# Used prices for old MDG Atmosphere units? Trying to find them.



## telmnstr (Sep 8, 2012)

I'm a laser / lighting geek and planning to do a Halloween party at our local hackerspace as our landlord is cheating us out of the rest of the year. 

I currently own a Chauvet "hazer" which is really just a fog machine with a fan. It's been fine for what it is and with my limited use. But there are some concerns with triggering smoke detectors, so I'm looking to take precautions.

I've long known about the MDG "oil crackers" but always thought they were bad for people. After doing some research, I'm digging the idea of one. I know it's not a be-all end all solution.

I can't find used pricing on the units. Anyone have a rough idea of what used prices would cost for one? I don't mean the current models that are fancy. 

Any insight into old equipment pricing on MDG's would be helpful! Thanks in advance!


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## Footer (Sep 8, 2012)

Cracked oil will set off particle detectors just the same as a water based unit.

Sent from my Galaxy Nexus using Tapatalk 2


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## derekleffew (Sep 8, 2012)

telmnstr said:


> ... I can't find used pricing on the units. Anyone have a rough idea of what used prices would cost for one?


The value of any used product is whatever the market will bear. There's no Kelly Blue Book for theatrical equipment. The closest is to see what the big boys are charging for a comparable item. See Sources for Used Equipment - ControlBooth .


telmnstr said:


> ... I've long known about the MDG "oil crackers" but always thought they were bad people. ...


I'm not sure what this means, but Dalamar , Int'l Sales Director for MDG Fog Generators, has been a valued contributor to ControlBooth.

Agree with Footer that, depending on they type of detector, an oil cracker can be just as bad as a glycol-based machine. From the thread http://www.controlbooth.com/forums/special-effects/15685-mdg-atmosphere-hazer.html :

Dalamar said:


> Ok... folks, here are a few pointers.
> 
> A) To understand your problem, thelightguy87, you need to first know what a particle detector is. In MOST cases, a particle detector, part of a fire detection system, consists of a photocell perpendicular and hidden from a light source (often times a LED). As the amount of airborne particle concentration augments, so is the light from said source reflected to the photoelectric cell. A threshold is set by the manufacturer and, once reached, it triggers a contactor that, in turn, triggers the alarm. See simple graph here.
> 
> ...


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## telmnstr (Sep 8, 2012)

EDITED EDITED! Sorry, I meant to say "bad for people." I type fast and cut my original post down quite a bit. I fixed this. The water based versus oil based thing, although water based means glycol based from my recent research.

I understand that smoke detectors will trigger on both, and was figuring for the upcoming event we will put surgical gloves over the smoke detectors and buy a panel that is better than the buildings fire alarm, add a network of heat change sensors, and add more fire exit signs. It will only be about 60 people in a room with direct access to outside, but I don't want to trip the building system nor do I want to take heat for making things unsafe.


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## Les (Sep 8, 2012)

telmnstr said:


> and was figuring for the upcoming event we will *put surgical gloves over the smoke detectors* and buy a panel that is better than the buildings fire alarm, add a network of heat change sensors, and add more fire exit signs. It will only be about 60 people in a room with direct access to outside, but I don't want to trip the building system nor do I want to take heat for making things unsafe.



For the time being, you could just see about having the fire department come by and bypass [silence] your alarm system while placing a fire watch (fire department personnel) at the panel to monitor any alarms and confirm whether or not they are false alarms or legitimate emergency situations during the event(s). Tampering with the alarm system in any way would certainly land you in a heap of trouble, not to mention guilt, should anything go wrong. Any changes or additions to the system would need to be inspected and approved prior to any events open to the public. 

The most cost-effective approach might be to contact the manufacturer of your current system and see about retrofit options -- say, removing the particulate sensors and installing heat sensors. These changes will need to be performed by qualified personnel as there are very specific codes that must be strictly followed.


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## telmnstr (Sep 9, 2012)

Les said:


> For the time being, you could just see about having the fire department come by and bypass [silence] your alarm system while placing a fire watch (fire department personnel) at the panel to monitor any alarms and confirm whether or not they are false alarms or legitimate emergency situations during the event(s). Tampering with the alarm system in any way would certainly land you in a heap of trouble, not to mention guilt, should anything go wrong. Any changes or additions to the system would need to be inspected and approved prior to any events open to the public.
> 
> The most cost-effective approach might be to contact the manufacturer of your current system and see about retrofit options -- say, removing the particulate sensors and installing heat sensors. These changes will need to be performed by qualified personnel as there are very specific codes that must be strictly followed.



It's a situation where we're going to be moving out, and it's a going away shin-dig. We're being cheated out of our lease, begging forgiveness is better than asking permission in this case. I have zero intentions to do anything to jeopardize the building, and plan to make things safer. Actually, I'll look tomorrow, last time I looked there were already ground faults on the fire alarm system and someone who worked for the fire alarm company made snide comments about the system not currently working. He said, "I wouldn't have anything valuable of mine in this building." Building was in foreclosure, another person snatched it up for a song and is going to be converting it to overpriced apartments. We're the last tenant and they're basically ejecting us against our lease, which they basically forced us to sign. I'm ready to be out of there so not that much of a deal. We're on good terms with the city and such so we're not out to cause issues, nothing insanely loud, I just want to put my 4 technobeams, 4 roboscan 1220s and my 1 watt laser projector to use for one night. 


What a week. Grr.


What do real venues that run hazers/fog machines all the time use for fire detection? Are they all heat change sensors or what?


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## techieman33 (Sep 9, 2012)

telmnstr said:


> What do real venues that run hazers/fog machines all the time use for fire detection? Are they all heat change sensors or what?



It varies venue to venue. Some have sensors that play nice with haze/fog, some silence the system and set a fire watch. I'm sure there are several other methods as well. It all depends on how the specific system is setup and how the local fire marshal wants things done.


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## derekleffew (Sep 12, 2012)

Those wacky Georgians: Adult entertainment club's smoke machine leads to false alarm | www.wsbtv.com


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