How do Heat Recovery units work?
Usually sited in the roof space, and connected to individual rooms via ducting, the unit sucks stale air out and recovers two-thirds of the warmth through a cross-flow heat exchanger. Fresh air brought in from the outside through a separate grille then passes through the heat exchanger and picks up the warmth, before being circulated through the building. There is no mixing of air flows: all that is transferred is the heat. The heat exchanger also incorporates a filter to trap pollens and other allergens.
