... axial ventilation fan,ventilator,rectangular duct fan,noiseless exhaust fan,heavy duty exhaust fan,tunnel ventilation fan, vane axial fan,centrifugal ... chemical plants, big factory workshops etc.Negative-pressure ventilating fan series are designed scientifically. Low cost, low noise ... the heat in the workshop.Ventilating fan is applicable for these areas: 1. Industrial field: textile, clothes making, ...