A ventilation appliance is usually mounted in your attic or utility area, connected via ductwork to ceiling terminals. One fan extracts stale warm air through these terminals from your wet rooms (kitchens, bathrooms etc) and takes it to the ventilation appliance to be exhausted outside.

Meanwhile, another fan draws fresh filtered air from outside and supplies it through ceiling terminals in the habitable rooms of your home (bedrooms, dining rooms, studies, living rooms).

In warmer months, the heat recovery process can be bypassed to ensure that cooler fresh air enters the home.