It is understood that "220V Cooling Fan" Speed is the number of revolutions per minute of the fan blades, the unit is rpm. Fan speed is determined by the motor inside the coil turns, operating voltage, the number of fan blades, angle, height, diameter and bearing systems. Fan speed and quality are not necessarily linked. "220V Cooling Fan" can be measured by the rotational speed of the internal speed signal, it can also be measured by the external. Automatic class radiator thermostat with a thermostat sensor in general, can automatically control the fan speed based on the current operating temperature, high temperature, then increase speed, low temperature, then reduce speed to achieve a dynamic balance, so that the wind noise maintaining an optimal combination of points and the cooling effect. For cooling "220V Cooling Fan" speed issues, from these data, I believe we all have an idea.