* https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.c...
If you live in US IECC Climate Zone 4 or above look for a cold climate air-source heat pump (ccASHP):
* https://neep.org/heating-electrification/ccashp-specificatio...
* https://ashp.neep.org/#!/
You can also get things installed in a dual fuel arrangement where you still have a gas furnace that kicks in if it does ever get 'too cold'.