What the other guy said. It's down to the fact that you aren't actually heating/cooling down a room, you're just moving the heat already there around. E.g. in winter, instead of producing your own heat with electricity, which is 100% efficient, you take heat from the outside and put it inside, using a lot less energy in the process than if you were to create the heat inside of your home.

Though I'm not sure if it's that efficient, I think I heard it's more around the 150-200% mark, but I'm not sure.

[–] Claidheamh@slrpnk.net 3 points 1 year ago* (last edited 1 year ago) (1 children)

I think I heard it's more around the 150-200% mark

Most cheap air conditioners have COPs (coefficients of performance) around 3.2-3.5, which means 320-350% efficiency. In real world conditions, the best systems reach 4.5, though the theoretical limit is about 8.0.

[–] chronically_crazy@lemmy.world 1 points 1 year ago

3.2-3.5 is also on a good day. It might not be as efficient when the outside temperature differences are further away from your thermostat setting inside, though if you have a geothermal setup, then you've got peak efficiency year round.