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I'm writing a story and would like some information about ceiling water sprinklers. This is set in an office. Let's say the character lights some papers on fire in the wasebasket. Would that be enough to get the sprinklers to kick in, and if so..could they come on intermittantly or do they stay on? What could catch on fire that would make them come on at least for a minute or so. Also do they always have alarms on them? Does it notify the fire department?I don't know anything about how this works.
It depends, I have one of the few homes with sprinklers and I have them in my shed as well. The sprinklers are brass nozzles with a glass plug filled with a liquid like alcohol. They are activated by heat. Some older ones have a lead coupling that holds the plug in. Once heated the plug falls out and water sprays on the fire. Depending on the temperature rating of the sprinklers and the spacing, as few as one sprinkler will be triggered. They do not all go off like on TV and in the movies. They stay on until turned off by the fire department. A master valve is located somewhere in the building, and a switch is triggered and/or a mechanical bell when the water is flowing. A wastebasket may or may not trigger the sprinklers depending on the height of sprinklers from the ground. However, if the fire spreads the heat will build up enough to trigger them.
It takes some fairly intense heat to set off the sprinklers. However, modern fire alarm systems have smoke detectors that will shut off HVAC units, release magnetic latches to close doors, and other stuff, along with notifying the alarm company or fire department.
Sprinkler systems are 1900s technology, and primarily designed to save the structure and prevent massive conflagrations. Tallrick has it pretty well covered.
Thank you so much for the information and the prompt response.
Right after her mean boss left, she lit the resume she'd edited for her, on fire, then someone shows up in the doorway--a strange yet attractive man asking her what's going on in there and whether she's okay. That's when the sprinklers would come on.
It's suppose to be just another thing gone wrong that day. And so she finds it so ridiculous that these events occur right now, that she reacts as if nothing unusual just happened.
Then i thought that if the room is smoky, she might not still be there kicking the charred wastebasket under the desk.
The closest experience I had with anything even similar to this was one time I'd written my estranged ex a letter and was going to hand it to him, but he showed up with some other woman, and so I said to heck with it, and I lit it on fire...in the toilet in a small bathroom. Someone knocked on the door to ask if I was okay in there. It was in a cold climate (Virginia) but I might have opened the window anyway--if it did open at all. It's a wonder the smoke didn't start up the room smoke detector in the connecting room after I opened the door.
In hindsight, it was pretty stupid--considering smoke inhalation and all.
Last edited by Dreamin1; 10-26-2008 at 04:55 PM..
Reason: errors
What you're talking about is fire sprinklers. Standard fire sprinklers go off at about 135 degrees. A fire in a trash can very well might be enough to set one off. Other sprinklers are rated higher, depending on the use - in kitchens, for example, they might even be rated well over 250.
Fire sprinklers are set off locally. They have a metal fuse or a glass bulb that holds a plug in (the metal fuse is an older design, but those type of sprinklers are still manufactured today). When the trigger temperature is reached, the fuse melts or the bulb pops, releasing the plug. The water is under pressure (the minimum allowed pressure is described in NFPA 13 if you really want to know), so it shoots out of the pipe, where it hits a deflector that causes it to spray out to the sides. Most fire sprinklers are of the "pendant" variety, meaning they hang down from the mains. As a result, oil and other gunk used in assembling the system tends to settle into the pipe, so you usually get a bunch of gunk first, before the water.
What you see in the movies, where all the sprinklers go off at once, just doesn't happen, except in specialized systems known as "deluge systems" - and those are a totally different type of design.
Modern systems also have a waterflow alarm that are powered by the flow of water through the pipe. So an audible alarm will be heard. Some systems tie that to an electronic device that notifies the FD, but not always.
It really varies by community as to whether the fire department automatically responds. For example, I grew up in an apartment building that has an automatic fire alarm. Every time it went off the alarm company automatically notified the fire department and they would respond with 3 fire trucks, and 1 aerial truck (ladder truck). Now I love in a much larger city and the fire department only responds when 911 is called. If the caller doesn't see any sign of fire they will only send 1 fire truck to check it out and turn off the alarm. One other thing to consider is that when the alarm goes off all elevators automatically stop at the nearest floor and the doors open up.
Okay, so the resume in the wastebasket is either on fire and/or smoking, could set off the fire sprinklers; If it has an alarm on it and it's equpped with that type of sensor, it would automatically notify the fire department.
re: elevators? Ahh I hadn't thought of that but now it's giving me good ideas about using it. Hmm. I suppose the elevators could malfunction and they'd be stuck in there together for a while. Are elevators fireproof? Later on, I could make them worry.
I had a smoke alarm in my kitchen at the previous place I lived in. If I remember right, you couldn't simply temporarily take out the battery. It was hooked up to the apartment somehow. or so it seemed. I couldn't broil anything without it going off, and boy was that annoying. Visuals of dead smoke alarms passed through my mind.
It really varies by community as to whether the fire department automatically responds.
You're talking about fire alarms, not fire sprinklers. Automatic fire sprinklers are purely mechanical. A fire sprinkler system alerting the fire dept. would be part of a different system.
Automatic fire sprinklers work if the power is cut, if the generators are out, if the batter backup fails, etc. About the only thing that would prevent them from working is if the water supply was interrupted.
Quote:
Originally Posted by iGlenn
One other thing to consider is that when the alarm goes off all elevators automatically stop at the nearest floor and the doors open up.
Again, not necessarily so with automatic fire sprinklers. That would only happen if they were tied in to an alarm system. Granted, that IS often the case today - but not necessarily, and certainly may not be the case with older systems.
Quote:
Originally Posted by TKramar
when our sprinkler system malfunctioned...it ran for MORE than a minute!
I would love to hear exactly how your system malfunctioned - that's not exactly easy to accomplish
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