Dayton downblast ventilators are roof-mounted for discharging dirty air from industries and commercial buildings. They operate continuously to vent foul air and odours under low to moderate static pressures. They have spun aluminium construction with a fully rolled windband bead for corrosion resistance, stability & portability and sealed / regreasable cast pillow block bearings for load support to the rotating shaft. These ventilators come without assembled belt drive packages that offer flexibility in terms of rpm speeds, as the motor is not directly in contact with the fan's moving parts. Choose from a wide range of these ventilators, available in wheel diameters ranging from 11 to 50 inches.