US Patent 7544122 Air shutter and installation method thereof

An air shutter of low cost, high efficiency, and easy maintainability is provided, which can interrupt efficiently the flowage of air across a doorway when the door is open based on the consideration of the experimental data of the flowage of air across the opening area of the doorway of a cold storage. The air shutter comprises a gatepost 12 and a gatepost 13 installed at both sides of the opening area of a doorway. The gatepost 12 is provided with a lower slit nozzle 12a, a suction opening 12b, and lower fans 12c and a suction duct 12d inside thereof, on the other hand, the gatepost 13 provided with an upper slit nozzle 13a, a suction opening 13b, and lower fans 13c and a suction duct 13d inside thereof.