A heat recovery ventilator (HRV) is a type of mechanical equipment that features a heat exchanger combined with a ventilation system for providing controlled ventilation into a building.
These units are typically installed in an attic, crawlspace, or storage/utility area.They require two connections to the outdoors – one to exhaust the stale indoor air and the other to bring in the fresh outside air. The inlet and outlet on the building exterior need to be distanced from each other to avoid cross contamination. It is preferred to have the inlet and outlet on different sides of the house.
Fresh air from the unit into the building’s interior can be supplied in two ways. A separate supply duct can carry the fresh air to a central location in the building. This supply outlet is best located where the air will not blow on people, since the air can be too cool or too warm depending on the season. The fresh air can also be placed into the existing duct work, typically, in the return duct.
The stale air from a building is typically drawn from the most humid locations – toilet room, bathroom and kitchen. An HRV works with bathroom, toilet room exhaust fans by continually drawing air from the bathroom, rest room. When the bathroom, rest room is in use, the exhaust fan boosts the exiting of humid air into the same duct used by the HRV. However, an HRV should not share the same exhaust duct as a range hood.