"24V DC Cooling Fan" of the composition is very simple blades, motors, bearings and frame. But a fan to do air volume, mute, and even speed-controlled, or require a lot of technical support for some. "24V DC Cooling Fan" motor usually brushless DC motor, the principle junior high school had a no nonsense here. The difference is larger bearing design. And mechanical hardware aspects of the bearing is different, bearing in the form of contact here refers to the way "24V DC Cooling Fan" rotor and stator, which largely determines the size of the fan noise.