"220V AC Cooling Fan" axial fans, centrifugal fans in people's lives is widely used, it is used in the process also appeared in one way or another problem. According to reflect the point of view, most of the problem is derived from the axial fan noise. First thing to know is in the "220V AC Cooling Fan" voltage in certain circumstances, to enhance the speed of the noise will certainly be followed by a corresponding increase. Effects when axial fan blade impeller axial fans would use the following analysis. When the axial fan blades before its thin and excessive grazing, the center of gravity center of the blade root section, the centrifugal force and the instability caused by high speed air flow changes caused by the blades into the lift, it is easy to excite blade vibration. Meanwhile "220V AC Cooling Fan" Because coupling, may also cause the blades galloping, so that leaves early fatigue damage, reduce fan efficiency, and greater aerodynamic noise.