What Is a Fuel-Efficient Temperature to Set Central Air Conditioning?

Setback Period

• You can save money on your air conditioning bill by setting your central air conditioning 10 to 15 degrees higher at times that you aren't at home or are asleep. For example, if you usually keep your thermostat at 75 degrees, you can set it to 90 degrees for times that you are not at home and lower the temperature again when you return. You can do this manually or set the thermostat to automatically cycle between these two temperatures at certain times of the day. In general, setting your thermostat to 78 degrees while at home and hotter while away is fuel efficient.

Conservation Rule

• The hotter your house is during the summer months, the less energy you use when you decide to cool the house. If your house is already at a high temperature, heat flows more slowly into the house; thus, your air conditioner has to work less to cool the air when you turn it on after having taken a break for several hours.

Programmable Thermostat

• It's easier to set your air conditioner to a fuel-efficient temperature if you get a programmable thermostat. You can set the thermostat to automatically change temperature at certain hours so that you don't have to worry about changing it back and forth. Consider the temperature you want the house to be when you are going to bed as well as what times of day you are likely to be out of the house to determine the most efficient way to cool the house.

Winter Heating

• You can use the same general principles to set your heater to heat in a fuel-efficient manner during the winter months. While you want your house to be hotter than normal during some portion of the summer day, you want it to be 10 to 15 degrees cooler than usual during the setback period in the winter. For example, you can set it to 68 degrees while at home and 58 degrees while not in the house.