With central living room ventilation, the ventilation unit is located at a central location, e.g. in the cellar or utility room. The unit is connected to the living rooms via an air duct network for fresh air and exhaust air in the floor or ceiling. A house is divided into supply air, extract air and intermediate overflow zones. Supply air zones are, for example, bedrooms, living rooms and lounges, the exhaust air areas include kitchen, bathroom, toilet and utility rooms, the corridor is a so-called overflow zone. Used air is removed from the exhaust air areas and fresh outside air is sucked into the house in the same quantity by the ventilation unit. The fresh air is distributed with the room air via supply air valves in the ceiling or in the upper wall area and automatically flows back into the exhaust air rooms via the overflow areas. The used air is "extracted" from the exhaust air spaces; here a door gap is sufficient to ensure an overflow from room to room. The pressure difference between supply air and exhaust air creates an air flow - the basis for controlled ventilation. However, this air flow is very gentle and silent. The supplied fresh air and discharged exhaust air are always kept in balance in a controlled manner (constant volume flow).