What is a Heat Pump? A heat pump is a device which transfers heat energy from one place to another.
Major Components Indoor coil Outdoor coil Compressor Fan Expansion Device
How It Works Liquid refrigerant is pumped through outdoor coil, picking up heat Vapor travels through compressor and is further heated (high pressure) Vapor continues to indoor coil where it expels heat, absorbs cool air, and condenses back to liquid Fans blow heat through ducts to heat house Cooled vapor passes through the expansion device where pressure is reduced, cooled and converted back to liquid refrigerant Other methods such as water or ground source heat can be used.
Efficiency Very efficient in use of energy Takes less electrical energy to move heat than convert electrical energy to heat Heat pumps generally magnify heat rather than just create it leading to high levels of efficiency Reduces heat costs by 30-50% compared to electric furnaces
How It Works (Diagram) http://www.ari.org/consumer/howdoesitwork/howHPwks.html