... FAN Product introductionThe special characteristics of farms fan1, big air volume design, the air volume of 4500m3/hour.2, the low consumption ... alkali resistant, durable, use fixed number of year long.6, air downstream principle shutters, no power, no switch, and can effectively ... /MINair volume M3/MIN400mm0.45220/380120140060certificates sales industrial ventilator fan,exhaust air use,quality good.