Why is the price of DC fans more expensive than AC fans, you will understand after comparing the two
Advantages of DC fans
Let us first introduce the related concepts of DC fans and AC fans for everyone.
AC AC fan
The AC fan uses an induction motor powered by alternating current, which can directly use the alternating current in the socket, without the need for an additional transformer, as long as it is plugged into the power supply to operate. The power supply voltage of the AC fan will alternate between positive and negative, and the motor speed is proportional to the power frequency. The higher the frequency, the faster the speed. When the AC induction motor is running at a high speed, it is easy to cause problems such as unstable rotation speed, overheating of the fan, noise, and even failure to start.
DC direct current fan
The DC DC fan uses a DC brushless motor, which requires a transformer to convert the alternating current into direct current, and then supply power to the fan. Most of the interior of DC fans are high-efficiency permanent magnets, which replace the copper-clad design of traditional AC fans. After power-on, the principle of current magnetic effect is used to drive the fan blades to rotate. The DC motor has high transmission efficiency and can reduce the frictional kinetic energy consumption during operation. The motor is not affected by the frequency of the power supply, and can maintain a stable running speed whether it is a low wind speed or a high wind speed.
Next, we will compare the two in detail from the three aspects of power consumption, air supply and quietness.
Power consumption comparison
The power consumption of the fan is generally measured in (KW/hr). For example, if the electric power is 40 watts, it means that the power consumption of the fan is 40 watts for one hour, and the power consumption of the fan only reaches 800 watts after 20 hours of operation. The power consumption of an AC fan is about 40-60 watts, while that of a DC fan is about 2-25 watts. Although the actual power consumption will vary according to the number of wind speeds, DC fans generally save 30% - 60% of electricity compared to traditional AC fans. about.
Due to different motor designs, the power consumption of DC fans and AC fans is different. Most AC fans use induction motors, with only 40%-50% conversion efficiency, and the remaining 50%-60% will be converted into heat. The DC fan uses a DC brushless motor, and the conversion efficiency is as high as 80%-85%, and only 15%-20% will be converted into heat. The DC fan has better conversion efficiency, reduces the heat generated during operation, and is more energy-saving.
Air volume comparison
The DC fan can blow out about 1.5 to 4.3 cubic meters of wind per minute per watt, while the AC fan is only 1 to 1.4 cubic meters per minute. It can be seen that the DC fan has a more ideal air supply performance. The wind speed switching of the AC fan is generally only 3-5 stages, and the wind force is also concentrated, and it is easy to feel uncomfortable after blowing for a long time. There are generally more than 5 gears for switching the wind speed of the DC fan. The lower wind speed can create a cool feeling like natural wind, and easily adjust the air volume that suits you. Compared with traditional AC fans, the wind speed and air volume of DC fans are more comfortable and soft.
Fan noise is mainly caused by the number of blades and the motor. When the number of fan blades is larger, the noise and wind shear generated are smaller. AC fans usually have 3-4 blades, while DC fans generally have more than 5-9 blades, which can greatly reduce the volume of wind cutting. In addition, the DC motor used in the DC fan can effectively reduce the noise generated when the fan is running. The operating sound is only 15 decibels at a minimum, which is more quiet than the AC fan.
