Chris Lawrence

VP Sales & Marketing

AGENDA
So what are

Chilled Ceilings & Beams ?

Part 1 Passive Systems

Chilled Ceilings
Chilled Sails
Passive Beams

Part 2 Active systems

Active Chilled Beams

Part 3 - Reducing Energy

Space Humidity concerns

Design Considerations
Water System Design
Savings & LEED

Part 4 - Solutions

All Air Core

6 Way
LoFlo
Overall 1st Costs

So What are Chilled

Ceilings & Beams?

A sensible cooling only device that uses chilled

water above the room dew point to remove heat
from the space.
They can be independent of, or combined with, a
method of introducing conditioned outside air to
the space to meet the ASHRAE 62 ventilation
requirements

Chilled
Ceilings
Radiant & Convective sensible cooling
independent of
Primary air delivery

ASHRAE
Engineering for the World We Live In

Chilled Ceiling
Radiant Effect
CW Supply
59-62F

CW Return
62-66F

55%
Convective
45%
Radiant

76F Dry Bulb

74F radiant
temperature
(black bulb)

Chilled Ceilings
Advantages

Design Issues

Excellent thermal
comfort
Can Heat
Reduced space
requirements
Will fit into 6-8
cavity
Self regulating
Simple controls
Low noise
Low maintenance

Low cooling output

20 to 25 BTUH/FT2
100% coverage
14 to 18 BTUH/FT2
70% coverage
Driven by surface area

Very High cost

Separate air system
required
Needs many
connections

Sails
Sensible cooling independent of
Primary air delivery.

ASHRAE
Engineering for the World We Live In

Sails
Operation Principle

Sails
Operation Principle

Increased convection

Chilled Sails

Advantages

Design Issues

Good thermal
comfort
Reduced space
requirements
Freely suspended
Self regulating
Simple controls
Low noise
Low maintenance

Cooling output
40 to 50 BTUH/FT2
dependent of amount of ceiling used

Separate air system

required
High cost
Can not heat
Need good acoustic
treatment to avoid hard
spaces
Many connections
Aesthetics ?

Ceilings & Sails Summary Cooling & Heating (Ceiling only)

Very High thermal comfort especially on
ceilings
Cooling capacity up to 18 Btuh/FT2 floor
space (Ceiling - average)
Cooling capacity up to 40 Btuh/FT2 floor
space (Sail - average)
Very low ceiling cavities needed, could in
installed in a 6 space.
Self regulating
simple two position controls
Low noise
Low maintenance

ASHRAE
Engineering for the World We Live In

Passive
Beams
Buoyancy driven sensible cooling
independent of
Primary air delivery

ASHRAE
Engineering for the World We Live In

Passive Chilled Beams

Operation Principle

Soffit
Suspension
rod
Water
coil

Fabric
skirt

Perforate
d tile

Passive Chilled Beams

Airflow Pattern

Faade driven cooling

Above the ceiling recessed

Exposed

Passive beams

Advantages

Design Issues

Good thermal
comfort
Low terminal
velocities
Self regulating
Simple controls
Low noise
Low maintenance
Ideal top up to
UFAD especially at
the faade

Cooling output
40 to 50 BTUH/FT2
Separate air system
required
Need High free area
ceilings
Can not heat
Need deep ceiling cavity
and space above coil
Need separate return air
passage for remove
primary air volume

Typical Installation

ASHRAE
Engineering for the World We Live In

Passive Beams Summary Cooling only

Good thermal comfort
Cooling capacity up to 50 Btuh/FT2 floor
space
Up to 450 BTUH per LF of beam
Reduced ductwork, riser and plant sizes
Water transports most of sensible cooling
Self regulating
simple two position controls
Low noise
Low maintenance

ASHRAE
Engineering for the World We Live In

Passive beams
Perforation beware!
Perforation Free Areas
Are critical to passive beam performance !
Painted ?

Usually, perforated free areas are quoted prior to paint application !

On a recent project

The tiles were specified 28% free area 1/10 hole. These turned out
to be when painted a 1/12 hole which equated to
19% free area.
This reduced the reduced performance by a further 20%

Rule of Thumb
Minimum 1/8 hole, approx 45% free area preferred, any reduction
in hole size or free area reduces output therefore it costs you more
because you need more beams

Passive beams Return

air passage
Passive beams need a return air passage to feed the
coil, typically the same area as the coil, split 50-50
along the 2 long sides of the beam.
As important, the removal of the fresh or conditioned
air must have a
Separate return
route if the return
is via the celling
cavity/void.
Better to have a
ducted return!

AGENDA
Part 2 Active systems

Active Chilled Beams

Part 3 - Reducing Energy

Space Humidity concerns

Design Considerations
Water System Design
Savings & LEED

Part 4 - Solutions

All Air Core

6 Way
LoFlo
Overall 1st Costs

So What are Chilled

Ceilings & Beams?

A sensible cooling only device that uses chilled

water above the room dew point to remove heat
from the space.
They can be independent of, or combined with, a
method of introducing conditioned outside air to
the space to meet the ASHRAE 62 ventilation
requirements

Chris Lawrence
VP Sales & Marketing

Active
Beams
Sensible cooling combined with primary air
delivery

ASHRAE
Engineering for the World We Live In

Active Chilled Beam

Operation Principle - Horizontal coil

Primary air nozzles

Primary air plenum

Suspended ceiling

Heat exchanger

Active Chilled Beam

Operation Principle - Vertical coils

Primary
air supply

Slab

Suspended
Ceiling

Active Chilled Beam

Airflow Pattern 2-way

Active Chilled Beams

2 way

Active Chilled Beams

1 Way perimeter (Concealed)

ASHRAE
Engineering for the World We Live In

Thermal Comfort
Perimeter CFD

Good air movement

throughout the room with
3-4:1 entrainment ratios

Uniform temperatures and

no drafts by thorough mixing
of the primary and room air

Active Chilled Beams

1 Way perimeter (Concealed)

Active beams

Advantages

Design Issues

All services in celling,

integrated cooling,
ventilation and heating
Lower pressure than
traditional induction
systems
Self regulating
Simple controls
Low maintenance
Fiber tile ceilings
Lower ceiling cavity,
lower slab to slab

Cooling output
to 100 Btuh/FT2 , beam
outputs up to 1800
Btuh/LF
Can be 2 or 4 pipe
Can heat
Need more primary air
than minimal fresh are,
suggest .3 cfm/SF
Primary air controls dew
point

Rule # 1

The Design with the

fewest number of chilled
beams will be the lowest
1st cost install, therefore
performance matters.

Performance matters

Reducing
energy
ASHRAE
Engineering for the World We Live In

Heat Removal
Active Chilled Beam

concept
Airflow
requirement
reduced by
70%

70% of sensible heat

removed by chilled
beam water coil

30% of sensible heat

removed by air

Chilled Water

On a Mass Flow Rate Basis:-

1 lbs of chilled water (6t) transports 4x more

cooling energy than 1 lbs of air (20t)

As water weighs 800 times that of air

On a Volume Flow Rate Basis:-

1 FT of chilled water transports 1000 more cooling

energy than 1 FT of air (20 t)

Transportation Energy

Transportation of a ton of cooling by air requires 7 to

10 times more energy than by chilled water.

Fan Energy Use in

Buildings

Energy Consumption Characteristics of Commercial Building HVAC

Systems - publication prepared for U.S. Department of Energy

Heat Removal Ratio

Airflow
requirement
reduced by 70%

Airside
Cooling
30%
Waterside
Cooling
70%
70% of sensible heat
removed by chilled beam
water coil

Rule # 2

If your not reducing the

air volume in a space by
25%, you could be
installing a very
expensive diffuser

Rule # 3

Even if your using chilled

beams on your design,
you dont have to use
them everywhere.

Water = Efficient
Transport

10

1 Ton of Cooling
requires 550 CFM of air

or
4 GPM of water

diameter
water pipe

Water is a
better cooling
medium, than air !

Water takes less

energy to transport
than air !

Room Load is still

Room load
Chilled Ceilings & Beams do not lower the heat
load of a space, solar gain is still a gain, lights and
equipment still give off heat and so do people.

So a room
BTU/h is still a
BTU/h,
however
.

Only enough
chilled Water is
Chilled to 45F
to dehumidify the reduced
primary airflow requirement.
So less energy is used to
produce the beams chilled water
at 58F - saving energy

We need less
primary air,
making
100% DOAS ideal and cost
effective, Improving IAQ
& Ventilation effectiveness

Space
Humidity
Concerns
ASHRAE
Engineering for the World We Live In

Independent Publications

This years 2012 ASHRAE HVAC

Systems and Equipment publication
covers chilled beam basics
Part of the European Commission Energie program, in partnership
with COSTIC (France),
BSRIA European
(UK), ISSO (Netherlands)
(Federation
Heating & & IDEA
(Spain).

REHVA

Ventilation)

Publication

Climatic Ceilings - Technical Note: Design Calculations

Climatic Ceilings and Chilled beams - Application of low
(being
worked
temperature heating and high temperature
cooling

AHRI Test Standard

on)

ASHRAE
Engineering for the World We Live In

Extract From Independent

Energie Climatic Ceilings

Passive
+ 0.5 C ( + 0.9 F )

Active
- 1.5 C ( - 2.7 F)
Relative to room air dew point

64 Dew Point

75/70% RH
58 CWS

75/50% RH
55.1 Dew Point

Condensation
Consideration

Condensation after 8.5 hours

on a chilled surface
intentionally held 7.8F colder
than the space DPT. Not one
droplet fell under these
conditions

Chilled Ceilings in Parallel

with Dedicated Outdoor Air
Systems: Addressing the
Concerns of Condensation,
Capacity, and Cost Stanley
A. Mumma, Ph.D., P.E.

Active Chilled beams could

be run at or below the room
dew point, but thats crazy!
Be safe, design at 2 to 3F above the
dew point and control the moisture
content of the primary air to control the
room RH

Rule # 4

If you can not measure

and control the space
humidity, and your not in the middle of
the desert, dont use chilled
beams !

Design
Considerations
ASHRAE
Engineering for the World We Live In

Building Suitability

Building Characteristics that favor Active Chilled Beams

Zones with moderate-high sensible load densities
Where primary airflows would be significantly higher than needed
for ventilation

Buildings most affected by space constraints

Hi rises, existing buildings with induction systems

Zones where the acoustical environment is a key

design criterion
Laboratories where sensible loads are driving airflows
as opposed to air change rates
Buildings seeking LEED or Green Globes certification

Building Suitability

Characteristics that less favor Active Chilled Beams

Buildings with operable windows or leaky

construction
Beams with drain pans could be considered

Zones with relatively low sensible load densities

Zones with relatively low sensible heat ratios
and low ventilation air requirements
Zones with high filtration requirements for the
re-circulated room air
Zone with high latent loads

Water System
design
ASHRAE
Engineering for the World We Live In

Secondary Loop
Supply
temperature
monitor

Secondary chilled water

supply to beams

T
Primary chilled
water supply

S
SCHW
Pump

Heat
Exchanger
Primary chilled
water return

Secondary chilled
water return

Dedicated Chiller
To chilled beam zones

Bypass Valve

Chilled water
pump

Cooling
Tower

64F

Dedicated
chiller
Geothermal
Heat
11+
COP
Pump

Geothermal Loop

58F

District Chilled
Water Loops

Tap into return pipe with heat

exchanger and secondary loop

No demand in district loop GPM

Increases main chiller plant COP

Waterside
Economizer
With mid-high 50Fs chilled water temperature
serving the Active Chilled Beams
Reduce chiller energy consumption through:
Using a water side economizer to minimize the chiller
operating hours serving the Active Chilled Beams

Savings
&
LEED
ASHRAE
Engineering for the World We Live In

Energy Savings
Compared to VAV

Source

Technology

Application

US Dept. of Energy Report (4/2001)

Beams/Radiant Ceilings

General

ASHRAE 2010 Technology Awards

Passive Chilled Beams

Call Center

41

ACEE Emerging Technologies Report (2009) Active Chilled Beams

General

20

ASHRAE Journal 2007

Active Chilled Beams

Laboratory

57

SmithGroup

Active Chilled Beams

Offices

24

*Compared to VAV

% Saving*
25-30

Call Center, Kentucky

Case Study

Call center, 350,000 sq ft

2200 occupants
LEED design
Considered radiant ceilings and passive beam systems
Article in ASHRAE Journal, December 2009

Call Center, Kentucky

Case Study

Real energy results based on comparison with

another building on the same campus
Energy usage data collected over 1 year
Electrical energy consumption reduced by 41%
Natural gas consumption reduced by 24%

First Costs
Compared to VAV

Energy Consumption Characteristics of Commercial

Building HVAC Systems - publication prepared for
U.S. Department of Energy

Maintenance

No moving parts
No filter
No condensate pumps
No consumable parts

Up to 4 year inspection & clean

Easy maintenance access

LEED Certification
Optimize Energy Performance
- up to 48% (new) or 44% (existing)more efficient than ASHRAE

90.1
(EA Credit 1) - up to 19 points
Increased Ventilation
- 30% more outdoor air than

ASHRAE 62
(IEQ Credit 2) - 1 point
Controllability of Systems
- individual temperature control
(IEQ Credit 6.2) -

1 point

Thermal Comfort

(Minimum 40 points needed

for certification
out of 100 maximum)

- meet ASHRAE 55
(IEQ Credit 7.1) -

1 point

Solutions
to reduce cost

ASHRAE
Engineering for the World We Live In

All Air Core

ASHRAE
Engineering for the World We Live In

Interior Zones
Induction Diffuser

277 cfm
48F

277 cfm
75F

555 cfm
60F

Lower airflows and fan energy consumption in the

interior VAV system through use of lower temperature
primary air

- 20% reduction if temperature lowered from 55F to 50F

- 26% reduction if temperature lowered from 55F to 48F

Improved comfort through increased air movement in the

low load interior zones
Increased latent cooling capacity and improved
humidity control

Latent
640 Btuh

2.2 times latent capacity for same sensible capacity

with 26% less primary air

Latent
1408 Btuh

6 Way valve

ASHRAE
Engineering for the World We Live In

2 or 4 Pipe
Chilled Beams?

Higher coil performance

4 pipe performance is
compromised
75% Cooling (12 pipes)
25% Heating (4 pipes)
Fewer or shorter beams
Lower hot water temperatures
90F for 2 pipe
130F for 4 pipe

2-Pipe Beams and

Terminal Heating
Chilled Water Supply

Terminal
Heating Coil

2-Pipe Active
Chilled Beams

Hot Water Supply

Hot Water Return

Chilled Water Return

6-way valve

6-way valve

6-way valve

One valve per zone

4-pipe to zone then 2-pipe to
chilled beams
Half controls costs
Increased chilled beam
performance
Increased energy efficiency

LoFlo

ASHRAE
Engineering for the World We Live In

Advantages
Reduced pipework
Higher system Delta T
Reduced pumping flow and horse power
Increased flexibility
Eliminate flow control valve and balancing valves
Reduced commissioning
Multiple water temperatures
Increased capacity at chilled beam (no 4-pipe req.)
Used in conjunction with 6 way valve
LMB requires no maintenance
One LMB for each zone (multiple ACBs)
Simple cartridge replacement

Disadvantages
Power required to each LMB
Requires low temperature water
at thermal plant

Overall
st
1 cost
ASHRAE
Engineering for the World We Live In

Viterbo

School of Nursing, WI
New $15.8m facility (original estimate $20m)
68,000 ft2, 7 floors
Consists of labs, lecture halls and classrooms
LEED Silver Certification

Completion fall 2011

HVAC First Costs

Savings Compared to VAV

Smaller AHUs
Smaller ductwork
Controls
Simple two position zone valves

Electrical infrastructure costs

Increased pump HP more than offset by reduced fan HP

HVAC First Costs

Increases Compared to VAV

More terminals (beams)

More distribution piping
More piping insulation
Requirement depends on chilled water temperature and dewpoint

Overall HVAC cost increase =

$300,000 compared to VAV

Construction Costs
Reduced height

Floor heights
reduced 10-14

Overall height
reduced by 6

Construction Costs
Savings due to reduced height

Building Component
Structural Steel
Masonry (int/ext)
Fire-Proofing
Steel Studs
Air Barrier
Overall cost
Insulation
Exterior Caulking
Curtain Wall
Stairs
Exterior Drywall
Elevators
Electrical
Total Cost Savings

Savings
$
7,200
$
97,692
$
600
$
22,824
$
8,787
neutral
$
3,424
$
1,522
$
10,500
$
2,500
$
55,249
$
5,000
$
30,000
$

Pricing provided by CD Smith Construction

245,298

Viterbo

School of Nursing, WI

Rule # 5

When budgeting chilled

beams, consider the
overall 1st cost, not just
the Mechanical vs VAV.

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