The right central air conditioning setting can save money on your utility bill.

Utility bills typically shoot up in the summer as homeowners crank up their central air conditioning. To keep costs down some folks may try to skimp on the air conditioning but that can create squabbles in the family over which temperature setting is more comfortable.

It may take some experimenting to reach a compromise but keep in mind that you’ll save about 3 percent on your utility bill for every degree you raise the set temperature for your central air, according to the Department of Energy.

So what is the best setting for your central AC? That depends on whether you care more about keeping cool or keeping your utility bill in check. We don’t want to pick sides, but we can give you some guidelines for finding a happy medium.

Energy Star, a joint federal program run by the DOE and the Environmental Protection Agency, recommends that for optimal cooling and energy efficiency, the coolest you should keep your house is 78° F—and that’s only when you’re at home and awake.

A programmable thermostat makes it easy to match your cooling needs to your schedule, but you can make the adjustments manually if you don’t have one for your central air system. Try the following settings:

• 78° F when you’re home.
• 85° F when you’re at work or away.
• 82° F when you’re sleeping.

If you’re more heat-tolerant, you can experiment with the temperature, raising it 1 degree at a time to see how it affects your comfort and your budget; 3 percent savings per degree adds up pretty quickly.

If you aren’t comfortable at 78° F, lower the temperature a degree at a time, and let your system reach the new setting before ratcheting it down further.

Other Ways to Beat the Heat

If you have a fan, turn it on. A ceiling fan or box fan causes a windchill effect that makes you feel cooler at a higher temperature setting, so long as the humidity isn’t too high.

If you live in an area with moderate temperatures, you may not need your central air conditioning all day and night. Take advantage of cooler night temperatures by keeping your windows open. Close them first thing in the morning and keep your shades and curtains drawn when it’s sunny outside to prevent the sun from heating up the house.

More on Air Conditioners

If you need the AC when you get home, you can program it to go on before you arrive or, with some thermostats, turn it on with a smartphone app.

If there’s a heat wave, avoid using your washer, dryer, and dishwasher during the heat of the day, and make sure you use the exhaust fans in your kitchen when you’re cooking or in the bathroom when you’re taking a shower.

Cooking outside on your grill is another way to keep the heat out of the house.

Smart Thermostats

Smart thermostats can save you money and make controlling your cooling easier. In our tests of smart thermostats, we found choices for folks who are very knowledgeable about automation and others for those who aren’t.

For the fully automated approach, try the Nest Learning Thermostat or Nest Thermostat E, which use sensors and geolocation to learn when you are and are not at home and adjust the temperature accordingly. Models such as the Carrier Cor thermostat offer manual control and remote control from a smartphone but very little in the way of automation.

The Honeywell Lyric T5, Ecobee 3, and Ecobee 4 offer a hybrid approach for those who require some automation but still want a full set of manual control features.


But I Have a Window Air Conditioner!

If you don’t have central air and depend on window air conditioners, it’s more difficult to reach the perfect temperature at home. Because the thermostat is in the unit itself, it registers the temperature in that part of the room and may not provide a consistent temperature throughout the space you want to cool, depending on how big and open the room is.

That means getting the right comfort level is more trial and error. Start with it set at 78° F and see how you feel. If you have a window unit in your bedroom, wait until 30 minutes or so before you go to bed to turn it on so that you’re not spending too much time cooling an empty room.