Fire & Life Safety--Get Your ‘Ducts’ in a Row
This article originally appeared in the July 2013 issue of SD&I magazine.
Q. If I supervise the duct detector by connecting it to the fire alarm system and it is powered from the FACP, does the HVAC contractor need to install a Remote Test Station?
A. Yes, if the detector cannot be reset at the FACP or annunciator, then a separate test/reset will need to be installed per NFPA 2013, section 23.8.5.4.6.4: “Where duct smoke detectors are not resettable from the protected premises fire alarm system, a listed alarm/supervisory indicator with an integral reset switch shall be provided in an accessible location.” This placement is usually directly below the detector, but should be placed as directed by the local fire department. Like annunciators, these are not required to be placed in range of ADAAG wheelchair heights. I suggest you install annunciators and test/reset stations about five feet above the floor, measured to the top of the device. The 2013 edition now seems to prohibit ceiling mounting test/reset stations or placing them high on a wall near the ceiling: “3.3.1 Accessible (as applied to equipment). Admitting close approach; not guarded by locked doors, elevation, or other effective means.”
Q. Can I shut off all the air handlers when any one of the seven duct detectors in this nursing home activate, or must I shut down just the one HVAC unit associated with that duct detector?
A. Trick question. The correct answer is “yes” to the first part and “yes” to the second part. The code requires that you shut down the air handler when/where smoke has been detected so it doesn’t blow the smoke to other (different, remote) parts of the building. That is what you “must” do. The part where you ask if you “can” shut off all the air handlers whenever any one of them is affected is also allowed. The inspector cannot make you do this and some businesses will absolutely refuse to consider a local inspector’s request for total shut down of all units by the fire alarm system. These are mostly the large national firms that have been acclimated to dealing with the local AHJ that wants some feature or equipment installed without being able to site a code number to support their ‘request.’ This shut-it-all-down reasoning used to be common with elevator recall. Today, we plan to use elevators for evacuation and not recall them all even though equipment is operating properly.
Q. Where in the code does it say duct detectors must be part of the fire alarm system?
A. The Mechanical Codes require duct detectors be installed in larger HVAC systems to shut down the air handlers so as to not spread smoke to other parts of a building. The International Building Code, International Fire Code and Life Safety Code all mandate a code required fire alarm evacuation system to annunciate the activation of code required duct detectors as a Supervisory Signal. Other than providing a better Test/Reset/Trouble placard, no other connection is required. Even if you elect to provide the duct detector as part of your code-required fire alarm warning system, they are not required to be furnished with standby power. The mechanical code also allows buildings protected throughout with spot-type smoke detectors to omit installing the duct detectors providing the activation of a spot-type detector causes the associated air handler to shut down using the fire alarm panel/relay. But again, anything you do other than annunciate the mechanical contractor’s duct detector as a Supervisory Signal is optional.
