Duct smoke detectors must comply with which standard?

Duct smoke detectors are specifically designed to detect smoke within heating, ventilation, and air conditioning (HVAC) ductwork. The standard that governs the performance and safety requirements for these types of detectors is UL 268A. This standard outlines the design, testing, and operating conditions that these detectors must meet to ensure they function effectively in a duct environment, which includes considerations for airflow, temperature, and potential false alarms caused by various environmental factors.

In comparison, UL 268 pertains to smoke detectors in general and may not encompass the specific conditions required for duct detectors. UL 2218 relates to ice and snow guards and doesn’t apply to smoke detection technology. UL 350 addresses smoke and heat detection products but does not specifically target the operational parameters of duct smoke detectors like UL 268A does. Therefore, the correct answer is based on the unique requirements set forth in UL 268A for ensuring reliable and effective smoke detection within ductwork systems.