"Small Cooling Fan" Noise is most concern to the user, to meet the cooling subject to the conditions, the general level of noise as possible. Fan noise and friction, about the air flow. Fan speed, the greater the amount of wind noise caused by the greater will be another "Small Cooling Fan" their shock factor can not be ignored. Of course, high-quality fans will shake itself is small, but the first two were, but it is difficult to overcome. To solve this problem, we can try to use larger size fan. Should be at the same air volume, a large "Small Cooling Fan" operating noise at a lower speed is less than the small fan operation noise at high speed. Another factor is that we tend to ignore the fan bearings.