[archontes]

I'll ask my landlord to install one right away.

Probably have to be an earth-exchange system to deal with temperatures lower than 40°F, given that heating my house in winter is the use case.

[throw0101b]

Mitsubishis can work down to -13F/-25C and have a COP of 2.08:

* 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'.

[PaulDavisThe1st]

My Mitsubishi Hyperheat units have a COP above 1 down to -15F and still work normally at 5F (northern New Mexico, 6000', overnight). You're getting bad information.

[Volundr]

My Lennox system is break even COP at -10 iirc. By then it's also running the heat strip, but we only hit those temps once or twice a year.