Mini air cooling fan which written notice are there?

"Mini Air Cooling Fan" major issues
Using the process in order to reduce the low-noise must note the following:
System Impedance: Air flow resistance will cause air flow noise generation.
Airflow turbulence: "Mini Air Cooling Fan" due to poor design of the flow channel of air turbulence caused by high-frequency noise will appear, if it does not improve the flow channel is difficult to have a qualitative improvement.
Fan speed and size: the cooling fan speed sooner the better, the greater the larger the size of the fan air flow, cooling effect is better. Fans of turn
The higher the speed the greater the noise, the larger the size the larger the noise.
Temperature rise: after reducing the temperature difference between the temperature rise, the cooling effect is reduced.
Vibration: vibration will cause the fan noise increased, reducing life expectancy as well as the speed is reduced.
Voltage fluctuation: "Mini Air Cooling Fan" voltage fluctuations can cause the fan speed changes, so that job insecurity and will generate additional noise.
Design considerations: Some other requirements for the design must also be taken into account, in order to ensure the cooling effect.