FAQ's - Fire and Smoke Dampers - U.S. Code and Maintenance Information

  • What is the code for testing and inspecting fire dampers?

    • NFPA 80 – Section 19.4 States
      • Each damper shall be tested and inspected one year after installation.
      • The test and inspection frequency shall then be every 4 years, except in hospitals, where the frequency shall be 6 years.
  • What is the code for the testing and inspecting of smoke dampers?

    • NFPA 105 – Section 6.5 States
      • Each damper shall be tested and inspected one year after installation.
      • The test and inspection frequency shall then be every 4 years, except in hospitals, where the frequency shall be 6 years.

FIRE AND SMOKE DAMPERS

  • What is the purpose of a fire damper?
    • Fire Dampers are used to maintain the required ratings of fire rated barriers (walls, partitions, floors) when they are penetrated by ductwork.
  • How does a fire damper work?
    • When a rise in temperature occurs a fire damper will close and prevent the spread of flame through the barrier. Dampers are typically curtain style that will close (shut) when a fusible link melts. The fusible link typically melts when the temperature rises to 165 degrees Fahrenheit. In some circumstances higher degree fusible links (e.g. 212°F) are installed in ductwork with consistently higher normal temperatures, such as hot decks in dual duct systems. Fire dampers are certified by Underwriters Laboratories (UL) to carry hourly fire resistance ratings, typically 1.5 to 3 hours.
  • What types of fire dampers exists?
    • Dynamic Fire Dampers – Dynamic Fire Damper is a damper that is approved for use where the HVAC System blower will remain on during an alarm (or “Fans On”). Dynamic fire dampers are rated to close against moving air.
    • Static Fire Dampers – Static Fire Damper is a damper that is approved for use where the HVAC System blower will cycle off during an alarm (or “Fans Off”).
  • What is the purpose of a smoke damper?
    • Smoke dampers are used is ductwork and air transfer openings that are designed to resist the passage of air and smoke. Smoke dampers may be required in smoke barriers and other smoke controlled systems.
  • How does a smoke damper work?
    • Typically smoke dampers are operated by smoke detectors in the ductwork that will close the smoke damper when smoke is detected. Smoke detectors often are hard wired to a central alarm panel in which the alarm will relay a signal to the smoke damper to cause smoke damper closure. The closure of smoke dampers are done by an actuator – the actuator is either electric or pneumatic. The actuator utilizes the jackshaft and linkage to open and close the blades of the smoke damper. Smoke dampers are UL certified with an air leakage class rating.
  • What is a Combination Fire and Smoke Damper?
    • These dampers are used in areas where both smoke and fire barriers are located to prevent the passage of both smoke and flames.
  • What is a Corridor Damper?
    • Corridors are means of egress travel to an exit. Corridor dampers are fire and smoke dampers that have been designed for use in corridors.
  • What is a Ceiling Damper?
    • Ceiling dampers lessen the passage of heat in fire resistance ceilings where ducts are made only through ceilings.

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