Use the program function on your AC thermostat. If you have a thermostat that can't be programmed, consider replacing it with a programmable one.

Programmable ... read full tip

Use the program function on your AC thermostat. If you have a thermostat that can't be programmed, consider replacing it with a programmable one.

Programmable thermostats allow you to set specific temperatures for certain times of the day based on your normal routine and preferences. During the summer, for example, you can set the thermostat to a balmy 83 degrees for the hours when the house is empty, and then program it to cool your home to 78 degrees about 30 minutes before you usually return from work.

Compared to using non-programmable thermostats to run central AC systems, programmable thermostats deliver energy savings of roughly 16 percent. For the average U.S. household, this is an extra $50 or more per summer.

If every air-conditioned home in the U.S. used a programmable thermostat, the total energy savings would equal almost 30 billion kWh annually-that's enough to meet the air conditioning needs of every mid-Atlantic household for nearly three straight years.