System for controlling the differential pressure of a room having laboratory fume hoods

摘要: A system whereby the pressure of a room containing one or more fume hoods, such as laboratory, is to maintained at predetermined level relative reference space in building, which may be an adjacent corridor like. The involves controller part heating, ventilating and air conditioning apparatus building. type can receive electrical signals from each hood controller, are proportional volume that being exhausted through hood. indicating communicated controllers enable modulate supplied thereby maintain differential desired with relatively quick response times.