Overflow openings are essential components of a comfort ventilation system that enable the exchange of air between different rooms. They ensure that the supplied fresh air can flow from supply air rooms to extract air rooms without doors or windows having to be opened. This ensures a continuous supply of fresh air and contributes to the energy efficiency of the building. In addition, overflow openings help to prevent moisture accumulation and mold growth by ensuring even air distribution. Their integration into the ventilation system therefore makes a significant contribution to a healthy and pleasant indoor climate.
The air velocity under the door should not exceed 1.5 m/s. For an air volume of 30 m³/h, a gap of 0.7 cm is therefore required for an 80 cm wide door.