I'm curious as to how low a temperature your heat pump will operate. I live in N...

apexalpha · 2026-05-03T15:34:14 1777822454

Mine can go until -25c they say: https://www.nibe.eu/en-eu/products/heat-pumps/air-water-heat...

We don't ever get those temps so I should be fine.

My biggest issue is not cold but mist. I live near a river in a valley and have underestimated how much mist hurts performance around ~1c outside.

It needs to defrost often, because of the high moisture content in the outside air where I live.

But it also has a normal, resistive heating 9kW backup. But for financial reasons this is considered 'emergency only'.

zihotki · 2026-05-03T16:53:59 1777827239

Keep in mind that heat pumps have a limit how much they can pump (it also depends on temp., there is less heat in 35F air). If your house is not well insulated, at a lower temperature it would be loosing more energy and eventually it would reach the threshold where it's performance is not enough to keep up.

testing22321 · 2026-05-03T15:24:08 1777821848

We got a heat pump in BC Canada, it’s rated down to -30C.

We also got solar, our entire power bill (all heating, cooking, lights, computers, etc) is $500 for the year. Best decision ever.

anotherhue · 2026-05-03T15:25:17 1777821917

That depends on the refrigerant, the new Mitsubishis are effective at that and lower temperatures.