# Fire Alarms Go OFF!



## audrey2 (Feb 4, 2007)

I Was in Evita and durring the waltz there was a TON of dry ice. Durring 3 of the shows, the dry ice set off the fire alarms and everyone, including the audience, had to Evacuate!


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## saxman0317 (Feb 4, 2007)

The dry ice set off the alarm? Thats a new one. usually gas alarms are set higher up on the walls and arent set to CO2. Either way...one of those things that deffinatly sucks. Ive had a couple false alarms during some of my shows..plus some that wernt so false..


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## Van (Feb 5, 2007)

I was doing a Nike gig in Hollywood Florida. We're loading in this giagantic video screen, huge deck, tons of lights.... All of a sudden the fire alarm goes off. Evacuate, evacuate, Sounded kinda like a Dalek from Dr. Who. Anyway we found out later that the culprit was one of the rigging guys. The hotel had a fancy schmancy new fire alarm installed. It used lasers, frickin lasers man, < best dr. evil voice>. Anyway apparently you cant get within 9 inches of the ceiling or you break the beams on the lasers and it sets off the smoke dectectors. What a worthless system in a multi-use ballroom.


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## Chris15 (Feb 5, 2007)

I agree Van. What a STUPID system. I was thinking that it might have been a VESDA (Very Early Smoke Detection Apparatus), but then did a quick brush up on VESDAs and it ain't. Intriguing none the less but insanely stupid.


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## MHSTech (Feb 5, 2007)

The dry ice probably set off the alarm because of the particles in the air. You can itch and complain about these systems, but they're doing what they are designed to. If you know that there's a chance you might be tripping on of these alarms on accident, you might want to give your fire chief or central dispatch a call a head of time.


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## Footer (Feb 5, 2007)

Van said:


> I was doing a Nike gig in Hollywood Florida. We're loading in this giagantic video screen, huge deck, tons of lights.... All of a sudden the fire alarm goes off. Evacuate, evacuate, Sounded kinda like a Dalek from Dr. Who. Anyway we found out later that the culprit was one of the rigging guys. The hotel had a fancy schmancy new fire alarm installed. It used lasers, frickin lasers man, < best dr. evil voice>. Anyway apparently you cant get within 9 inches of the ceiling or you break the beams on the lasers and it sets off the smoke dectectors. What a worthless system in a multi-use ballroom.



I have worked in a few spaces like that. They laser is actually there to detect smoke. I was doing a ballroom type thing that had them and one of the decorators let go of some balloons and it just so happens balloons rise just like smoke, and it tripped the laser. Another space had a few in their grid, and we were hanging some new loft blocks and one of the people on the crew got their shoulder in the way and had the evacuate the entire building. But then again you do get to see the big red truck come!


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## saxman0317 (Feb 6, 2007)

MHSTech said:


> The dry ice probably set off the alarm because of the particles in the air. You can itch and complain about these systems, but they're doing what they are designed to. If you know that there's a chance you might be tripping on of these alarms on accident, you might want to give your fire chief or central dispatch a call a head of time.



Dry ice gives off nothing but CO2 though, which immediatly sinks to the floor. Shouldnt set anything off. the lasers though, ive heard of them. We toured one of the histroical places round bout here with the fire dept. not long ago after they did a multimillion dollor upgrade. from what i gathered the lasers are so precise that they will sense a change in their refraction through the air cause by a change in temp. Supposedly really senstive and very hard to fool, unless someone breaks the beam. Good for museums and the like though since their considered to be dual purpose fire and burgular alarms. pricy though!


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## MHSTech (Feb 6, 2007)

saxman0317 said:


> Dry ice gives off nothing but CO2 though, which immediatly sinks to the floor. Shouldnt set anything off.


Allow me to explain this...

Consider this; HVAC systems recirculate air. Newer ventilation systems are static now rather than the on demand style of systems, which means that air is ALWAYS moving. Also, NFPA 72 requires there to be projected light beam style detectors located in the air ducts. It was said that there was a large amount of haze out on the stage, it is entirely possible that enough of it got sucked into the air return and set off the alarm.

Here is another interesting fact. There are some fire alarm systems out there that do measure the amount of carbon monoxide AND carbon dioxide in the air to help detect possible spikes in a growing fire. Or here is another gas detector possibility: the large amount of CO2 could have displaced enough oxygen that may have tripped an alarm.

It is also possible that the large amount CO2 could have set off an Ionization Smoke Detector if there was enough particles between the two plates on the inside of them.

There are plenty more ways the alarm could of been tripped. What I'm getting at is that just because something SHOULDN'T trip an alarm doesn't mean that it CAN'T.


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## mbenonis (Feb 7, 2007)

My question is this: why didn't you talk to your local AHJ (authority having jurisdiction) about what you planned to do, whether it was safe, and if so, how to do it without creating false alarms? Usually the local AHJ is friendly and will work with you to meet your needs without causing a safety problem.


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## u_dakka (Feb 8, 2007)

saxman0317 said:


> Dry ice gives off nothing but CO2 though, which immediatly sinks to the floor. Shouldnt set anything off.



Possibility of the dry ice going into the orchestra pit and setting off an alarm there?
just an idea
andy


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## astrotechie (Apr 17, 2007)

I hope flash powder doesn't set off the fire alarm. That would stink since this is the first show in this theater.


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## gafftaper (Apr 17, 2007)

It could. So I would keep your powder use to a minimum. I've used it in a theater with fire alarms before with no problems. But, I've always been REAL careful about the quantity of powder.


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## PadawanGeek (Apr 29, 2007)

One time I was at my church and we were doing a live recording, and it was a slow song and I was falling asleep, when the smoke alarm goes off and I get freaked out. The had to re-record that song =0


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## mbenonis (Apr 29, 2007)

astrotechie said:


> I hope flash powder doesn't set off the fire alarm. That would stink since this is the first show in this theater.



I'm sure you know this already, but if you're using flash powder make sure you have the local Fire Marshall come out and inspect exactly how you will be using it, as well as have stage managers on both sides of the stage with appropriate fire extinguishers. The Fire Marshall will also be able to tell you whether the flash powder will be a concern in terms of the fire detection system.


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## David Ashton (Oct 5, 2007)

saxman0317 said:


> Dry ice gives off nothing but CO2


All commercial CO2 foggers either my father or I have come across use the CO2 to cool vaporised heavy fog fluid. Our big fogger uses an air-con unit to cool it.

This was a Dry ice fogger right?

Edit: This is Sean, aka. Bean. (should've changed accounts since I'm on his computer...)


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## Logos (Oct 5, 2007)

Traditional low smoke machines like the LeMaitre PeaSouper simply douse dry ice in boiling water. They are still around although I haven't seen one in Australia recently.


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