"220V Cooling Fan" is divided into two kinds of centrifugal and axial flow. As the name suggests, axial direction of the wind along the fan axis direction, a direction that is perpendicular to the plane of rotation of the blades out of the wind; centrifugal direction of the wind along the blade is rotating surface diameter of yearning in all directions of the wind. CPU cooler basically using axial flow "220V Cooling Fan", by utilizing centrifugal fans only Coolermaster "Tornado" series. And from a practical point of view, when the centrifugal fan work out the wind can not be fully utilized, it will increase noise, so not a good choice. But the use of centrifugal "220V Cooling Fan" radiator relatively easy to do thin shape, so often been used in some video card cooling system.