Duct Smoke Detector Calculator
Determine duct detector requirements per NFPA 72 and 90A.
NFPA 90A Thresholds
| CFM Threshold | Requirement |
|---|---|
| > 2,000 CFM | Supply duct detector required |
| > 15,000 CFM (common return) | Return detector required |
| > 2,000 CFM (return, each floor) | Detector on each floor return |