Heat pumps deliver more heat to your home than they consume. How?
The magic is in the ability of refrigerants to absorb heat when they expand, and release it when they compress. The refrigerant is compressed inside a home, releasing heat, then moved through pipes and allowed to expand in copper tubes outside, absorbing heat. Essentially the heat pump is simply moving the heat from outside to inside. Most of the energy used is in the compressor to make the phase change happen, and the fans that push air over the coils on the inside and outside. The great thing is that all air, at every tempurature above absolute zero contains energy. At this point in time, in a residential setting, we can only extract that energy efficiently from about 5F. So if you install a heat pump and have lots of cold days, it would make sense to install a back up form of heat like a natural gas or wood fireplace.