Cooling fan blowing form (on)

　　In the form of air cooling fan is the most widely used form of hair down with axial fans, why so popular is because the combined effect of good and inexpensive. In addition, there will be the direction of axial fans, in turn, into a form of upward ventilation, this approach seems to be becoming more and more common recently.

　　Two cooling fan air flow in the form of the difference lies in the different forms, generated when the blast is turbulent, but susceptible to wind pressure resistance big loss; generated when ventilation is laminar flow, pressure small but steady flow. In theory, the turbulent heat transfer efficiency is much greater than the laminar flow, and therefore did not become mainstream design form. But the flow of movement and the heat sink has a direct relationship. In some heat sink designs (such as too closely fins), airflow obstruction by the heat sink is very large, this time using the ventilation may have better results. The only problem with the design of the side of the blast, not usually at the top of the blast and the effect of any difference. The improved method is more effective to establish a dedicated CPU cooling duct, so they are not affected by the hot air near the CPU, the equivalent of reducing the ambient temperature. Fan

　　Axial fan though widely used, but there are inherent flaws. Axial fan motor position by blocking the air flow is not flowing through the middle of the blast area, which is called "dead zone." In a typical heat sink, the highest temperature precisely the middle of the fin. Because of this conflict, when the use of axial fans, cooling effect of the heat sink is not sufficient.