Automatic Closing Fire Doors and Dampers
How many will actually work when called upon?
Automatic closing Fire Doors and Dampers are designed to prevent the spread of smoke and flames from one section of a structure to another. Some release when a fire alarm activates some activate strictly by a certain amount of heat 135o to 185o F. or higher from a fire melting a link and a counter balance closes the door or damper. They come in all sizes and types of closing styles including rolling and sliding doors or simply are hall doors at tops of steps or in hallways that are held by electro magnets that drop the doors closed .By using auto closing fire doors this saves always having to open a door and prevents fire doors from being propped open but
While most doors operate as they are supposed to many do not due to failure to properly maintain the mechanisms and wear and tear and deliberate acts of damage.
Which often leaves doors that are propped open with wedges or if they do operate they do not fully close and latch thereby allowing smoke and flames to continue there destructive path.
Other problems develop when contractors and other individuals deliberately run wires and piping and thru these Dampers and doors which also prevents them from closing. How many times when I am running wire for Alarms or computer and telephone systems above drop ceilings I find some one has run wiring thru an auto closing damper thereby disabling the damper, which is designed to prevent flame and smoke from traveling thru duct work. In the case of air plenum ceilings where the entire above ceiling area is used as ductwork the dampers are installed in firewalls to allow return air flow above the ceiling from room to room.
Still more problems happen when painters paint the thermal links on auto doors or dampers which greatly reduces the sensitivity of the link and allows for a fire to get much hotter before it activates. You will also find were links have been broken or otherwise removed and the wire cables just re-spliced without a link.
There have been several instances I have seen were fire doors were deliberately blocked open in plants so pipes and wires could be brought thru the opening and the door itself covered up completely with out the AHJ knowledge.
You see this often were a plant has closed down and new tenants move in and do not maintain the fire safety features the previous plant used. For some reason new tenants feel they do not have to maintain fire systems, sprinklers and doors and dampers. Till the AHJ shows up or their insurance company comes and inspects and demands the systems be put back in place. Per NFPA fire safety systems such as Sprinklers, Fire Alarms etc.
Must be maintained in perpetuity for the life of the structure unless the AHJ in writing otherwise authorizes it.
But how many building owners ever bother with that little detail till something goes wrong and then the shit hits the fan as they say.
The other problem you encounter with fire doors is how they are released the more complex the releasing device the more the chance it gets broken. In a high income school district were I maintain fire systems with auto releasing doors the architect specified a fancy and expensive mechanical holding release mechanism on the school auto doors in the hallways and almost every set of doors did not close properly because of the kids pulling the doors shut instead of using the release buttons. The result doors with wedges under them and the AHJ putting the school district on notice. I replaced the fancy mechanisms with plain old Electro Magnets and the problem was solved. For 1/10th the cost of replacing the fancy auto closers.
But what it all comes down to is the proper use and maintenance of auto operating units.
Failure to install and use them on fire doors always being propped open is just a time bomb waiting to happen.
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