Duct smoke detectors, when installed in HVAC systems, automatically stop their respective fans upon the detection of smoke. 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.
But when duct smoke detectors are required, where should they be located? Lets look at the requirements in two of the prominent codes and standards.