Fire Damper
Fire dampers are installed in an air-distribution system, and are designed to close automatically upon detection of heat, to interrupt migratory air flow, and to restrict the passage of flame. They are required in order to maintain the required integrity of a fire resistance assembly when ducts penetrate fire-rated walls, partitions, or floors.
Fire dampers are required by either the model building or mechanical codes or National Fire Protection Association
(NFPA) 90A,Standard for the Installation of Air Conditioning and Ventilating Systems

