Dampers fall into five types, each with a specific function. Types of dampers include fire dampers, smoke dampers, combination fire-smoke dampers, ceiling radiation dampers and corridor dampers. Their functions vary depending on the damper type.

Damper Types

Fire Dampers - Fire dampers are used to restrict the spread of fire where ducts and air transfer openings penetrate firewalls, fire barriers, fire partitions, horizontal assemblies and shaft enclosures. They can also be employed in air transfer openings in walls and partitions. The building codes specify where fire dampers are required. 

• Dynamic Fire Dampers – Are installed in vertical barriers, where the HVAC system fan will continue to blow in the event of a fire. Because the fan will stay on, the spring-loaded design helps the damper to spring shut against the air pressure. In addition to an hour fire-protection ratings, fire dampers for use in dynamic systems are also provided with an airflow rating which indicates the maximum velocity and static pressure that the damper is designed for.
  
• Static Fire Dampers – Are installed in duct systems or penetrations where the HVAC system is automatically shut down in the event of a fire. Because the fan will turn off, these dampers are designed like a curtain, allowing the damper to fall and shut due to gravity.

These two types of fire dampers are certified by Underwriter’s Laboratory to carry an hourly fire-protection rating, usually 1 ½ - 3 hours.

Smoke Dampers - Smoke dampers are used to restrict the movement of smoke where ducts and air transfer openings penetrate assemblies that are designed to restrict the movement of smoke. They are typically operated by a smoke detector, which would also be located in the duct. Once smoke has been detected, the smoke detector sends a signal to the damper actuator, which uses the jackshaft and linkage to open and close the blades of the smoke damper. There are two types of actuators:

• Pneumatic Actuators – Needs air to function properly
• Electrical Actuators – Needs power to function properly
  

Combination Fire-Smoke Dampers - Combination fire-smoke dampers are used to restrict the spread of fire and movement of smoke where ducts and air transfer opening penetrate assemblies that are designed to restrict the passage of both fire and smoke.  Dampers that are marked as combination dampers comply with UL’s standard for fire dampers and their standard for Smoke Dampers.

Ceiling Radiation Dampers - Ceiling radiation dampers are used to limit the passage of heat in fire-resistance-rated floor-ceiling or roof-ceiling assemblies. Ceiling radiation dampers are intended to function only as heat barriers to limit heat transfer into the concealed space of a floor-ceiling or roof-ceiling assembly. 

Corridor Dampers - Corridor dampers are combination fire-smoke dampers that have been evaluated for mounting only in specific tunnel corridor ceiling construction. In most cases the ceiling construction of a tunnel corridor will be as required for the corridor walls.

Fire and Smoke Damper Codes per NFPA 80 & 105

Fire and smoke dampers are a critical component in a Passive Fire Protection plan and it’s important to keep up to date with inspections per code requirements. LSS technicians will assist you in keeping your facility in compliance with all local and state building codes. The National Fire Protection Association (NFPA) and the International Building and Fire Codes require regular maintenance of fire and smoke dampers. Authorities Having Jurisdiction (AHJ’s) such as the Joint Commission, fire marshals and insurance risk auditors enforce these requirements. 

Fire Damper - NFPA 80 – Section 19.4

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.

Smoke Damper - NFPA 105 – Section 6.5

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 Damper Deficiencies

It is not uncommon to have a list of deficient dampers that are in need of repairs after facility performance testing. LSS’ technicians have fulfilled extensive damper repair training with major industry manufacturers such as Belimo, Lloyds, Ruskin and Greenheck.

Top 10 Fire and Smoke Damper Deficiencies:

1. Inoperable Actuator

2. No Power to Actuator

3. No Power Wired to Actuator

4. No Air to Actuator

5. No Airline to Actuator

6. Not Enough Air to Actuator

7. Screw in track

8. Linkage out of Alignment or Broken

9. Bound in tracks (racking)

10. Damper rusted

LSS Life Safety Services® can provide the peace of mind when it comes to fire and smoke damper inspections, repairs and installation. Contact Us Here or call us today to schedule!