Including "220V Cooling Fan" fan, is a source of generating air flow, fan axis, to support balanced rotating blades, rotor magnetic, permanent magnets, magnetic level switch promote critical speed, magnetic frame, fixed ring There sickle, trapezoidal and AVC patent folding edge type. Relatively speaking, "220V Cooling Fan" sickle blades when quiet operation is relatively stable, but the pressure can be generated is also small; trapezoidal blades prone to greater pressure, but the noise is large. Fold edge type is the best design, "220V Cooling Fan" while maintaining low noise can have a greater pressure, but only for AVC own products. Currently appear more is sickle design.