I don’t know much about heat pumps, but don’t they draw heat from ambient air around the units? How does that work when it’s 10 degrees below?
Not very good. I had a home with a heat pump. It feels like a constant cold drafty air being pushed over you when it’s very cold. I have a natural gas furnace now. Still forced air, but at least it is warm. My favorite was when I was a kid. We had a coal furnace with radiators.
Correct, heat pumps are not efficient in low temps. Electric heating strips will do the job but use enormous amounts of electricity