> So if you are in a basement that is cold and the outside is hot it will just bring in outside air instead of turning on the heater. Uh. Purpose of the HRV i

> So if you are in a basement that is cold and the outside is hot it will just bring in outside air instead of turning on the heater. Uh. Purpose of the HRV is to attempt to preserve the inside heat (usually both latent and sensible, using a rotating exchanger wheel) while bringing in fresh outside air. They allow you to seal the building up really good, which is good for energy efficiency, without having insufficient ventilation and getting high CO2 levels. Because they're not perfectly efficient, you can use them to move the inside temp closer to outside-- but just plain outside air exchange would do it better. :)