Where do you put a duct smoke detector?
To ensure correct operation, install the duct detector using the following guidelines: Install the duct smoke detector on a flat section of HVAC duct between six and ten duct widths from any bends or obstructions. Install supply-side detectors at a point downstream from the supply fan and after the air filter.
Do duct detectors go on the supply or return?
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.
What CFM requires a duct detector?
For HVAC systems with airflows exceeding 2,000 cfm, duct smoke detectors are required. This includes where multiple air handling systems utilize common ducts with a combined design capacity greater than 2,000 cfm.
Are duct detectors required at fire smoke dampers?
Smoke dampers operate automatically on detection of smoke and must function so that smoke movement through the duct is halted. Their activation can be by area detectors that are installed in the related smoke compartment or by detectors that are installed in the air duct systems.
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.
Are duct detectors required?
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 are two of the major requirements for detector placement according to NFPA 72 in residential occupancies?
For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home. (Additional smoke alarms are required for larger homes.)
Are duct smoke detectors required on exhaust fans?
Duct-mounted smoke detectors, however, are not required in a return air system if the spaces served by the HVAC system are protected by ceiling-mounted smoke detectors. Duct-mounted smoke detectors are also not required downstream of exhaust fans.
What are duct detectors?
Why are Duct Smoke Detectors required : NFPA 90A is specific to Air Conditioning and Heating Systems installation. The purpose of the NFPA 90A is to prevent the spread of smoke and fire through ductwork and ventilation systems for air conditioning and heating systems with high capacities.
What NFPA code is smoke detectors?
For many years NFPA 72, National Fire Alarm and Signaling Code, has required as a minimum that smoke alarms be installed inside every sleep room (even for existing homes) in addition to requiring them outside each sleeping area and on every level of the home.
Does a makeup air unit require a duct detector?
Occasionally the design professional will specify a duct detector on a makeup air unit due to concerns from smoke being generated outside of the building and pulled into the building by the unit, but that is the prerogative of the design professional and the owner, and minimum code does not require it.
https://www.youtube.com/watch?v=-Oh-aM3gOZY