Under NFPA 90A, supply-side smoke detection is mandated for HVAC systems with capacity of

Under NFPA 90A, supply-side smoke detection is mandated for HVAC systems with capacity of

• A. 1500 CFM
• B. 2000 CFM
• C. 3000 CFM
• D. 4000 CFM

Answer: (B)

NFPA 90A requires smoke detection on the supply side of an HVAC system when the system can move a large amount of air, because bigger systems can spread smoke quickly through ducts. The threshold used in the standard is 2000 CFM. If the supply airflow is at least 2000 CFM, a smoke detector in the supply duct is mandated to enable rapid detection and a quick control response (such as shutting down fans or closing dampers) to limit smoke distribution. Systems below 2000 CFM aren’t mandated to have supply-side smoke detection, though other detection options may still be used.

NFPA 90A requires smoke detection on the supply side of an HVAC system when the system can move a large amount of air, because bigger systems can spread smoke quickly through ducts. The threshold used in the standard is 2000 CFM. If the supply airflow is at least 2000 CFM, a smoke detector in the supply duct is mandated to enable rapid detection and a quick control response (such as shutting down fans or closing dampers) to limit smoke distribution. Systems below 2000 CFM aren’t mandated to have supply-side smoke detection, though other detection options may still be used.