What is the design capacity limit for fan powered terminal units before smoke detectors are not required?

The correct design capacity limit for fan powered terminal units before smoke detectors are not required is 2,000 cfm. This threshold is significant because it aligns with safety standards established to ensure that ventilation systems can reliably contain and control smoke in the event of a fire.

When fan powered terminal units operate above this capacity, they introduce a greater volume of air flow that can potentially spread smoke throughout the building. As a result, smoke detectors become a necessary component of the system to provide early warning and enhance fire safety measures.

Understanding this limit is crucial for maintaining compliance with local codes and ensuring adequate safety protocols are in place to protect occupants in a commercial or residential setting. Therefore, any units designed to exceed this capacity must include smoke detection systems to mitigate the risks associated with fire and smoke movement within the HVAC system.