The fan of the CAB-D series are particularly designed for air extraction, supply or filtration. Their main characteristic is the low noise level which makes them ideal for urban environments (apartments, houses, restaurants, gymnasiums, offices) and industrial sites where radiated noise is a problem. The low noise level is due to that is plenum, lined with acoustic material that allows a remarkable reduction of noise level inevitably generated by the fan. The blower consists of a double inlet forward curve centrifugal fan with built-in motor.