# Something that wont set off a smoke alarm!!!!



## Dkick (Sep 8, 2014)

Is there anything that gives you a fog effect for lights that will not set off smoke alarms!?!


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## porkchop (Sep 8, 2014)

There are a variety of options at an even larger variety of prices, but it really depends on what kind of fire alarm system you have.


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## Joshualangman (Sep 12, 2014)

And what kind of "fog" you want … or smoke … or haze …


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## Calc (Sep 12, 2014)

Test it well in advance, and consider ALL the variables too. We had a problem with a smoke effect setting off the alarms a while back. FD came out the first night, verified that our fluid and machines shouldn't do that, and brushed it off as a fluke in the system. They weren't happy when they were back out the next night.
The smoke was drifting into the scene shop (we knew it would). The sensors in there are rated for the fog fluid, but the combination of fog and years of paint vapors pushed them over the edge. Neither was enough to set them off, but the combination did.

Ugh. That show was cursed.


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## gafftaper (Sep 12, 2014)

Yeah the only way to know for sure is to test them. I'm finding that the recently built theaters in this area, only have heat detectors in the theater. However somewhere deep in the HVAC exhaust they have a smoke detector. So you can use smoke and haze, but if it doesn't dissipate fast enough you'll set off the alarm. Fun! You simply have to test it to see what happens when you fog the place up. Be sure to contact whomever runs your system first to know if you need to be in a test mode, or if you have to call the fire department first. You don't want to set off false alarm testing the system.


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## StradivariusBone (Sep 12, 2014)

Whomever is your facility manager should have a contact number for your alarm company. They can call and put the system into "test" mode which will allow it to still respond to a smoke or heat trigger, but the service won't relay the call to the FD. Haze or fog the crap out of the room until the alarm trips to find the sweet spot. We just did this at my church with a hazer and weren't able to get it to go (which is a little unsettling). The building manager there claimed to have seen a bit more advanced systems that allow you to actually see which sensors are tripping and even isolate and disable certain ones. But I would guess that goes into the realm of what your fire marshal thinks is appropriate and safe.


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## MNicolai (Sep 12, 2014)

StradivariusBone said:


> Whomever is your facility manager should have a contact number for your alarm company. They can call and put the system into "test" mode which will allow it to still respond to a smoke or heat trigger, but the service won't relay the call to the FD. Haze or fog the crap out of the room until the alarm trips to find the sweet spot. We just did this at my church with a hazer and weren't able to get it to go (which is a little unsettling). The building manager there claimed to have seen a bit more advanced systems that allow you to actually see which sensors are tripping and even isolate and disable certain ones. But I would guess that goes into the realm of what your fire marshal thinks is appropriate and safe.



Shouldn't be anything unsettling about that. They've been working on these sensors like they're the cure for cancer. It's incredible with some of them how they're going about distinguishing between real smoke and non-threats such as dust, haze, fog, sawdust, etc. Won't be long before nuisance alarms are a thing of the past, at least in new construction.


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## StradivariusBone (Sep 12, 2014)

MNicolai said:


> Shouldn't be anything unsettling about that. They've been working on these sensors like they're the cure for cancer. It's incredible with some of them how they're going about distinguishing between real smoke and non-threats such as dust, haze, fog, sawdust, etc. Won't be long before nuisance alarms are a thing of the past, at least in new construction.



There was a discussion in our district regarding that, but unfortunately they've not adopted the new tech. In the case of this church though, I'd guess the duct sensors are close to 20 years old. On that note, how tragically difficult is it to retrofit a fire control system with these newer sensors? I'd love to be able to haze with wild abandon. How much do they cost and I'm guessing a licensed contractor would be required to install them?


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## MNicolai (Sep 12, 2014)

StradivariusBone said:


> There was a discussion in our district regarding that, but unfortunately they've not adopted the new tech. In the case of this church though, I'd guess the duct sensors are close to 20 years old. On that note, how tragically difficult is it to retrofit a fire control system with these newer sensors? I'd love to be able to haze with wild abandon. How much do they cost and I'm guessing a licensed contractor would be required to install them?



You'd have to get in touch with a mechanical contractor or consultant to find out. On our projects, architect or theater consultant usually gives the mechanical consultant a heads-up the systems are going to need tolerance of atmospheric effects and shop sawdust. Mechanical consultant takes care of the rest.


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## Dalamar (Jan 9, 2015)

The main problem with most alarm systems is that the detectors are particle detectors... and they do their job to a fault. And therein lies the problem. They don't make the difference between dust, fog, and combustion, and since they are the cheapest... 

Fire will ALWAYS do at least two of four things: It'll generate CO. It'll generate airborne particles (smoke). It'll generate flame (flame signature detectors). It'll generate Heat. Multi-criteria requires at least one to set off a warning, and two to trigger an alarm. It would satisfy most Fire Marshall's requirements and prevent shutting off alarm systems in show mode. In this day and age, and with the technology widely available, I still do not understand why isn't it not only the STANDARD, but an imperative to have multi-criteria fire detectors installed gradually in performance venues ("performance" used at large - read school, Churches, Theatres, Arenas...).


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## BillConnerFASTC (Jan 9, 2015)

When there are experienced people on the design team, like a professional theater consultant, or usually is standard. Usually heat detectors are used. Return air ducts present a special problem in that until someone changes the codes, particle are required.


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## RickR (Jan 9, 2015)

A common practice has been to talk with the local fire marshal/authority and see about shutting off the system. They usually want fire watch people in place at all times near manual alarms and everything else they can think of...


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## Dalamar (Feb 3, 2015)

BillConnerASTC said:


> When there are experienced people on the design team, like a professional theater consultant, or usually is standard. Usually heat detectors are used. Return air ducts present a special problem in that until someone changes the codes, particle are required.



Hi Bill, Rick. 
Could you enlighten us on what the "standards" are, and why are we not going more towards these multi-criteria detectors? I still can't believe we are not there yet...

And as for the common practice, I had a few people coming to see me from different States and it appears one set of rules can't apply across the board. I remember specifically a younf woman working out of a theatre in R.I. where fog /haze was banned altogether because the Fire Marshall refused to have a fire watch on stage while the system was turned off on a timer...


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## BillConnerFASTC (Feb 3, 2015)

First, I'm not a fire alarm expert. I try to plan for atmospheric effects in all of our projects, but the design team is limited. The International Building Code - the most widely adopted model building code in the US - requires smoke detectors in return air systems of 2000 cfm or greater size. NFPA 72 is the standard for fire alarms. Neither, as best I can tell, embraces the multi-criteria detectors for this application. I don't know why. It has been a long term goal of mine to dig into this and go about changing the codes and standards to more permanently solve this problem. At least, there should be specific requirements in the codes and standards permitting the fire watch concept, hopefully with a system that allows other than just off duty fire service to perform that task, like some simple training criteria. What the other options are, I don't know.

I have been a proponent for a number of changes to the codes, beginning in 1987, so I can tell you that anyone - willing to invest the time - can propose changes. It takes time. You have to prepare good proposals with good substantiation, you need to go to the meetings and hearings, and you need to make the case you are creditable and that the result will still be reasonably safe for the occupants. I'd guess if I do try this, it's probably a full month or two of work spread over 3 to 5 years. Alternatively, you could hire a code consultant to do the work. No guarantee, and probably not inexpensive, but a lot less frustration.


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## robartsd (Feb 3, 2015)

BillConnerASTC said:


> First, I'm not a fire alarm expert. I try to plan for atmospheric effects in all of our projects, but the design team is limited. The International Building Code - the most widely adopted model building code in the US - requires smoke detectors in return air systems of 2000 cfm or greater size. NFPA 72 is the standard for fire alarms. Neither, as best I can tell, embraces the multi-criteria detectors for this application. I don't know why.


I can't imagine that a heat or flame signature sensor would be useful in the return air system; however, I wonder how well a sensitive CO detector in conjunction with a reasonably tolerent particle detector would do at providing safety while preventing false alarms. It might depend on how these indicators tend to be distributed in a space where a fire occurs.


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## Les (Feb 8, 2015)

I am going to be dealing with this same issue at a community theatre where I'm designing a show this spring. I'm bringing in 6 Varilites (4 VL500, 2 VL1000) and 4 Design Spots, but unfortunately there is a "no haze" policy in place. 

Personally, I have never known a time when haze was used in the space, but I know that they are touchy about fog machines. I'm not sure if they just don't know the difference or actually have tested both types of systems, but they're pretty rigid on the subject. 

The building is using a 20 year-old alarm system and it doesn't help that there are two 18" return ducts which suck air from under the apron of the stage. I also have a feeling that the detectors above the stage (dead-hung, no fly loft) are particulate only.


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## MikeJ (Aug 3, 2015)

All fog or haze will set off particle detectors.

@MNicolai Saw dust from the wood shop should never be entering the HVAC system. This is dangerous, you really can cause an explosion from sawdust. A dust collection system should be utilized, and people should be sweeping an vacuuming up sawdust created by tools where dust collection systems are not practical. 

@Les Investigate the alarm system, usually in an old and basic system its just heat sensors. Try to convince them that you will not use fog or haze, but "diffusion." Running a DF-50 in a far corner for a bit every few minutes, can give you just enough to see the beams without anyone noticing that its there otherwise, and it has no scent.


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