UL 555 classified dampers for use in HVAC systems that remain operational during a fire. These dampers have a fire-resistance rating of 3 hours.

The FSD-331 is a combination fire smoke damper with airfoil blades. This model is rated for use in walls, floors, or partitions with a fire resistance rating of 3 hours or more and a Class I leakage rating. Pressure: Up to 8 in. wg; Velocity: Up to 4000 fpm; Temperature: Up to 350°F

Which damper best fits the application? Greenheck’s damper interactive selection guide removes the guesswork. Find blade type, velocity, pressure, AMCA listings, submittals, drawings and more, all in one easy-to-use format.

Fire Resistance Rating* Leakage Class Damper Maximum Size (Inches) Submittal Installation Instructions CSI Specs DWG Drawings Roof/Floor Assembly Wood Truss Assembly Wood Joist Assembly Ceiling Radiation Dampers CRD-1 Butterfly 3 Hour - 24 x 24 - - CRD-1WJ Butterfly 1 Hour (UL Wood Joist) - - - 16 x 12 CRD-1WT Butterfly 1 Hour (UL Wood Truss ...

Select a fire damper and combination fire smoke damper with a 1½ hour rating for use with a wall, floor, or partition with a less than 3 hour fire resistance rating.

dampers are required. Fire dampers are available in two types, static fire dampers and dynamic fire dampers. Both fire dampers for use in static systems and dynamic systems are certified by UL to carry an hourly fire-protection rating, usually 1-1/2 or 3 hours. Fire dampers for use in static systems, as their name implies, are used in duct ...

Fire dampers are required by all building codes to maintain the required fire resistance ratings of walls, partitions and floors when they are penetrated by air ducts and transfer openings.

The FD-150X series is for use in walls, floors, and partitions with fire-resistance ratings less than three hours. This model has an integral sleeve. Static-rated-fire dampers used in HVAC systems that automatically shut down in the event of a fire emergency.

Complete line of damper products for fire and smoke control in life safety systems and for airflow control in commercial HVAC.

Fire damper assemblies expand during periods of intense heat. Therefore, it is essential that openings in walls or floors be larger than the fire or combination fire smoke damper assembly to allow for this expansion. The wall/floor opening must be a minimum of 7⁄ 8 in. (22 mm) larger than the outside diameter of the damper.