... ,light weightOver 15 years No power turbine ventilator parameterModel 300,500,600 ventilator generally refers to the diameter of caliber ... ,500 mm,600 mm.Subassembly parameter of different models ventilator as follows:ModelTurbine headdiameterDiameter of tubeWaterproof negativeBladeqtyMain material300430 mm300 ... indoor and outdoor is 0.35 0ÂșC,the ventilator begins to rotate when wind speed outside is 0 ...