"Waterproof Cooling Fan" fan and the friction relating to the air flow. Fan speed, the greater the amount of wind noise caused will be greater, in addition to the fan's own shock factor can not be ignored. Of course, fans of high-quality shock itself will be very small, but the first two were but it is difficult to overcome. "Waterproof Cooling Fan" To solve this problem, we can try to use larger size fan. Should be at the same air volume, a large operating noise at a lower fan rotational speed must be less than the operating noise of small fan at high speed. Another factor is that we tend to ignore "Waterproof Cooling Fan" fan bearings. Due to the high-speed rotation of the fan to be friction between the shaft and the bearing collision, it is also a major source of cooling fan noise.