Ceiling Radiation Damper Requirements

Figure 1 non actuated heat and fire dampers.

Ceiling radiation damper requirements.

Connection of ceiling radiation damper grille and steel duct drop may be satisifed in two ways. Ceiling fire damper ul classified radiation dampers ul fire rated floor ceiling assemblies and roof ceiling assemblies require specially tested and classified ceiling dampers also called ceiling fire dampers or radiation dampers to provide fire and heat protection where hvac components penetrate the ceiling membrane. Connection of ceiling radiation damper grille and steel duct drop may be satisfied in two ways. Ceiling radiation dampers shall comply with ul 555c and shall be installed in accordance with the manufacturer s installation instructions in the fire resistive ceiling element of floor ceiling and roof ceiling assemblies where required by the building code fire dampers not meeting the temperature limitation of ceiling radiation dampers shall not be used as a substitute.

Ceiling radiation dampers serve a critical safety element where hvac ducting penetrates a fire rated ceiling. Of ceiling damper i e. Figure 2 actuated fire smoke and combination dampers. If the radiation damper is 12 x 12 305mm x 305mm nominal the ceiling membrane opening is larger than 13 x 13 330mm x 330mm.

Figure 1 shows a ceiling damper used to prevent heat transfer a curtain damper and a multi blade fire damper. Ceiling radiation damper and air device neck may be connected directly to the duct drop see detail a figure. Er than nominal size of ceiling damper i e. Figure 2 shows actuated life safety dampers.

When elevated temperatures are detected by a ceiling radiation damper the damper activates to close off the area of the open ceiling typically located above a supply air register and in doing so maintains the fire rated integrity of the ceiling. Radiation damper could have a maximum ceiling membrane opening of 13 in. The ceiling radiation damper described in the design reflects the damper used during the ul 263 fire exposure test. The design may also call for the use of duct outlet protection system a and or b which are described in the.

Depending on the application they have varying requirements for periodic testing. A thermal blanket is required. If the radiation damper is 12 x 12 nominal the ceiling membrane opening is larger than 13 x 13 a thermal blanket is required. For assemblies utilizing an acoustical ceiling a hinged door type damper typically protects hvac openings.