Reduce your home’s heat load
Eliminate heat-generating sources inside your home and you may not need to rely on the air conditioner as much. Close the shades on windows that get a lot of direct sunlight, and refrain from running appliances that generate heat, such as the oven, dishwasher or clothes dryer, during the hottest parts of the day. And make sure to switch your incandescent light bulbs to energy-efficient compact fluorescent ones. “Every incandescent bulb in your house is a little extra heater,” CFLs use less energy and release less heat. Take these steps and you can set the thermostat two degrees warmer, saving about $4 a month.
Make sure your unit is in top shape
Even if you have the most efficient [air-conditioning] system, if it’s not operating the way it should, you’re wasting energy, Problems like a worn-out filter or unsealed duct won’t keep your A/C from working, but they could make the unit as much as 20% less efficient. Typically, an inspection from a licensed contractor costs about $50, an expense you should easily recoup in energy savings by Labor Day. (A unit operating back at peak efficiency again could cut as much as $20 a month from your electricity bill.) On your own, clean or replace air filters at least once a month. That cuts down how hard the fan has to work to move air throughout your home.
Turn back the thermostat
There’s no point in keeping the air conditioning on full blast when no one’s home to enjoy it. Turn the thermostat higher while you’re at work or asleep. Setting it five degrees higher for an eight-hour period each day shaves 10% from your monthly bill. You don’t have to come home to a space that’s as sweltering inside as it is outside, either. Program the air conditioner to kick in at the more comfortable temperature just before you get home.
Use a fan
Set your ceiling fan to its counterclockwise mode. That pushes the cool air down and redistributes the warm air. Or use other types of fans to create a breeze. The result: The room feels about two degrees cooler. Adjust the thermostat accordingly, and you’ll save another $4 per month. Just be sure to turn the fan off when you leave the room. Fans don’t cool rooms — they cool people!
Seal up your home
Sad but true: At least some of that chilled air your system generates isn’t going to stay inside. Cracks along window and door frames, attic eaves and electrical outlets enable it to escape — and force your air conditioner to work much harder to maintain a cool temperature. The equivalent of leaving a window open all year, such leaks can tack on another 20% to your bill. Seal everything up with some caulk, insulation and weather-stripping for as little as $50. Doing so could help cut your annual energy bill by as much as $470. Sealing basement cavities can double that amount.