Written by by Ron Barmby at wattsupwiththat.com
When you need heat pumps the most, they pump heat the least.
This is according to an unbreakable law of physics that applies to the entire universe without exception, even black holes, and especially to heat pumps.
Heat pump promoters who claim otherwise must have defeated the second law of thermodynamics, which would theoretically also allow them to make time run backward.
In addition to denunciation by physics, the cost of operating heat pumps is often very high compared to natural gas-fired heating.
Heat pumps are often accurately described as an air conditioner in reverse. To understand how a heat pump works, it helps to know how an air conditioner works.