"Brushless Cooling Fan" process in order to reduce the use of low-noise must note the following: System Impedance: air flow resistance will cause the air flow noise generation. Air turbulence: due to poor air flow channel design turbulence caused by the high-frequency noise will occur, if the stream channel does not improve very difficult to have a qualitative improvement. Fan speed and size: "Brushless Cooling Fan" cooling effect of the speed of the faster the better, the greater the larger the size of the fan air flow, heat the better. The larger the fan speed, the higher the noise, the greater the size of the larger noise. Increase in temperature: the temperature difference between the temperature rise is reduced, the cooling effect is reduced. Vibration: Vibration can cause the fan noise rise, reducing life expectancy and reduce speed. Voltage fluctuation: voltage fluctuations can cause the fan speed changes so unstable and will generate additional noise. "Brushless Cooling Fan" Design Considerations: Some other requirements for design must also be taken into account to ensure that the cooling effect.