There are two main heat dissipation methods for DC cooling fans, one is suction type and the other is blowing type. These two heat dissipation methods use different methods according to different occasions. The blowing type is to aim the cooling fan at the heat source and blow. , Is to suck in the cold air from the outside to replace the hot air inside, so that the heat does not always collect at the heat source, but dissipates around the heat source. This is a rapid heat dissipation method. This method dissipates heat faster, but the fan’s service life is shorter because it attracts more dust. The suction type is just the opposite. It drains the heat through the hot air inside the fan to the outside, and the other enters the cold air. An air duct takes in cold air while using a fan to discharge hot air. This kind of heat dissipation effect is a little bit worse, and the life of the heat dissipation fan will be longer.