... frame, galvanized steel cover.Intake and Exhaust System: 1 unit 5.5KW double intake centrifugal fan, model YDW ... 15500 m 3/h, electric damper for exhausting.Purification System: Pre-filter, high efficiency filter, exhaust fiberglass filterRoof ... : Galvanized steel platesControl System: Fan operation switch, lighting switch, emergency stop;Install ...