An energy-efficient HRV is one of the best ways to control indoor air quality. An HRV saves on energy costs compared to conventional ventilation systems because it recovers heat from exhausted air. The HRV exhausts stale air and passes it through a heat exchanger. The exchanger transfers the heat to the fresh incoming air before it exhausts the stale air to the outside. The HRV must be balanced to maximize performance and not affect the house pressure.

The warmed, outdoor air is distributed through an existing forced-air distribution system or a dedicated ductwork system in a balanced manner.

A balanced-flow ERV also recovers heat from exhausted air, but in comparison to an HRV, it does not remove as much moisture from the house. These features are recommended where cooling load demand is high or where the relative humidity (i.e. humidity level) tends to be on the low side (e.g. in northern Canada). Thus, an ERV can help to keep the house from drying out.

A major advantage of HRVs and ERVs is that their controls give the homeowner the ability to manage and even turn off the ventilation system instead of the weather controlling the rate of air change. Unfortunately, the majority of HRVs are not installed or maintained properly. HRVs and ERVs must be installed and commissioned properly by a certified technician. Like all HVAC equipment, once properly set up, HRVs and ERVs must be serviced regularly. The homeowner should be able to do this because this requires only cleaning filters and checking components as noted in the service manual for the unit. Visit the Heat/energy recovery ventilators section of our website for more helpful tips.