They can be made to work in the cold but....
Though Ventusky says no -40°C (or °F, the scales cross at that point) right now, I would not want to depend on a heat pump in the center of Greenland in midwinter.
From Knowable Magazine, November 1:
Innovative thinking has done away with problems that long dogged the electric devices — and both scientists and environmentalists are excited about the possibilities
It was an engineering problem that had bugged Zhibin Yu for years — but now he had the perfect chance to fix it. Stuck at home during the first UK lockdown of the Covid-19 pandemic, the thermal engineer suddenly had all the time he needed to refine the efficiency of heat pumps: electrical devices that, as their name implies, move heat from the outdoors into people’s homes.
The pumps are much more efficient than gas heaters, but standard models that absorb heat from the air are prone to icing up, which greatly reduces their effectiveness.
Yu, who works at the University of Glasgow, UK, pondered the problem for weeks. He read paper after paper. And then he had an idea. Most heat pumps waste some of the heat that they generate — and if he could capture that waste heat and divert it, he realized, that could solve the defrosting issue and boost the pumps’ overall performance. “I suddenly found a solution to recover the heat,” he recalls. “That was really an amazing moment.”
Yu’s idea is one of several recent innovations that aim to make 200-year-old heat pump technology even more efficient than it already is, potentially opening the door for much greater adoption of heat pumps worldwide. To date, only about 10 percent of space heating requirements around the world are met by heat pumps, according to the International Energy Agency (IEA). But due to the current energy crisis and growing pressure to reduce fossil fuel consumption in order to combat climate change, these devices are arguably more crucial than ever.
Since his 2020 lockdown brainstorming, Yu and his colleagues have built a working prototype of a heat pump that stores leftover heat in a small water tank. In a paper published in the summer of 2022, they describe how their design helps the heat pump to use less energy. Plus, by separately rerouting some of this residual warmth to part of the heat pump exposed to cold air, the device can defrost itself when required, without having to pause heat supply to the house.
The idea relies on the very principle by which heat pumps operate: If you can seize heat, you can use it. What makes heat pumps special is the fact that instead of just generating heat, they also capture heat from the environment and move it into your house — eventually transferring that heat to radiators or forced-air heating systems, for instance. This is possible thanks to the refrigerant that flows around inside a heat pump. When the refrigerant encounters heat — even a tiny amount in the air on a cold day — it absorbs that modicum of warmth....
....MUCH MORE
Come to think of it I would not want to depend on anything in the center of Greenland in midwinter. Check Ventusky around January 10, the place is crazy cold.
