Note: The ‘no central equipment’ group includes households whose main heating equipment is a portable heater, fireplace, or stove, or main cooling equipment is a room air conditioner.
Thermostats are used to control central heating equipment in 85% of households, and less than half of those thermostats are programmable. For households with central cooling equipment, 60% have a central thermostat and about half of those are programmable.
Because they automatically respond to temperature changes, thermostats play a key role in weather-related changes in energy demand. Programmable thermostats can be used to help households set temperatures back at night or when occupants are away. Of course, humans can also accomplish these tasks, and the mere presence of a programmable thermostat does not in itself save energy—most of them must be appropriately programmed. The ENERGY STAR® website provides guidelines for programmable thermostat usage.