2001 Airfoil Belt Drive Tube Axial Stack - Cap Roof Ventilator. Model: TASC24007503BD. Fan diameter: 24 in. Cast aluminum blades. The Airfoil design is highly efficient. Designed to move large volumes of air at low operating cost, the blades are non-overloading to prevent motor burnout. Baldor industrial motor, 3/4 hp. Inlets/outlets: (2) 2 ft. 7 in. dia. ports. Overall dimensions: 3 ft. 9 in. L x 3 ft. W x 4 ft. 10 in. H.(ACN22a).