The centrifugal fan consists of an external rotor motor with a plastic or metallic backward curved impeller assembly. Centrifugal backward-curved fans are used mainly for intake suction. It is used for continuous operation. Centrifugal fans have very good efficiency and a low noise level. These centrifugal fans are used in applications such as air conditioning units and in clean room equipments. High Hydraulic Efficiency Range Ø190mm to Ø400mm. Air flow 570CMH to 3150CMH Static Pressure 180 Pa to 250 Pa Noise Level 53dB(A) to 68dB(A)