# Running a hazer with smoke alarms in exhaust ducts

#### gafftaper

##### Senior Team
Senior Team
Fight Leukemia
My theater was built with heat detectors everywhere except for the exhaust ducts... Sigh. I would really like to get a hazer. My thought is that I should be able to pump in a consistent lower level of haze before triggering the alarm. So my thought is to find a hazer with a reliable accurate level control. I can test it out with our alarm guy there. With a little trial and error, we will be able to figure out that I can safely run it on say level 4 all day but if I turn it up to say 7 it triggers the alarm. If level 4 is enough haze for the look we want, it should work great.

So does anyone have experience running a hazer with smoke detectors? What do you use? Do you think this idea makes sense or is it crazy? Any suggestions on which hazer to test out?

Thanks!

RonHebbard

#### almorton

##### Well-Known Member
We found that the only reliable way to avoid triggering non heat detecting alarms was to disable them for the duration of the show and turn them back on after the show and the haze has cleared.

#### chausman

##### Chase
Fight Leukemia
Maybe stating the obvious, but it might be worth talking to either the alarm company or a mechanical engineer. I make no claims of being an expert, but there are some exceptions to when exhaust duct smoke detectors are required. It also looks like they don't have to trigger an alarm, only issue a warning at a supervised location. If this is a college campus that has security monitoring those signals, I'm sure you could develop a policy with them for how to handle it during events that are using the hazer.

And for another idea, if the alarm guy and security is friendly and willing to help, you might even be able to design a sort of system so that when the hazer was running (and for an additional time after that) their dispatch office could see that the hazer is running. So in a real situation that the smoke detectors are triggered but you're not using the hazer they immediately could know the hazer isn't running. Could eliminate some points of failure in trying to pass on information about when it will be used to everyone who might be involved every time.

#### Amiers

##### Renting to Corporate One Fixture at a Time.
You could get a fan that pushes the haze away from your intakes. Obviously have them turned off if you can. Could take it a step further and plastic your intakes so that no haze gets in the system at all.
Turning them off is the ideal situation though. Nothing can beat that. Extra step is to have fire safety there to cover your bases.

RonHebbard

#### gafftaper

##### Senior Team
Senior Team
Fight Leukemia
Our alarm guy in the district thinks that it's possible to find a level to run a hazer under the level of triggering the detectors. Given all the smoke that has been in the air this last week from the west coast wild fires, I've had an amazing level of natural haze which tells me that it is possible.

That's not haze its smoke from the fires and it's exactly what I want...

#### ScottT

##### Lighting Programmer
That looks exactly like an MDG Atmosphere that was left on over lunch break. I'm guessing you don't want to deal with CO2?

#### gafftaper

##### Senior Team
Senior Team
Fight Leukemia
That looks exactly like an MDG Atmosphere that was left on over lunch break. I'm guessing you don't want to deal with CO2?
Yeah I'm interested in CO2 for ground effects, but would love a good hazer for air effects.

RonHebbard

#### soundlight

##### Well-Known Member
Yeah I'm interested in CO2 for ground effects, but would love a good hazer for air effects.
The MDG Atmosphere uses CO2 as a pressure source to generate the best haze I've ever seen - it's not a CO2 low fogger. You might want to take a look at it as super small particle size could help in your case. However, they are very expensive and you have to buy CO2 gas as well as the MDG fluid - but if there are CO2 bottles used elsewhere in your building, getting CO2 may not be an issue at all.

RonHebbard

#### ScottT

##### Lighting Programmer
The MDG Atmosphere uses CO2 as a pressure source to generate the best haze I've ever seen - it's not a CO2 low fogger.
Yep. They are pretty amazing. The newer version, the ATMe, is also a fantastic unit and lets you control the CO2 pressure, as well as the flow from the console. I am a big fan. The Unique 2.1 is also a good option, and it doesn't use CO2, but instead of a fine mist it creates more of a smoke cloud. Perfect for entrance/exit effects, but not so great for a continual haze without perfect airflow.

LSG MKII for low lying fog. Again, uses CO2, but an amazing effect.

It is an art, not a science. Between tank pressure, on/off effect timing, and dwell time... You're in for a fun time

#### danTt

##### Well-Known Member
It is an art, not a science. Between tank pressure, on/off effect timing, and dwell time... You're in for a fun time
You forgot misbehaving foggers, frozen solonoids, and unpredictable Dewar tanks in your list. They're awesome when they work, but a full time headache to maintain and keep consistent

#### Footer

##### Senior Team
Senior Team
I have the same thing. Heats on the stage. Smokes in the ducts. I've only hit the ones in the ducts twice in 12 years. Both times it was with water based haze. Get a DF50 in there... it doesn't travel as far. We never have a problem. The newer hazers that give a much better look tend to travel a lot farther.

#### Scarrgo

##### Well-Known Member
I work at a high school theater, we also have particle/smoke detectors in the room and cold air returns.
Awhile back we tried an oil hazer and well lets say some folks were not to happy...the strobes and sirens during a rehearsal are not a welcome thing.

We asked if we have a fire watch, could the alarm be turned off? They said "No!"

We tried several brands, and the Ultratec Radiance Hazer was the first one we found would not set the system off, and we hazed that room heavy, no alarms....YMMV

Sean...

#### RonHebbard

##### Well-Known Member
You forgot misbehaving foggers, frozen solenoids, and unpredictable Dewar tanks in your list. They're awesome when they work, but a full time headache to maintain and keep consistent.
Your mention of Dewar tanks sparked memories.
In the late seventies / early eighties the Stratford Festival built our own liquid nitro' foggers.
At the time we had three theatres spread out across the city and built six units, two per venue.

The heart of each fogger was a double walled, 3/4" Russian Birch, glued, screwed and fiber glassed, castered box approximately 30" square in plan view by two feet tall plus its 4" casters. Each box was heated by two 2 KW 240 volt immersion heaters each powered by a dual pole, fused, disconnect switch via dual poled adjustable thermostats and commonly referred to as the "rumble pots" due to the noise generated each time the liquid nitro' hit the steaming water. For handling convenience during changeovers, (All three venues operate in a rotating rep'.) a large Dewar sat atop each rumble pot with incoming and outgoing DeWars stored closer to our loading docks.
Each of the three theatres had four Dewar tanks, two in use and two standing by.
Stratford was in the heart of pig farming country thus adding our tanks to the regular weekly route of the liquid nitro' delivery truck was no trouble.

One of my better memories was when a local hog breeder found his liquid nitro tank empty when he, and his main male, were most in need.
Our production manager received a desperate call asking if we could loan the breeder any partial tanks of liquid nitro to carry him over 'til next week's delivery.
We agreed to give him a partial tank from each theatre if he drove to all three venues to fetch the three Dewars.
Imagine everyone's surprise and delight when the hog breeder returned our empty tanks accompanied by a large quantity of his butchered, wrapped, and frozen pork ready for grilling.

I wonder what ever happened to the young high school student who posted here a few years ago and was planning on operating his own liquid nitro' production and delivery company? Any one remember him??
EDIT #1: Varietyler, that was his name; a search found him fairly quickly.
EDIT #2: Here he is:
varietyler
Member · 16 · From Utah
Joined Apr 29, 2019
Last seen May 3, 2019

Toodleoo!
Ron Hebbard

Last edited:
Ben Stiegler

#### gafftaper

##### Senior Team
Senior Team
Fight Leukemia
The MDG Atmosphere uses CO2 as a pressure source to generate the best haze I've ever seen - it's not a CO2 low fogger. You might want to take a look at it as super small particle size could help in your case. However, they are very expensive and you have to buy CO2 gas as well as the MDG fluid - but if there are CO2 bottles used elsewhere in your building, getting CO2 may not be an issue at all.
Interesting... I'll have to look into that.
I have a mid loading gallery stage right, the air ducts for the stage come in just below that, so I figure it's a great location to place the hazer. The air returns are in the same position 60' away stage left. My hope is if we kept it low enough the haze wouldn't quite make it all the way across. CO2 base and tiny particles seems like a great way to be able to get more control. And again based on the pictures I know I can get a good amount of real smoke in the room without it triggering.

I have the same thing. Heats on the stage. Smokes in the ducts. I've only hit the ones in the ducts twice in 12 years. Both times it was with water based haze. Get a DF50 in there... it doesn't travel as far. We never have a problem. The newer hazers that give a much better look tend to travel a lot farther.
Sounds like I need to give a DF 50 a try too.

RonHebbard

#### derekleffew

##### Resident Curmudgeon
Senior Team
Sounds like I need to give a DF 50 a try too.
I wouldn't bother. While I love the DF-50 (for arenas!), it has some severe shortcomings for your application.
1. Control. It's either off or on--no volume, duration, flow rate, none of that fancy stuff.
2. It's loud. Sound just like an air compressor, which it is.
3. The water-based fluid doesn't have nearly the "hang time" of the oil-based.
4. Cost. I'm sure it's more than you want to spend.

A good HVAC system can suck almost any haze out of a space. Rather than temporarily disabling the fire alarm, could you turn off the air flow? Or might that be a violation also?

#### MNicolai

##### Well-Known Member
Fight Leukemia
I wouldn't bother. While I love the DF-50 (for arenas!), it has some severe shortcomings for your application.
1. Control. It's either off or on--no volume, duration, flow rate, none of that fancy stuff.
2. It's loud. Sound just like an air compressor, which it is.
3. The water-based fluid doesn't have nearly the "hang time" of the oil-based.
4. Cost. I'm sure it's more than you want to spend.

A good HVAC system can suck almost any haze out of a space. Rather than temporarily disabling the fire alarm, could you turn off the air flow? Or might that be a violation also?
On #3, the DF50 is oil based, but on #1 and #2 I fully agree. On #4, I'm sure there are some good deals on the used market.

As to HVAC, I have seen some systems where the controls are programmed with an override during shows. System ramps up prior to the show, goes into "low noise, low airflow" mode during the performance, and cycles back up afterward. I'm not sure it's fully viable as a means of circumventing the particle detectors though, and simply shutting the airflow off allows quite a bit of carbon dioxide and heat to build-up if you have a full house.

@gafftaper In response to some of the other comments, in a modern HVAC system for a theater, typically the full volume of air cycles every 10 minutes or so -- subject to environmental conditions and such. Not easy to fool the system by trying to keep haze away from the return grilles. Also, if you are doing testing with a specific hazer, I would recommend putting the alarm system in bypass mode and having someone drive the HVAC controls via override so you're testing when the system is operating at typical volume for a show. If you just fire up a hazer and test when the room doesn't have 600 people heating it up and the lights are off, you may be testing very different ventilation conditions than you would see during a live show.

I'll take a look at Article 606 when I get a chance and see if anything pops out that might help you here but I'm pretty slammed the next couple weeks.

#### derekleffew

##### Resident Curmudgeon
Senior Team
On #3, the DF50 is oil based,
As I've stated here many times (either no one is listening and/or nobody likes the water-based fluid),
there are TWO types of Df-50 fluid:

Reel EFX Products
Df-50 Fluid

DF-50 Fluid

List price for oil based diffusion fluid: $60/gallon List price for oil-less diffusion fluid:$65/gallon

List price for 55-gallons of oil based fluid: $2,400.00 List price for 55-gallons of oil-less fluid:$3,000.00

Allana

#### MNicolai

##### Well-Known Member
Fight Leukemia
Can't say I've ever played with the oil-less version to have an opinion between the two.

On a related note for any house of worship or IMAG applications -- if someone buys a nice new $30k projector and doesn't use the haze filters and pumps the room full of oil-based haze for 6 months while running the projectors, that's a good way to find out what it's like to buy two$30k projectors in a year.

#### tjrobb

##### Well-Known Member
Maybe you'll be lucky and the detector was installed in the outside air intake duct? (Don't laugh, I've seen it).

RonHebbard

#### lwinters630

##### Well-Known Member
My theater was built with heat detectors everywhere except for the exhaust ducts... Sigh. I would really like to get a hazer. My thought is that I should be able to pump in a consistent lower level of haze before triggering the alarm. So my thought is to find a hazer with a reliable accurate level control. I can test it out with our alarm guy there. With a little trial and error, we will be able to figure out that I can safely run it on say level 4 all day but if I turn it up to say 7 it triggers the alarm. If level 4 is enough haze for the look we want, it should work great.

So does anyone have experience running a hazer with smoke detectors? What do you use? Do you think this idea makes sense or is it crazy? Any suggestions on which hazer to test out?

Thanks!
I am using the MDG Atmosphere in 4 venues all with alarms in ducts and one with beam detectors on the ceiling. Before purchasing the last one I tested it thoroughly for three hours on two different days whith hvac running. Extremely dense haze as I was trying to trip the alarm (it was of line and on watch). It passed the test.
I run the MDG from several consoles including an ETC ION and Jands. It is very easy to control. It has a Co2 20# tank (food grad) and uses very little Co2. The Co2 is basically to push the haze fluid the micron atomizer. it's not the co2 causing the effects, it is the micro haze particles that put a perfect look every time.
Although it has a muffin fan , I add a small fan to help steer it for an event. Let's see if I have some pi cs on my phone. pm me if you need anything. Also check out "CCCLIFE.org/service NJ by"9 am sunday

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