This is based on the concept of draft-free ventilation, after the german concept of "zugfreie Haltung".
The system uses an additional air duct to that of normal vents allowing the air to be discharged with a circular flow and spread over a wide area. This means that instead of air coming at you from one point, it creates a swirl effect whereby the air is all around you. The draft-free diffused flow creates greater warmth or cooling for drivers and passengers by distributing even air flow around all parts of the body. The Comfort Vent will be fitted to passenger and commercial vehicles during manufacture.
If you note most newer german cars will have this central diffuser vent in the middle top of the dash.