Supply plenums that discharge from the face and are isolated from the exhaust hood by the continuously welded shell extending to the hood's lower outer perimeter do not require which device?

Supply plenums that discharge from the face and are isolated from the exhaust hood by the continuously welded shell extending to the hood's lower outer perimeter do not require which device?

• A. Fire-Actuated Damper
• B. Smoke Detector
• C. Temperature Sensor
• D. Access Door

Answer: (A)

The idea to focus on is how fire barriers and dampers control flame spread through ductwork. A fire-actuated damper is used to close ducts that penetrate a fire barrier, helping to stop fire from moving from one area to another. Here, the supply plenums discharge from the face and are isolated from the exhaust hood by a continuously welded shell that extends to the hood’s lower outer perimeter. That welded shell creates a sealed boundary and prevents any duct path from crossing a fire barrier. Because there isn’t a duct penetrating a fire barrier that could propagate fire, an automatic fire-actuated damper isn’t required. Other safety devices like detectors or access provisions can still be needed for detection and maintenance, but the automatic damper isn’t necessary in this configuration.

The idea to focus on is how fire barriers and dampers control flame spread through ductwork. A fire-actuated damper is used to close ducts that penetrate a fire barrier, helping to stop fire from moving from one area to another. Here, the supply plenums discharge from the face and are isolated from the exhaust hood by a continuously welded shell that extends to the hood’s lower outer perimeter. That welded shell creates a sealed boundary and prevents any duct path from crossing a fire barrier. Because there isn’t a duct penetrating a fire barrier that could propagate fire, an automatic fire-actuated damper isn’t required. Other safety devices like detectors or access provisions can still be needed for detection and maintenance, but the automatic damper isn’t necessary in this configuration.