... to install. Fiberglass FRP Axial Ventilation Fans for Chemical, Medical, dyeing and printing industryApplication:smoke ventilation fans;portable ventilation fan,tunnel ventilation ... .6, No6.3, No7.1, No8, No9, No10, No11.2.The Impeller angle could be installed into 15°, 20°, 25°, 30 ... °, 35° . So the air volume and power of each fan is different.Of course, Fans ...