... Air flow, high air pressure, low noise etc. The DF series blower fan is the form of impeller as follows ... :“leafy, forward direction, narrow wheel”, it has a series characters of big flow zone, accelerate circulation of fluid ... as follows: TypePowerKWFlow RateM3/hTotal Pressure Pa Noise≤DB(A)Rorate Speedr/minVoltageVDF-20.18406450722840380DF-30.25504860752840380DF-40.37660850762840380DF-50 ...