Fire Damper Sizing Calculator

Size fire and smoke dampers for HVAC duct penetrations.

Width of rectangular duct.
inches
Height of rectangular duct.
inches
Air velocity in duct.
FPM
Enter 1 for fire damper, 2 for smoke damper, 3 for combo.
type

Results

Damper Nominal Size-inches
Estimated Pressure Drop-in w.c.
Required Fire Rating-hours
References: NFPA 80, Standard for Fire Doors and Fire Windows; NFPA 90A; IBC Section 717