This article doesn't mention one of the main points heat pump gurus have been banging on about for ages - temperature compensation. Essentially, the colder it i

This article doesn't mention one of the main points heat pump gurus have been banging on about for ages - temperature compensation. Essentially, the colder it is outside the hotter you run the flow temperatures. You ideally want this setup so that there is very little intervention from an external thermostat, the balance of flow temperature and heat loss can be set such that one perfectly offsets the other. It's the secret sauce which can take the heat pump from expensive toy to practical replacement for gas. The payoff time is still too long but at least it exists!