As more home buyers come to accept whole-house ventilation as a necessity rather than an option, the question of heat recovery becomes an important consideration. Anytime you exhaust stale air and bring in fresh air, you are blowing out heat and replacing it with cold air that must be heated. This obviously increases a home's heating load. However, if some of the heat from the exhaust air can be recovered, the additional heat load is reduced. There are two ways to recover this heat — with air-to-air heat exchangers, or with ventilating heat pumps. This month, I want to talk about the ventilating heat pump. This technology is little talked about, but is a bit simpler to install than air-to-air heat