A fire damper is a normally closed valve that can be opened either by a control center via 24V DC power or manually. It closes automatically at 280°C, and reset is required manually. Its function is to prevent the spread of fire when the smoke temperature reaches 280°C—by that time, people are mostly evacuated, and smoke exhaust is no longer necessary, as the smoke has already caught fire. The system's smoke exhaust outlets can also be equipped with normally closed fire and smoke exhaust outlets, eliminating the need for smoke and fire dampers on branch pipes. During a fire, these outlets are opened by the control center via 24V DC power or manually, and they close automatically when the smoke temperature reaches 280°C; reset is also manual. 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 level where the fan room is located.