Fresh air ventilation. 

With the building regulations requiring properties to have more thermal insulation and draft free dwellings, fresh air ventilation systems are a way of exhausting air and introducing fresh air.

For WC’s, offices and a like which do not have an opening window, building control have started enforcing these systems.

With a heat exchanger built into the design, 70% of the heat can be replenished back into the room with the fresh air.