What do the external static pressure and internal static pressure of central fresh air system mean? Is the higher the static pressure, the farther the air supply is?

Static pressure (Pi): Due to the irregular movement of fluid molecules, the pressure acting on the pipe wall is called static pressure. When calculating, the zero static pressure calculated by absolute vacuum is called absolute static pressure. Static pressure with atmospheric pressure as zero point is called relative static pressure. ?

Static wind pressure in fresh air system refers to relative static pressure.

Dynamic pressure (Pb): From the point of view of flow mechanics, the kinetic energy generated by fluid flow is called dynamic pressure. As long as the air flows in the air duct, there is a certain dynamic pressure. It is an expression related to fluid density, velocity square and gravitational acceleration.

Extended data:

Static pressure determines the distance of gas supply or the ability to overcome resistance. In the installation process of fresh air, there will be some wind loss in the transportation process because of the need to lay pipelines in a large area. The higher the static pressure, the better the normal transportation of fresh air can be ensured. This is equivalent to a water pipe. When the water pressure reaches a certain level, there will naturally be water.

For any fan, there is a total pressure, total pressure = static pressure+dynamic pressure; Dynamic pressure ensures the size of the air volume, and static pressure ensures how long the wind energy will send when the air volume remains unchanged; In other words, "static pressure at the outlet" is what you call "static pressure outside the machine", which is mainly used to express "the resistance that the air duct can overcome under the condition of ensuring the constant air volume"; When replacing the fan motor, replacing the capacitor and changing the voltage, the static pressure outside the fan will change.