What is the difference between a fire door that is always closed and a fire door that is always open?
Often closed fire doors in peacetime show closed state, when there are people need to push open. Often close fire door this kind of open state has certain shortcoming, because the place that fire door installs, it is the passageway that personnel often walks normally, caused certain contradiction. In particular, large shopping malls have large personnel flow. If normally closed fire doors are set in the internal evacuation staircases, they will soon be damaged and fall off due to frequent opening and closing, thus failing to play a role in fire prevention and forming a fire hazard.
Normally open fire doors are usually open, fire automatically closed. Due to stay open at ordinary times, traffic convenience, ventilated daylighting is convenient, in the case of a fire can be shut down on its own, play a role in smoke proof, thus completely solve the fire door normally closed to traffic inconvenience and fire door due to frequent switch of artificial damage, and ensure the fire safety at the same time. Therefore, in the evacuation staircases of some large shopping malls, fire doors should be set up, usually open state, in case of fire through a variety of sensors to control the door closures.
Under which circumstances should fire doors be normally opened or closed?
The fire door set in the building where people often pass is appropriate to use often open fire doors, building public parts (traffic core) including smoke prevention stairwells, fire elevator front room and Shared front room and other parts of the fire door should always open fire doors, hallway evacuation corridor at the fire door should always open fire doors.
Normally closed fire doors shall be used for fire doors in all positions except those where normally open fire doors are permitted. That is to say, the design in addition to the drawings marked as open fire doors, other fire doors should be normally closed fire doors. This asks a designer to be in when choosing fire door, if normative requirement is often open fire door, must make clear in door window table, review personnel can undertake examining accordingly.