A heat pump is different than a heat strip. A heat pump is a machine which moves heat. Heat exists in all air at all temperatures down to “absolute zero” (-460º F). In the winter, a heat pump draws heat from the outdoor air and circulates it through ducts into your home. During the summer, it reverses the process and draws heat from your interior air and releases it outdoors. It also dehumidifies the indoor air as it cools it.
A heat pump in an air conditioner that contains a valve that lets it switch between “air conditioner” and “heater.” When the valve is switched one way, the heat pump acts like an air conditioner, and when it is switched the other way it reverses the flow of Freon and acts like a heater.
The heat pump serves as a heater by absorbing heat from outdoor air and pumping it indoors. All air, even cold winter air, contains a certain amount of heat. As the outdoor air passes over the outdoor coil, heat from that air is absorbed by the refrigerant contained inside the coil. This absorption of heat changes the refrigerant from a low-temperature liquid to a low-temperature, low-pressure vapor. The vapor then passes through a compressor where it is compressed into a high pressure, high-temperature vapor. The hot vapor then circulates into the indoor coil. As indoor air passes over the indoor coil, it absorbs heat from the coil. The warmed air is then redistributed through the duct system.