4-72 style centrifugal ventilator can be used in indoor ventilation for factories and big buildings. It’s used not only for air in but for air out. It delivers air or other gas with can not ignite by itself and is not harmful to people and corrosive to steel with the temperature not higher than 80 centigrade.
4-72 centrifugal ventilators may also be made into anti-explosion type ( B4-72) and roof type ( WT 4-72 ) whose power allocation is the same as 4-72.