Heat pumps are marvelous devices for keeping a home comfortable year round. But how exactly does a heat pump both heat and cool? Even when people know a bit more about the process of heat exchange that allows a heat pump to perform these two different tasks, they still feel puzzled about how heat pumps function during cold weather.
We’ll explain in a bit more depth in this post how heat pumps provide heat during the cold weather, even when they have to extract heat from the chilly outdoors. If you need repair, installation, or maintenance for a heat pump in Atlanta, GA, contact our skilled technicians at Cool Air Mechanical.
Heat pump operation: heat from the cold air
Here are the basics of how a heat pump works: using refrigerant that cycles through it in a closed loop, a heat pump moves heat from one location (the indoor unit or the outdoor unit) and moves it to another. This is called heat exchange, and the heat pump uses the air as its heat exchange medium. During hot weather, a heat pump acts as an air conditioner, taking heat from inside a home and moving it to the outside. Then, during colder weather, it moves heat from outdoors and brings it indoors.
And that’s where people become confused. Where is this heat coming from if the outside is already cold?
Although it may be hard to believe when you’re standing outdoors on a chilly day, there is still heat in cold air. As long as there is some molecular motion, there is heat available. (Absolute zero, the point of no molecular motion, is only a theoretical temperature.) Using evaporation along the outdoor coil, a heat pump absorbs some of this available heat and brings it indoors.
However, there is less heat outdoors in lower temperatures, which leads to one of the few drawbacks of a heat pump: they perform less effectively in extreme low temperatures. Once the thermometer drops below freezing, heat pumps will struggle with efficient performance. To balance this, some homeowners have a dual fuel hybrid system installed, where a second heating system (such as propane-powered furnace) comes on when the heat pump can no longer handle the low temperature.
Fortunately, Atlanta weather rarely plunges to temperatures where a heat pump will struggle, which makes them ideal for our city. Cool Air Mechanical can install a heat pump—or a dual fuel hybrid system if you need it—in your home to give you fantastic year-round comfort. Contact us today for all your needs for a heat pump in Atlanta, GA.