Can detectors be installed in air duct systems as substitutes for open area protection?

Detectors installed in air duct systems serve a specific purpose related to detecting smoke or heat in the air handling units and should not be considered substitutes for open area protection. Open area protection is designed to detect fire conditions in occupied spaces where people might be present, utilizing smoke detectors or other types of alarms that can sense the specific conditions indicative of a fire occurring in that space.

While duct detectors can be utilized to provide an early warning system by detecting smoke before it spreads into the occupied areas, they do not replace the need for standalone detectors located throughout a building. The rationale behind this is that duct detectors may not effectively protect areas distant from the air handler, and their operational characteristics may differ from those of standard smoke detectors, which are optimized for open environments. Therefore, relying exclusively on duct detectors can lead to safety risks, leaving some areas unmonitored for smoke and missing signs of fire.

In summary, while duct detectors are a valuable component of fire detection systems, they must work in conjunction with other detection methods to ensure comprehensive protection throughout the facility.