What is the function of a fire/smoke damper in an air distribution system?

The function of a fire/smoke damper in an air distribution system is to prevent the spread of fire and smoke through the ductwork to other areas of a building. These dampers are designed to automatically close upon detection of high temperatures (in the case of fire dampers) or smoke (in the case of smoke dampers), effectively sealing off the duct and preventing the passage of fire and smoke. Fire dampers are typically activated by a fusible link that melts at a specific temperature, causing the damper to close. Smoke dampers are typically controlled by a smoke detection system and can be closed remotely by the building's fire alarm system. By compartmentalizing the fire and smoke, these dampers help to protect occupants, minimize property damage, and facilitate fire suppression efforts. Fire/smoke dampers are typically installed at locations where ductwork penetrates fire-rated walls or floors. For example, if a fire starts in one area of a building, the fire/smoke dampers in the ductwork serving that area will close, preventing the fire and smoke from spreading to other areas through the ventilation system. This is a critical safety feature in buildings and is required by building codes.