Many local codes require that exhaust fans installed in fire-rated ceilings must be protected by dampers, which, in case of fire, protect against the spread of heat and flame. Being fire-rated means the ability of a wall, floor ceiling, or roof ceiling to withstand the effects of fire for a specified period of time. Broan ceiling radiation dampers are designed to protect the openings in 1-, 2-, or 3-hour fire-rated floor-ceiling and roof-ceiling designs. When the temperature of the air passing through the damper exceeds 165°F, the fusible link melts and the thermal fabric across the damper closes automatically to interrupt the airflow by becoming a flame and heat barrier, preventing rapid spread of fire to other areas.Housings and finishes (motor assembly and grille) sold separately in units of four per carton - purchase housings for rough-in and blower assemblies grilles later for finishing UL classified (UL standard 555C) for use in 1-, 2-, or 3-hour fire-rated floor-ceiling and roof-ceiling designs Warnock Hersey Listing allows use in combustible ceilings with ducted fans High temperature, non-asbestos, reinforced fiber thermal fabric Galvanized steel frame 165°F fusible link Stainless steel negator-type closure spring Available from 50 CFM to 110 CFM Radiation damper comes attached to housing Blower assembly will fit into housing without the removal of the radiation damper - one less step in installation processDuct Size: 4 Round Function: Housing Pack, Utility Fan Gauge: 26 Housing Depth: 8-3 4 Installation Type: Ceiling Material: Galvanized Steel Weight: 5.60
