A closed fire door prevents the spread of smoke and flame throughout a facility. Fire doors maintain and protect the compartmentation of a building, if a fire door does not close the integrity of the building will be compromised and building occupants will be in danger.
Self-Closing Fire Door
In simpler terms, every time the door is pushed open it will return to the closed position immediately via the closer arm (see picture). These doors are continuously kept in the closed position except when someone is walking through the door.
Automatic Closing Door
An automatic-closing door is a door that is normally held in the open position, but closes when the automatic-closing device is activated. The automatic-closing device is a device that causes the door to close when activated by a fusible link or detector. Though NFPA does allow fusible links they are not the most effective and reliable method to ensure your fire doors close in case of a fire. A fusible link is heat activated, meaning it must be exposed to fire before it can melt and release the fire door to close. This helps prevent the spread of flame, but a fusible link will not help to slow the spread of smoke. A smoke detector can sense smoke in the air, and sends a signal to close the fire door before flames can reach the door.
Power-Operated Fire Door
Power-Operated Fire Doors are doors that normally are opened and closed electrically or pneumatically.
Power operated fire doors shall be equipped with a releasing device that shall automatically disconnect the power operator at the time of fire, allowing a self-closing or automatic device to close the door regardless of power failure or manual operation.
This means, power-operated fire doors must be integrated with the fire alarm system of the building. This will allow the fire alarm to deactivate the open doors, and retract them into the closed position should there be an electrical or power failure.