More specifically, they take an efficiency hit around freezing temperatures because of the need to periodically go into defrost mode to melt ice build-up on the outside condenser coil. When in defrost mode, the auxiliary heating strips come on to counteract the cold air that is being generated (defrost mode is actually "air conditioning"). As the outside temperature drops, the number of BTUs that the unit can produce drops and it might be necessary to have the auxiliary heating strips come on to maintain the temperature set point. There are robust heat pumps for cold temperatures. They aren't needed around here.
Quote:
Originally Posted by CWGUY
 I'm sure the Toymeister will explain it better than I could.
From a 10 second search:
Heat pumps don't work well below 25-30 degrees Fahrenheit. But what you might not know is that the heat pump temperature range is broader than most people think. |