A heat pump water heater will slightly cool and dehumidify the space around it. But the effect is typically subtle, and it can be avoided completely with the right installation.
Heat pump water heaters take heat energy from the air around them and move (or pump!) that heat into the water that you'll use for showering, washing, etc. When heat is removed from air, that air gets cooler.
We are often asked if the cooling effect of a heat pump water heater will make the surrounding room uncomfortably cool – and the answer, almost always, is no.
A typical heat pump water heater will cool the surrounding area to a similar extent as if you had a fridge and freezer, and left the doors open.
A heat pump water heater in a closet.
You can get a feel for this by leaving the doors open of your fridge and freezer in your kitchen. At first, there will be a rush of cold air "falling" out of your fridge. Then the fridge compressor will run, trying to cool the fridge, but just dumping the cold air into your kitchen. You'll start to feel that a fridge just isn't that powerful in terms of cooling a room – same thing with a heat pump water heater!
Heat pump water heaters are typically installed in garages, basements, or utility rooms where the slightly lower temperature is acceptable. In some cases, the lower temperature is actually desirable, like in an otherwise-hot garage in the summer!
If the only available location for a heat pump water heater is in the "conditioned space" of your home (the interior area that is heated by your home's heating system), then there are installation options that avoid the cooling affect inside your home. QuitCarbon will review your home and make recommendations about where and how to install your heat pump water heater.
In addition to slightly cooling the air around them, heat pump water heaters also dehumidify that air. When installed in an otherwise humid basement, this is like getting a dehumidifier that costs you nothing to run! Note that the dehumidification effect is relatively subtle, and if you have serious humidity issues, you should not rely on a heat pump water heater to solve them.