Where should a smoke detector be placed on a duct?
NFPA 90A requires duct smoke detectors to be located in the supply duct downstream of air filters and ahead of any branch connections.
Are duct detectors required to be monitored?
Even though duct smoke detectors are not highly visible, they must be inspected regularly to remain in compliance like the rest of your fire alarm system. Per NFPA 72, duct smoke detectors should be visually inspected twice a year.
How many duct smoke detectors do I need?
NFPA 90A requires the first duct smoke detector to be installed on the supply side of air handler units of more than 2,000 cubic feet per minute (cfm) and requires one on the return side of units of more than 15,000 cfm and serving more than one story.
Are duct detectors required at fire smoke dampers?
1. Duct smoke detectors will not be required at each fire smoke damper where the supply fan shall shut down and all the fire smoke dampers associated with the supply system automatically close upon actuation of an automatic alarm initiating device on the floor(s).
How do duct smoke detectors work?
How Do They Work? Duct detectors sample currents in the air handling equipment to determine if smoke or fumes are present. If smoke is detected, the device will close dampers, stop fans and blowers, and trigger an audible and visible signal at the fire control panel, Kapparos explains.
Do duct detectors go in supply or return?
The International Mechanical Code requires a duct smoke detector in the return for units over 2,000 cfm and requires a detector in the supply duct for systems over 15,000 cfm.
What is the difference between a fire damper and a fire smoke damper?
Whilst fire dampers function to help stop the passage of fire, smoke dampers work in a similar way to preserve the integrity of physical smoke barriers e.g. floors and walls. They can also be found within air conditioning and ventilation ductwork.