A fire damper is a normally closed valve that can be opened by a control center's 24V DC power or manually. It closes automatically at 280℃ and must be manually reset. Its function is to prevent the spread of fire when the smoke temperature reaches 280℃; by then, people should have been mostly evacuated, and smoke extraction is no longer practical. The fire damper automatically closes to prevent the fire from spreading. The smoke exhaust outlets in the system can also be of the normally closed type, eliminating the need for smoke and fire dampers on the branches. During a fire, the outlets can be opened by the control center's 24V DC power or manually, and they will automatically close at 280℃ smoke temperature, requiring manual reset. A smoke and fire damper should also be installed at the entrance of the smoke exhaust fan room to prevent the fire from spreading to the floor where the fan room is located.