How does ventilation with an extract air system work?

In the extract air rooms, a fan removes the extract air and guides it out of the building as exhaust air. The air heats up on its way to the extract air rooms, taking odours and moisture with it as it goes. The resulting underpressure pulls the outdoor air into the living and sleeping areas through a supply air vent. The supply air is filtered as it enters through the outdoor air vent.