What is a Heat Recovery Ventilator (HRV) and how does it work?
A Heat Recovery Ventilator (HRV) is a device that serves a purpose opposite of that of economizer: it allows to dump the stale indoor air and accept fresh outdoor air without losing as much energy as you would if you just opened a window. This is important in tight new houses to prevent indoor pollutants from reaching unhealthy levels. A typical HRV uses two fans, one to expel household air and the other to bring fresh air in. The key feature of an HRV is its heat-exchange core, which transfers heat from the outgoing stream to the incoming stream in the same way that a car radiator transfers heat from the engine’s coolant to the outside air. The heat-exchange core is usually made up of multiple plates of aluminum or plastic separated by narrow passages through which incoming and outgoing airstreams flow. As the streams move through, heat is transferred from the warm side of each passage to the cold, without the airstreams coming into direct contact. Depending on the model, HRVs can rec
