The relationship between fan air pressure and air volume
The ratio of pressure is equal to the square of the air volume ratio and also to the square of the speed ratio.
Air volume refers to the amount of air flow caused by fan rotation per unit of time, or more simply, how much gas passes through the fan per unit of time. The larger the air volume of the fan, the greater the amount of air "sucked" in to participate in heat exchange per unit time, and generally, its heat dissipation effect will be more obvious. And wind pressure refers to the difference in air pressure between the fan's outlet and inlet. Simply put, it is a parameter used to describe how far the fan can blow air. The higher the wind pressure, the stronger the fan's channel, and the air will be blown further away.
Air volume and air pressure are a pair of mutually constraining parameters. Generally speaking, the larger the air pressure, the smaller the air volume, while the larger the air volume, the smaller the air pressure. Two identical fans, one with a higher air volume than the other, will definitely have a lower air pressure than the other.
Reasonable selection of fans
Due to the obstruction of fan heat patches or components in the airflow path during air flow, its impedance will limit the free flow of air. When the air volume increases, the air pressure will decrease. Therefore, there must be a good operating point, which is the intersection point between the fan performance curve and the wind resistance curve. At the working point, the slope of the fan characteristic curve is Z small, while the rate of change of the system characteristic curve is Z low. Of course, sometimes in order to reduce system impedance, even smaller fans can be selected to achieve the same air volume.
