Duct Detector information Utah Salt Lake

Brands of Fire Alarm

Duct Detector information Yesterday my fire alarm designer Kenny Fox and I took a CEU class on Duct Detectors which was interesting. A few highlights from the class are as follows:

1. The recommended detector type from the NFPA annex is Photoelectric not Ion – Photoelectric work better with smoldering type fires and Ion would work better in a hot flash fire and lower altitudes. 2. NFPA 90A HVAC requires duct detection on the supply side when the cfm greater than 2000cfm 3. IMC 2012 section 606 requires duct detection on the return side when the cfm is greater than 2000cfm (5 ton or larger) 4. When the cfm is greater than 2000 when the duct work is shared even with units under 2000 cfm each duct detection is required 5. When a smoke control system is involved then shut down may not be required. This comes back to what the AHJ may require. 6. NFPA 72 discusses RTS or Remote Test Switches which are required when you cannot see the LED lights on a duct detector or it is mounted over 10’ in the air above the finished floor. They need to be audible and visible. 7. If you have an addressable fire alarm system and the annunciator is in a normally occupied space the AHJ may approve that rather than remote test switches as long as it tells exactly which duct is in trouble/supervisory 8. See NFPA 72 (2010)

Separate notes on manual pull boxes and panel smoke detection for your information:

At least one manual pull box (Pull Station) is required even on fully sprinkled buildings according to IFC/IBC 907.2 second paragraph “Where other sections of this code allow elimination of fire alarm boxes due to sprinklers, a single fire alarm box shall be installed.


1. Dedicated system for elevator recall (not monitoring flow and tampers) 2. Pulls not required in R-2 Occupancies unless the AHJ requires the pull to initiate an alarm during a sprinkler system impairment event. Where provided, the pull shall not be located in an area that is accessible to the public. We are finding that many times the Fire Marshals are requiring these pulls either in the riser room or other approved AHJ location.

We are also finding plans that do not show a smoke detector at the fire alarm panel location nor at the remote power supply locations. NFPA 101 Section 9.6 . NFPA 72 (2013) - Smoke detector still required at the Fire Alarm Panel 10.4.4 Exception: Where ambient conditions prohibit smokes a heat shall be permitted. If the Fire Alarm Panel is constantly manned the AHJ may decide to have a smoke or not to have a smoke. ( also applies to Horn/Strobe power supplies) If the building is continuously occupied the AHJ may still require a smoke detector at the FACP location. (Check with local AHJ) Alternate reference using older code NFPA 72 (2010) 10.15

Many of the fire marshals are requiring a weather proof horn/strobe on the outside of the buildings.

When you have information that you would like us to be aware of please let me know. We are striving to stay updated with the latest codes and technology information.

For comments, corrections or questions please email Larry@peakalarm.com when you would like to be taken off this email list just let me know and I will take you off. I do not spam and only send pertinent information to the industry periodically. Call Larry at (801) 428 1384