Ball bearing mounted small room ventilator with automatic louvre. The louvre opens automatically after approximately 30 seconds of operation. The fan is additionally equipped with an overrun relay, which is adjustable from 2 to 30 minutes, and with a hygrostat, which is adjustable from 60 to 90 percent. Ideally suited for ventilation in small and medium-sized rooms, such as kitchens, toilets, or bathrooms. Suitable for wall and ceiling mounting.