TrueAlarm Addressable Duct Sensors

HVAC Duct Smoke Detection

HVAC ductwork can quickly spread smoke throughout a facility, far from the source of the fire. Simplex duct detectors can quickly sense when smoke is traveling through ducts and enable HVAC airflow to be shut down or redirected to contain smoke dispersion.

  • Addressability pinpoints alarms and troubles to the exact sensor and location. Each sensor is constantly monitored for failure or removal.
  • Drift compensation helps maintain sensor performance and alerts you when cleaning is needed
  • UL268 7th edition listed to meet the latest standards
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Swiftly Sensing Smoke Which Spreads Through Ducts

Simplex air duct smoke detector housings provide TrueAlarm smoke sensor monitoring of air conditioning or ventilating ducts. The housing is mounted directly to the duct and sampling tubes are installed into the duct, allowing air to be directed to the smoke detector mounted in the housing. The addressable sensors inside the housing are individually configurable, allowing the location label, sensitivity range, and other properties to be optimized for each duct detector. TrueAlarm photoelectric sensors are also designed to sense the buildup of dust and other contaminants that can affect performance and cause nuisance alarms, automatically adjusting their sensitivity to maintain the correct response range and alerting system operators when cleaning is needed.
Swiftly Sensing Smoke Which Spreads Through Ducts


  • Prevent smoke propagation:Sense smoke inside duct work and divert to shut down flow to prevent its spread through the facility.
  • Individual programmability:Sensitivity level, label, time of day, and operation are individually programmable.
  • Dynamic Contamination Response:Sensitivity automatically adjusts for dust buildup, maintaining safety, and performance.
  • UL 7th Edition listing:Tested and approved to meet the latest standards.
  • Flexible installation:Mount to rectangular or round ducts. Sampling tubes are available in a variety of lengths to match duct size.
  • Easier troubleshooting and service:Addressability allows alarms and troubles to be pinpointed to the exact sensor and location. Each sensor is also constantly monitored for failure or removal.
  • Cleaning alerts:“Dirty Sensor” warnings tell you when a sensor needs cleaning.


Industry-Leading Technology

Simplex sensors and detectors offer performance and reliability for quick detection of fire, smoke and heat events.

Tailored Solutions For Every Space

The wide range of Simplex TrueAlarm addressable sensors and initiating devices lets you choose the right technology for your facility’s needs.

Meaningful Innovation

A detection platform designed for faster response and fewer nuisance alarms.

Long-Term Value

Our sensors and detection devices are reliable, efficient, easy to manage, and simple to upgrade.