Centrifugal Cabinet Fans – BDF
Duct mounted supply, exhaust, or return air fans shall be of the centrifugal, belt driven, inline type. The fan housing shall be of the rectangular design and constructed of heavy gauge galvanized steel, and shall include rectangular duct mounting collars on the inlet and outlet. Removable panels shall be provided on each side of the fan cabinet, and shall be of sufficient size to permit access for service to all of the fans internal components without further dismantling of the cabinet. The fan wheel shall be of the galvanized steel, forward curved, centrifugal type. Wheels shall be statically and dynamically balanced. Motors shall be of the heavy duty type with permanently lubricated and sealed ball bearings. The wheel shaft shall be ground and polished steel mounted in permanently sealed bearings. The bearings shall be selected for a minimum L10 life in excess of 100,000 hours (L50 average life of 500,000 hours) at maximum cataloged RPM. Drives shall be sized for a minimum of 150% of the driven horsepower. Pulleys shall be of the machined cast type, keyed and securely attached to the wheel and motor shafts. The motor pulley shall be adjustable for final system balancing. Heavy gauge galvanized steel mounting rails shall support the drive assembly, motor, wheel, and scroll.