HEAVY DUTY ALL-WELDED DIRECT DRIVE ROOF VENTILATORS 24" Diameter Fan - Single Phase 1HP Motor Roof ventilation fan is weatherproof to ensure long life. Industrial roof ventilator provides vertical discharge using enclosed, fan cooled motors. Rolled venturi surrounds fan within the 18 gauge galvanized steel wind band. Wind band has 2" double rolled edge top and bottom for extra strength. Rugged one-piece cast aluminum propellers are made with 1/8" to 1/4" thick blades and hub. Direct drive roof ventilator features rubber stop and gaskets under dampers. Heavy duty 14 gauge fan panels are welded to 10 gauge motor base. 24" Ventilator features 1/2" schedule 40 pipe motor base supports. Single Phase Motor is field convertible from 115V to 230V. Horsepower rating based upon maximum speed/load.