"Waterproof Cooling Fan" in addition to the cooling effect of the fan's operating noise is also widespread concern. Fan noise is the size of the generated noise of the fan work, influenced by many factors, in decibels (dB). When measuring the noise of the fan needs to be less than 17dB noise silencer chamber carried away from the fan a meter, and the fan air intake port is aligned along a direction "Waterproof Cooling Fan" shaft, the use of A-weighted manner measurement. The spectral characteristics of the fan noise is also very important, so we must also use a spectrum analyzer records the fan noise frequency distribution, the general requirements of the fan noise to be as small as possible, but can not exist different tone. "Waterproof Cooling Fan" noise and friction, air flow related. 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.