The choice of cooling fan, direct current (DC) and alternating current (AC) have their own advantages and disadvantages, which one is better depends on the actual application scenarios and needs. The following is a detailed comparison of the two:

A, The power supply and voltage

AC fan: directly using AC power, such as 110V, 220V and other utility power, without additional power conversion.
DC fan: use DC power supply, usually need to convert AC power to DC power through the rectifier, such as 5V, 12V, 24V, 48V, etc.. If applied to the chassis, power supply, lights, etc., the internal power supply of the equipment for the DC power will be more suitable for use.

B, The air volume and cooling effect
DC fans: DC fans are widely used, mature technology programs, the speed can be made higher, so the air volume can often do more, better heat dissipation.
AC fan: due to technical limitations, its air volume is often smaller than the same specifications of the DC fan. However, in some application scenarios, such as air volume is not required, AC fans can also meet the demand. For example: the same specification 8038 fan, DC can do 6500 RPM, AC zui high 3000 RPM.

C, The size and function
DC fan: due to small devices (such as: power supplies, chargers, printers, chassis, communication instruments, switches, servers, etc.) usually the internal power supply for the DC voltage, so the application of a wide range of dimensions of 3CM or even smaller. Especially in the case of limited space, DC fans are more advantageous. And because small devices usually need to monitor the fan operating status and speed, DC wind support speed, signal feedback and other functions.
AC fan: the size of large and medium-sized, mostly used in industrial equipment and the internal structure of the equipment is relatively simple, such as wiring closet, the use of AC power supply is not only more convenient, but also do not need to adjust the speed and other functions. Then if you need power supply for AC but also need speed control function, you can choose EC fan, EC fan that is AC to DC, power supply is still AC, but the internal circuit of the fan is converted to DC, the motor is still a DC motor, taking into account the higher speed of DC, speed monitoring function, low power consumption, low heat, high performance, high stability, simplified structure and many other advantages.

D, Noise and life
DC fans: usually have lower noise and longer service life. The motor structure of DC fans is relatively simple and does not require the use of starting capacitors, which reduces the aging of capacitors and the possibility of failure. Also, DC fans have good speed regulation and can be adjusted as needed to reduce noise.
AC fans: Noise and speed are directly proportional to each other. AC fans cannot be speed-regulated, are relatively noisy in some cases, and may have a slightly shorter service life than DC fans. The motor structure of AC fans is more complex, and requires the use of a starting capacitor, increasing the possibility of failure.

E, Safety
DC fan: using DC power supply, the voltage is relatively low, so the safety is higher. It is safe to work even under 48V.
AC fans: use mains power as a source of supply, the voltage is higher and there is a danger of electric shock. Therefore, special attention needs to be paid to safety when using AC fans.