Because of the relatively mild winters we have in the Tennessee Valley, many homeowners here choose to install an incredibly energy efficient type of heating system known as a heat pump, rather than a traditional furnace. Using a heat pump can save you a significant amount on your energy bills, but only if you know how to use it properly.
One of the major differences between a heat pump and a standard furnace is that with a heat pump, it can actually cost you more money to turn it down at night and turn it back up in the morning—or turn it down when you leave for work and back up when you get home—rather than leaving it at a constant temperature all the time.
The reason for this is that when your heat pump detects that the temperature in your home is more than two degrees below the thermostat setting, it kicks on the auxiliary heat in order to get your home back to the desired temperature faster. With most heat pumps, the auxiliary heat consists of electric resistance heat strips.
The problem is that these heat strips are much less efficient than your actual heat pump. In fact, it costs two to five times as much to get the same amount of heat from the heat strips as it does from the normal operation of the heat pump system. As a result, reheating your home in the morning can actually cost more than keeping it at a constant temperature all day and night!
Thanks to modern technology, however, there is a solution to this efficiency problem. Programmable thermostats that are designed specifically to work with heat pumps can make it possible for you to reap the benefits of setting back the temperature at night and when you’re away from home. These thermostats, such as the Nest Learning Thermostat with Heat Pump Balance, can be programmed to reheat your home slowly, one degree at a time, so that the auxiliary heat doesn’t kick on.
So ultimately, the answer to the question is, it depends. With a traditional thermostat, no. But with a heat pump-specific programmable thermostat, yes, you can enjoy both the outstanding efficiency of your heat pump and the added efficiency that comes with turning down the heat when you need it least.