About "220V Cooling Fan" noise problem in the cooling fan use is a commonplace problem. If it is found in the use of the AC fan noise is too large, to check the bolts to see if loose. Also check the AC fan impeller is not loose, often alternating fan noise and leaves are all inextricably linked to this, so once "220V Cooling Fan" appeared noise, many users will think to check the AC fans The impeller section. Cooling fan bearing vibration is running common failure, vibration can cause bearing fan and leaf damage, loose bolts, damaged housing duct failure, seriously endanger the safe operation of the fan. "220V Cooling Fan" bearing vibration causes more excessive, such as to analyze the reasons for taking the appropriate approach for different phenomena, often play a multiplier effect.