Q: What is an assembly?
A:
Assembly, Floor Ceiling Assembly, Roof Ceiling Assembly or Floor Truss Assembly: A form of construction comprised of floor-ceiling or roof-ceiling as an assembly which, when fire tested as a unit, has been assigned a fire endurance rating expressed in hours.
*Fire, Smoke, and Radiation Damper Installation Guide for HVAC Systems, SMACNA, 2002.
Q: What is a ceiling radiation damper?
A:
Ceiling Radiation Damper: A specialized form of a heat stop installed in the air distribution portion of a fire-rated floor-ceiling or roof –ceiling assembly; the sole purpose of which is to help maintain the fire endurance rating of the assembly.
*Fire, Smoke, and Radiation Damper Installation Guide for HVAC Systems, SMACNA, 2002
Q: Can I use ceiling radiation dampers in the floor if it is a membrane penetration and not a through penetration?
A: It is not necessary to use a damper in this situation because fire burns up and the floor is protected from the sheet rock / drywall side. A CRD in a boot (or any other enclosure) installed in a floor rather than a ceiling is on the incorrect side of the assembly and affords no protection to the combustible structure. However, when installed in the ceiling at the level of the sheetrock the CRD/Boot reestablishes the rating of the barrier in which the penetration was cut thereby protecting against heat and flame radiating upward into the ductwork &/or annular space. This protects the occupants of the space above the sheetrock on the next floor.
Q: What damper do I use if the plans specify a 2 hour rated fire partition?
A: The NFPA90A Chapter 3 Section 4 and the New International Building Code (IBC 2009) Table 716.3.2.1 states: it is acceptable to install 1½-hour dampers in penetrations rated less than 3 hours.
Q: What damper do I use if the plans specify a 4 hour rated fire partition?
A: The NFPA90A Chapter 3 Section 4 and the New International Building Code (IBC 2009) Table 716.3.2.1 states: it is acceptable to install 3-hour dampers in penetrations rated 3 hours or greater.
Q: What is a fusible link? (Mechanical fusible link)
A: A fusible link is a bi-metal, heat activated device used to hold damper blades in the open position. These links are comprised of two materials 1. two pieces of carbon steel held together by 2. heat sensitive solder (a fusible alloy). They are designed to activate at specific temperatures (most commonly 165°F or 212°F) and a specific load limit (most commonly 10lbs).
RECOMMENDATIONS: Dampers should NOT be stored in adverse conditions; specifically exposed to excessive heat. Examples might be in non-conditioned job trailers, portable storage units, or outdoors. Such exposures can lead to premature failure.
Q: The painting contractor has covered the fusible links with overspray, & the inspector is denying acceptance – what should we do?
A: The Authority Having Jurisdiction always has sovereignty over the job. NFPA-80, chapter 19, also mandates that the links be replaced, or cleaned to the satisfaction of the AHJ.
RECOMMENDATIONS: If in doubt: REPLACE THEM.
Q: What is a fire rated partition or barrier?
A:
Fire Rated Partition: A partition having an assembly of materials that will afford a given fire resistance rating (expressed in hours) to impede the spread of fire from one area to another.
*Fire, Smoke, and Radiation Damper Installation Guide for HVAC Systems, SMACNA, 2002
Fire Rated Barrier: A fire-resistance-rated wall assembly of materials designed to restrict the spread of fire in which continuity is maintained.
*International Building Code, 2009
Q: What type of Ceiling Radiation Damper/enclosure should I use in a ceiling with multiple layers of sheetrock?
A: You should first verify the Floor-Ceiling-Assembly design number (ie: Aire Technologies, Inc. L-587) in the UL Fire Resistance Directory. Typically, multiple layers of sheet rock and/or metal channel spacers that would require an extended boot throat or a plan that does not demonstrate a Ceiling Radiation Damper does not permit penetrations for duct openings of any kind.
Q: What is the purpose or intended use of a Fire Damper?
A: Fire Dampers are installed in HVAC ductwork to reestablish the fire rating of the barrier (walls, floors or other rated partitions) in which the penetration was created.
Q: What is the purpose or intended use of a Combination Fire/Smoke Damper?
A: A Combination Fire/Smoke Damper is a listed device installed in ducts and air transfer openings designed to close automatically upon the detection of heat and resist the passage of flame and smoke. The device is installed to operate automatically, controlled by a smoke detection system, and where required, is capable of being positioned from a fire command center.
*International Building Code, 2009
Q: What is the purpose or intended use of a Smoke Damper?
A: A Smoke Damper is a listed device installed in ducts and air transfer openings designed to resist the passage of smoke. The device is installed to operate automatically, controlled by a smoke detection system, and where required, is capable of being positioned from a fire command center.
*International Building Code, 2009
Q: Do you have an O & M manual?
A: Please refer to NFPA 80, Chapter 19, where intervals for inspection and service are found for Fire & Ceiling Radiation dampers. Generally speaking this should occur every four years.
Q: Do you have low height clearance ceiling dampers?
A: As the maximum height of a ‘standard’ Ceiling damper/ boot assembly is normally not greater than 16”, and the trusses are normally specified at 19”, this should not be an issue. You should first verify the Floor-Ceiling-Assembly design number (ie: Aire Technologies, Inc. L-587) in the UL Fire Resistance Directory.
Q: Can UL Classified Fire Dampers be field modified?
A: No. A UL classified device (Fire Damper, Combination Fire/Smoke Damper, Smoke Damper, Corridor/Egress Damper, or Ceiling Radiation Damper) can NOT be field modified. The device must be returned to the manufacturer for modifications or be REPLACED with the proper device.
Q: Why do I need an access door when I install a Fire Damper?
A: Access doors are utilized for the purposes of inspection & maintenance. Aire Technologies recommends an access door on either side of the fire rated barrier sized large enough to afford easy access for maintenance and repair. Please refer to typical SMACNA duct construction standards for sizing and pressure class requirements.
Q: What is break-away connection?
A: A joint connecting a fire damper sleeve and attached duct work which will allow collapse of the duct work during a fire without disturbing the integrity of the fire damper.
*Fire, Smoke, and Radiation Damper Installation Guide for HVAC Systems, SMACNA, 2002
Q: What are the guidelines for use of caulking with Fire Dampers or Ceiling Radiation Dampers?
A: Please first refer to SMACNA guidelines for sizing of penetrations and typical installation of Fire Dampers.
RECOMMENDATIONS: Damper installation is designed to have free space, or a gap, around the perimeter (SMACNA Duct Construction Standards) to accommodate thermal expansion. NO Aire Technologies, Inc. product has been tested with any type of caulking or fire stopping material. Therefore, use of any of these chemicals or materials is not recommended unless specified by the mechanical designer and approved by the AHJ.
Q: When should I use a thin (Thinline) 2” profile Fire Damper instead of a Standard 4” profile Fire Damper?
A: The damper must be completely contained within the boundaries of the barrier. Therefore, if the barrier thickness is less than the dimensions of the damper you must install a damper to fit within the barrier.