Mechanical ventilation system e.g. for apartment building has pressure detector controlling fan motor speed

摘要

The system consists of a housing (2) containing an extractor fan (3) driven by a motor (4) and connected by ducts (5) to the various apartments in a building. It incorporates a detector (13) for the pressure inside the housing, linked to a motor frequency or voltage regulator (9), so that the extractor fan maintains a constant pressure in the apartments and a pressure corresponding to atmospheric pressure when the temperature of the extracted air rises above a predetermined threshold level.