A tight building exterior is undoubtedly state of the art in most new buildings these days. This makes it all the more important to ensure a continuous supply of fresh air to the building's interior. Retrofitting rooms with ventilation systems is complex and in many buildings space requirements and costs are limiting factors. In addition, the design qualities of rooms suffer from the installation of ventilation ducts and suspended ceilings. The patented Ventilation system "Air" solves these problems in an innovative way and impresses with above-average energy efficiency and significant cost savings.