"Micro Cooling Fan" noise and conflict force, air activities. Fan speed, the greater the amount of wind, the greater the noise will constitute another fan itself is not enough to ignore the elements of sensation. Of course, fans of high-quality sensation in itself will be small, but the first two were is difficult to overcome. To deal with this problem, we can test the use of large-scale "Micro Cooling Fan". Should be under the same amount of wind conditions, a large fan at low speed operation noise is less than the small fan at high speed operation noise. Another factor is our simple negligence fan bearings. Because the fan speed bump transition to a conflict between the shaft and the bearing, it is also a main source of "Micro Cooling Fan" noise.