Drum fan 
 Circular duct fan is our advanced technology designed draw new fans. Inlet and outlet duct is the standard design, the same diameter, both ends of the duct can be connected directly. New design of the chassis and high-efficiency centrifugal impeller design and performance of the rumored sub-components of the pipeline fan motor, small, small vibration, low noise, long life, high efficiency, security, performance, and easy installation. Widely used for hotel, restaurant, auditorium, conference rooms, offices, shopping malls, supermarkets, railway stations, airports and other public places, air supply and exhaust. 250 air volume air flow .330 .650 .450 air volume air volume air flow 1100 .1000 .1300 air volume air flow options. Product Structure: Piped exhaust fan series drum major from the shell, impeller and external rotor motor, junction box four parts. 
 1, shell: The quality can be cold-rolled deep drawing dies stretch from iron. Surface spray treatment, with a strong ability to engage in eclipse. The computer optimization of the flow channel design, so that the impeller to produce maximum efficiency. Inlet and outlet diameter of the same size as the standard pipeline design, easy installation, maintenance and cleaning. 
 2 / specifications Φ100mm; Φ125mm; Φ150mm; Φ160mm; Φ200mm; Φ250mm; Φ315mm.2, wheel: diameter Φ190mm; Φ220mm; Φ250mm; Φ280mm; Φ315. For the backward curved impeller design, impeller and housing are a good match overall, the fan can produce the maximum air flow and maximum efficiency, the most s noise. 
 3, external rotor motor: The single-phase asynchronous external rotor motor, the rotor of the motor home, impeller and motor rotor directly loaded by pressure from the impeller directly driven by the rotor, which can greatly reduce the fan size, and the smooth operation and high efficiency long life. 
 4, junction box: PVC by adding flame-retardant fiber material injection. Fire performance, use of safety. In the case outside the terminal easy disassembly.