Since there are no combustion products, no venting to the outside is required nor often desired with heat pump water heaters. In a hot room, like a garage in the summer, it is nice to have the cold air output to cool the space.
In the winter the problem is more challenging for livable spaces. A cold garage becomes colder, but that’s ok since no one lives in that space. Venting does not help, since porting out the cold air requires the same volume to ingress to the air intake from the path of least resistance outside the room. This ultimately means pulling cold air inside the space from outside the home.
Certainly if the air in the space it occupies is very cold, the heat pump runs least efficiently (ambient operating range 37-145° F) and if cold enough only works in resistive mode.
In terms of physical space occupied by the water heater, the smallest 50G is 61" tall x 22-1/4" wide and the largest 80G is 74" tall x 24-1/4" wide.
Piggy backing off the ASHP central heater and looks like winter temp low averages 13ºF (-10 to -11ºC) in Waterloo, Ontario. That’s some challenging ASHP “terrain”. If you can pull that off in your climate, that’s fantastic.
Supposing in the basement, an ASHP gets a bit of ground source heat sink benefit– nice.
Yes, please check back in when you have winter numbers!
