COP = heat (or cooling) delivered in BTUs/hour divided by the electrical energy consumed to do so, measured in BTUs/hour. How do we do that? 1 Watt of electrical energy consumed for an hour (one Watt-Hour) = 3.413 BTUs/hour. COP is a nicer measure than EER in that it doesn't...
The key to the best heat pump in the winter is the HSPF rating. It determines how well does a specific unit uses electricity for heating. HSPF rating of mini-split heat pumps ranges from 8 HSPF to 10 HSPF. Exceptional heat pumps can, on occasion, have an HSPF rating beyond 10. Obvious...