Originally Posted by hooziewhatsit
It really is pretty impressive what they're able to do now.

Quote
Enjoy unparalleled heating performance from one of our all-climate heat pump systems with Hyper-Heating INVERTER® (H2i®) technology. Hyper-heating systems can perform at 100 percent of rated capacity in outdoor ambient temperatures as low as 5° F with guaranteed operation down to -13° F. Available in select systems, H2i plus® technology increases the performance to 100 percent at temperatures as low as -5° F.


https://www.mitsubishicomfort.com/blog/mythbusters-heat-pumps-for-extreme-cold-climates

The cold side expansion gets, well, cold. Depending on the heat pump, it's around -40F. If the air temperature is -5F, that's still 35 degrees of heat that it can capture and move inside.


I have a H2I and yeah it operates in the cold down to -15 but the problem is they can only run about 15 minutes below 0 before they go back to defrost for at least 10 minutes so they can't keep up. I checked it the other day @ 40 and it was producing heat at 115 well above the average of 55 over temp which would = 95.