Cooling fan is essential to all systems that produce a large amount of heat. It can take away heat by air convection to guarantee those system in working order. So, cooling fan is widely used in telecom, power supply, medical & health care, industrial & instrument, Computer & IT, Led lighting, Transportation, Home & hotel electrics etc.

Normally, the RPM will increase with increasing of voltage, and then air flow also will increase. So, they are directly proportional.

There are four parts for a fan, frame, impeller, motor kit and lead wire.

AC Brushless fan, DC brushless fan, DC brushless centrifugal fan, DC motor, EC fan, Fan guard

Selecting a fan involves a variety of factors which should influence your decision. First, you should have a knowledge of its working environment, mounting direction and position; also you should consider your budget for whole project. Normally, DC fans offer as good (mostly better) airflow at much lower power consumption than AC fans. Meanwhile, DC fans also operate with lower motor noise. Of course, DC fans are generally more expensive than AC fans. So, you should comprehensively consider these factors and make a correct choice.

Concerning cooling fans, there are two primary types of motors, known as AC and DC motors. In AC fans, the flow of electric charge periodically reverses direction. But in DC fans, the flow of that electric charge is only in one direction.

AC/DC fan is an important component for heat dissipation.AC fans operate by being connected directly to standard power, which is what creates the energy and force needed to run the fan's motor.AC fans are normally suitable voltages: 110V, 220V. DC fans have a transformer which converts the standard power to DC. The effect is that it decreases the amount of power used on all fan speeds, as the fan is only utilizing a direct current instead of an alternating current. DC fans are usually available at some nominal voltages: 5V, 12V, 24V and 48V.

AC (alternating current) motors primarily differ from DC (direct current) motors in the way their names suggest: AC motors convert electrical energy to mechanical energy using alternating current while DC motors use direct current. Direct current is supplied by batteries, fuel cells and other power sources that provide current that travels in one direction. Alternating current, on the other hand, is the kind of current provided from an outside source (like a power plant) via a wall outlet.