hk=1(35) and Ėhk=1(35) is to use the following equations to
𝑄𝑄̇ℎ𝑘𝑘=1 (35) = 0.90 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=1 (47) − 𝑄𝑄̇ℎ𝑘𝑘=1 (17)��
𝐸𝐸̇ℎ𝑘𝑘=1 (35) = 0.985 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=1 (47) − 𝐸𝐸̇ℎ𝑘𝑘=1 (17)��
562
In evaluating the above equations, determine the quantities Q̇hk=1(47) from the H11 Test and
evaluate them according to section 3.7. Determine the quantities Q̇hk=1(17) and Ėhk=1(17)
from the H31 Test and evaluate them according to section 3.10. Use the paired values of
Q̇hk=1(35) and Ėhk=1(35) derived from conducting the H21 Frost Accumulation Test and
evaluated as specified in section 3.9.1 or use the paired values calculated using the above
default equations, whichever contribute to a higher Region IV HSPF based on the DHR.
b. Conducting a Frost Accumulation Test (H23) with the heat pump operating at its booster
capacity is optional. If this optional test is not conducted, determine Q̇hk=3(35) and Ėhk=3(35)
using the following equations to approximate this capacity and electrical power:
𝑄𝑄̇ℎ𝑘𝑘=3 (35) = 𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝑄𝑄̇ℎ𝑘𝑘=3 (17) + 1.20 ∗ �𝑄𝑄̇ℎ𝑘𝑘=3 (17) − 𝑄𝑄̇ℎ𝑘𝑘=3 (2)��
𝐸𝐸̇ℎ𝑘𝑘=3 (35) = 𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) ∗ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) + 1.20 ∗ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) − 𝐸𝐸̇ℎ𝑘𝑘=3 (2)��
where,
𝑄𝑄̇ℎ𝑘𝑘=2 (35)
𝑄𝑄𝑅𝑅ℎ𝑘𝑘=2 (35) = 𝑘𝑘=2
𝑄𝑄̇ℎ (17) + 0.6 ∗ �𝑄𝑄̇ℎ𝑘𝑘=2 (47) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)�
𝐸𝐸̇ℎ𝑘𝑘=2 (35)
𝑃𝑃𝑅𝑅ℎ𝑘𝑘=2 (35) =
𝐸𝐸̇ℎ𝑘𝑘=2 (17) + 0.6 ∗ �𝐸𝐸̇ℎ𝑘𝑘=2 (47) − 𝐸𝐸̇ℎ𝑘𝑘=2 (17)�
Determine the quantities Q̇hk=2(47) and Ėhk=2(47) from the H12 Test and evaluate them according
to section 3.7. Determine the quantities Q̇hk=2(35) and Ėhk=2(35) from the H22Test and evaluate
them according to section 3.9.1. Determine the quantities Q̇hk=2(17) and Ėhk=2(17) from the
H32Test, determine the quantities Q̇hk=3(17) and Ėhk=3(17) from the H33Test, and determine the
quantities Q̇hk=3(2) and Ėhk=3(2) from the H43Test. Evaluate all six quantities according to section
3.10. Use the paired values of Q̇hk=3(35) and Ėhk=3(35) derived from conducting the H23Frost
Accumulation Test and calculated as specified in section 3.9.1 or use the paired values calculated
563
using the above default equations, whichever contribute to a higher Region IV HSPF based on
the DHR.
c. Conduct the high-temperature cyclic test (H1C1) to determine the heating mode cyclic-
degradation coefficient, CDh. If a triple-capacity heat pump locks out low capacity operation
at lower outdoor temperatures, conduct the high-temperature cyclic test (H1C2) to determine
the high-capacity heating mode cyclic-degradation coefficient, CDh (k=2). The default CDh
(k=2) is the same value as determined or assigned for the low-capacity cyclic-degradation
coefficient, CDh [or equivalently, CDh (k=1)]. Finally, if a triple-capacity heat pump locks out
both low and high capacity operation at the lowest outdoor temperatures, conduct the low-
temperature cyclic test (H3C3) to determine the booster-capacity heating mode cyclic-
degradation coefficient, CDh (k=3). The default CDh (k=3) is the same value as determined or
assigned for the high-capacity cyclic-degradation coefficient, CDh [or equivalently, CDh
Table 14 Heating Mode Test Conditions for Units with a Triple-Capacity Compressor
Test description Air entering indoor Air entering outdoor unit Compressor Heating air
°F °F
bulb
Minimum1
Load2
564
Minimum1
Load2
Load2
Minimum1
Load2
Load2
Minimum1
Load2
1
Defined in section 3.1.4.5.
2
Defined in section 3.1.4.4.
3
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure or
Test.
7
Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure or
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3.7 Test procedures for steady-state Maximum Temperature and High Temperature heating mode
a. For the pretest interval, operate the test room reconditioning apparatus and the heat pump
until equilibrium conditions are maintained for at least 30 minutes at the specified section 3.6
test conditions. Use the exhaust fan of the airflow measuring apparatus and, if installed, the
indoor blower of the heat pump to obtain and then maintain the indoor air volume rate and/or
the external static pressure specified for the particular test. Continuously record the dry-bulb
temperature of the air entering the indoor coil, and the dry-bulb temperature and water vapor
content of the air entering the outdoor coil. Refer to section 3.11 for additional requirements
that depend on the selected secondary test method. After satisfying the pretest equilibrium
for the Indoor Air Enthalpy method and the user-selected secondary method. Make said
Table 3 measurements at equal intervals that span 5 minutes or less. Continue data sampling
until a 30-minute period (e.g., four consecutive 10-minute samples) is reached where the test
tolerances specified in Table 15 are satisfied. For those continuously recorded parameters,
use the entire data set for the 30-minute interval when evaluating Table 15 compliance.
Determine the average electrical power consumption of the heat pump over the same 30-
minute interval.
Table 15 Test Operating and Test Condition Tolerances for Section 3.7 and Section 3.10
Steady-State Heating Mode Tests
Test Test
operating tolerance1 condition tolerance1
Indoor dry-bulb, °F:
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Entering temperature 2.0 0.5
Leaving temperature 2.0
Indoor wet-bulb, °F:
Entering temperature 1.0
Leaving temperature 1.0
Outdoor dry-bulb, °F:
Entering temperature 2.0 0.5
2
Leaving temperature 2.0
Outdoor wet-bulb, °F:
Entering temperature 1.0 0.3
2
Leaving temperature 1.0
3
External resistance to airflow, inches of water 0.12 0.02
Electrical voltage, % of rdg 2.0 1.5
Nozzle pressure drop, % of rdg 8.0
1
See section 1.2, Definitions.
2
Only applies when the Outdoor Air Enthalpy Method is used.
3
Only applies when testing non-ducted units.
b. Calculate indoor-side total heating capacity as specified in sections 7.3.4.1 and 7.3.4.3 of
ASHRAE Standard 37-2009. Do not adjust the parameters used in calculating capacity for
the permitted variations in test conditions. Assign the average space heating capacity and
electrical power over the 30-minute data collection interval to the variables Q̇hk and Ėhk(T)
respectively. The “T” and superscripted “k” are the same as described in section 3.3.
Additionally, for the heating mode, use the superscript to denote results from the optional
H1N Test, if conducted.c. For heat pumps tested without an indoor blower installed, increase
Q̇hk(T) by
𝐵𝐵𝐵𝐵𝐵𝐵
1505 ℎ
∗ 𝑉𝑉̇𝑠𝑠
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
567
441 𝑊𝑊 �̇
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠
where V̇̅s is the average measured indoor air volume rate expressed in units of cubic feet
per minute of standard air (scfm). During the 30-minute data collection interval of a High
Temperature Test, pay attention to preventing a defrost cycle. Prior to this time, allow the
heat pump to perform a defrost cycle if automatically initiated by its own controls. As in
all cases, wait for the heat pump's defrost controls to automatically terminate the defrost
cycle. Heat pumps that undergo a defrost should operate in the heating mode for at least
10 minutes after defrost termination prior to beginning the 30-minute data collection
interval. For some heat pumps, frost may accumulate on the outdoor coil during a High
Temperature test. If the indoor coil leaving air temperature or the difference between the
leaving and entering air temperatures decreases by more than 1.5 °F over the 30-minute
data collection interval, then do not use the collected data to determine capacity. Instead,
initiate a defrost cycle. Begin collecting data no sooner than 10 minutes after defrost
termination. Collect 30 minutes of new data during which the Table 15 test tolerances are
satisfied. In this case, use only the results from the second 30-minute data collection
c. For heat pumps tested without an indoor blower installed, increase Q̇hk(T) by
1250 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ �
∗ 𝑉𝑉𝑠𝑠̇
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
365 𝑊𝑊 �̇
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠
where V̇̅s is the average measured indoor air volume rate expressed in units of cubic feet per
minute of standard air (scfm). During the 30-minute data collection interval of a High
568
Temperature Test, pay attention to preventing a defrost cycle. Prior to this time, allow the
heat pump to perform a defrost cycle if automatically initiated by its own controls. As in all
cases, wait for the heat pump's defrost controls to automatically terminate the defrost cycle.
Heat pumps that undergo a defrost should operate in the heating mode for at least 10 minutes
after defrost termination prior to beginning the 30-minute data collection interval. For some
heat pumps, frost may accumulate on the outdoor coil during a High Temperature test. If the
indoor coil leaving air temperature or the difference between the leaving and entering air
temperatures decreases by more than 1.5 °F over the 30-minute data collection interval, then
do not use the collected data to determine capacity. Instead, initiate a defrost cycle. Begin
collecting data no sooner than 10 minutes after defrost termination. Collect 30 minutes of
new data during which the Table 15 test tolerances are satisfied. In this case, use only the
results from the second 30-minute data collection interval to evaluate Q̇hk(47) and Ėhk(47).
d. If conducting the cyclic heating mode test, which is described in section 3.8, record the
average indoor-side air volume rate, V̇̅, specific heat of the air, Cp,a (expressed on dry air
basis), specific volume of the air at the nozzles, vn′ (or vn), humidity ratio at the nozzles, Wn,
and either pressure difference or velocity pressure for the flow nozzles. If either or both of
the below criteria apply, determine the average, steady-state, electrical power consumption of
1. The section 3.8 cyclic test will be conducted and the heat pump has a variable-speed
569
2. The heat pump has a (variable-speed) constant-air volume-rate indoor blower and
during the steady-state test the average external static pressure (ΔP1) exceeds the
applicable section 3.1.4.4 minimum (or targeted) external static pressure (ΔPmin) by 0.03
Determine Ėfan,1 by making measurements during the 30-minute data collection interval, or
immediately following the test and prior to changing the test conditions. When the above “2”
criteria applies, conduct the following four steps after determining Ėfan,1 (which corresponds
to ΔP1):
i. While maintaining the same test conditions, adjust the exhaust fan of the airflow measuring
apparatus until the external static pressure increases to approximately ΔP1 + (ΔP1 − ΔPmin).
ii. After re-establishing steady readings for fan motor power and external static pressure,
determine average values for the indoor blower power (Ėfan,2) and the external static pressure
iii. Approximate the average power consumption of the indoor blower motor if the 30-minute
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,2 ̇
− 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,min = (Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
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iv. Decrease the total space heating capacity, Q̇hk(T), by the quantity (Ėfan,1 − Ėfan,min), when
expressed on a Btu/h basis. Decrease the total electrical power, Ėhk(T) by the same fan power
e. If the temperature sensors used to provide the primary measurement of the indoor-side dry
bulb temperature difference during the steady-state dry-coil test and the subsequent cyclic
dry-coil test are different, include measurements of the latter sensors among the regularly
sampled data. Beginning at the start of the 30-minute data collection period, measure and
compute the indoor-side air dry-bulb temperature difference using both sets of
instrumentation, ΔT (Set SS) and ΔT (Set CYC), for each equally spaced data sample. If
using a consistent data sampling rate that is less than 1 minute, calculate and record minutely
averages for the two temperature differences. If using a consistent sampling rate of one
minute or more, calculate and record the two temperature differences from each data sample.
After having recorded the seventh (i=7) set of temperature differences, calculate the
𝑖𝑖
1 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝑆𝑆𝑆𝑆)
𝐹𝐹𝐶𝐶𝐶𝐶 = �
7 Δ𝑇𝑇(𝑆𝑆𝑆𝑆𝑆𝑆 𝐶𝐶𝐶𝐶𝐶𝐶)
𝑖𝑖−6
Each time a subsequent set of temperature differences is recorded (if sampling more
frequently than every 5 minutes), calculate FCD using the most recent seven sets of values.
Continue these calculations until the 30-minute period is completed or until a value for FCD is
calculated that falls outside the allowable range of 0.94–1.06. If the latter occurs,
immediately suspend the test and identify the cause for the disparity in the two temperature
571
required. If all the values for FCD are within the allowable range, save the final value of the
ratio from the 30-minute test as FCD*. If the temperature sensors used to provide the primary
measurement of the indoor-side dry bulb temperature difference during the steady-state dry-
coil test and the subsequent cyclic dry-coil test are the same, set FCD*= 1.
3.8 Test procedures for the cyclic heating mode tests (the H0C1, H1C, H1C1 and H1C2 Tests).
a. Except as noted below, conduct the cyclic heating mode test as specified in section 3.5. As
adapted to the heating mode, replace section 3.5 references to “the steady-state dry coil test”
with “the heating mode steady-state test conducted at the same test conditions as the cyclic
heating mode test.” Use the test tolerances in Table 16 rather than Table 9. Record the
outdoor coil entering wet-bulb temperature according to the requirements given in section 3.5
for the outdoor coil entering dry-bulb temperature. Drop the subscript “dry” used in variables
cited in section 3.5 when referring to quantities from the cyclic heating mode test. , The
default CD value for heating is 0.25. If available, use electric resistance heaters (see section
2.1) to minimize the variation in the inlet air temperature. Determine the total space heating
delivered during the cyclic heating test, qcyc, as specified in section 3.5 except for making the
following changes:
(1) When evaluating Equation 3.5-1, use the values of V̇̅, Cp,a,vn′, (or vn), and Wn that
were recorded during the section 3.7 steady-state test conducted at the same test
conditions.
∗ 𝜏𝜏
∫𝜏𝜏 [𝑇𝑇𝑎𝑎1 (𝜏𝜏) − 𝑇𝑇𝑎𝑎2 (𝜏𝜏)]𝛿𝛿𝛿𝛿, ℎ𝑟𝑟 × ∘ 𝐹𝐹,
2
(2) Calculate Γ using, Γ = 𝐹𝐹𝐶𝐶𝐶𝐶
1
572
where FCD* is the value recorded during the section 3.7 steady-state test conducted at the
b. For ducted heat pumps tested without an indoor blower installed (excluding the special
case where a variable-speed fan is temporarily removed), increase qcyc by the amount
calculated using Equation 3.5-3. Additionally, increase ecyc by the amount calculated using
Equation 3.5-2. In making these calculations, use the average indoor air volume rate (V̇̅s)
determined from the section 3.7 steady-state heating mode test conducted at the same test
conditions.
c. For non-ducted heat pumps, subtract the electrical energy used by the indoor blower during
the 3 minutes after compressor cutoff from the non-ducted heat pump's integrated heating
capacity, qcyc.
during the OFF/ON cycling, operate the heat pump continuously until 10 minutes after
defrost termination. After that, begin cycling the heat pump immediately or delay until the
specified test conditions have been re-established. Pay attention to preventing defrosts after
beginning the cycling process. For heat pumps that cycle off the indoor blower during a
defrost cycle, make no effort here to restrict the air movement through the indoor coil while
the fan is off. Resume the OFF/ON cycling while conducting a minimum of two complete
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3.8.1 Heating mode cyclic-degradation coefficient calculation.
Use the results from the cyclic test and the required steady-state test that were conducted at
the same test conditions to determine the heating mode cyclic-degradation coefficient CDh. Add
“(k=2)” to the coefficient if it corresponds to a two-capacity unit cycling at high capacity. For the
below calculation of the heating mode cyclic degradation coefficient, do not include the duct loss
correction from section 7.3.3.3 of ASHRAE Standard 37-2009 in determining Q̇hk(Tcyc) (or qcyc).
𝐶𝐶𝐶𝐶𝑃𝑃𝑐𝑐𝑐𝑐𝑐𝑐
1 − 𝐶𝐶𝐶𝐶𝑃𝑃
𝑠𝑠𝑠𝑠 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
𝐶𝐶𝐷𝐷ℎ =
1 − 𝐻𝐻𝐻𝐻𝐻𝐻
where,
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐
𝐶𝐶𝐶𝐶𝑃𝑃𝑐𝑐𝑐𝑐𝑐𝑐 = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝑒𝑒𝑐𝑐𝑐𝑐𝑐𝑐
the average coefficient of performance during the cyclic heating mode test,
dimensionless.
𝑄𝑄̇ℎ𝑘𝑘 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
𝐶𝐶𝐶𝐶𝑃𝑃𝑠𝑠𝑠𝑠 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝐸𝐸̇ℎ𝑘𝑘 �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 �
the average coefficient of performance during the steady-state heating mode test
conducted at the same test conditions—i.e., same outdoor dry bulb temperature, Tcyc, and
dimensionless.
𝑞𝑞𝑐𝑐𝑐𝑐𝑐𝑐
𝐻𝐻𝐻𝐻𝐻𝐻 =
𝑄𝑄̇ℎ �𝑇𝑇𝑐𝑐𝑐𝑐𝑐𝑐 � ∗
𝑘𝑘
Δ𝜏𝜏𝑐𝑐𝑐𝑐𝑐𝑐
574
the heating load factor, dimensionless.
Tcyc , the nominal outdoor temperature at which the cyclic heating mode test is
conducted, 62 or 47 °F.
Δτcyc, the duration of the OFF/ON intervals; 0.5 hours when testing a heat pump having a
single-speed or two-capacity compressor and 1.0 hour when testing a heat pump having a
variable-speed compressor.
Round the calculated value for CDh to the nearest 0.01. If CDh is negative, then set it equal to
zero.
Table 16—Test operating and test condition tolerances for cyclic heating mode tests.
Test Test
operating condition
tolerance1 tolerance1
Indoor entering dry-bulb temperature,2 °F 2.0 0.5
Indoor entering wet-bulb temperature,2 °F 1.0
Outdoor entering dry-bulb temperature,2 °F 2.0 0.5
Outdoor entering wet-bulb temperature,2 °F 2.0 1.0
External resistance to air-flow,2 inches of water 0.12
Airflow nozzle pressure difference or velocity pressure,2 % 2.0 3
2.0
of reading
Electrical voltage,4 % of rdg 8.0 1.5
1
See section 1.2, Definitions.
2
Applies during the interval that air flows through the indoor (outdoor) coil except for the first 30
seconds after flow initiation. For units having a variable-speed indoor blower that ramps, the
tolerances listed for the external resistance to airflow shall apply from 30 seconds after achieving
full speed until ramp down begins.
575
3
The test condition shall be the average nozzle pressure difference or velocity pressure measured
during the steady-state test conducted at the same test conditions.
4
Applies during the interval that at least one of the following—the compressor, the outdoor fan,
or, if applicable, the indoor blower—are operating, except for the first 30 seconds after
compressor start-up.
3.9 Test procedures for Frost Accumulation heating mode tests (the H2, H22, H2V, and
H21 Tests).
a. Confirm that the defrost controls of the heat pump are set as specified in section 2.2.1.
Operate the test room reconditioning apparatus and the heat pump for at least 30 minutes at
the specified section 3.6 test conditions before starting the “preliminary” test period. The
preliminary test period must immediately precede the “official” test period, which is the
heating and defrost interval over which data are collected for evaluating average space
b. For heat pumps containing defrost controls which are likely to cause defrosts at intervals
less than one hour, the preliminary test period starts at the termination of an automatic defrost
cycle and ends at the termination of the next occurring automatic defrost cycle. For heat
pumps containing defrost controls which are likely to cause defrosts at intervals exceeding
one hour, the preliminary test period must consist of a heating interval lasting at least one
hour followed by a defrost cycle that is either manually or automatically initiated. In all
cases, the heat pump's own controls must govern when a defrost cycle terminates.
c. The official test period begins when the preliminary test period ends, at defrost
termination. The official test period ends at the termination of the next occurring automatic
defrost cycle. When testing a heat pump that uses a time-adaptive defrost control system (see
576
section 1.2, Definitions), however, manually initiate the defrost cycle that ends the official
test period at the instant indicated by instructions provided by the manufacturer. If the heat
pump has not undergone a defrost after 6 hours, immediately conclude the test and use the
results from the full 6-hour period to calculate the average space heating capacity and
For heat pumps that turn the indoor blower off during the defrost cycle, take steps to
cease forced airflow through the indoor coil and block the outlet duct whenever the heat pump's
controls cycle off the indoor blower. If it is installed, use the outlet damper box described in
d. Defrost termination occurs when the controls of the heat pump actuate the first change in
converting from defrost operation to normal heating operation. Defrost initiation occurs when
the controls of the heat pump first alter its normal heating operation in order to eliminate
e. To constitute a valid Frost Accumulation test, satisfy the test tolerances specified in Table
17 during both the preliminary and official test periods. As noted in Table 17, test operating
tolerances are specified for two sub-intervals: (1) When heating, except for the first 10
minutes after the termination of a defrost cycle (Sub-interval H, as described in Table 17) and
(2) when defrosting, plus these same first 10 minutes after defrost termination (Sub-interval
D, as described in Table 17). Evaluate compliance with Table 17 test condition tolerances
and the majority of the test operating tolerances using the averages from measurements
577
recorded only during Sub-interval H. Continuously record the dry bulb temperature of the air
entering the indoor coil, and the dry bulb temperature and water vapor content of the air
entering the outdoor coil. Sample the remaining parameters listed in Table 17 at equal
f. For the official test period, collect and use the following data to calculate average space
heating capacity and electrical power. During heating and defrosting intervals when the
controls of the heat pump have the indoor blower on, continuously record the dry-bulb
temperature of the air entering (as noted above) and leaving the indoor coil. If using a
thermopile, continuously record the difference between the leaving and entering dry-bulb
temperatures during the interval(s) that air flows through the indoor coil. For heat pumps
tested without an indoor blower installed, determine the corresponding cumulative time (in
hours) of indoor coil airflow, Δτa. Sample measurements used in calculating the air volume
rate (refer to sections 7.7.2.1 and 7.7.2.2 of ASHRAE Standard 37-2009) at equal intervals
that span 10 minutes or less. (Note: In the first printing of ASHRAE Standard 37-2009, the
second IP equation for Qmi should read: .) Record the electrical energy consumed, expressed
Table 17 Test Operating and Test Condition Tolerances for Frost Accumulation Heating
Mode Tests.
Sub-interval H2
4
Indoor entering dry-bulb temperature, °F 2.0 4.0 0.5
578
Indoor entering wet-bulb temperature, °F 1.0
Outdoor entering dry-bulb temperature, °F 2.0 10.0 1.0
Outdoor entering wet-bulb temperature, °F 1.5 0.5
External resistance to airflow, inches of water 0.12 0.025
Electrical voltage, % of rdg 2.0 1.5
1See section 1.2, Definitions.
2Applies when the heat pump is in the heating mode, except for the first 10 minutes after termination of a defrost
cycle.
3Applies during a defrost cycle and during the first 10 minutes after the termination of a defrost cycle when the heat
pump is operating in the heating mode.
4For heat pumps that turn off the indoor blower during the defrost cycle, the noted tolerance only applies during the
10 minute interval that follows defrost termination.
5Only applies when testing non-ducted heat pumps.
a. Evaluate average space heating capacity, Q̇hk(35), when expressed in units of Btu per hour,
using:
where,
V̇̅ = the average indoor air volume rate measured during Sub-interval H, cfm.
Cp,a = 0.24 + 0.444 · Wn, the constant pressure specific heat of the air-water vapor
mixture that flows through the indoor coil and is expressed on a dry air basis, Btu /
lbmda · °F.
vn′ = specific volume of the air-water vapor mixture at the nozzle, ft3 / lbmmx.
Wn = humidity ratio of the air-water vapor mixture at the nozzle, lbm of water vapor per
ΔτFR = τ2 − τ1, the elapsed time from defrost termination to defrost termination, hr.
𝜏𝜏
Γ = ∫𝜏𝜏 2[𝑇𝑇𝑎𝑎2 (𝜏𝜏) − 𝑇𝑇𝑎𝑎1 (𝜏𝜏)]𝑑𝑑𝑑𝑑, ℎ𝑟𝑟 ∗ ∘ 𝐹𝐹
1
579
Tal(τ) = dry bulb temperature of the air entering the indoor coil at elapsed time τ, °F; only
recorded when indoor coil airflow occurs; assigned the value of zero during periods (if
Ta2(τ) = dry bulb temperature of the air leaving the indoor coil at elapsed time τ, °F; only
recorded when indoor coil airflow occurs; assigned the value of zero during periods (if
τ1 = the elapsed time when the defrost termination occurs that begins the official test
period, hr.
τ2 = the elapsed time when the next automatically occurring defrost termination occurs,
vn = specific volume of the dry air portion of the mixture evaluated at the dry-bulb
temperature, vapor content, and barometric pressure existing at the nozzle, ft3 per lbm of
dry air.
To account for the effect of duct losses between the outlet of the indoor unit and the
section 2.5.4 dry-bulb temperature grid, adjust Q̇hk(35) in accordance with section 7.3.4.3 of
b. Evaluate average electrical power, Ėhk(35), when expressed in units of watts, using:
𝑒𝑒𝑑𝑑𝑑𝑑𝑑𝑑 (35)
𝐸𝐸̇ℎ𝑘𝑘 (35) =
Δ𝜏𝜏𝐹𝐹𝐹𝐹
For heat pumps tested without an indoor blower installed, increase Q̇hk(35) by,
𝐵𝐵𝐵𝐵𝐵𝐵
1505 Δ𝜏𝜏𝑎𝑎
ℎ
∗ 𝑉𝑉̇𝑠𝑠 ∗
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 Δ𝜏𝜏𝐹𝐹𝐹𝐹
580
441𝑊𝑊 �̇ ∗ Δ𝜏𝜏𝑎𝑎
∗ 𝑉𝑉
1000 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠 Δ𝜏𝜏𝐹𝐹𝐹𝐹
where V̇̅s is the average indoor air volume rate measured during the Frost Accumulation
heating mode test and is expressed in units of cubic feet per minute of standard air
(scfm).
c. For heat pumps having a constant-air-volume-rate indoor blower, the five additional steps
listed below are required if the average of the external static pressures measured during sub-
Interval H exceeds the applicable section 3.1.4.4, 3.1.4.5, or 3.1.4.6 minimum (or targeted)
1. Measure the average power consumption of the indoor blower motor (Ėfan,1) and record
the corresponding external static pressure (ΔP1) during or immediately following the
Frost Accumulation heating mode test. Make the measurement at a time when the heat
pump is heating, except for the first 10 minutes after the termination of a defrost cycle.
2. After the Frost Accumulation heating mode test is completed and while maintaining
the same test conditions, adjust the exhaust fan of the airflow measuring apparatus until
3. After re-establishing steady readings for the fan motor power and external static
pressure, determine average values for the indoor blower power (Ėfan,2) and the external
581
4. Approximate the average power consumption of the indoor blower motor had the Frost
Accumulation heating mode test been conducted at ΔPmin using linear extrapolation:
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,2 ̇
− 𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,1
̇
𝐸𝐸𝑓𝑓𝑓𝑓𝑓𝑓,min = (Δ𝑃𝑃min − Δ𝑃𝑃1 ) + 𝐸𝐸̇𝑓𝑓𝑓𝑓𝑓𝑓,1
Δ𝑃𝑃2 − Δ𝑃𝑃1
5. Decrease the total heating capacity, Q̇hk(35), by the quantity [(Ėfan,1 − Ėfan,min)·
(Δτ a/Δτ FR], when expressed on a Btu/h basis. Decrease the total electrical power,
a. Assign the demand defrost credit, Fdef, that is used in section 4.2 to the value of 1 in all
cases except for heat pumps having a demand-defrost control system (see section 1.2,
Δ𝜏𝜏𝑑𝑑𝑑𝑑𝑑𝑑 − 1.5
𝐹𝐹𝑑𝑑𝑑𝑑𝑑𝑑 = 1 + 0.03 ∗ �1 − �
Δ𝜏𝜏max − 1.5
where,
Δτdef = the time between defrost terminations (in hours) or 1.5, whichever is greater.
Accumulation test and the heat pump has not completed a defrost cycle.
Δτmax = maximum time between defrosts as allowed by the controls (in hours) or 12,
whichever is less, as provided in the installation manuals included with the unit by the
manufacturer.
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b. For two-capacity heat pumps and for section 3.6.2 units, evaluate the above equation using
the Δτdef that applies based on the Frost Accumulation Test conducted at high capacity and/or
at the Heating Full-load Air Volume Rate. For variable-speed heat pumps, evaluate
Δτdef based on the required Frost Accumulation Test conducted at the intermediate
compressor speed.
3.10 Test procedures for steady-state Low Temperature heating mode tests (the H3, H32, H31 and
H42 Tests).
Except for the modifications noted in this section, conduct the Low Temperature heating
mode test using the same approach as specified in section 3.7 for the Maximum and High
Temperature tests. After satisfying the section 3.7 requirements for the pretest interval but before
beginning to collect data to determine Q̇hk(17) and Ėhk(17), conduct a defrost cycle. This defrost
cycle may be manually or automatically initiated. The defrost sequence must be terminated by
the action of the heat pump's defrost controls. Begin the 30-minute data collection interval
described in section 3.7, from which Q̇hk(17) and Ėhk(17) are determined, no sooner than 10
minutes after defrost termination. Defrosts should be prevented over the 30-minute data
3.11.1 If using the Outdoor Air Enthalpy Method as the secondary test method.
During the “official” test, the outdoor air-side test apparatus described in section 2.10.1 is
connected to the outdoor unit. To help compensate for any effect that the addition of this test
apparatus may have on the unit's performance, conduct a “preliminary” test where the outdoor
air-side test apparatus is disconnected. Conduct a preliminary test prior to the first section 3.2
583
steady-state cooling mode test and prior to the first section 3.6 steady-state heating mode test. No
other preliminary tests are required so long as the unit operates the outdoor fan during all cooling
mode steady-state tests at the same speed and all heating mode steady-state tests at the same
speed. If using more than one outdoor fan speed for the cooling mode steady-state tests,
however, conduct a preliminary test prior to each cooling mode test where a different fan speed
is first used. This same requirement applies for the heating mode tests.
a. The test conditions for the preliminary test are the same as specified for the official test.
Connect the indoor air-side test apparatus to the indoor coil; disconnect the outdoor air-side
test apparatus. Allow the test room reconditioning apparatus and the unit being tested to
operate for at least one hour. After attaining equilibrium conditions, measure the following
Continue these measurements until a 30-minute period (e.g., four consecutive 10-minute
samples) is obtained where the Table 8 or Table 15, whichever applies, test tolerances are
satisfied.
b. After collecting 30 minutes of steady-state data, reconnect the outdoor air-side test
apparatus to the unit. Adjust the exhaust fan of the outdoor airflow measuring apparatus until
averages for the evaporator and condenser temperatures, or the saturated temperatures
corresponding to the measured pressures, agree within ±0.5 °F of the averages achieved
584
when the outdoor air-side test apparatus was disconnected. Calculate the averages for the
reconnected case using five or more consecutive readings taken at one minute intervals.
Make these consecutive readings after re-establishing equilibrium conditions and before
Connect the outdoor-side test apparatus to the unit. Adjust the exhaust fan of the outdoor
airflow measuring apparatus to achieve the same external static pressure as measured during the
prior preliminary test conducted with the unit operating in the same cooling or heating mode at
a. Continue (preliminary test was conducted) or begin (no preliminary test) the official test
by making measurements for both the Indoor and Outdoor Air Enthalpy Methods at equal
intervals that span 5 minutes or less. Discontinue these measurements only after obtaining a
30-minute period where the specified test condition and test operating tolerances are
(2) For cases where a preliminary test is conducted, the capacities determined using the
Indoor Air Enthalpy Method from the official and preliminary test periods must agree
585
b. For space cooling tests, calculate capacity from the outdoor air-enthalpy measurements as
specified in sections 7.3.3.2 and 7.3.3.3 of ASHRAE Standard 37-2009. Calculate heating
7.3.3.4.3 of the same ASHRAE Standard. Adjust the outdoor-side capacity according to
section 7.3.3.4 of ASHRAE Standard 37-2009 to account for line losses when testing split
systems. Use the outdoor unit fan power as measured during the official test and not the
value measured during the preliminary test, as described in section 8.6.2 of ASHRAE
3.11.2 If using the Compressor Calibration Method as the secondary test method.
a. Conduct separate calibration tests using a calorimeter to determine the refrigerant flow
rate. Or for cases where the superheat of the refrigerant leaving the evaporator is less than 5
°F, use the calorimeter to measure total capacity rather than refrigerant flow rate. Conduct
these calibration tests at the same test conditions as specified for the tests in this appendix.
Operate the unit for at least one hour or until obtaining equilibrium conditions before
collecting data that will be used in determining the average refrigerant flow rate or total
capacity. Sample the data at equal intervals that span 5 minutes or less. Determine average
flow rate or average capacity from data sampled over a 30-minute period where the Table 8
(cooling) or the Table 15 (heating) tolerances are satisfied. Otherwise, conduct the calibration
9, and 11 of ASHRAE Standard 41.9-2011; and section 7.4 of ASHRAE Standard 37-2009.
586
b. Calculate space cooling and space heating capacities using the compressor calibration
Standard 37-2009.
Conduct this secondary method according to section 7.5 of ASHRAE Standard 37-2009.
Calculate space cooling and heating capacities using the refrigerant-enthalpy method
measurements as specified in sections 7.5.4 and 7.5.5, respectively, of the same ASHRAE
Standard.
a. When reporting rated capacities, round them off as specified in 10 CFR Part 430.23 (for a
b. For the capacities used to perform the section 4 calculations, however, round only to the
nearest integer.
Conduct one of the following tests after the completion of the B, B1, or B2 Test, whichever
comes last: if the central air conditioner or heat pump lacks a compressor crankcase heater,
perform the test in Section 3.13.1; if the central air conditioner or heat pump has compressor
crankcase heater that lacks controls, perform the test in Section 3.13.1; if the central air
conditioner or heat pump has a compressor crankcase heater equipped with controls, perform the
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3.13.1 This test determines the off mode average power rating for central air conditioners and
heat pumps that lack a compressor crankcase heater, or have a compressor crankcase heater that
lacks controls.
a. Configure Controls: Configure the controls of the central air conditioner or heat pump so
that it operates as if connected to a building thermostat that is set to the OFF position. This
particular test contains no requirements as to ambient conditions within the test rooms, and
room conditions are allowed to change during the test. Ensure that the low-voltage
b. Measure 𝑃𝑃1𝑥𝑥 : Determine the average power from non-zero value data measured over a 5-
minute interval of the non-operating central air conditioner or heat pump and designate the
average power as 𝑃𝑃1𝑥𝑥 , the shoulder season total off mode power.
c. Measure 𝑃𝑃𝑥𝑥 for coil-only split systems (that would be installed in the field with a furnace
having a dedicated board for indoor controls) and for blower-coil split systems for which a
furnace is the designated air mover: Disconnect all low-voltage wiring for the outdoor
components and outdoor controls from the low-voltage transformer. Determine the average
power from non-zero value data measured over a 5-minute interval of the power supplied to
the (remaining) low-voltage components of the central air conditioner or heat pump, or low-
588
d. Calculate P1:
Single-package systems and blower coil split systems for which the designated air mover is
not a furnace: Divide the shoulder season total off mode power (𝑃𝑃1𝑥𝑥 ) by the number of
compressors to calculate P1, the shoulder season per-compressor off mode power. If the
compressor is a modulating-type, assign a value of 1.5 for the number of compressors. Round
P1 to the nearest watt and record as both P1 and P2, the latter of which is the heating season
𝑃𝑃1
𝑥𝑥
𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐.
Coil-only split systems (that would be installed in the field with a furnace having a dedicated
board for indoor controls) and blower-coil split systems for which a furnace is the designated
air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the shoulder season total off mode
power (𝑃𝑃1𝑥𝑥 ) and divide by the number of compressors to calculate P1, the shoulder season
1.5 for the number of compressors. Round P1 to the nearest watt and record as both P1 and
P2, the latter of which is the heating season per-compressor off mode power. The expression
𝑃𝑃1 −𝑃𝑃
𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
3.13.2 This test determines the off mode average power rating for central air conditioners and
heat pumps that have a compressor crankcase heater equipped with controls.
temperature in the air between 2 and 6 inches from the crankcase heater temperature sensor
589
or, if no such temperature sensor exists, position it in the air between 2 and 6 inches from the
crankcase heater. Utilize the temperature measurements from this sensor for this portion of
the test procedure. Configure the controls of the central air conditioner or heat pump so that it
operates as if connected to a building thermostat that is set to the OFF position. Ensure that
the low-voltage transformer and low-voltage components are connected. Adjust the outdoor
temperature at a rate of change of no more than 20 °F per hour and achieve an outdoor dry-
bulb temperature of 72 °F. Maintain this temperature within +/-2 °F for at least 5 minutes,
b. Measure 𝑃𝑃1𝑥𝑥 : Determine the average power from non-zero value data measured over a 5-
minute interval of the non-operating central air conditioner or heat pump and designate the
average power as 𝑃𝑃1𝑥𝑥 , the shoulder season total off mode power.
c. Reconfigure Controls: In the process of reaching the target outdoor dry-bulb temperature,
adjust the outdoor temperature at a rate of change of no more than 20 °F per hour. This target
Certification Database at which the crankcase heater turns on, minus five degrees Fahrenheit.
Maintain this temperature within +/-2 °F for at least 5 minutes, while maintaining an indoor
d. Measure 𝑃𝑃2𝑥𝑥 : Determine the average non-zero power of the non-operating central air
conditioner or heat pump over a 5-minute interval and designate it as 𝑃𝑃2𝑥𝑥 , the heating season
590
e. Measure 𝑃𝑃𝑥𝑥 for coil-only split systems (that would be installed in the field with a furnace
having a dedicated board for indoor controls) and for blower-coil split systems for which a
furnace is the designated air mover: Disconnect all low-voltage wiring for the outdoor
components and outdoor controls from the low-voltage transformer. Determine the average
power from non-zero value data measured over a 5-minute interval of the power supplied to
the (remaining) low-voltage components of the central air conditioner or heat pump, or low-
f. Calculate P1:
Single-package systems and blower coil split systems for which the air mover is not a
furnace: Divide the shoulder season total off mode power (𝑃𝑃1𝑥𝑥 ) by the number of
compressors to calculate P1, the shoulder season per-compressor off mode power. Round to
the nearest watt. If the compressor is a modulating-type, assign a value of 1.5 for the number
𝑃𝑃1𝑥𝑥
of compressors. The expression for calculating P1 is as follows:𝑃𝑃1 = .
𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
Coil-only split systems (that would be installed in the field with a furnace having a
dedicated board for indoor controls) and blower-coil split systems for which a furnace is the
designated air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the shoulder season total off
mode power (𝑃𝑃1𝑥𝑥 ) and divide by the number of compressors to calculate P1, the shoulder season
per-compressor off mode power. Round to the nearest watt. If the compressor is a modulating-
type, assign a value of 1.5 for the number of compressors. The expression for calculating P1 is as
follows:
591
𝑃𝑃1 −𝑃𝑃
𝑃𝑃1 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
h. Calculate P2:
Single-package systems and blower coil split systems for which the air mover is not a
furnace: Divide the heating season total off mode power (𝑃𝑃2𝑥𝑥 ) by the number of compressors
to calculate P2, the heating season per-compressor off mode power. Round to the nearest
watt. If the compressor is a modulating-type, assign a value of 1.5 for the number of
𝑃𝑃2
𝑥𝑥
𝑃𝑃2 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐.
Coil-only split systems (that would be installed in the field with a furnace having a dedicated
board for indoor controls) and blower-coil split systems for which a furnace is the designated
air mover: Subtract the low-voltage power (𝑃𝑃𝑥𝑥 ) from the heating season total off mode power
(𝑃𝑃2𝑥𝑥 ) and divide by the number of compressors to calculate P2, the heating season per-
compressor off mode power. Round to the nearest watt. If the compressor is a modulating-
type, assign a value of 1.5 for the number of compressors. The expression for calculating P2
is as follows:
𝑃𝑃2 −𝑃𝑃
𝑃𝑃2 = 𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜𝑥𝑥𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
𝑥𝑥
.
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4.1 Seasonal Energy Efficiency Ratio (SEER) Calculations. SEER must be calculated as follows:
For equipment covered under sections 4.1.2, 4.1.3, and 4.1.4, evaluate the seasonal energy
efficiency ratio,
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗)
∑8𝑗𝑗=1 𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗) ∑8𝑗𝑗=1
Equation 4.1-1 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 = ∑8𝑗𝑗=1 𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
= 𝑁𝑁
𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
∑8𝑗𝑗=1
𝑁𝑁
where,
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗)
= the ratio of the total space cooling provided during periods of the space cooling
𝑁𝑁
season when the outdoor temperature fell within the range represented by bin temperature
𝑒𝑒𝑐𝑐 (𝑇𝑇𝑗𝑗)
= the electrical energy consumed by the test unit during periods of the space cooling
𝑁𝑁
season when the outdoor temperature fell within the range represented by bin temperature
Tj = the outdoor bin temperature, °F. Outdoor temperatures are grouped or “binned.” Use
bins of 5 °F with the 8 cooling season bin temperatures being 67, 72, 77, 82, 87, 92, 97,
Additionally, for sections 4.1.2, 4.1.3, and 4.1.4, use a building cooling load, BL(Tj). When
593
�𝑇𝑇𝑗𝑗 − 65� 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (95)
𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 � = ∗
95 − 65 1.1
where,
Q̇ck=2(95) = the space cooling capacity determined from the A2 Test and calculated as
The temperatures 95 °F and 65 °F in the building load equation represent the selected
4.1.1 SEER calculations for an air conditioner or heat pump having a single-speed compressor
that was tested with a fixed-speed indoor blower installed, a constant-air-volume-rate indoor
a. Evaluate the seasonal energy efficiency ratio, expressed in units of Btu/watt-hour, using:
where,
𝑄𝑄̇𝑐𝑐 (82)
𝐸𝐸𝐸𝐸𝐸𝐸𝐵𝐵 = 𝐸𝐸̇𝑐𝑐 (82)
= the energy efficiency ratio determined from the B Test described in
PLF(0.5) = 1 − 0.5 · CDc, the part-load performance factor evaluated at a cooling load
b. Refer to section 3.3 regarding the definition and calculation of Q̇c(82) and Ėc(82).
594
4.1.2 SEER calculations for an air conditioner or heat pump having a single-speed compressor
4.1.2.1 Units covered by section 3.2.2.1 where indoor blower capacity modulation correlates
with the outdoor dry bulb temperature. The manufacturer must provide information on how the
indoor air volume rate or the indoor blower speed varies over the outdoor temperature range of
67 °F to 102 °F. Calculate SEER using Equation 4.1-1. Evaluate the quantity qc(Tj)/N in
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗 ) 𝑛𝑛
Equation 4.1.2-1 = 𝑋𝑋�𝑇𝑇𝑗𝑗 � ∗ 𝑄𝑄̇𝑐𝑐 �𝑇𝑇𝑗𝑗 � ∗ 𝑁𝑁𝑗𝑗
𝑁𝑁
where,
Q̇c(Tj) = the space cooling capacity of the test unit when operating at outdoor
nj/N = fractional bin hours for the cooling season; the ratio of the number of hours during
the cooling season when the outdoor temperature fell within the range represented by bin
a. For the space cooling season, assign nj/N as specified in Table 18. Use Equation 4.1-2 to
595
where,
the space cooling capacity of the test unit at outdoor temperature Tj if operated at the Cooling
the space cooling capacity of the test unit at outdoor temperature Tj if operated at the Cooling
b. For units where indoor blower speed is the primary control variable, FPck=1 denotes the fan
speed used during the required A1 and B1 Tests (see section 3.2.2.1), FPck=2 denotes the fan
speed used during the required A2 and B2 Tests, and FPc(Tj) denotes the fan speed used by
the unit when the outdoor temperature equals Tj. For units where indoor air volume rate is the
primary control variable, the three FPc's are similarly defined only now being expressed in
terms of air volume rates rather than fan speeds. Refer to sections 3.2.2.1, 3.1.4 to 3.1.4.2,
and 3.3 regarding the definitions and calculations of Q̇ck=1(82), Q̇ck=1(95),Q̇c k=2(82), and
Q̇ck=2(95).
where,
596
Ėc(Tj) = the electrical power consumption of the test unit when operating at outdoor
temperature Tj, W.
c. The quantities X(Tj) and nj /N are the same quantities as used in Equation 4.1.2-1.
where,
the electrical power consumption of the test unit at outdoor temperature Tj if operated at
the electrical power consumption of the test unit at outdoor temperature Tj if operated at
e. The parameters FPck=1, and FPck=2, and FPc(Tj) are the same quantities that are used when
evaluating Equation 4.1.2-2. Refer to sections 3.2.2.1, 3.1.4 to 3.1.4.2, and 3.3 regarding the
4.1.2.2 Units covered by section 3.2.2.2 where indoor blower capacity modulation is used to
adjust the sensible to total cooling capacity ratio. Calculate SEER as specified in section 4.1.1.
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4.1.3 SEER calculations for an air conditioner or heat pump having a two-capacity compressor.
Calculate SEER using Equation 4.1-1. Evaluate the space cooling capacity, Q̇ck=1 (Tj), and
electrical power consumption, Ėck=1 (Tj), of the test unit when operating at low compressor
where Q̇ck=1 (82) and Ėck=1 (82) are determined from the B1 Test, Q̇ck=1 (67) and Ėck=1 (67) are
determined from the F1Test, and all four quantities are calculated as specified in section 3.3.
Evaluate the space cooling capacity, Q̇ck=2 (Tj), and electrical power consumption, Ėck=2 (Tj), of
the test unit when operating at high compressor capacity and outdoor temperature Tj using,
where Q̇ck=2(95) and Ėck=2(95) are determined from the A2 Test, Q̇ck=2(82), and Ėck=2(82), are
determined from the B2Test, and all are calculated as specified in section 3.3.
The calculation of Equation 4.1-1 quantities qc(Tj)/N and ec(Tj)/N differs depending on
whether the test unit would operate at low capacity (section 4.1.3.1), cycle between low and
high capacity (section 4.1.3.2), or operate at high capacity (sections 4.1.3.3 and 4.1.3.4) in
responding to the building load. For units that lock out low capacity operation at higher
598
outdoor temperatures, the manufacturer must supply information regarding this temperature
so that the appropriate equations are used. Use Equation 4.1-2 to calculate the building load,
4.1.3.1 Steady-state space cooling capacity at low compressor capacity is greater than or equal to
𝑞𝑞𝑐𝑐 (𝑇𝑇𝑗𝑗 ) 𝑛𝑛𝑗𝑗 𝑒𝑒𝑐𝑐 �𝑇𝑇𝑗𝑗 � 𝑋𝑋 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �∗𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � 𝑛𝑛𝑗𝑗
= 𝑋𝑋 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗ 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗ = ∗
𝑁𝑁 𝑁𝑁 𝑁𝑁 𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 𝑁𝑁
where,
Xk=1(Tj) = BL(Tj)/Q̇ck=1(Tj), the cooling mode low capacity load factor for temperature
bin j, dimensionless.
nj/N, the fractional bin hours for the cooling season; the ratio of the number of hours
during the cooling season when the outdoor temperature fell within the range represented
by bin temperature Tj to the total number of hours in the cooling season, dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use
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4 80-84 82 0.161
5 85-89 87 0.104
6 90-94 92 0.052
7 95-99 97 0.018
8 100-104 102 0.004
4.1.3.2 Unit alternates between high (k=2) and low (k=1) compressor capacity to satisfy the
where,
bin j, dimensionless.
Xk=2(Tj) = 1 − Xk=1(Tj), the cooling mode, high capacity load factor for temperature bin j,
dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations
4.1.3-1 and 4.1.3-2, respectively, to evaluate Q̇ck=1(Tj) and Ėck=1(Tj). Use Equations 4.1.3-3
600
4.1.3.3 Unit only operates at high (k=2) compressor capacity at temperature Tj and its capacity is
greater than the building cooling load, BL(Tj) <Q̇ck=2(Tj). This section applies to units that lock
where,
Xk=2(Tj) = BL(Tj)/Q̇ck=2(Tj), the cooling mode high capacity load factor for temperature
bin j, dimensionless.
𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 = 1 − 𝐶𝐶𝐷𝐷𝑐𝑐 (𝑘𝑘 = 2) ∗ �1 − 𝑋𝑋 𝑘𝑘=2 �𝑇𝑇𝑗𝑗 ��, the part load factor, dimensionless.
𝑛𝑛
Obtain the fraction bin hours for the cooling season, 𝑁𝑁𝑗𝑗, from Table 18. Use Equations 4.1.3-3 and
4.1.3.4 Unit must operate continuously at high (k=2) compressor capacity at temperature Tj,
BL(Tj) ≥Q̇ck=2(Tj).
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations 4.1.3-
4.1.4 SEER calculations for an air conditioner or heat pump having a variable-speed compressor.
Calculate SEER using Equation 4.1-1. Evaluate the space cooling capacity, Q̇ck=1(Tj), and
electrical power consumption, Ėck=1(Tj), of the test unit when operating at minimum compressor
601
𝑄𝑄 ̇ 𝑘𝑘=1 (82)−𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (67)
Equation 4.1.4-1 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (67) + 𝑐𝑐 ∗ (𝑇𝑇𝑗𝑗 − 67)
82−67
𝐸𝐸 ̇ 𝑘𝑘=1
(82)−𝐸𝐸𝑐𝑐 (67) ̇ 𝑘𝑘=1
Equation 4.1.4-2 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (67) + 𝑐𝑐 ∗ (𝑇𝑇𝑗𝑗 − 67)
82−67
where Q̇c (82) and Ėc (82) are determined from the B1 Test, Q̇ck=1(67) and Ėck=1(67)
k=1 k=1
are determined from the F1 Test, and all four quantities are calculated as specified in section 3.3.
Evaluate the space cooling capacity, Q̇ck=2(Tj), and electrical power consumption, Ėck=2(Tj), of
the test unit when operating at maximum compressor speed and outdoor temperature Tj. Use
Equations 4.1.3-3 and 4.1.3-4, respectively, where Q̇ck=2(95) and Ėck=2(95) are determined from
the A2 Test, Q̇ck=2(82) and Ėck=2(82) are determined from the B2 Test, and all four quantities are
calculated as specified in section 3.3. Calculate the space cooling capacity, Q̇ck=v(Tj), and
electrical power consumption, Ėck=v(Tj), of the test unit when operating at outdoor temperature
Tj and the intermediate compressor speed used during the section 3.2.4 (and Table 7) EV Test
using,
4.1.4.1 Steady-state space cooling capacity when operating at minimum compressor speed is
greater than or equal to the building cooling load at temperature Tj, Q̇ck=1(Tj) ≥BL(Tj).
where,
Xk=1(Tj) = BL(Tj) / Q̇ck=1(Tj), the cooling mode minimum speed load factor for
602
PLFj = 1 − CDc · [1 − Xk=1(Tj)], the part load factor, dimensionless.
nj/N, the fractional bin hours for the cooling season; the ratio of the number of hours
during the cooling season when the outdoor temperature fell within the range represented
by bin temperature Tj to the total number of hours in the cooling season, dimensionless.
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. Use Equations 4.1.3-
4.1.4.2 Unit operates at an intermediate compressor speed (k=i) in order to match the building
where,
Q̇ck=i(Tj) = BL(Tj), the space cooling capacity delivered by the unit in matching the
building load at temperature Tj, Btu/h. The matching occurs with the unit operating at
compressor speed k = i.
𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
𝐸𝐸̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = the electrical power input required by the test unit when
𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
EERk=i(Tj) = the steady-state energy efficiency ratio of the test unit when operating at a
603
Obtain the fractional bin hours for the cooling season, nj/N, from Table 18. For each
temperature bin where the unit operates at an intermediate compressor speed, determine the
EERk=i(Tj) = A + B · Tj + C · Tj2.
For each unit, determine the coefficients A, B, and C by conducting the following
calculations once:
𝑇𝑇 2 −𝑇𝑇 2 𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 (𝑇𝑇1 )−𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=2 (𝑇𝑇2 )−𝐷𝐷∗[𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 (𝑇𝑇1 )−𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=𝑣𝑣 (𝑇𝑇𝑣𝑣 )]
𝐷𝐷 = 𝑇𝑇22 −𝑇𝑇12 𝐵𝐵 = 𝑇𝑇1 −𝑇𝑇2 −𝐷𝐷∗(𝑇𝑇1 −𝑇𝑇𝑣𝑣 )
𝑣𝑣 1
where,
T1 = the outdoor temperature at which the unit, when operating at minimum compressor
speed, provides a space cooling capacity that is equal to the building load (Q̇ck=l (Tl) =
BL(T1)), °F. Determine T1 by equating Equations 4.1.3-1 and 4.1-2 and solving for
outdoor temperature.
Tv = the outdoor temperature at which the unit, when operating at the intermediate
compressor speed used during the section 3.2.4 EV Test, provides a space cooling
capacity that is equal to the building load (Q̇ck=v (Tv) = BL(Tv)), °F. Determine Tv by
equating Equations 4.1.4-1 and 4.1-2 and solving for outdoor temperature.
T2 = the outdoor temperature at which the unit, when operating at maximum compressor
speed, provides a space cooling capacity that is equal to the building load (Q̇ck=2 (T2) =
BL(T2)), °F. Determine T2 by equating Equations 4.1.3-3 and 4.1-2 and solving for
outdoor temperature.
604
𝑄𝑄̇𝑐𝑐𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �[𝐸𝐸𝐸𝐸𝐸𝐸. 4.1.4 − 1, 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑇𝑇1 𝑓𝑓𝑓𝑓𝑓𝑓 𝑇𝑇𝑗𝑗 ]
𝐸𝐸𝐸𝐸𝐸𝐸 𝑘𝑘=1 (𝑇𝑇1 ) = 𝑘𝑘=1 , 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ per 𝑊𝑊
𝐸𝐸̇𝑐𝑐 �𝑇𝑇𝑗𝑗 �[𝐸𝐸𝐸𝐸𝐸𝐸. 4.1.4 − 2, 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑇𝑇1 𝑓𝑓𝑓𝑓𝑓𝑓 𝑇𝑇𝑗𝑗 ]
4.1.4.3 Unit must operate continuously at maximum (k=2) compressor speed at temperature Tj,
as specified in section 4.1.3.4 with the understanding that Q̇ck=2(Tj) and Ėck=2(Tj) correspond to
maximum compressor speed operation and are derived from the results of the tests specified in
section 3.2.4.
4.1.5 SEER calculations for an air conditioner or heat pump having a single indoor unit with
multiple blowers. Calculate SEER using Eq. 4.1– 1, where qc(Tj)/N and ec(Tj)/N are evaluated as
4.1.5.1 For multiple blower systems that are connected to a lone, single-speed outdoor unit. a.
Calculate the space cooling capacity, 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), and electrical power consumption, 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), of
the test unit when operating at the cooling minimum air volume rate and outdoor temperature Tj
using the equations given in section 4.1.2.1. Calculate the space cooling capacity, 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), and
electrical power consumption, 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), of the test unit when operating at the cooling full-load
605
air volume rate and outdoor temperature Tj using the equations given in section 4.1.2.1. In
evaluating the section 4.1.2.1 equations, determine the quantities 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (82) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (82) from
the B1 Test, 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (95) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (95) from the Al Test, 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (82) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (82) from the B2
Test, and 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (95) and 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (95) from the A2 Test. Evaluate all eight quantities as specified in
section 3.3. Refer to section 3.2.2.1 and Table 5 for additional information on the four referenced
laboratory tests. b. Determine the cooling mode cyclic degradation coefficient, CDc, as per
sections 3.2.2.1 and 3.5 to 3.5.3. Assign this same value to CDc(K=2). c. Except for using the
above values of 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), 𝐸𝐸̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ), 𝐸𝐸̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ), CDc, and CDc (K=2), calculate the
quantities qc(Tj)/N and ec(Tj)/N as specified in section 4.1.3.1 for cases where 𝑄𝑄̇𝑐𝑐𝑘𝑘=1 (𝑇𝑇𝑗𝑗 ) ≥
BL(Tj). For all other outdoor bin temperatures, Tj, calculate qc(Tj)/N and ec(Tj)/N as specified in
section 4.1.3.3 if 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ) > BL (Tj) or as specified in section 4.1.3.4 if 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (𝑇𝑇𝑗𝑗 ) ≤ BL(Tj).
4.1.5.2 For multiple blower systems that are connected to either a lone outdoor unit having a
two-capacity compressor or to two separate but identical model single-speed outdoor units.
CFR 429.70(e), HSPF must be calculated as follows: Six generalized climatic regions are
depicted in Figure 1 and otherwise defined in Table 19. For each of these regions and for each
applicable standardized design heating requirement, evaluate the heating seasonal performance
factor using,
606
𝑛𝑛𝑗𝑗
∑𝐽𝐽𝑗𝑗 𝑛𝑛𝑗𝑗 ∗𝐵𝐵𝐵𝐵(𝑇𝑇𝑗𝑗 ) ∑𝐽𝐽𝑗𝑗� ∗𝐵𝐵𝐵𝐵(𝑇𝑇𝑗𝑗 )�
𝑁𝑁
Equation 4.2-1 𝐻𝐻𝐻𝐻𝐻𝐻𝐻𝐻 = ∗ 𝐹𝐹𝑑𝑑𝑑𝑑𝑑𝑑 = ∗ 𝐹𝐹𝑑𝑑𝑑𝑑𝑑𝑑
∑𝐽𝐽𝑗𝑗 𝑒𝑒ℎ (𝑇𝑇𝑗𝑗 )+∑𝐽𝐽𝑗𝑗 𝑅𝑅𝑅𝑅(𝑇𝑇𝑗𝑗 ) 𝐽𝐽𝑒𝑒ℎ (𝑇𝑇𝑗𝑗 )
∑𝑗𝑗 𝐽𝐽𝑅𝑅𝑅𝑅(𝑇𝑇𝑗𝑗)
+∑𝑗𝑗
𝑁𝑁 𝑁𝑁
where,
eh(Tj) / N, the ratio of the electrical energy consumed by the heat pump during periods of
the space heating season when the outdoor temperature fell within the range represented
by bin temperature Tj to the total number of hours in the heating season (N), W. For heat
pumps having a heat comfort controller, this ratio may also include electrical energy used
RH(Tj) / N, the ratio of the electrical energy used for resistive space heating during
periods when the outdoor temperature fell within the range represented by bin
temperature Tj to the total number of hours in the heating season (N), W. Except as noted
in section 4.2.5, resistive space heating is modeled as being used to meet that portion of
the building load that the heat pump does not meet because of insufficient capacity or
because the heat pump automatically turns off at the lowest outdoor temperatures. For
heat pumps having a heat comfort controller, all or part of the electrical energy used by
resistive heaters at a particular bin temperature may be reflected in eh(Tj) / N (see 4.2.5).
Tj, the outdoor bin temperature, °F. Outdoor temperatures are “binned” such that
calculations are only performed based one temperature within the bin. Bins of 5 °F are
used.
nj / N, the fractional bin hours for the heating season; the ratio of the number of hours
during the heating season when the outdoor temperature fell within the range represented
by bin temperature Tj to the total number of hours in the heating season, dimensionless.
607
j, the bin number, dimensionless.
J, for each generalized climatic region, the total number of temperature bins,
dimensionless. Referring to Table 19, J is the highest bin number (j) having a nonzero
entry for the fractional bin hours for the generalized climatic region of interest.
Tj; the heating season building load also depends on the generalized climatic region's
608
13 2 0 0 .001 .006 .029 0
14 −3 0 0 0 .002 .018 0
15 −8 0 0 0 .001 .010 0
16 −13 0 0 0 0 .005 0
17 −18 0 0 0 0 .002 0
18 −23 0 0 0 0 .001 0
�𝑇𝑇𝑧𝑧𝑧𝑧 −𝑇𝑇𝑗𝑗 �
Equation 4.2-2 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 � = ∗ 𝐷𝐷𝐷𝐷𝐷𝐷
𝑇𝑇𝑧𝑧𝑧𝑧 −𝑇𝑇𝑂𝑂𝑂𝑂
where,
TOD, the outdoor design temperature, °F. An outdoor design temperature is specified for
DHR, the design heating requirement (see section 1.2, Definitions), Btu/h.
Calculate the design heating requirements for each generalized climatic region as follows:
𝑇𝑇𝑧𝑧𝑧𝑧 − 𝑇𝑇𝑂𝑂𝑂𝑂
𝐷𝐷𝐷𝐷𝐷𝐷 = 𝑄𝑄̇𝑐𝑐𝑘𝑘=2 (95) ∗ 𝐶𝐶 ∗
𝑇𝑇𝑧𝑧𝑧𝑧 − 5
where,
C = 1.3, a multiplier to provide the appropriate slope for the heating load line,
dimensionless.
609
Tzl, the zero load temperature, °F
Q̇ck=2(95), the space cooling capacity of the unit as determined from the A or A2 Test,
𝑇𝑇𝑧𝑧𝑧𝑧 − 𝑇𝑇𝑂𝑂𝑂𝑂
𝐷𝐷𝐷𝐷𝐷𝐷 = 𝑄𝑄̇ℎ𝑘𝑘 (47) ∗ 𝐶𝐶 ∗
𝑇𝑇𝑧𝑧𝑧𝑧 − 5
where,
C = 1.3, a multiplier to provide the appropriate slope for the heating load line,
dimensionless.
1. For a single-speed heating only heat pump tested as per section 3.6.1, Q̇hk(47) =
2. For a variable-speed heating only heat pump, a section 3.6.2 single-speed heating only
heat pump, or a two-capacity heating only heat pump, Q̇nk(47) = Q̇nk=2(47), the space
For all heat pumps, HSPF accounts for the heating delivered and the energy consumed by
auxiliary resistive elements when operating below the balance point. This condition occurs when
the building load exceeds the space heating capacity of the heat pump condenser. For HSPF
calculations for all heat pumps, see either section 4.2.1, 4.2.2, 4.2.3, or 4.2.4, whichever applies.
610
For heat pumps with heat comfort controllers (see section 1.2, Definitions), HSPF also
accounts for resistive heating contributed when operating above the heat-pump-plus-comfort-
controller balance point as a result of maintaining a minimum supply temperature. For heat
pumps having a heat comfort controller, see section 4.2.5 for the additional steps required for
4.2.1 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor
that was tested with a fixed-speed indoor blower installed, a constant-air-volume-rate indoor
where,
whichever is less; the heating mode load factor for temperature bin j, dimensionless.
Q̇h(Tj), the space heating capacity of the heat pump when operating at outdoor
Ėh(Tj), the electrical power consumption of the heat pump when operating at outdoor
temperature Tj, W.
611
PLFj = 1 − ĊDh · [1 −X(Tj)], the part load factor, dimensionless.
Use Equation 4.2-2 to determine BL(Tj). Obtain fractional bin hours for the heating season, nj/N,
𝑄𝑄̇ℎ �𝑇𝑇 �
𝑗𝑗
⎧ 0, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 <1 ⎫
3.413∗𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 �
⎪ ⎪
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 �
Equation 4.2.1-3 𝛿𝛿�𝑇𝑇𝑗𝑗 � = 1⁄2 , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 < 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑑𝑑 3.413∗𝐸𝐸̇ �𝑇𝑇 � ≥ 1
⎨ ℎ 𝑗𝑗 ⎬
⎪ ̇ �𝑇𝑇
𝑄𝑄ℎ 𝑗𝑗 � ⎪
1, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 > 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎩ 3.413∗𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � ⎭
where,
Toff, the outdoor temperature when the compressor is automatically shut off, °F. (If no
Ton, the outdoor temperature when the compressor is automatically turned back on, if
Equation 4.2.1-4
Equation 4.2.1-5
612
[𝐸𝐸̇ℎ (47)−𝐸𝐸̇ℎ (17)]∗(𝑇𝑇𝑗𝑗 −17)
𝐸𝐸̇ℎ (17) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � = � 47−17
[𝐸𝐸̇ℎ (35)−𝐸𝐸̇ℎ (17)]∗(𝑇𝑇𝑗𝑗 −17)
𝐸𝐸̇ℎ (17) + , 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
35−17
where,
Q̇h(47) and Ėh(47) are determined from the H1 Test and calculated as specified in section
3.7
Q̇h(35) and Ėh(35) are determined from the H2 Test and calculated as specified in section
3.9.1
Q̇h(17) and Ėh(17) are determined from the H3 Test and calculated as specified in section
3.10.
4.2.2 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor
information about how the indoor air volume rate or the indoor blower speed varies over the
in Equation 4.2-1 as specified in section 4.2.1 with the exception of replacing references to the
H1C Test and section 3.6.1 with the H1C1 Test and section 3.6.2. In addition, evaluate the space
heating capacity and electrical power consumption of the heat pump Q̇h(Tj) and Ėh(Tj) using
613
where the space heating capacity and electrical power consumption at both low capacity
(k=1) and high capacity (k=2) at outdoor temperature Tj are determined using
Equation 4.2.2-3
Equation 4.2.2-4
̇ 𝑘𝑘 ̇ 𝑘𝑘
⎧𝐸𝐸̇ 𝑘𝑘 (17) + �𝐸𝐸ℎ (47) − 𝐸𝐸ℎ (17)� ∗ (𝑇𝑇𝑗𝑗 − 17) , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≥ 45 ℉ 𝑜𝑜𝑜𝑜 𝑇𝑇𝑗𝑗 ≤ 17 ℉
⎪ ℎ 47 − 17
̇ 𝑘𝑘
𝐸𝐸ℎ �𝑇𝑇𝑗𝑗 � =
⎨ �𝐸𝐸ℎ𝑘𝑘̇ (35) − 𝐸𝐸̇ℎ𝑘𝑘 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
⎪ 𝐸𝐸̇ℎ (17) +
𝑘𝑘
, 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 < 45 ℉
⎩ 35 − 17
For units where indoor blower speed is the primary control variable, FPhk=1 denotes the fan
speed used during the required H11 and H31 Tests (see Table 11), FPhk=2 denotes the fan
speed used during the required H12, H22, and H32 Tests, and FPh(Tj) denotes the fan speed
used by the unit when the outdoor temperature equals Tj. For units where indoor air volume
rate is the primary control variable, the three FPh's are similarly defined only now being
expressed in terms of air volume rates rather than fan speeds. Determine Q̇hk=1(47) and
Ėhk=1(47) from the H11 Test, and Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all
four quantities as specified in section 3.7. Determine Q̇hk=1(35) and Ėhk=1(35) as specified in
section 3.6.2; determine Q̇hk=2(35) and Ėhk=2(35) and from the H22 Test and the calculation
specified in section 3.9. Determine Q̇hk=1(17) and Ėhk=1(17 from the H31 Test, and Q̇hk=2(17)
and Ėhk=2(17) from the H32 Test. Calculate all four quantities as specified in section 3.10.
614
4.2.3 Additional steps for calculating the HSPF of a heat pump having a two-capacity
compressor. The calculation of the Equation 4.2-1 quantities differ depending upon whether the
heat pump would operate at low capacity (section 4.2.3.1), cycle between low and high capacity
(Section 4.2.3.2), or operate at high capacity (sections 4.2.3.3 and 4.2.3.4) in responding to the
building load. For heat pumps that lock out low capacity operation at low outdoor temperatures,
the manufacturer must supply information regarding the cutoff temperature(s) so that the
a. Evaluate the space heating capacity and electrical power consumption of the heat pump
b. Evaluate the space heating capacity and electrical power consumption (Q̇hk=2(Tj) and
Ėhk=2 (Tj)) of the heat pump when operating at high compressor capacity and outdoor
temperature Tj by solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. Determine
Q̇hk=1(62) and Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test, and
Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all six quantities as specified in section
615
3.7. Determine Q̇hk=2(35) and Ėhk=2(35) from the H22 Test and, if required as described in
section 3.6.3, determine Q̇hk=1(35) and Ėhk=1(35) from the H21 Test. Calculate the required 35
°F quantities as specified in section 3.9. Determine Q̇hk=2(17) and Ėhk=2(17) from the H32 Test
and, if required as described in section 3.6.3, determine Q̇hk=1(17) and Ėhk=1(17) from the
4.2.3.1 Steady-state space heating capacity when operating at low compressor capacity is
greater than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj) ≥BL(Tj).
where,
Xk=1(Tj) = BL(Tj) / Q̇hk=1(Tj), the heating mode low capacity load factor for temperature
bin j, dimensionless.
where,
616
Toff and Ton are defined in section 4.2.1. Use the calculations given in section 4.2.3.3, and
(a) The heat pump locks out low capacity operation at low outdoor temperatures and
4.2.3.2 Heat pump alternates between high (k=2) and low (k=1) compressor capacity to satisfy
𝑒𝑒ℎ (𝑇𝑇𝑗𝑗 ) 𝑛𝑛
=[𝑋𝑋 𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � ∗ 𝐸𝐸̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � + 𝑋𝑋 𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �] ∗ 𝛿𝛿�𝑇𝑇𝑗𝑗 � ∗ 𝑁𝑁𝑗𝑗
𝑁𝑁
where,
𝑘𝑘=1
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � − 𝐵𝐵𝐵𝐵(𝑇𝑇𝑗𝑗 )
𝑋𝑋 �𝑇𝑇𝑗𝑗 � = 𝑘𝑘=2
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � − 𝑄𝑄̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
Xk=2(Tj) = 1 − Xk=1(Tj) the heating mode, high capacity load factor for temperature bin j,
dimensionless.
Determine the low temperature cut-out factor, δ′(Tj), using Equation 4.2.3-3.
4.2.3.3 Heat pump only operates at high (k=2) compressor capacity at temperature Tj and its
capacity is greater than the building heating load, BL(Tj) <Q̇hk=2(Tj). This section applies to units
that lock out low compressor capacity operation at low outdoor temperatures.
617
𝑒𝑒ℎ �𝑇𝑇𝑗𝑗 � 𝑋𝑋 𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � ∗ 𝛿𝛿�𝑇𝑇𝑗𝑗 � 𝑛𝑛𝑗𝑗
= ∗
𝑁𝑁 𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 𝑁𝑁
where,
Determine the low temperature cut-out factor, δ(Tj), using Equation 4.2.3-3.
4.2.3.4 Heat pump must operate continuously at high (k=2) compressor capacity at temperature
Where
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎧ 0, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 𝑜𝑜𝑜𝑜 <1
⎪ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
𝛿𝛿′�𝑇𝑇𝑗𝑗 � = 1⁄2 , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 < 𝑇𝑇𝑗𝑗 ≤ 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎨ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪ 𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
⎪ 1, 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 > 𝑇𝑇𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎 ≥1
⎩ 3.413 ∗ 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �
4.2.4 Additional steps for calculating the HSPF of a heat pump having a variable-speed
compressor. Calculate HSPF using Equation 4.2-1. Evaluate the space heating capacity,
Q̇hk=1(Tj), and electrical power consumption, Ėhk=1(Tj), of the heat pump when operating at
618
where,
Evaluate the space heating capacity, Q̇hk=2(Tj), and electrical power consumption, Ėhk=2(Tj),
of the heat pump when operating at maximum compressor speed and outdoor temperature Tj by
solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. Determine the Equation 4.2.2-3 and
4.2.2-4 quantities Q̇hk=2(47) and Ėhk=2(47) from the H12 Test and the calculations specified in
section 3.7. Determine Q̇hk=2(35) and Ėhk=2(35) from the H22 Test and the calculations specified
in section 3.9 or, if the H22 Test is not conducted, by conducting the calculations specified in
section 3.6.4. Determine Q̇hk=2(17) and Ėhk=2(17) from the H32 Test and the calculations specified
in section 3.10. Calculate the space heating capacity, Q̇hk=v(Tj), and electrical power
consumption, Ėhk=v(Tj), of the heat pump when operating at outdoor temperature Tj and the
intermediate compressor speed used during the section 3.6.4 H2V Test using
where,
Q̇hk=v(35) and Ėhk=v(35) are determined from the H2V Test and calculated as specified in
section 3.9. Approximate the slopes of the k=v intermediate speed heating capacity and
619
𝑄𝑄̇ℎ𝑘𝑘=1 (62) − 𝑄𝑄̇ℎ𝑘𝑘=1 (47) 𝑄𝑄̇ℎ𝑘𝑘=2 (35) − 𝑄𝑄̇ℎ𝑘𝑘=2 (17)
𝑀𝑀𝑄𝑄 = � ∗ �1 − 𝑁𝑁𝑄𝑄 �� + �𝑁𝑁𝑄𝑄 ∗ �
62 − 47 35 − 17
where,
Use Equations 4.2.4-1 and 4.2.4-2, respectively, to calculate Q̇hk=1(35) and Ėhk=1(35). The
calculation of Equation 4.2-1 quantities eh(Tj)/N and RH(Tj)/N differs depending upon
whether the heat pump would operate at minimum speed (section 4.2.4.1), operate at an
4.2.4.1 Steady-state space heating capacity when operating at minimum compressor speed is
greater than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj ≥BL(Tj). Evaluate
Equations 4.2.4-1 and 4.2.4-2 to evaluate Q̇hk=1(Tj) and Ėhk=1(Tj), respectively, and replace
section 4.2.3.1 references to “low capacity” and section 3.6.3 with “minimum speed” and section
3.6.4. Also, the last sentence of section 4.2.3.1 does not apply.
620
4.2.4.2 Heat pump operates at an intermediate compressor speed (k=i) in order to match the
𝑅𝑅𝑅𝑅�𝑇𝑇𝑗𝑗 �
building heating load at a temperature Tj, Q̇hk=1(Tj) <BL(Tj) <Q̇hk=2(Tj). Calculate using
𝑁𝑁
𝑒𝑒ℎ �𝑇𝑇𝑗𝑗 �
Equation 4.2.3-2 while evaluating using:
𝑁𝑁
where,
𝑄𝑄̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
𝐸𝐸̇ℎ𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �
Q̇hk=i(Tj) = BL(Tj), the space heating capacity delivered by the unit in matching the
building load at temperature (Tj), Btu/h. The matching occurs with the heat pump
COPk=i(Tj), the steady-state coefficient of performance of the heat pump when operating
For each temperature bin where the heat pump operates at an intermediate compressor speed,
COPk=i(Tj) = A + B . Tj + C . Tj2.
621
For each heat pump, determine the coefficients A, B, and C by conducting the following
calculations once:
𝑇𝑇 2 −𝑇𝑇 2 𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=2 (𝑇𝑇4 )−𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=1 (𝑇𝑇3 )−𝐷𝐷∗�𝐶𝐶𝐶𝐶𝐶𝐶 𝑘𝑘=2 (𝑇𝑇4 )−𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=𝑣𝑣 (𝑇𝑇𝑣𝑣ℎ )�
𝐷𝐷 = 𝑇𝑇 23 −𝑇𝑇42 𝐵𝐵 = 𝑇𝑇4 −𝑇𝑇3 −𝐷𝐷∗(𝑇𝑇4 −𝑇𝑇𝑣𝑣ℎ )
𝑣𝑣ℎ 4
where,
T3, the outdoor temperature at which the heat pump, when operating at minimum
compressor speed, provides a space heating capacity that is equal to the building load
(Q̇hk=1(T3) = BL(T3)), °F. Determine T3 by equating Equations 4.2.4-1 and 4.2-2 and
Tvh, the outdoor temperature at which the heat pump, when operating at the intermediate
compressor speed used during the section 3.6.4 H2V Test, provides a space heating
capacity that is equal to the building load (Q̇hk=v(Tvh) = BL(Tvh)), °F. Determine Tvh by
equating Equations 4.2.4-3 and 4.2-2 and solving for outdoor temperature.
T4, the outdoor temperature at which the heat pump, when operating at maximum
compressor speed, provides a space heating capacity that is equal to the building load
(Q̇hk=2(T4) = BL(T4)), °F. Determine T4 by equating Equations 4.2.2-3 (k=2) and 4.2-2
622
𝑄𝑄̇ℎ𝑘𝑘=2 (𝑇𝑇4 )�𝐸𝐸𝐸𝐸𝐸𝐸. 4.2.2 − 3, 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑇𝑇4 𝑓𝑓𝑓𝑓𝑓𝑓 𝑇𝑇𝑗𝑗 �
𝐶𝐶𝐶𝐶𝐶𝐶𝑘𝑘=2 (𝑇𝑇4 ) = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413 𝑊𝑊
∗ 𝐸𝐸̇ℎ𝑘𝑘=2 (𝑇𝑇4 )�𝐸𝐸𝐸𝐸𝐸𝐸. 4.2.2 − 4, 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑢𝑢𝑢𝑢𝑢𝑢𝑢𝑢𝑢𝑢 𝑇𝑇4 𝑓𝑓𝑓𝑓𝑓𝑓 𝑇𝑇𝑗𝑗 �
For multiple-split heat pumps (only), the following procedures supersede the above requirements
for calculating COPhk=i(Tj). For each temperature bin where T3 >Tj >Tvh,
4.2.4.3 Heat pump must operate continuously at maximum (k=2) compressor speed at
as specified in section 4.2.3.4 with the understanding that Q̇hk=2(Tj) and Ėhk=2(Tj)
correspond to maximum compressor speed operation and are derived from the results of
the specified section 3.6.4 tests. If H42 test is conducted in place of H12, evaluate
Q̇hk=2(Tj) and Ėhk=2(Tj) using the following equation instead of equations 4.2.2-3 and
4.2.2-4.
where, TL is the ambient dry bulb temperature where H42 test is conducted.
623
4.2.5 Heat pumps having a heat comfort controller. Heat pumps having heat comfort
controllers, when set to maintain a typical minimum air delivery temperature, will cause the heat
pump condenser to operate less because of a greater contribution from the resistive elements.
With a conventional heat pump, resistive heating is only initiated if the heat pump condenser
cannot meet the building load (i.e., is delayed until a second stage call from the indoor
thermostat). With a heat comfort controller, resistive heating can occur even though the heat
pump condenser has adequate capacity to meet the building load (i.e., both on during a first stage
call from the indoor thermostat). As a result, the outdoor temperature where the heat pump
compressor no longer cycles (i.e., starts to run continuously), will be lower than if the heat pump
4.2.5.1 Heat pump having a heat comfort controller: additional steps for calculating the HSPF
of a heat pump having a single-speed compressor that was tested with a fixed-speed indoor
installed. Calculate the space heating capacity and electrical power of the heat pump without the
heat comfort controller being active as specified in section 4.2.1 (Equations 4.2.1-4 and 4.2.1-5)
for each outdoor bin temperature, Tj, that is listed in Table 19. Denote these capacities and
electrical powers by using the subscript “hp” instead of “h.” Calculate the mass flow rate
(expressed in pounds-mass of dry air per hour) and the specific heat of the indoor air (expressed
624
where V̇̅s, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0 �𝑇𝑇𝑗𝑗 � = 70℉ +
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj/N), RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified in section 4.2.1. For each
bin calculation, use the space heating capacity and electrical power from Case 1 or Case
2, whichever applies.
Case 1. For outdoor bin temperatures where To(Tj) is equal to or greater than TCC (the
maximum supply temperature determined according to section 3.1.9), determine Q̇h(Tj) and
Ėh(Tj) as specified in section 4.2.1 (i.e., Q̇h(Tj) = Q̇hp(Tj) and Ėhp(Tj) = Ėhp(Tj)). Note: Even
though To(Tj) ≥Tcc, resistive heating may be required; evaluate Equation 4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) >Tcc, determine Q̇h(Tj) and Ėh(Tj) using,
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
where,
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though To(Tj) <Tcc, additional resistive heating may be required; evaluate
625
4.2.5.2 Heat pump having a heat comfort controller: additional steps for calculating the HSPF
indoor blower. Calculate the space heating capacity and electrical power of the heat pump
without the heat comfort controller being active as specified in section 4.2.2 (Equations 4.2.2-1
and 4.2.2-2) for each outdoor bin temperature, Tj, that is listed in Table 19. Denote these
capacities and electrical powers by using the subscript “hp” instead of “h.” Calculate the mass
flow rate (expressed in pounds-mass of dry air per hour) and the specific heat of the indoor air
(expressed in Btu/lbmda · °F) from the results of the H12 Test using:
where V̇̅S, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0 �𝑇𝑇𝑗𝑗 � = 70℉ +
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj)/N , RH(Tj)/N, X(Tj), PLFj, and δ(Tj) as specified in section 4.2.1 with the
exception of replacing references to the H1C Test and section 3.6.1 with the H1C1 Test
and section 3.6.2. For each bin calculation, use the space heating capacity and electrical
Case 1. For outdoor bin temperatures where To(Tj) is equal to or greater than TCC (the
maximum supply temperature determined according to section 3.1.9), determine Q̇h(Tj) and
626
Ėh(Tj) as specified in section 4.2.2 (i.e. Q̇h(Tj) = Q̇hp(Tj) and Ėh(Tj) = Ėhp(Tj)). Note: Even
though To(Tj) ≥TCC, resistive heating may be required; evaluate Equation 4.2.1-2 for all bins.
Case 2. For outdoor bin temperatures where To(Tj) <TCC, determine Q̇h(Tj) and Ėh(Tj) using,
𝑄𝑄̇ℎ �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
where,
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though To(Tj) <Tcc, additional resistive heating may be required; evaluate
4.2.5.3 Heat pumps having a heat comfort controller: additional steps for calculating the HSPF of
a heat pump having a two-capacity compressor. Calculate the space heating capacity and
electrical power of the heat pump without the heat comfort controller being active as specified in
section 4.2.3 for both high and low capacity and at each outdoor bin temperature, Tj, that is listed
in Table 19. Denote these capacities and electrical powers by using the subscript “hp” instead of
“h.” For the low capacity case, calculate the mass flow rate (expressed in pounds-mass of dry air
per hour) and the specific heat of the indoor air (expressed in Btu/lbmda · °F) from the results of
627
where V̇̅s, V̇̅mx, v′n (or vn), and Wn are defined following Equation 3-1. For each outdoor
bin temperature listed in Table 19, calculate the nominal temperature of the air leaving
the heat pump condenser coil when operating at low capacity using,
𝑄𝑄̇ℎ𝑝𝑝
𝑘𝑘=1
�𝑇𝑇𝑗𝑗 �
𝑇𝑇0𝑘𝑘=1 �𝑇𝑇𝑗𝑗 � = 70℉ + 𝑘𝑘=1 𝑘𝑘=1
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Repeat the above calculations to determine the mass flow rate (ṁdak=2) and the specific heat
of the indoor air (Cp,dak=2) when operating at high capacity by using the results of the
H12 Test. For each outdoor bin temperature listed in Table 19, calculate the nominal
temperature of the air leaving the heat pump condenser coil when operating at high capacity
using,
𝑘𝑘=2
𝑄𝑄̇ℎ𝑝𝑝 �𝑇𝑇𝑗𝑗 �
𝑇𝑇0𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 70℉ + 𝑘𝑘=2 𝑘𝑘=2
𝑚𝑚̇𝑑𝑑𝑑𝑑 ∗𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑
Evaluate eh(Tj)/N, RH(Tj)/N, Xk=1(Tj), and/or Xk=2(Tj), PLFj, and δ′(Tj) or δ″(Tj) as
specified in section 4.2.3.1. 4.2.3.2, 4.2.3.3, or 4.2.3.4, whichever applies, for each
temperature bin. To evaluate these quantities, use the low-capacity space heating capacity
and the low-capacity electrical power from Case 1 or Case 2, whichever applies; use the
high-capacity space heating capacity and the high-capacity electrical power from Case 3
Case 1. For outdoor bin temperatures where Tok=1(Tj) is equal to or greater than TCC (the
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and Ėhk=1(Tj) as specified in section 4.2.3 (i.e., Q̇hk=1(Tj) = Q̇hpk=1(Tj) and Ėhk=1(Tj) =
Ėhpk=1(Tj).
NOTE: Even though Tok=1(Tj) ≥TCC, resistive heating may be required; evaluate RH(Tj)/N for
all bins.
Case 2. For outdoor bin temperatures where Tok=1(Tj) <TCC, determine Q̇hk=1(Tj) and Ėhk=1(Tj)
using,
where,
𝑘𝑘=1
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=1 𝑘𝑘=1
�𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 𝑘𝑘=1
∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0𝑘𝑘=1 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=1
�𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though Tok=1(Tj) ≥Tcc, additional resistive heating may be required; evaluate
Case 3. For outdoor bin temperatures where Tok=2(Tj) is equal to or greater than TCC,
determine Q̇hk=2(Tj) and Ėhk=2(Tj) as specified in section 4.2.3 (i.e., Q̇hk=2(Tj) = Q̇hpk=2(Tj) and
Ėhk=2(Tj) = Ėhpk=2(Tj)).
NOTE: Even though Tok=2(Tj) <TCC, resistive heating may be required; evaluate RH(Tj)/N for
all bins.
Case 4. For outdoor bin temperatures where Tok=2(Tj) <TCC, determine Q̇hk=2(Tj) and Ėhk=2(Tj)
using,
629
𝑄𝑄̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 𝑄𝑄̇ℎ𝑝𝑝
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � + 𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � 𝐸𝐸̇ℎ𝑘𝑘=2 �𝑇𝑇𝑗𝑗 � = 𝐸𝐸̇ℎ𝑝𝑝
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � + 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 �
where,
𝑘𝑘=2
𝑄𝑄̇𝐶𝐶𝐶𝐶 �𝑇𝑇𝑗𝑗 �
𝑄𝑄̇𝐶𝐶𝐶𝐶
𝑘𝑘=2 𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � = 𝑚𝑚̇𝑑𝑑𝑑𝑑 𝑘𝑘=2
∗ 𝐶𝐶𝑝𝑝,𝑑𝑑𝑑𝑑 ∗ [𝑇𝑇𝐶𝐶𝐶𝐶 − 𝑇𝑇0𝑘𝑘=2 �𝑇𝑇𝑗𝑗 �] 𝐸𝐸̇𝐶𝐶𝐶𝐶
𝑘𝑘=2
�𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵𝐵𝐵⁄ℎ
3.413
𝑊𝑊
NOTE: Even though Tok=2(Tj) <Tcc, additional resistive heating may be required; evaluate
4.2.5.4 Heat pumps having a heat comfort controller: additional steps for calculating the HSPF of
4.2.6 Additional steps for calculating the HSPF of a heat pump having a triple-capacity
compressor. The only triple-capacity heat pumps covered are triple-capacity, northern heat
pumps.
For such heat pumps, the calculation of the Eq. 4.2–1 quantities
differ depending on whether the heat pump would cycle on and off at low capacity (section
4.2.6.1), cycle on and off at high capacity (section 4.2.6.2), cycle on and off at booster capacity
(4.2.6.3), cycle between low and high capacity (section 4.2.6.4), cycle between high and booster
capacity (section 4.2.6.5), operate continuously at low capacity (4.2.6.6), operate continuously at
high capacity (section 4.2.6.7), operate continuously at booster capacity (4.2.6.8), or heat solely
using resistive heating (also section 4.2.6.8) in responding to the building load. As applicable,
the manufacturer must supply information regarding the outdoor temperature range at which
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each stage of compressor capacity is active. As an informative example, data may be submitted
in this manner: At the low (k=1) compressor capacity, the outdoor temperature range of
operation is 40 °F ≤ T ≤ 65 °F; At the high (k=2) compressor capacity, the outdoor temperature
range of operation is 20 °F ≤ T ≤ 50 °F; At the booster (k=3) compressor capacity, the outdoor
a. Evaluate the space heating capacity and electrical power consumption of the heat pump
when operating at low compressor capacity and outdoor temperature Tj using the equations
given in section 4.2.3 for Q̇hk=1(Tj) and Ėhk=1 (Tj)) In evaluating the section 4.2.3 equations,
Determine Q̇hk=1(62) and Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test,
and Q̇hk=2(47) and Ėhk=2(47) from the H12 Test. Calculate all four quantities as specified in
section 3.7. If, in accordance with section 3.6.6, the H31 Test is conducted, calculate Q̇hk=1(17)
and Ėhk=1(17) as specified in section 3.10 and determine Q̇hk=1(35) and Ėhk=1(35) as specified in
section 3.6.6.
b. Evaluate the space heating capacity and electrical power consumption (Q̇hk=2(Tj) and
Ėhk=2 (Tj)) of the heat pump when operating at high compressor capacity and outdoor temperature
Tj by solving Equations 4.2.2-3 and 4.2.2-4, respectively, for k=2. Determine Q̇hk=1(62) and
Ėhk=1(62) from the H01 Test, Q̇hk=1(47) and Ėhk=1(47) from the H11 Test, and Q̇hk=2(47) and
Ėhk=2(47) from the H12 Test, evaluated as specified in section 3.7. Determine the equation input
for Q̇hk=2(35) and Ėhk=2(35) from the H22, evaluated as specified in section 3.9.1. Also, determine
Q̇hk=2(17) and Ėhk=2(17) from the H32 Test, evaluated as specified in section 3.10.
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c. Evaluate the space heating capacity and electrical power consumption of the heat pump
𝐸𝐸̇ℎ𝑘𝑘=3 �𝑇𝑇𝑗𝑗 �
⎧ ̇ 𝑘𝑘=3 �𝐸𝐸̇ℎ 𝑘𝑘=3
(35) − 𝐸𝐸̇ℎ𝑘𝑘=3 (17)� ∗ (𝑇𝑇𝑗𝑗 − 17)
⎪𝐸𝐸ℎ (17) + , 𝑖𝑖𝑖𝑖 17 ℉ < 𝑇𝑇𝑗𝑗 ≤ 45 ℉
= 35 − 17
⎨ �𝐸𝐸̇ℎ𝑘𝑘=3 (17) − 𝐸𝐸̇ℎ𝑘𝑘=3 (2)� ∗ (𝑇𝑇𝑗𝑗 − 2)
⎪ 𝐸𝐸̇ℎ𝑘𝑘=3 (2) + , 𝑖𝑖𝑖𝑖 𝑇𝑇𝑗𝑗 ≤ 17 ℉
⎩ 17 − 2
Determine Q̇hk=3(17) and Ėhk=3(17) from the H33 Test and determine Q̇hk=2(2) and Ėhk=3(2) from
the H43 Test. Calculate all four quantities as specified in section 3.10. Determine the equation
4.2.6.1 Steady-state space heating capacity when operating at low compressor capacity is greater
than or equal to the building heating load at temperature Tj, Q̇hk=1(Tj) ≥BL(Tj)., and the heat
using Eqs. 4.2.3-1 and 4.2.3-2, respectively. Determine the equation inputs Xk=1(Tj), PLFj, and
δ′(Tj) as specified in section 4.2.3.1. In calculating the part load factor, PLFj , use the low-
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4.2.6.2 Heat pump only operates at high (k=2) compressor capacity at temperature Tj and its
capacity is greater than or equal to the building heating load, BL(Tj) <Q̇hk=2(Tj). Evaluate the
quantities
as specified in section 4.2.3.3. Determine the equation inputs Xk=2(Tj), PLFj , and δ′(Tj) as
specified in section 4.2.3.3. In calculating the part load factor, PLFj , use the high-capacity
4.2.6.3 Heat pump only operates at high (k=3) compressor capacity at temperature Tj and its
capacity is greater than or equal to the building heating load, BL(Tj) ≤Q̇hk=3(Tj).
where
𝑋𝑋 𝑘𝑘=3 �𝑇𝑇𝑗𝑗 � = 𝐵𝐵𝐵𝐵�𝑇𝑇𝑗𝑗 ��𝑄𝑄̇ℎ𝑘𝑘=3 �𝑇𝑇𝑗𝑗 � and 𝑃𝑃𝑃𝑃𝑃𝑃𝑗𝑗 = 1 − 𝐶𝐶𝐷𝐷ℎ (𝑘𝑘 = 3) ∗ [1 − 𝑋𝑋 𝑘𝑘=3 (𝑇𝑇𝑗𝑗 )
Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3-3. Use the booster-capacity
4.2.6.4 Heat pump alternates between high (k=2) and low (k=1) compressor capacity to satisfy
the building heating load at a temperature Tj, Q̇hk=1(Tj) <BL(Tj) <Q̇hk=2(Tj). Evaluate the
quantities
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as specified in section 4.2.3.2. Determine the equation inputs Xk=1(Tj), Xk=2(Tj), and δ′(Tj) as
4.2.6.5 Heat pump alternates between high (k=2) and booster (k=3) compressor capacity to
satisfy the building heating load at a temperature Tj, Q̇hk=2(Tj) <BL(Tj) <Q̇hk=3(Tj).
where:
and Xk=3(Tj) = Xk=2(Tj) = the heating mode, booster capacity load factor for temperature bin j,
dimensionless. Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3-3.
4.2.6.6 Heat pump only operates at low (k=1) capacity at temperature Tj and its capacity is less
Determine the low temperature cut-out factor, δ′(Tj), using Eq. 4.2.3.4 if the heat pump is
operating at its booster compressor capacity. If the heat pump system converts to using only
4.2.7 Additional steps for calculating the HSPF of a heat pump having a single indoor unit with
multiple blowers. The calculation of the Eq. 4.2–1 quantities eh(Tj)/N and RH(Tj)/N are
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4.2.7.1 For multiple blower heat pumps that are connected to a singular, single-speed outdoor
unit.
a. Calculate the space heating capacity, 𝑄𝑄̇ℎ𝑘𝑘=1 (Tj), and electrical power consumption,
𝐸𝐸̇ℎ𝑘𝑘=1 (Tj), of the heat pump when operating at the heating minimum air volume rate and
outdoor temperature Tj using Eqs. 4.2.2–3 and 4.2.2–4, respectively. Use these same
equations to calculate the space heating capacity, 𝑄𝑄̇ℎ𝑘𝑘=2 (Tj) and electrical power
consumption, 𝐸𝐸̇ℎ𝑘𝑘=2 (Tj), of the test unit when operating at the heating full-load air volume
rate and outdoor temperature Tj. In evaluating Eqs. 4.2.2–3 and 4.2.2– 4, determine the
quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (47) and 𝐸𝐸̇ℎ𝑘𝑘=1 (47) from the H11 Test; determine 𝑄𝑄̇ℎ𝑘𝑘=2 (47) and 𝐸𝐸̇ℎ𝑘𝑘=2 (47)
from the H12 Test. Evaluate all four quantities according to section 3.7. Determine the
quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (35) and 𝐸𝐸̇ℎ𝑘𝑘=1 (35) as specified in section 3.6.2. Determine 𝑄𝑄̇ℎ𝑘𝑘=2 (35) and
𝐸𝐸̇ℎ𝑘𝑘=2 (35) from the H22 Frost Accumulation Test as calculated according to section 3.9.1.
Determine the quantities 𝑄𝑄̇ℎ𝑘𝑘=1 (17) and 𝐸𝐸̇ℎ𝑘𝑘=1 (17) from the H31 Test, and 𝑄𝑄̇ℎ𝑘𝑘=2(17) and
𝐸𝐸̇ℎ𝑘𝑘=2 (17) from the H32 Test. Evaluate all four quantities according to section 3.10. Refer to
section 3.6.2 and Table 11 for additional information on the referenced laboratory tests.
b. Determine the heating mode cyclic degradation coefficient, CDh, as per sections 3.6.2 and
c. Except for using the above values of 𝑄𝑄̇ℎ𝑘𝑘=1(Tj), 𝐸𝐸̇ℎ𝑘𝑘=1 (Tj), 𝑄𝑄̇ℎ𝑘𝑘=2 (Tj), 𝐸𝐸̇ℎ𝑘𝑘=2 (Tj), CDh, and
CDh(k = 2), calculate the quantities eh(Tj)/N as specified in section 4.2.3.1 for cases where
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𝑄𝑄̇ℎ𝑘𝑘=1 (Tj) ≥ BL(Tj). For all other outdoor bin temperatures, Tj, calculate eh(Tj)/N and
4.2.7.2 For multiple blower heat pumps connected to either a lone outdoor unit with a two-
capacity compressor or to two separate but identical model single-speed outdoor units. Calculate
4.3.1 For central air conditioners and heat pumps with a cooling capacity of:
less than 36,000 Btu/h, determine the off mode rating, 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 , with the following
equation:
greater than or equal to 36,000 Btu/h, calculate the capacity scaling factor according to:
𝑄𝑄̇𝐶𝐶 (95)
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 = ,
36,000
where, 𝑄𝑄̇𝐶𝐶 (95) is the total cooling capacity at the A or A2 Test condition, and determine
𝑃𝑃1
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
𝑖𝑖𝑖𝑖 𝑃𝑃2 = 0
the off mode rating, 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 , with the following equation: 𝑃𝑃𝑊𝑊,𝑂𝑂𝑂𝑂𝑂𝑂 = �(𝑃𝑃1+𝑃𝑃2)� ;
2
𝐹𝐹𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
𝑜𝑜𝑜𝑜ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒
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4.3.2 Calculate the off mode energy consumption for both central air conditioner and heat
pumps for the shoulder season, E1, using:𝐸𝐸1 = 𝑃𝑃1 · 𝑆𝑆𝑆𝑆𝑆𝑆; and the off mode energy
consumption of a CAC, only, for the heating season, E2, using: 𝐸𝐸2 = 𝑃𝑃2 · 𝐻𝐻𝐻𝐻𝐻𝐻; where P1
and P2 is determined in Section 3.13. HSH can be determined by multiplying the heating
season-hours from Table 21 with the fractional Bin-hours, from Table 19, that pertain to the
range of temperatures at which the crankcase heater operates. If the crankcase heater is
controlled to disable for the heating season, the temperature range at which the crankcase
the crankcase heater is operated during the heating season, the temperature range at which
the crankcase heater operates is defined to be from 72 °F to -23 °F, the latter of which is a
temperature that sets the range of Bin-hours to encompass all outside air temperatures in the
heating season.
SSH can be determined by multiplying the shoulder season-hours from Table 21 with the
Table 21 Representative Cooling and Heating Load Hours and the Corresponding Set of
Seasonal Hours for Each Generalized Climatic Region
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I 2400 750 6731 1826 203
𝐻𝐻𝐻𝐻𝐻𝐻∙(65−𝑇𝑇𝑂𝑂𝑂𝑂 )
HSH is evaluated as: 𝐻𝐻𝐻𝐻𝐻𝐻 = 𝑛𝑛𝑗𝑗 ,
∑𝐽𝐽𝑗𝑗=1�65−𝑇𝑇𝑗𝑗 �∙
𝑁𝑁
𝑛𝑛𝑗𝑗
where 𝑇𝑇𝑂𝑂𝑂𝑂 and are listed in Table 18 and depend on the location of interest relative to
𝑁𝑁
Figure 1. For the six generalized climatic regions, this equation simplifies to the
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Region V: 𝐻𝐻𝐻𝐻𝐻𝐻 = 2.5295𝐻𝐻𝐻𝐻𝐻𝐻;
SSH is evaluated: 𝑆𝑆𝑆𝑆𝑆𝑆 = 8760 − (𝐶𝐶𝐶𝐶𝐶𝐶 + 𝐻𝐻𝐻𝐻𝐻𝐻), where CSH = the cooling season hours
calculated using CSH = 2.8045 · CLH.
Table 22 Fractional Bin Hours for the Shoulder Season Hours for All Regions
72 0.333 0.167
67 0.667 0.333
62 0 0.333
57 0 0.167
4.3.3 If a shoulder season crankcase heater time delay and/or a heating season crankcase heater
𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,𝑖𝑖
time delay is specified by the manufacturer, multiply E1 and/or E2, by �1 − �, where
60
𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,1 is the time delay for operation during the shoulder season and 𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,2 is the time delay
for operation during the heating season, in minutes. If a time delay is not specified, 𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑,𝑖𝑖 is 15
minutes.
4.3.4 For air conditioners, the annual off mode energy consumption, ETOTAL, is:𝐸𝐸𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 =
𝐸𝐸1 + 𝐸𝐸2.
4.3.5 For heat pumps, the annual off mode energy consumption, ETOTAL, is E1.
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4.4 Calculations of the Actual and Representative Regional Annual Performance Factors for
Heat Pumps.
4.4.1 Calculation of actual regional annual performance factors (APFA) for a particular location
𝐴𝐴𝐴𝐴𝐹𝐹𝐴𝐴 =
where,
CLHA = the actual cooling hours for a particular location as determined using the map
Q̇ck(95) = the space cooling capacity of the unit as determined from the A or A2 Test,
HLHA = the actual heating hours for a particular location as determined using the map
DHR = the design heating requirement used in determining the HSPF; refer to section 4.2
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SEER = the seasonal energy efficiency ratio calculated as specified in section 4.1,
Btu/W·h.
HSPF = the heating seasonal performance factor calculated as specified in section 4.2 for
the generalized climatic region that includes the particular location of interest (see Figure
1), Btu/W·h. The HSPF should correspond to the actual design heating requirement
(DHR), if known. If it does not, it may correspond to one of the standardized design
P1 is the shoulder season per-compressor off mode power, as determined in section 3.13,
W.
P2 is the heating season per-compressor off mode power, as determined in section 3.13,
W.
4.4.2 Calculation of representative regional annual performance factors (APFR) for each
generalized climatic region and for each standardized design heating requirement.
where,
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CLHR = the representative cooling hours for each generalized climatic region, Table 23,
hr.
HLHR = the representative heating hours for each generalized climatic region, Table 23,
hr.
HSPF = the heating seasonal performance factor calculated as specified in section 4.2 for
the each generalized climatic region and for each standardized design heating requirement within
The SEER, Q̇ck(95), DHR, and C are the same quantities as defined in section 4.3.1.
Figure 1 shows the generalized climatic regions. Table 20 lists standardized design heating
requirements.
Table 23—Representative Cooling and Heating Load Hours for Each Generalized Climatic
Region
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4.5. Rounding of SEER, HSPF, and APF for reporting purposes. After calculating SEER
according to section 4.1, HSPF according to section 4.2, and APF according to section 4.3, round
the values off as specified in subpart B 430.23(m) of Title 10 of the Code of Federal Regulations.
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Figure 2—Cooling Load Hours (CLHA) for the United States
4.6 Calculations of the SHR, which should be computed for different equipment
Table 24—Applicable Test Conditions For Calculation of the Sensible Heat Ratio
Reference SHR computation
Appendix M from
blower
Requirements
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The SHR is defined and calculated as follows:
𝑄𝑄̇𝑠𝑠𝑠𝑠
𝑘𝑘
(𝑇𝑇)
= 𝑘𝑘
𝑄𝑄̇𝑐𝑐 (𝑇𝑇)
Where both the total and sensible cooling capacities are determined from the same
cooling mode test and calculated from data collected over the same 30-minute data collection
interval.
4.7 Calculations of the Energy Efficiency Ratio (EER). Calculate the energy efficiency
ratio using,
𝑄𝑄̇𝑐𝑐𝑘𝑘 (𝑇𝑇)
= 𝑘𝑘
𝐸𝐸̇𝑐𝑐 (𝑇𝑇)
where 𝑄𝑄̇𝑐𝑐𝑘𝑘 (𝑇𝑇) and 𝐸𝐸̇𝑐𝑐𝑘𝑘 (𝑇𝑇) are the space cooling capacity and electrical power consumption
determined from the 30-minute data collection interval of the same steady-state wet coil cooling
mode test and calculated as specified in section 3.3. Add the letter identification for each steady-
state test as a subscript (e.g., 𝐸𝐸𝐸𝐸𝑅𝑅𝐴𝐴2 ) to differentiate among the resulting EER values.
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7. Section 430.32 is amended by revising paragraph (c) to read as follows:
§430.32 Energy and water conservation standards and their compliance dates.
* * * * *
(c) Central air conditioners and heat pumps. The energy conservation standards defined in terms
of the heating seasonal performance factor are based on Region IV, the minimum standardized
(1) Each basic model of single-package central air conditioners and central air conditioning
heat pumps and each individual combination of split-system central air conditioners and central
air conditioning heat pumps manufactured on or after January 1, 2015, shall have a Seasonal
Energy Efficiency Ratio and Heating Seasonal Performance Factor not less than:
Heating seasonal
Seasonal energy efficiency performance
Product class ratio (SEER) factor (HSPF)
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heat pumps
(2) In addition to meeting the applicable requirements in paragraph (c)(2) of this section,
products in product class (i) of that paragraph (i.e., split-system air conditioners) that are
installed on or after January 1, 2015, and installed in the States of Alabama, Arkansas, Delaware,
Oklahoma, South Carolina, Tennessee, Texas, or Virginia, or in the District of Columbia, shall
have a Seasonal Energy Efficiency Ratio not less than 14. The least efficient combination of each
(3) In addition to meeting the applicable requirements in paragraphs (c)(2) of this section,
products in product classes (i) and (iii) of paragraph (c)(2) (i.e., split-system air conditioners and
single-package air conditioners) that are installed on or after January 1, 2015, and installed in the
States of Arizona, California, Nevada, or New Mexico shall have a Seasonal Energy Efficiency
Ratio not less than 14 and have an Energy Efficiency Ratio (at a standard rating of 95 °F dry
(i) Split-system rated cooling capacity less than 45,000 Btu/hr 12.2
The least efficient combination of each basic model must comply with this standard.
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(4) Each basic model of single-package central air conditioners and central air conditioning
heat pumps and each individual combination of split-system central air conditioners and central
air conditioning heat pumps manufactured on or after January 1, 2015, shall have an average off
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