> Even when it is below freezing outside? Yes. For instance, one of the heat pumps in my house has a coefficient of performance of 3.2 at 17F/-8C. Reference:

> Even when it is below freezing outside? Yes. For instance, one of the heat pumps in my house has a coefficient of performance of 3.2 at 17F/-8C. Reference: https://ashp.neep.org/#!/product/51106 https://ashp.neep.org/#!/product/51106