How does the noise of cooling fan come into being?
The unit of fan noise is decibel (dB). Fan noise is the amount of noise produced by the fan when it works. It is affected by many factors, such as friction and air flow.
The higher the speed of the fan and the larger the volume of the fan, the greater the noise will be. In addition, the vibration of the fan itself is also a factor that can not be ignored. Of course, the self-vibration of high-quality fans will be very small, but the first two are difficult to overcome. To solve this problem, we can try to use larger fans. In the case of the same air flow, the working noise of large fan at lower speed is less than that of small fan at higher speed. Another factor that we can easily overlook is the bearing of the fan. Because of friction and collision between shaft and bearing when fan rotates at high speed, it is also a main source of fan noise.
The measurement of fan noise needs to be carried out in a muffler with noise less than 17 dB, one meter away from the fan, and aligned with the fan's inlet along the direction of the fan's rotation axis. A-weighted method is used to measure the fan's inlet. The frequency spectrum characteristics of fan noise are also very important, so it is necessary to record the frequency distribution of fan noise with a spectrum analyzer. Generally, the noise of fan should be as small as possible, and there can be no abnormal sound.
How does the DC cooling fan work?
What's the difference between DC fans and AC fans?