... supermaket, chemical plants, big factory workshops etc.Negative-pressure ventilating fan series are designed scientifically. Low cost, low noise, good ... hall, waiting room etc.3. Agriculture field: large farms, green houses, animal houses etc. StyleModelSize(L*W*H)mmInput power ... -900B1000*1000*4000.55 shutter, frame, wind set, fan blade are galvanized9FJ-1000B1100*1100*4000.759FJ-1250B1385*1385*4001 ...