"220V AC Cooling Fan" maximum with minimum loss of energy; for the impeller vanes, as well as the kinetic energy is converted into rotational movement of the pressure energy effect. Vane setting shown in Figure 4-9. After setting the impeller vanes, said after the wicket. After the "220V AC Cooling Fan" vane axial fans and axial set commonly used. Set in front of the impeller vanes called leading leaf. Currently, medium and small axial fan is often used leading leaf devices. Before and after "220V AC Cooling Fan" impeller vanes are set to be more than two types of integrated, rotatable leading leaf also for regulating working conditions. Although this type of work is good, but the structure is complicated, only for axial fans.