dry ice smoke alarms and availability

[henryc]

hello everyone , ive stumbled across this site tonight while looking fro info regarding the usage of dry ice in a stage production.

 

my background is that I am a science technician working in a glasgow secondary school , for this years summer end of term stage show we were looking at using some sort of fog / smoke machine however we have been told that due to the the councils regulations school shave been told that they cannot make use of such machines for fear of triggering filre alarms, and under no circumstances can smoke detectors be covered up, now for my part I am the schools science technician , I made mention of the fact that using dry ice could provide a fog type setup but I wasnt sure either about where we could getenough dry ice from for the effect to work or if the cost would make it ano no, BUT more importantly I need to know whatis the chances of dry ice triggering a smoke alarm .

 

from my usage of dry ice ..small scale years agao working in chemical lab ...I remember it didnt rise greatly above the flooor and evaporated fairly quickly .

 

henc eany info form you folk who are in the know would be greatly appreciated

 

cheers

 

henry c

[GridGirl]

Can you double-check that there's no way to legally isolate the smoke alarms - the council may have said that you can't use fog machines, but when the alarms were installed there may have been an isolation switch put in, which will allow you to disable smoke alarms within the theatre while the switch is on - we have a half-hour timer which does this. If that turns out to be a no-go, then dry ice may be an option. Most smoke alarms are particle detectors - when the particles in the air go above a certain concentration, they go off. Dry ice won't trigger this type of alarm, as it's (obviously!) not made up of particles in the air like smoke. However, it does give you a very different effect to smoke - because it's heavier than air it rolls along the ground, rather than smoke machine smoke which rises and hangs in the air, and that may not be the effect you're after. I can't help with getting hold of it, as I'm in New Zealand, but be aware that storage is difficult - you can't put it in a working freezer because it's too cold and will wreck the freezer! - and it will lose half its weight every day, so you really need deliveries every other day at least. It's also tricky stuff to handle as it will burn skin on contact, and you have to dump it into near-boiling water to get the effect - so you need good procedures and risk management in place. A lot of people reckon that dry ice is more trouble than it's worth, but it depends on the need for it.

[Dodgecaliber]

PM Sent

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[Ellis]

Hi,

 

For a dry-ice supplier, look around the international airports. Dry ice is often used to cool food for long-haul flights. For that reason, dry-ice suppliers tend to locate themselves nearby.

 

No use for you, but I was told about this when I was lookign for a supplier Gatwick.

 

HTH

[JSalisbury]

Hi,

Any idea where to hire such a machine near Swansea?

 

Thanks

[richard]

You can hire a 'pea souper' from Stage Electrics (who are based in Bristol but deliver anywhere pretty much) - www.stage-electrics.co.uk

 

Dry ice I usually get from BOC Gasses - you'll find them with google, they usually have local branches everywhere and are not too expensive, however as mentioned above you probably would need to get it delivered every other day so the delivery charges would be more than the CO2 itself.

[mar]

Stage Electrics don't stock pea soupers anymore I was told by their rep last week. Only low fog machines or the big old 'londoner' dry ice machine which they had forgotten they had till we asked for it.

[ianknight]

"Should've gone to..." to quote an ad.

 

But as overt advertising isn't really done here - check my profile if you still need a pea souper...

[henny]

there is 2 pea souper's on ebay at the mo

[godd2]

My school is doing Les Mis. yesterday we had our first "performance" which was for junior high kids mainly. well we have been using a smoke machine for 2 weeks with a hazer as well with no problems. but of course yesterday during the show was the first time it set off the alarms. pretty much I think it is the cooling system with 800+ people in the house changed the air currents plus the added body heat. so long story short, smoke is not allowed to be used now.

 

so we are now thinking dry ice specifically for the brige scene. the set designer made a bridge that rolls on and we were putting smoke under it so it would roll out which allowed the GAM fx gobo mover or whatever it is called to project on it. very nice effect really.

 

so we want to do this with dry ice. is it best to have a container with large surface area but shallow water? obviously hot water is needed. should we crush the dry ice just before the scene and through it in there before the curtain goes up?

 

suggestions?

[Andrew C]

my background is that I am a science technician working in a glasgow secondary school ,

Haven't you got an account with BOC or similar for gasses? I'd try there first.

 

Should be fire wrt to fire alarm.

[Grahame]

When do you need them? Scottish Ballet will have four Pea Soupers available from next week. Which reminds me, I'd better go switch them on for tonight's show...