Fire and smoke dampers must pass a rigorous series of tests prior to installation in a fire life safety building system with further requirements for how they are installed. However, even with excellent installation, regular maintenance and inspection of the dampers is necessary to ensure optimal performance. Any number of factors might lead to damper malfunction which are discovered only through the inspection process, or worse, upon failure during an FLS event.
Three of the most common factors are illustrated here, including: obstruction, failed linkage and failed actuator.
Obstruction is one of the most common factors contributing to damper failure. Obstruction can be caused by something as minor as dust build-up or as significant as another trade installing its materials through damper openings.
Fire dampers are held open by fusible links. A fusible link is rated specifically for temperatures indicative of fire, above the design ambient temperature of the HVAC system. If a fusible link breaks and is not replaced with the proper rated component, the fire damper may fail to close under fire conditions.
Actuators provide the power component to rotate dampers open or closed. Failure of an actuator causes failure of a damper to rotate as needed during a fire life safety event.