Application & Flow
Sizing Results
Required Face Area
ft²
Required Area
in²
Recommended Size
inches
Actual Face Velocity
FPM
Standard Grille Sizes — CFM Capacity at Various Face Velocities
Size (W×H in)Net Area (ft²)CFM @ 400 FPMCFM @ 500 FPMCFM @ 600 FPMCFM @ 750 FPMYour CFM
Net free area is approximately 70% of gross face area for typical bar grilles. Ceiling diffusers vary by manufacturer — consult product data for Ak factor. Face velocity above 600 FPM may cause noise in occupied spaces (NC > 35).
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