13 Guide To Energy-Efficient Heating Cooling
13 Guide To Energy-Efficient Heating Cooling
13 Guide To Energy-Efficient Heating Cooling
Start
with
ENERGY
STAR
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The average household spends more than $2,200 a
year on energy bills, with nearly half of this going to
heating and cooling costs. The U.S. Environmental
Protection Agency (EPA) can help you make smart
decisions about your homes heating, ventilating, and
air conditioning (HVAC) system that can help save on
energy costs, improve your overall comfort at home,
and help fight global warming.
Contents
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Why Read
this Guide?
Use this guide to help you:
Learn how best to maintain your heating
and cooling equipment.
Take steps around your home to improve
the efficiency of your HVAC system.
Decide when its time to replace your old
heating and cooling equipment with more
energy-efficient equipment that has earned
EPA's ENERGY STAR.
Maintain
Your Equipment
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Dirt and neglect are the top causes of heating and cooling
system inefficiency and failure. To ensure efficient system
operation, its important to perform routine maintenance.
Change your air filter regularly. A clean filter will prevent dust and dirt from
building up in the system, which can lead to expensive maintenance and/or
early system failure. Check your filter every month, especially during winter and
summer months, when use tends to be heavier. Change your filter if it's dirty
or at least every three months.
Tune up your HVAC equipment. Proper maintenance by a qualified technician is
one of the most important steps you can take to prevent future problems.
Contractors get busy during summer and winter months, so it is best to check
the cooling system in spring and the heating system in the fall. Plan the checkups around the beginning and end of daylight-saving time each spring and fall.
For tips on hiring the right contractor, see page 18, Work with a Heating and
Cooling Contractor.
Your contractor should complete the following each spring and fall:
Check thermostat settings to ensure the heating and cooling system turns
on and off at the programmed temperatures.
Tighten all electrical connections and measure voltage and current on
motors. Faulty electrical connections can cause your system to operate
unsafely and reduce the life of major components.
Lubricate moving parts. Parts that lack lubrication cause friction in motors
and increase the amount of electricity you use. Lack of lubrication can also
cause equipment to wear out more quickly, requiring more frequent repairs
or replacements.
Check and inspect the condensate drain in your central air conditioner,
furnace, and/or heat pump (when in cooling mode). If plugged, the drain
can cause water damage in the house, affect indoor humidity levels, and
breed bacteria and mold.
Check system controls to ensure proper and safe operation. Check the starting
cycle of the equipment to assure the system starts, operates, and shuts
off properly.
Inspect, clean, or change the air filter in your central air conditioner, furnace,
and/or heat pump. Your contractor can show you how to do this yourself.
Depending on your system, your filter may be located in the duct system versus
the heating and cooling equipment itself.
Use a Programmable
Thermostat Properly
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Setting
Time
Wake
6:00 a.m.
< 70 F
> 78 F
Day
8:00 a.m.
Setback at least 8 F
Setup at least 7 F
< 70 F
> 78 F
Sleep
Setback at least 8 F
Setup at least 4 F
10:00 p.m.
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10
B
A
B
A
restricting airflow
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12
Homeowners are often concerned about sealing their house too tightly;
however, this is very unlikely in many older homes. A certain amount of fresh air
is needed for good indoor air quality, and there are specifications that set the
minimum amount of fresh air needed for a house. If you are concerned about
how tight your home is, hire a contractor, such as a Home Energy Rater, who
can use diagnostic tools to measure your home's actual air leakage. If your
home is too tight, a fresh air ventilation system may be recommended.
After any project where you reduce air leakage, have a heating and cooling
technician check to make sure that your combustion appliances (gas- or oilfired furnace, water heater, and dryer) are venting properly. For additional
information on Indoor Air Quality (IAQ) issues related to homes, such as
combustion safety, visit EPAs Indoor Air Quality Web site at www.epa.gov/iaq.
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Adding Insulation
Insulation keeps your home warm in the winter and cool in the summer.
There are several common types of insulationfiberglass (in both batt and
blown forms), cellulose, rigid foam board, and spray foam. Reflective
insulation (or radiant barrier) is another insulating product that can help
save energy in hot, sunny climates. When correctly installed with air
sealing, each type of insulation can deliver comfort and lower energy bills
during the hottest and coldest times of the year.
Insulation performance is measured by R-valueits ability to resist heat
flow. Higher R-values mean more insulating power. Different R-values are
recommended for walls, attics, basements, and crawlspaces, depending on
your area of the country. Insulation works best when air is not moving
through or around it, making it very important to seal air leaks before
installing insulation to ensure that you get the best performance from
the insulation.
To get the biggest savings, the easiest place to add insulation is usually in
the attic. A quick way to see if you need more insulation is to look across
your uncovered attic floor. If your insulation is level with or below the attic
floor joists, you probably need to add more. The recommended insulation
level for most attics is R-38 (or about 12 15 inches, depending on the
insulation type). In the coldest climates, insulating up to R-49
is recommended.
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Multiple Panes
Low E-Coating
Gas Fill
Improved
frame materials
Improve comfort. ENERGY STAR qualified windows do more than just lower
energy bills; they keep your homes temperature consistently comfortable.
During the winter, the interior glass of ENERGY STAR qualified windows stays
warmer compared to typical windows, even when the temperature outside dips
well below freezing. In the summer, most ENERGY STAR qualified windows
reduce the heat gain into your home, without reducing the visible light.
Protect your valuables. Drapes, wood floors, a favorite photograph: all these
things can fade or discolor after repeated exposure to direct sunlight. ENERGY
STAR qualified windows have coatings that keep out the summer heat and act
like sunscreen for your house, protecting your valuables from harmful, fading
ultraviolet light without noticeably reducing visible light.
Look for the ENERGY STAR. The ENERGY STAR guidelines for windows are
tailored to four climate zones. For example, windows in the North are optimized
to reduce heat loss in the winter, while windows in the South are optimized to
reduce heat gain during the summer. For optimal results, select ENERGY STAR
qualified windows that are appropriate for your climate zone.
15
Making a Change?
Choose the Right
Equipment
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If youve taken the steps outlined in the previous sections to improve efficiency
and you continue to experience problems, or if your HVAC system is old
(10 15 years) or not working, consider replacing your equipment with a highefficiency unit that has earned the ENERGY STAR. Its a good idea to do some
research on options for a new heating or cooling system before your current
one breaks, so you can make an informed decision if you need to act quickly.
How much energy you save will vary based on your use and climate, with
colder regions saving more with ENERGY STAR heating equipment and hotter
regions saving more with ENERGY STAR cooling equipment.
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Furnaces
Furnaces are the most commonly used residential heating system in the
United States. Running most often on gas, but sometimes on oil,
propane, or electricity, furnaces deliver their heat through a duct
system. Furnaces that have earned the ENERGY STAR have higher AFUE
(Annual Fuel Utilization Efficiency) ratings. AFUE is the measure of
heating equipment efficiency, represented as a percentage. Most
furnaces that can qualify for the ENERGY STAR will be condensing
furnaces where the transfer of heat is so thorough water or condensate
is a byproduct of combustion. This condensing occurs with systems
over 90 percent efficient. Another feature of efficient furnaces is a
highly efficient blower motor (commonly an ECM, Electronically
Commutated Motor, or another type of advanced main air
circulating fan).
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Boilers
A boiler heats your home by burning gas, propane, or oil to heat water or
steam that circulates through radiators, baseboards, or radiant floor
systems. Boilers do not use a duct system. Boilers that have earned the
ENERGY STAR have higher AFUE ratings. Features that improve boiler
efficiency include electronic ignition, which eliminates the need to have
the pilot light burning all the time, and technologies that extract more
heat from the same amount of fuel.
16
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Heat Pumps
Heat pumps provide both heating and cooling in one integrated system.
Electric Air-Source Heat Pumps (ASHPs). ASHPs, often used in
moderate climates, use the difference between outdoor and indoor air
temperatures to cool and heat. ENERGY STAR qualified ASHPs have
higher SEER and EER ratings than conventional models. They also have
a higher Heating and Seasonal Performance Factor (HSPF), which
measures the heating efficiency of the heat pump.
Geothermal Heat Pumps (GHPs). GHPs are similar to air source heat
pumps, but use the ground instead of outside air to provide heating,
cooling, and often water heating. Because they use the earth's natural
heat, they are among the most efficient and comfortable heating and
cooling technologies currently available. Although initially expensive,
you can achieve significant cost savings on energy bills. GHPs are most
often installed in new homes and require a duct system.
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Whether you want to schedule an annual equipment
maintenance check-up or youve decided that you need to
purchase and install new heating or cooling equipment,
you will need to hire a contractor.
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The following sections will help you find the right contractor, get quality and
value from the contractor and your new equipment, and get a signed agreement
on the work to be done. Many of the following recommendations also apply if
you choose to work with a contractor to make other home improvements such
as home sealing or duct work.
Perform an on-site inspection of the work you want completed and provide a
detailed bid in a timely manner.
Demonstrate to you that the company is licensed and insured to repair and
install heating and cooling equipment (many states require this).
Be able to provide his/her certification for refrigerant handling, required
since 1992.
Have several years of experience as a business in your community.
Provide examples of quality installation of energy-efficient heating and/or
cooling equipment work, with names of customers that you can contact.
Complete and submit the warranty information card on your behalf.
Leave all equipment manuals and provide documentation of installation
procedures, including sizing calculations, AHRI certificate, and records of any
measurements or testing.
Clearly explain the benefits of regular maintenance and help you set up a
schedule to keep your system operating at its best.
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19
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Replacing your old heating and cooling equipment with new, energy-efficient
models is a great start. But to make sure that you get the best performance, the
new equipment must be properly installed. In fact, improper installation can
reduce system efficiency by up to 30 percentcosting you more on your utility
bills and possibly shortening the equipments life.
Proper Sizing
of Equipment
100%
95%
90%
85%
80%
75%
70%
65%
Incorrect
Incorrect
Refrigerant Charge Sizing + Duct
+ Low Airflow
Leakage
+ Incorrect Sizing
+ Duct Leakage
Installed to
Duct
Leakage ENERGY STAR
Guidelines
Installing the right size equipment for the home is essential to getting the best
performance and comfort. Many homeowners believe that bigger is always
better when buying new heating and cooling equipment. In reality, a system
thats too large will not keep your home comfortable because of frequent on/off
cycling. Incorrect sizing can also put stress on system components and shorten
the equipments life. With an ENERGY STAR Quality Installation, your contractor
will make sure that you get a system that is the right size for your home.
Sealing Ducts
To help ensure that your new system delivers the heated or cooled air to all the
rooms of your home, contractors using ENERGY STAR Quality Installation
guidelines will evaluate your duct system to identify leaks, and then seal them
using mastic, metal-backed tape, or an aerosol-based sealant. In some
instances, your contractor may advise you that it is necessary to replace or
add ducts.
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United States
Environmental
Protection Agency
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