Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.
German fire damper in underground parking of a commercial building. Unlike its North American contemporaries, this damper addresses smoke migration through the damper's annulus.
Intumescent damper insert. Openings in the unit swell shut as a result of intumescence in case of fire or heat exposure.
Both mechanical and intumescent dampers form part of passive fire protection (PFP) systems, such as fire-resistance rated walls, floors, or even ducts or cable tray fireproofing. As such, they are PFP systems. However, whether an opening is mechanically closed or whether its is the physical/chemical action of an intumescent that does the work, the fact that they are activated by heat and then move to fulfill a fire safety function, also technically qualifies them to form part of active fire protection (AFP) systems.
In the US, the Joint Commission, State Fire Marshals and Other Authorities Having Jurisdiction (AHJ's), require Fire and Smoke Dampers to be tested at specified intervals. Similarly, European authorities mandate maintenance and repairs of fire dampers also, as part of approvals or listings issued following successful testing of fire damper assemblies. Therefore, fire dampers that are not demonstrably maintained per regulations constitute fire code violations because installed but unmaintained fire dampers no longer comply with their certification listings.
Excerpt Scheuermann, Praxishandbuch Brandschutz (Practice Handbook Fire Potection, Paragraph 5.5.4 Fire Dampers), 2008
- Access to DIN EN 1366-2:1999-10 (replaces DIN4102 Part 6) Fire resistance tests on service installations - Part 2: Fire dampers; German version EN 1366-2:1999
- Abstract ISO 10294-1:1996 Fire resistance tests -- Fire dampers for air distribution systems -- Part 1: Test method
- Abstract ISO 10294-5:2005 Fire dampers for air distribution systems -- Part 5: Intumescent fire dampers
- Fire Damper: one of the leading suppliers to the HVAC wholesaler market in the United States
