"220V Cooling Fan" is very widely used, and sometimes requires a different fan speed to meet demand. Some vendors specially designed adjustable fan speed cooling fan, manual and automatic modes. Manual is designed to allow users to use low speed in winter to obtain a low noise, high speed to get a good cooling effect in the summer. Automatic class thermostat "220V Cooling Fan" Usually with a temperature sensor, according to the current working temperature control fan speed, temperature is increased by high speed, low temperature, then reduce speed to achieve a dynamic balance, thus so that the cooling effect of wind noise and maintaining an optimal combination of points. "220V Cooling Fan" can bring a lot of air flow, but the pressure is small, the wind not blowing the bottom of the radiator, on the contrary, it often means big pressure on the small amount of wind, not enough cold air and heat sink heat exchange, the cooling effect will be bad.