Thank you very much...
According to the given codes, for a 3 x 7 hinged door P = 5 lbf / 21 sqft = 0.238 lbf/sqft which is exactly 0.05 in wg. PERFECT!
This means that the Differential Pressure could turn dependent on the door size, eg, Bigger doors less Delta P.
Smaller doors higher Delta P. Is...