Inscrivez-vous ou connectez-vous pour rejoindre votre communauté professionnelle.
from0.01 in.wg to0.1 in.wg >>>> that is for dasco products >>>>the number vary due to the cfm from the same diffuser
grilles and diffuser are generally selected based on the cfm there is sizing criteria for the same based on noise criteria we have to maintain NC level based on application generally between the range of NC to NC.
The losses in dampers are based on size and orientation of louvers, depends on the application.
The standard pressure loss in the damper is not constant because it depend on the other factors. fore more ference read ASHRAE book on damper systems and diffuser systems
You have to get it from the approved catalog or you could use SMACNA systems duct design