Cold-weather residential heat pumps have gotten a lot better in the last 10 years or so.
Mitsubishi's residential air-source ductless mini-split heat pumps that have their "Hyper-heating inverter" technology are greater than 100% down to at least -13℉ (-25℃), although their capacity starts dropping fairly linearly from 100% at 23℉ (-5℃) to 76% at -13℉ (-25℃), so unless you oversized your system a bit you might have to put up with your house being a few degrees cooler when it gets very cold outside for a long time.
Their efficiency remains above 180% down to around -5℉ (-20℃).
In most of the major cities of Texas these would have worked fine and remained around 200% or higher efficiency and around 90% capacity. Only a small number of people would have had them get down to 100% efficiency.
Fujitsu and Daikon have similarly performing heat pumps.
That's interesting to know. I had this heat pump in Florida that couldn't keep up with an external temperature of 49 F. That kind of made decide they were useless. Maybe if at some point in the future I have to buy a unit I will reconsider it.
Recently the guy from Technology Connections on YouTube made a very good point:
Consider technology and tools as they are now, not as you last disliked them.
Mitsubishi's residential air-source ductless mini-split heat pumps that have their "Hyper-heating inverter" technology are greater than 100% down to at least -13℉ (-25℃), although their capacity starts dropping fairly linearly from 100% at 23℉ (-5℃) to 76% at -13℉ (-25℃), so unless you oversized your system a bit you might have to put up with your house being a few degrees cooler when it gets very cold outside for a long time.
Their efficiency remains above 180% down to around -5℉ (-20℃).
In most of the major cities of Texas these would have worked fine and remained around 200% or higher efficiency and around 90% capacity. Only a small number of people would have had them get down to 100% efficiency.
Fujitsu and Daikon have similarly performing heat pumps.