it look,s like science fiction but it is not
it is possible to heat your home with air from outside where it is cold.
using an airconditioning unit.
When you use an good energy efficient air conditioning with an heatpump.
it is possible to get four times more energy out then you put in.
so if you want to buy one what is important.
first thing to look for is the COP value.
This value tell,s you how much energy you can get from 1 kw/h
so if you have an COP of 4 you get for every KW/h 4 KW/H return.
Where do you live
If it is very cold say -20 degrees the effeciency of an airconditioning is not enough.
How greater the temperture diffrence the lower the COP value
-5 is still enough to heat your home
For more information look for inverter airconditioning with R-410A gas