3 ms·

Well, heat pumps extracting from air would function until -35C (at least some models), but obviously the efficiency goes down a bit. But most do a fine job unti

Well, heat pumps extracting from air would function until -35C (at least some models), but obviously the efficiency goes down a bit. But most do a fine job until -20/-25C. For even colder climates, one can use ground source heat pumps. So this should not be a problem for heating purposes. Cheaper cooling designed heat pumps do not obviously function to so low temperatures, but all Nordic models for example will function just fine.

tzs 6y ago
To put some specific numbers on it, Mitsubishi's "Hyper-Heating" heat pumps claim 100% capacity down to 23℉ (-5℃), and 76% capacity down to -13℉ (-25℃). This is for their ductless mini-split systems. Fujitsu is similar. Mr Cool makes the claim [1] that theirs "can heat at 100% capacity at –5 degrees Fahrenheit, even with outdoor temperatures as low as -22 degrees Fahrenheit". I think Mr Cool is talking about a central system, and so they are claiming 100% with the outdoor unit at -22℉ (-30℃) and the indoor unit, presumably in your unheated crawlspace, is at -5℉ (-21℃). Mr Cool also claims cooling with an outdoor temperature up to 115℉ (46℃), which so far is under the max for much of Texas, so heat pumps are a good choice still in Texas as long as you get one of the newer models with the good low temperature performance. [1] https://mrcool.com/blog/introducing-mrcool-universal/ https://mrcool.com/blog/introducing-mrcool-universal/