By / Norm Grusnick
Fire and smoke dampers are a proven and effective way to protect ductwork and wall openings and shafts. Once Underwriters Laboratories (UL) created Standard 555 for fire dampers and Standard 555S for smoke dampers, the damper industry has worked closely with building code authorities to design, manufacture, and outline correct installation procedures.
Life safety dampers have evolved from black iron, single blade, gravity operated products to the actuated and dynamically operated products used today. As time progressed with it the test criteria has also become more stringent. In testing, non-actuated fire dampers are required to complete 250 full open/close cycles. Actuated dampers are required to complete 20,000 open/close cycles. Minimum airflow ratings of 2000 fpm through the fully open damper and 4 inches of static pressure across the fully closed damper have also been established to eliminate marginal products from being installed. In addition, safety factor of 400 fpm and 0.5 inches of static pressure are used during the testing. A damper with the minimum 2000 fpm and 4” static pressure rating is tested at 2400 fpm and 4.5” static pressure.
Even with stringent test requirements, the proper performance of life safety dampers in the field requires that the manufacturer’s instructions be followed. UL requires that installation instructions are provided with each package and now most have this information on line, as well. Although installation requirements vary by damper manufacturer and model, the following items are generally covered in the installation instructions:
- The wall/floor framing details
- Clearance requirements between the damper and the wall/floor opening
- Duct to damper sleeve connections
- How to properly secure the damper to the wall/floor opening
As with any mechanical device, propermaintenance is necessary to ensure that dampers will operate as designed and save lives. Inspection and maintenance requirements are established by the individual manufacturers and by the National Fire Protection Association (NFPA). The most important step in making certain that a life safety damper will operate correctly is done during the commissioning process. Chapter 19 of NFPA’s Standard 80 states that “after the installation of the life safety damper is completed, an operational test shall be conducted.” The standard goes on to state that for combination fire and smoke dampers, “the operational test shall be conducted under non-fire HVAC conditions as well as static flow conditions.” The National Building Code references NFPA for proper maintenance of life safety dampers.
After the initial commissioning process, it is essential to implement a periodic maintenance program for a building’s life safety dampers. Chapter 19 of NFPA 80 including fire dampers states, “Each damper shall be tested and inspected one year after installation. The test and inspection frequency shall then be every four years, except in hospitals, where the frequency shall be every six years.”
Safety of our buildings and their occupants is of prime importance. The continued routine maintenance and documentation by the end user allows the systems to perform and function as designed and intended. ■
