The easiest way to save money and energy from cooling is to reduce the need for air conditioning. Here are some tips from the American Council for an Energy-Efficient Economy, Iowa Energy Center and U.S. Department of Energy:
Change the filter in your air conditioner — Put a clean one in for summer and change it at least monthly. Replacing a dirty filter can lower your unit’s energy use by up to 15 percent.
Clean the unit’s evaporator coil and condenser coil — The evaporator coil will collect dirt over time, which reduces airflow and prevents the coil from absorbing heat. Clean the area around the outside condenser coil, and hose it down if necessary.
Properly locate room conditioners — Put a room air conditioner in a window or wall near the center of a room and on the shadiest wall; seal gaps between the unit and the window with foam weatherstripping.
Add dampers — A home improvement expert with Microsoft Network Home Advisor recommends talking with your air conditioning contractor about installing dampers to restrict the flow of cooled air to rooms you rarely use. Also discuss whether closing doors or registers in those rooms will affect your system’s efficiency.
Seal ducts — According to the Consumer Energy Center, leaking ductwork accounts for 25 percent of cooling costs in an average home, so repairing leaking ducts could save as much as 20 percent on cooling and heating costs.
Seal out the hot air — Weatherstrip, caulk and insulate to keep the hot air out. The same winter insulation rules apply to summer insulation. Look for weatherization tips at www.energy.gov/energysaver/weatherize. Here’s a short list of the most important areas to insulate:
- Ceilings and finished attic walls
- Wall to unheated garage
- Crawl spaces
- All exterior walls, including basements
- Under floors and slabs
- Cathedral ceilings
- Around air conditioning ducts in unconditioned spaces
Change light bulbs — If you haven’t already, switch to compact fluorescent light bulbs or even better light-emitting diodes to save more than 75 percent energy. You’ll notice the difference on your electric bill.
Close up the fireplace — Shut up the fireplace for the season by closing the damper and cleaning out the flue.
Clear attic vents — Attic fans cool hot attics by drawing in cooler outside air through attic vents (soffit and gable) and pushing hot air to the outside, explains ENERGY STAR. However, if your attic has blocked soffit vents and is not well-sealed from the rest of the house, attic fans will suck cool conditioned air out of the house and into the attic. So, make sure vents aren’t blocked with insulation.
Go light outside — If your house has a dark-colored exterior, paint it lighter to reflect more of the sun’s radiant energy. A dark color absorbs 70 to 80 percent of light rays. Use light-colored or other cool roofing and siding products that can reduce your peak cooling demand by 10 to 15 percent.
Ventilate the attic — A dark-shingled house absorbs a lot of heat – attic temperatures can reach 150 degrees. Some of that heat will seep downstairs into your conditioned space and make your air conditioner work harder. Properly ventilation can keep the attic temperature below 110 degrees. Check to see if your home’s soffit vents and attic vents are adequate, and if not, add more. The vents and louvers also will prevent moisture buildup.
Add fans — Circulating air with fans will help cool your house, reduce your air conditioning use by as much as 30 percent and use little energy doing it. Install window fans in windows facing away from the prevailing wind and exhausting hot air from your home, according to the U.S. Department of Energy. To cool as much of your home as possible, tightly close windows near the fan and open windows in rooms far from the fan, preferably on the windward side of your home. Windows near cooler, shaded outdoor areas provide the best intake air.
Cool with air movement and ventilation — You can lower the thermostat 4 degrees when using a ceiling fan, without discomfort. Adjust your fan so it turns counterclockwise and blows air downward. Even portable fans can make you feel 3 or 4 degrees cooler. House or attic fans can cool your entire house without central air conditioning. However, if it’s humid outside, don’t use the house fan.
Shade or improve windows — According to the Missouri Division of Energy, sunny windows make air conditioners work two to three times harder. To keep out the sun, install drapes, blinds, exterior shades and other window coverings. Applying solar control window films to existing glass is another effective method to reduce solar light and heat.
Also consider horizontal trellises for your east- and west-facing windows. Protect south-facing windows with deciduous trees or climbing foliage so you can take advantage of low-angle sun in the winter. New windows on those walls that get the most summer sun should have low-E glazings to block unwanted heat gain. Seal leaks in old windows with caulking.
Open or shut windows appropriately — According to the Iowa Energy Center, if you use air conditioning, it’s better to close windows when the humidity is high and not open them at all even when it cools down outside. On the other hand, when humidity is low, open those windows up when it’s cool outside.
Use shade — Combined with adequate attic insulation and attic ventilation, strategically placed trees, shrubs and vines can cut energy use by one-third, according to the Iowa Energy Center. Also shade your outdoor air conditioning unit with a screen or foliage to protect it from direct sunlight, or place it on the north side of your house. Don’t block air flow, though, and remove leaves, twigs and grass cuttings that could block air.
Bump up the thermostat — Every degree raised uses about 4 percent less energy. Start at 78 degrees. You’ll discover your comfort level may be a higher temperature than you thought, particularly if you add fans to the cooling mix.
Turn down the AC when you’re away — It’s a myth that to keep the house cool, you must keep your air conditioner running full tilt while you’re at work. Turn up the temperature while you’re away, then adjust by a few degrees when you come home. A programmable thermostat can automate this process.
Get rid of inefficient appliances and wasteful energy uses — Inefficient appliances emit a lot of heat. Old refrigerators are prime suspects. ENERGY STAR-rated refrigerators and other appliances may be as much as 50 percent more efficient than other models. Unplug electronic equipment not being used. Air-dry dishes and laundry and wash only full loads of each. Use a microwave oven or cook outside. Lower the thermostat on your hot water heater; 120 degrees is comfortable for most uses. Wash only full loads of dishes and clothes. Finally plug electronic equipment into a power strip and turn it off when not in use. Don’t place lamps or TVs near the conditioner’s thermostat; their heat may cause the conditioner to run longer.