Sounds like you might be after a cold-climate [0] heat pump. They'll use advances in things like variable speed compressors and flash / vapor injection to draw

Sounds like you might be after a cold-climate [0] heat pump. They'll use advances in things like variable speed compressors and flash / vapor injection to draw useful heat from the air at well below -5C, without the need for auxillary heat sources like resistance heat. I'm doubtful it was simply mis-communication. Another point of contention was that heat pumps can be over 100% efficient - to the point that asking "Will they be more than 100% efficient with outside temps at 15C or 25C, and in indoor target of 20C?" got an emphatic no. That's less a miscommunication than a poor education, IMO. [0] https://en.wikipedia.org/wiki/Air_source_heat_pump#In_cold_climates https://en.wikipedia.org/wiki/Air_source_heat_pump#In_cold_c...