A duct smoke detector samples air inside HVAC ductwork so that smoke carried by the air handling system is detected and the fan can be shut down before it spreads smoke through the building. It is not a substitute for area smoke detection; its job is to control the mechanical equipment, and code generally calls for it on larger air handlers and in return air paths.
The housing mounts on the outside of the duct and draws a sample through a pair of tubes: an inlet sampling tube sized to the width of the duct, and a shorter exhaust tube. Units come as 2-wire or 4-wire conventional detectors and as addressable detectors that report a point address to the panel, and most accept a remote test and reset station and auxiliary relays for fan shutdown.
We carry duct detectors, housings, sampling tubes, remote test stations and replacement covers from System Sensor, Simplex, Siemens, Notifier, Fire-Lite, Edwards, Potter, Kidde, Silent Knight and Air Products and Controls. Legacy duct detectors can be requested on our quote page.

Siemens FDBZ492-HR (S54319-B23-A1) Duct Detector 2-Wire

Fire-Lite D365PL Duct Detector (Replaces D355PL)

System Sensor DNRW Duct Smoke Detector (Detector Head Sold Separately)

Edwards SIGA-SD Duct Smoke Detector

System Sensor D4120 Duct Smoke Detector

APC SM-501-P Duct Smoke Detector Photo

System Sensor D4120W Duct Smoke Detector 4-Wire

APC SL-2000-P Photoelectric Duct Smoke Detector

Simplex 565-925 4-Wire Duct Sensor PC Board

Edwards SIGA-DDOS Optical Intelligent Duct Smoke Detector

Siemens FDBZ492 Air Duct Detector Housing, Two-Wire, No Relay, S54319-B22-A1

Fire-Lite D355PL Duct Smoke Detector (Replaced by D365PL)

System Sensor D4S InnovairFlex 4-Wire Photoelectric Duct Smoke Sensor Component, Requires D4120 or D4P120 Power Board

Potter PAD200-DD Photoelectric Duct Smoke Detector Head for PAD200-DUCT and PAD200-DUCTR

Simplex 4098-9687 Duct Detector

Simplex 4098-9842 Duct Control Station

Silent Knight SK-DUCT-W Intelligent Photoelectric Duct Smoke Detector

Notifier FSP-851R Intelligent Photoelectric Sensor Head, Remote Test Capable, for DNR and DNRW Duct Housings

Kidde FX-PDD Intelligent Addressable Optical Duct Detector





