Greetings,

I would be so greatful if you can advice me on the velocity issue at a air terminal.
I have one exhaust system for the pump room. The fan is 20000 CMH @ 300 pa. The duct is 1200x620 and it got 3 wiremesh grille (700x700). I am worry that the last grille cant extract to the desire pump dissipated heat cos we cant extend the duct anymore.
So kindly advise me the mathematical formula that is related b/w flow,velocity and head.
Is (p = 0.0981 h SG ) can use in this application? If so, the pressure is the fan total pressure -(friction+fitting loss).
Thanks for your time.