Heat pumps are popular in VT where it does go down to -40 somewhat regularly. Most places still have a backup heat for the really cold days - either wood stove and/or oil.

[–] [email protected] 6 points 5 days ago (2 children)

heat pumps are great and i love the idea, but for places where it gets really cold your right that backup heat is still required.

[–] [email protected] 6 points 5 days ago

I’m on oil (and a renter so it’s not like I have a choice) but a friend of mine is on a heat pump and loves it. She has backup heat too, a wood stove and I believe either heating oil or gas. But most of the time she runs the heat pump and the wood stove.

[–] [email protected] 2 points 5 days ago* (last edited 5 days ago)

I have one in Wisconsin, and this last week has had a few exceptionally cold days. Those days, the heat pump doesn't go at all, but most days, it does.

Here's what the usage looks like over the past week:

Dark red is the furnace, light red is the heat pump. Green line is outdoor temperature, and you can see we've had some wild swings over the past week. Yellow line is the 71F inside temp. You can see that even on a 25F day (Dec 6), it was predominantly using the heat pump. That tends to be a fairly typical temperature in a Wisconsin winter most of the time.