DC fan speed is the number of revolutions of the fan blades per minute, in rpm. The fan speed is determined by the number of turns in the motor, the operating voltage, the number of fan blades, the angle of inclination, the height, the diameter, and the bearing system. There is no necessary connection between speed and fan quality. The speed of the fan can be measured by the internal speed signal or by external measurement.

     As the application conditions and ambient temperature change, fans of different speeds are sometimes required to meet the demand. Some manufacturers have deliberately designed DC fans that can adjust the fan speed, both manual and automatic. The main purpose of the manual is to allow users to use low speed for low noise in winter and high speed for good heat dissipation in summer.

The automatic temperature-regulating radiator usually has a temperature-controlled sensor, which can automatically control the speed of the fan according to the current working temperature. When the temperature is high, the speed is increased, and when the temperature is low, the speed is reduced to achieve a dynamic balance, thereby making the wind noise. Maintain a better combination with the heat dissipation effect.