Due to heat pump inefficiencies, they only make sense if you can get like a 3-4x multiplier out of them. Beyond that you break even energy-wise. Basically if it

Due to heat pump inefficiencies, they only make sense if you can get like a 3-4x multiplier out of them. Beyond that you break even energy-wise. Basically if it’s -10F outside, your heat pump isn’t going to be cheaper than a resistive heater. On the other hand when it’s 50F outside you do better than 4X.