AC "220V Cooling Fan" With the application and ambient temperature changes, sometimes requires a different fan speed to meet demand. Some vendors specially designed adjustable fan speed cooling fan, manual and automatic modes. Manual "220V Cooling Fan" is designed to allow users to use a low speed in the winter to obtain a low noise, high speed to get a good cooling effect in the summer. Automatic class radiator thermostat with a thermostat sensor generally, according to the current working temperature control "220V Cooling Fan" speed, speed is increased by high temperature, low temperature, then reduce speed to achieve a dynamic balance, so that the cooling effect of wind noise and to maintain an optimal combination of points.