Do you know DC Fan Pressure ?

"DC Fan" Pressure: changes to normal ventilation, ventilation fan stroke to overcome resistance within the fan must overcome the air resistance generates a pressure, measured pressure value is called static pressure, ie, the maximum static pressure and atmospheric pressure differential pressure. It is the role of gas parallel to the surface of the object and static pressure is measured by a surface perpendicular to the hole out. The gas flow in kinetic energy into pressure needed form is called dynamic pressure.