A heat pump is an extremely efficient, year round heating and cooling system that runs on electricity. During the summer, it "pumps" heat inside your home to the outside to cool and dehumidify your home. In the winter, it "pump" heat from the outside to the inside of your home.
Why is it so efficient?
Most heating systems convert energy from one form to another to create heat, (gas to flame, liquid to flame and electric energy to heat energy). Therefore they can only give out as much heat energy as the original form contained (most systems cannot convert 100% efficency because heat escapes up the flue with hot exhaust gases). A heat pump does not change energy to forms to create heat. It simply moves free heat from the outside to the inside. The only energy it needs is in the compressor motor which pumps the freon through the system. Because it is moving heat and not creating it, a heat pump is from 170% to 330% efficient, depending on the unit and the outside air temperature.
As the temperature difference between the air inside your home and the air outside increases, the amount of heat energy (BTU's) needed inside also increases. Conversely, as the outside air temperature decreases, the amount of energy (BTU's) that the heat pump can absorb from it decreases. Where these two rates are equal is called the balance point. Below this, the heat pump cannot supply enough heat to maintain the inside air temperature. This is when some type of auxiliary heating system is required.
For more information on heat pumps, download the Heat Pump Reference Guide. This 74 page document has been prepared by the Cooperative Research Network for use by our consumer-members.