What to consider when choosing a cooling fan?

What to consider when choosing a cooling fan ?

First, the cooling fan must be able to provide enough air volume (i.e. rotational speed) to keep the hot air in the cooling device at a high temperature, and when the hot air temperature is low or the hot air flow is small, it works in reverse.
      Secondly, when installing the sensor, be sure to choose the correct position to ensure that it can be placed in the right position. Whenever possible, clamp the sensor directly to the surface to be dissipated. In operation, with a temperature-controlled fan, if the heating temperature is high, the regulator will feel it rev faster, while at lower temperatures, there is little change in fan speed between these high and low temperatures. When the temperature changes slowly, when the fan speed changes slowly, it will not suddenly change the cooling fan speed and noise. The response time depends on the length of the sensor and its thermal sensitivity.

The purpose of the cooling fan: using a large windmill fan in the upper power supply case can absorb the heat of the CPU in time, but it will also increase its own temperature; the power supply temperature of the small fan will be lower, which can avoid the airflow dead zone at the top of the case. If it is a chassis with a power supply at the bottom, the big windmill fan directly enters the air from the outside of the chassis, the power supply will be very cool, which is conducive to the stability of the power supply and prolongs the service life, but the dust will be relatively large; the power supply of the small fan will not be very cool, Nor will it be a vacuum cleaner. Some people like to install the bottom windmill power supply upside down, if you are interested, you can try it. For a fanless power supply, when there is a positive pressure air duct, most of the heat will be discharged outside the case; with a negative pressure air duct, most of the heat will be discharged into the case. In addition, the fanless power supply has many openings, which will bring certain inconvenience to the design of the air duct of the chassis, and special attention should be paid to it. Heat dissipation is a must for industrial equipment, including today's mobile phones. If the cooling effect is not good, it is especially easy to crash.