California/Arizona Energy Council
Providing Renewable Energy Solutions and Awareness to Homeowners

CAEC is not a government agency. This corporation was created to provide energy saving information to homeowners and help promote energy efficient improvements.

page: 1, 2, 3, 4, 5


CAEC Energy Education Center

Your Home's Energy Use

The first step to taking a whole-house energy efficiency approach is to find out which parts of your house use the most energy. A home energy audit will pinpoint those areas and suggest the most effective measures for cutting your energy costs. You can conduct a simple home energy audit yourself, contact your local utility, or call an independent energy auditor for a more comprehensive examination. For more information about home energy audits, including free tools and calculators, visit www.energysavers.gov or www.natresnet.org.

Graphic of a pie chart: space heating 31%, space cooling 12%, water heating 12%, lighting 11%, computers and electronics 9%, appliances 9%, refrigeration 8%, other 8%.

How We Use Energy in Our Homes
Heating accounts for the biggest chunk of a typical utility bill.
Source: 2007 Buildings Energy Data Book, Table 4.2.1., 2005 energy cost data.

Energy Auditing Tips

  • Check the insulation levels in your attic, exterior and basement walls, ceilings, floors, and crawl spaces. Visit www.energysavers.gov for instructions on checking your insulation levels.

  • Check for holes or cracks around your walls, ceilings, windows, doors, light and plumbing fixtures, switches, and electrical outlets that can leak air into or out of your home.

  • Check for open fireplace dampers.

  • Make sure your appliances and heating and cooling systems are properly maintained. Check your owner's manuals for the recommended maintenance.

  • Study your family's lighting needs and use patterns, paying special attention to high-use areas such as the living room, kitchen, and outside lighting. Look for ways to use lighting controls — like occupancy sensors, dimmers, or timers — to reduce lighting energy use, and replace standard (incandescent) light bulbs and fixtures with compact or standard fluorescent lamps.

Tips for Finding a Contractor

  • Ask neighbors and friends for recommendations
  • Look in the Yellow Pages
  • Focus on local companies
  • Look for licensed, insured contractors
  • Get three bids with details in writing
  • Ask about previous experience
  • Check references
  • Check with the Better Business Bureau

Formulating Your Plan

After you have identified where your home is losing energy, assign priorities by asking yourself a few important questions:

  • How much money do you spend on energy?

  • Where are your greatest energy losses?

  • How long will it take for an investment in energy efficiency to pay for itself in energy cost savings?

  • Do the energy-saving measures provide additional benefits that are important to you (for example, increased comfort from installing double-paned, efficient windows)?

  • How long do you plan to own your current home?

  • Can you do the job yourself or will you need to hire a contractor?

  • What is your budget and how much time do you have to spend on maintenance and repair?

Once you assign priorities to your energy needs, you can form a whole house efficiency plan. Your plan will provide you with a strategy for making smart purchases and home improvements that maximize energy efficiency and save the most money.

Another option is to get the advice of a professional. Many utilities conduct energy audits for free or for a small charge. For a fee, a professional contractor will analyze how well your home's energy systems work together and compare the analysis to your utility bills. He or she will use a variety of equipment such as blower doors, infrared cameras, and surface thermometers to find leaks and drafts. After gathering information about your home, the contractor or auditor will give you a list of recommendations for cost-effective energy improvements and enhanced comfort and safety. A reputable contractor can also calculate the return on your investment in high-efficiency equipment compared with standard equipment.

Thermal photograph of ranch style house shows heat escaping through windows, doors, and front porch.
Heat Loss from a House
A picture is worth=85in this case, lost heating dollars. This thermal photograph shows heat leaking from a house during those expensive winter heating months. The white, yellow, and red colors show heat escaping. The red represents the area of the greatest heat loss.

Tips: Windows

Windows can be one of your home's most attractive features. Windows provide views, daylighting, ventilation, and solar heating in the winter. Unfortunately, they can also account for 10% to 25% of your heating bill. During the summer, your air conditioner must work harder to cool hot air from sunny windows. Install ENERGY STAR windows and use curtains and shade to give your air conditioner and energy bill a break. If you live in the Sun Belt, look into low-e windows, which can cut the cooling load by 10% to 15%.

If your home has single-pane windows, as many U.S. homes do, consider replacing them with new double-pane windows with high-performance glass (e.g., low-e or spectrally selective). In colder climates, select windows that are gas filled with low emissivity (low-e) coatings on the glass to reduce heat loss. In warmer climates, select windows with spectrally selective coatings to reduce heat gain. If you are building a new home, you can offset some of the cost of installing more efficient windows because they allow you to buy smaller, less expensive heating and cooling equipment.

If you decide not to replace your windows, the simpler, less costly measures listed here can improve their performance.

Cold-Climate Window Tips

Illustration shows how a double-pane window with low-e coating keeps hot air inside by reflecting heat  back into the room.
Cold-Climate Windows Keep Heat In
Double-pane windows with low-e coating on the glass reflect heat back into the room during the winter months.

  • You can use a heavy-duty, clear plastic sheet on a frame or tape clear plastic film to the inside of your window frames during the cold winter months. Remember, the plastic must be sealed tightly to the frame to help reduce infiltration.

  • Install tight-fitting, insulating window shades on windows that feel drafty after weatherizing.

  • Close your curtains and shades at night; open them during the day.

  • Keep windows on the south side of your house clean to let in the winter sun.

  • Install exterior or interior storm windows; storm windows can reduce heat loss through the windows by 25% to 50%. Storm windows should have weatherstripping at all movable joints; be made of strong, durable materials; and have interlocking or overlapping joints. Low-e storm windows save even more energy.

  • Repair and weatherize your current storm windows, if necessary.

Illustration shows how a double-pane window with spectrally selective coatings prevents heat coming in from the outside and allows light to come inside.

Warm-Climate Windows Keep Heat Out
In the summertime, the sun shining through your windows heats up the room. Windows with low-e coatings on the glass reflect some of the sunlight, keeping your rooms cooler.

Warm-Climate Window Tips

  • Install white window shades, drapes, or blinds to reflect heat away from the house.

  • Close curtains on south- and west-facing windows during the day.

  • Install awnings on south- and west-facing windows.

  • Apply sun-control or other reflective films on south-facing windows to reduce solar gain.

Long-Term Savings Tip

  • Installing, high-performance windows will improve your home's energy performance. While it may take many years for new windows to pay off in energy savings, the benefits of added comfort and improved aesthetics and functionality may make the investment worth it to you. Many window technologies are available that are worth considering.

    Efficient windows may have two or more panes of glass, warm-edge spacers between the window panes, improved framing materials, and low-e coating(s), which are microscopically thin coatings that help keep heat inside during the winter and outside during the summer.

Shopping Tips for Windows

  • Look for the ENERGY STAR label.

  • Check with local utilities to see what rebates or other financial incentives are available for window replacement.

  • High-performance windows have at least two panes of glass and a low-e (low emissivity) coating.

  • Remember, the lower the U-factor, the better the insulation. In colder climates, focus on finding a low U-factor.

  • Low solar heat gain coefficients (SHGCs) reduce heat gain. In warm climates, look for a low SHGC.

  • In temperate climates with both heating and cooling seasons, select windows with both low U-factors and low SHGCs to maximize energy savings.

  • Look for whole-unit U-factors and SHGCs, rather than center-of-glass, or COG, U-factors and SHGCs. Whole-unit numbers more accurately reflect the energy performance of the entire product.

  • Have your windows installed by trained professionals. Be sure they're installed according to manufacturer's instructions; otherwise, your warranty may be void.

Tips: Water Heating

Illustration of a gas water heater with an EnergyGuide label.
Keep Your Energy Bills Out of Hot Water
Look for the ENERGY STAR label.

Water heating is the third largest energy expense in your home. It typically accounts for about 12% of your utility bill. There are four ways to cut your water heating bills: use less hot water, turn down the thermostat on your water heater, insulate your water heater, or buy a new, more efficient model.

Water Heating Tips

  • Install aerating, low-flow faucets and showerheads.

  • Repair leaky faucets promptly; a leaky faucet wastes gallons of water in a short period of time.

  • Lower the thermostat on your water heater; water heaters sometimes come from the factory with high temperature settings, but a setting of 120=B0F provides comfortable hot water for most uses.

  • Insulate your electric hot-water storage tank, but be careful not to cover the thermostat. Follow the manufacturer's recommendations.

  • Insulate your natural gas or oil hot-water storage tank, but be careful not to cover the water heater's top, bottom, thermostat, or burner compartment. Follow the manufacturer's recommendations; when in doubt, get professional help.

  • Insulate the first 6 feet of the hot and cold water pipes connected to the water heater.

  • If you are in the market for a new dishwasher or clothes washer, consider buying an efficient, water-saving ENERGY STAR model to reduce hot water use. See Appliances for more information.

  • Install heat traps on the hot and cold pipes at the water heater to prevent heat loss. Some new water heaters have built-in heat traps.

  • Drain a quart of water from your water tank every 3 months to remove sediment that impedes heat transfer and lowers the efficiency of your heater. The type of water tank you have determines the steps to take, so follow the manufacturer's advice.

  • Although most water heaters last 10=9615 years, it's best to start shopping now for a new one if yours is more than 7 years old. Doing some research before your heater fails will enable you to select one that most appropriately meets your needs.

Chart showing Average Hot Water Use (Activity/Gallons per Use): Clothes washing: 32, Showering: 20, Bathing: 20, Automatic dishwashing: 12, Preparing food: 5, Hand dishwashing: 4.  Source: ACEEE
Source: ACEEE

Long-Term Savings Tips

  • Buy a new energy-efficient water heater. While it may cost more initially than a standard water heater, the energy savings will continue during the lifetime of the appliance. Look for the ENERGY STAR and EnergyGuide labels.

  • Look for the ENERGY STAR label on efficient water heaters in the following categories: high efficiency gas non-condensing, gas condensing, electric heat pump, gas tankless, and solar.

  • Consider installing a drain water waste heat recovery system. A recent DOE study showed energy savings of 25% to about 30% for water heating using such a system.

  • Consider natural gas on-demand or tankless water heaters. Researchers have found savings can be up to 30% compared with a standard natural gas storage tank water heater.

  • Heat pump water heaters can be very cost-effective in some areas.

Solar Water Heaters

If you heat water with electricity, have high electric rates, and have an unshaded, south-facing location (such as a roof) on your property, consider installing an ENERGY STAR qualified solar water heater. The solar units are environmentally friendly and can now be installed on your roof to blend with the architecture of your house.

More than 1.5 million homes and businesses in the United States have invested in solar water heating systems, and surveys indicate that more than 94% of these customers consider the systems a good investment. Solar water heating systems are also good for the environment. Solar water heaters avoid the greenhouse gas emissions associated with electricity production. During a 20-year period, one solar water heater can avoid more than 50 tons of carbon dioxide emissions. When shopping for a solar water heater, look for the ENERGY STAR label and for systems certified by the Solar Rating and Certification Corporation or the Florida Solar Energy Center.

Long-Term Savings Tip

  • Visit the Database of State Incentives for Renewables & Efficiency Web site (http://www.dsireusa.org/) to see if you might qualify for tax credits or rebates for buying a solar water heater.

Sealing Air Leaks

Warm air leaking into your home during the summer and out of your home during the winter can waste a lot of your energy dollars. One of the quickest dollar-saving tasks you can do is caulk, seal, and weatherstrip all seams, cracks, and openings to the outside. You can save on your heating and cooling bill by reducing the air leaks in your home.

Tips for Sealing Air Leaks

Pie chart shows how air escapes from a typical home: 31% floors, ceiling, walls; 15% ducts; 14% fireplace; 13% plumbing penetrations, 11% doors; 10% windows; 4% fans and vents; 2% electric outlets.

How Does the Air Escape?
Air infiltrates into and out of your home through every hole and crack. About one-third of this air infiltrates through openings in your ceilings, walls, and floors.

  • First, test your home for air tightness. On a windy day, carefully hold a lit incense stick or a smoke pen next to your windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures, attic hatches, and other locations where there is a possible air path to the outside. If the smoke stream travels horizontally, you have located an air leak that may need caulking, sealing, or weatherstripping.

  • Caulk and weatherstrip doors and windows that leak air.

  • Caulk and seal air leaks where plumbing, ducting, or electrical wiring penetrates through walls, floors, ceilings, and soffits over cabinets.

  • Install foam gaskets behind outlet and switch plates on walls.

  • Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes with low-expansion spray foam made for this purpose.

  • Look for dirty spots on your ceiling paint and carpet, which may indicate air leaks at interior wall/ceiling joints and wall/floor joists. These joints can be caulked.

  • Install storm windows over single-pane windows or replace them with more efficient windows, such as double-pane.

  • When the fireplace is not in use, keep the flue damper tightly closed. A chimney is designed specifically for smoke to escape, so until you close it, warm air escapes=9724 hours a day!

  • For new construction, reduce exterior wall leaks by installing house wrap, taping the joints of exterior sheathing, and comprehensively caulking and sealing the exterior walls.

  • Use foam sealant around larger gaps around windows, baseboards, and other places where warm air may be leaking out.

  • Kitchen exhaust fan covers can keep air from leaking in when the exhaust fan is not in use. The covers typically attach via magnets for ease of replacement.

  • Replacing existing door bottoms and thresholds with ones that have pliable sealing gaskets is a great way to eliminate conditioned air leaking out from underneath the doors.

  • Fireplace flues are made from metal, and over time repeated heating and cooling can cause the metal to warp or break, creating a channel for hot or cold air loss. Inflatable chimney balloons are designed to fit beneath your fireplace flue during periods of non-use. They are made from several layers of durable plastic and can be removed easily and reused hundreds of times. Should you forget to remove the balloon before making a fire, the balloon will automatically deflate within seconds of coming into contact with heat.

Cutaway house illustration showing areas of home where air leaks. Refer to caption for list.
Sources of Air Leaks in Your Home
Areas that leak air into and out of your home cost you lots of money. Check the areas listed below.

  1. Dropped ceiling
  2. Recessed light
  3. Attic entrance
  4. Sill plates
  1. Water and furnace flues
  2. All ducts
  3. Door frames
  4. Chimney flashing
  1. Window frames
  2. Electrical outlets and switches
  3. Plumbing and utility access

Tips: Insulation and Sealing Air Leaks

Checking your home's insulation is one of the fastest and most cost-effective ways to use a whole-house approach to reduce energy waste and make the most of your energy dollars. A good insulating system includes a combination of products and construction techniques that protect a home from outside hot or cold temperatures, protect it against air leaks, and control moisture. You can increase the comfort of your home while reducing your heating and cooling needs by investing in proper insulation and sealing air leaks.

Should I Insulate My Home?

Insulate your home when:

  • You have an older home and haven't added insulation. Only 20% of homes built before 1980 are well insulated.
  • You are uncomfortably cold in the winter or hot in the summer — adding insulation creates a more uniform temperature and increases comfort.
  • You build a new home, addition, or install new siding or roofing.
  • You pay high energy bills.
  • You are bothered by noise from outside — insulation muffles sound.
Cutaway illustration of house showing insulation in walls, foundation, crawlspace, floors, and attic.
Where to Insulate
Adding insulation in the areas shown above may be the best way to improve your home's energy efficiency. Insulate either the attic floor or under the roof. Check with a contractor about crawl space or basement insulation.

Insulation

First, check the insulation in your attic, ceilings, exterior and basement walls, floors, and crawl spaces to see if it meets the levels recommended for your area. Insulation is measured in R-values — the higher the R-value, the better your walls and roof will resist the transfer of heat. DOE recommends ranges of R-values based on local heating and cooling costs and climate conditions in different areas of the nation. The map and chart below show the DOE recommendations for your area. State and local code minimum insulation requirements may be less than the DOE recommendations, which are based on cost effectiveness. For more customized insulation recommendations, check out the Zip Code Insulation Calculator. This tool provides insulation levels for your new or existing home based on your zip code and other basic information about your home. Although insulation can be made from a variety of materials, it usually comes in four types; each type has different characteristics.

Rolls and batts — or blankets — are flexible products made from mineral fibers, such as fiberglass and rock wool.

They are available in widths suited to standard spacings of wall studs and attic or floor joists: 2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.

Loose-fill insulation — usually made of fiberglass, rock wool, or cellulose in the form of loose fibers or fiber pellets, it should be blown into spaces using special pneumatic equipment. The blown-in material conforms readily to building cavities and attics. Therefore, loose-fill insulation is well suited for places where it is difficult to install other types of insulation.

Rigid foam insulation — foam insulation typically is more expensive than fiber insulation. But it's very effective in buildings with space limitations and where higher R-values are needed. Foam insulation R-values range from R-4 to R-6.5 per inch of thickness, which is up to 2 times greater than most other insulating materials of the same thickness.

Foam-in-place insulation — this type can be blown into walls and reduces air leakage, if blown into cracks, such as around window and door frames.

Insulation Tips

  • Consider factors such as your climate, building design, and budget when selecting insulation R-values for your home.

  • Use higher density insulation on exterior walls, such as rigid foam boards, in cathedral ceilings and on exterior walls.

  • Ventilation helps with moisture control and reducing summer cooling bills. Attic vents can be installed along the entire ceiling cavity to help ensure proper airflow from the soffit to the attic to make a home more comfortable and energy efficient. Do not ventilate your attic if you have insulation on the underside of the roof. Check with a qualified contractor.

  • Recessed light fixtures can be a major source of heat loss, but you need to be careful how close you place insulation next to a fixture unless it is marked IC — designed for direct insulation contact. Check your local building codes for recommendations. See Lighting for more about recessed cans.

  • As specified on the product packaging, follow the product instructions on installation and wear the proper protective gear when installing insulation.

  • Long-Term Savings Tip
    One of the most cost-effective ways to make your home more comfortable year-round is to add insulation to your attic.

Adding insulation to the attic is relatively easy and very cost effective. To find out if you have enough attic insulation, measure the thickness of the insulation. If it is less than R-30 (11 inches of fiber glass or rock wool or 8 inches of cellulose), you could probably benefit by adding more. Most U.S. homes should have between R-30 and R-60 insulation in the attic. Don't forget the attic trap or access door.

If your attic has enough insulation and your home still feels drafty and cold in the winter or too warm in the summer, chances are you need to add insulation to the exterior walls as well. This is a more expensive measure that usually requires a contractor, but it may be worth the cost if you live in a very hot or cold climate. If you replace the exterior siding on your home, you should consider adding insulation at the same time.

You may also need to add insulation to your crawl space or basement. Check with a professional contractor.

New Construction

For new homes in most climates, you will save money and energy if you install a combination of cavity insulation and insulative sheathing. Cavity insulation can be installed at levels up to R-15 in a 2 in. x 4 in. wall and up to R-21 in a 2 in. x 6 in. wall. The insulative sheathing, used in addition to this cavity insulation, helps to reduce the energy that would otherwise be lost through the wood frame. The table below shows the recommended combinations. For example, in Zone 5, you could use either a 2x4 wall with R-13 or a 2x6 wall with R-21. For either of those two walls, you should also use an inch of insulative sheathing that has an R-value of R-5 or R-6.

Today, new products are on the market that provide both insulation and structural support and should be considered for new home construction or additions. Structural insulated panels, known as SIPs, and masonry products like insulating concrete forms are among these. Some homebuilders are even using an old technique borrowed from the pioneers: building walls using straw bales. Check online at www.energysavers.gov for more information on structural insulation.

Radiant barriers (in hot climates), reflective insulation, and foundation insulation should all be considered for new home construction. Check with your contractor for more information about these options.

U.S. map showing recommended insulation levels for the home based on climate regions and heating type. For specific recommendations for your home, go to http://www.ornl.gov/~roofs/Zip/ZipHome.html or contact Energy Savers webmaster (http://www.energysavers.gov/webmaster.cfm) for more information.
All of Alaska in Zone 7 except for the following boroughs in Zone 8:
  • Bethel
  • Northwest Arctic
  • Dellingham
  • Southeast Fairbanks
  • Fairbanks N. Star
  • Wade Hampton
  • Nome
  • Yukon-Koyukuk
  • North Slope
Zone 1 includes
  • Hawaii
  • Guam
  • Puerto Rico
  • Virgin Islands
How Much Insulation Does My Home Need?
For insulation recommendations tailored to your home, visit the DOE Zip Code Insulation Calculator at www.ornl.gov/~roofs /zip/ziphome.html.
*These recommendations are cost-effective levels of insulation based on the best available information on local fuel and materials costs and weather conditions. Consequently, the levels may differ from current local building codes.
Chart showing recommended insulation levels for the home based on climate regions and heating type. For specific recommendations for your home, go to http://www.ornl.gov/~roofs/Zip/ZipHome.html or contact Energy Savers webmaster (http://www.energysavers.gov/webmaster.cfm) for more information.