What exactly is static pressure w.r. to ducts? Is it not the pressure due to the air column at rest in the duct , before motion. Pls. clarify.Then what is External Static pressure? How do we calculate for an AHU?
When it comes to ducts, static pressure is simply the pressure of the gas (air or natural gas or whatever) in the duct. When gas is being pushed thru a duct it will be at a higher pressure than the gas outside the duct.
Static pressure may be confused with "velocity pressure" in a duct. Velocity pressure is the pressure rise due to the gas colliding with a fixed surface that is perpendicular to the flow. In fluid mechanics this would be called stagnation pressure. Velocity pressure allows you to determine the velocity of gas in a duct based on its pressure rise when it hits a static surface.
__________________
Everything I know about opera I learned from Bugs Bunny
HVAC-Static Pressure
Re: HVAC-Static Pressure
