Still better than electrical resistive heating (space heaters) which has a COP of 1. Even when it's super cold outside, heat pumps with a HPSF around 10 would

Still better than electrical resistive heating (space heaters) which has a COP of 1. Even when it's super cold outside, heat pumps with a HPSF around 10 would still have a COP around 2. See the graph: https://www.researchgate.net/figure/e-efficiency-of-an-Air-Source-Heat-Pump-at-different-ambient-air-temperatures-and-with_fig1_266471673 https://www.researchgate.net/figure/e-efficiency-of-an-Air-S... Of course space heaters are far easier to move around the house compared to a mini-split system and would use less power if you only plan to heat a small room.