As per other posters, these are ASHP.Aren't those ground sourced heat pumps, not air sourced?
You are quite out of date on heat pumps. 25 years ago? Yes. Now? There are very good low temperature models available. You can get down to sort of 10-15F before you hit COP of 1.0
The high efficiency Air Source HPs have existed for quite a long time, in Japan and in Europe. Sweden and Norway for example now install a lot of *Air* sourced heat pumps (Air to Water mostly, I presume). Equivalent climates in the USA would probably be Wisconsin/ Minnesota.
When they started to be available in the USA, I am not exactly sure. Because HPs in the USA come from a cooling-led market (ie the southern states, primarily) the market was slow to adopt them. The distribution channel is the HVAC installers, and they are conservative by nature - no new-fangled anything.
But they are available now. As posters indicate above, I am being too conservative re performance. You can get above COP 1.0 at 0 degrees F.
Because of the structure of US retail prices for utilities - typically relatively cheap gas (compared to Europe) and higher electricity prices (on a per kwhr basis, equivalent for gas), the rollout of HPs for heating has been retarded. But it will no doubt come.
Statistics: Posted by Valuethinker — Thu Dec 11, 2025 4:09 am — Replies 51 — Views 3521