During cooling season, setting the thermostat to 78 degrees Fahrenheit when at home and 85 when away offers greater energy efficiency. The California Energy Center reminds consumers they save 1 to 3 percent for each degree they increase the thermostat above 72 degrees during the cooling season.
Programmable thermostats help to save energy by automatically raising the setting before the occupants leave the home and then lowering the temperature one to three hours before they return home.
In areas where nighttime temperatures make a significant drop, the off position is the most efficient setting for the thermostat. Occupants then open windows to allow natural ventilation to cool the home. In the morning, they close the windows to trap the cool air inside the home.