"24V DC Cooling Fan" main role is to heat, and radiators are required by forced convection fan to accelerate heat loss, so a fan is good or bad, on the whole cooling effect plays a decisive role. With an excellent performance of the CPU fan is one of the key factors to ensure the smooth functioning of the entire computer. Because as the ambient temperature changes, sometimes "24V DC Cooling Fan" requires a different speed fan to meet demand. Some manufacturers specially designed heat sink can adjust the fan speed, manual and automatic modes. Manual is designed to allow users to use a low speed in the winter to get low noise, high speed to get good cooling effect in the summer. Automatic class radiator thermostat with a temperature sensor in general, according to the current operating temperature (such as the heat sink temperature) automatic control "24V DC Cooling Fan" speed, then increase the speed of high temperature, low temperature, then reduce speed in order to achieve a dynamic balance, so that the cooling effect of wind noise and maintain an optimal combination of points.