Steam FX

[skienblack]

We are doing Rent and would like to have a "steam" effect coming from a manhole in the stage. We considered using a hazer and some ducting but have decided to go with 3 humidifiers since it will run the whole show. Would a hazer work better or would running it for 2.5 hours straight be to much?

[seanandkate]

Remember that you wouldn't have to run the hazer for the whole show. Pick your moments when the audience would actually be noticing the "steam." (And truth be known, I would probably be tempted to use a fogger on a very low setting as opposed to a hazer). If your audience is watching a manhole instead of the actors for 2.5 hours, you may have a bigger problem on your hands. I would be concerned with water from the humidifiers slicking up the stage around the manhole.

[TheatrePros]

In my experience running a hazer for more than 30 min you run the risk of setting off smoke alarms, the humidifer is a smarter idea and gives you more felxibility to not have to always deal with the haze.

[skienblack]

In my experience running a hazer for more than 30 min you run the risk of setting off smoke alarms, the humidifer is a smarter idea and gives you more felxibility to not have to always deal with the haze.

My concern is the humidifers will not put off a strong enough "push" to get the apearance we are looking for.

[rochem]

seanandkate kind of hinted at this, but I'd be hesitant to create an effect like this that ran for the entire show. For one, the steam is obviously going to be moving and changing and taking form, which can be a huge distraction from whatever else is going on. You don't think about it until you see it, but having something on stage that moves constantly, like the pendulum on a grandfather clock, can quickly become annoying and distracting. Also, as Rent is traditionally done with an abstracted set, having something like rising steam running for the whole show will effectively lock the action into one setting.

However, to actually answer your question, I'd agree that a hazer wouldn't be your best option. Haze is designed to be virtually invisible and to fill a room, which is the opposite of what you want. This is one situation where a very cheap DJ-style fogger would probably be fine - you only need a very small (relatively) amount of fog, so this should fit your needs.

[skienblack]

Thanks. We are running them off our dimmers set to a dimmer curve of 100% or off. This way we will be able to turn them on and off easily.

[sk8rsdad]

Thanks. We are running them off our dimmers set to a dimmer curve of 100% or off. This way we will be able to turn them on and off easily.

Humidifiers are only going to produce visible water vapor as long as there is some condensation going on. That's hard to guarantee unless you have really good climate control in your facility. You would get more reliable results using a a DMX-controlled fog machine with quick dissipate fluid. If your fogger is anything like ours, you won't be able to run it continuously unless it is hooked up to a really large reservoir. As others have said, you wouldn't want to run it continuously anyway. This one of those effects you use to establish a scene then allow to fade away rather than constantly drawing the audience' attention away from the actors.

[len]

One dj style fogger shoots straight up, but I don't remember who makes it or if its still available. Can you fit the fogger directly under?

Another possibility, albeit more expensive, is a CO2 jet but you also run into the issues of monitoring, since too much CO2 can cause other problems.

[FatherMurphy]

Mount a small muffin fan under the nozzle of the DJ fogger, blowing up, and the smoke will be guaranteed to go up, and will disperse some at the same time, instead of staying a solid cloud.

I'm assuming that you're looking for wispy steam, not jet steam.

[skienblack]

Yeah, wispy steam. We have access to beneath the space.

[soundlight]

I wouldn't use a humidifier because that would get too much condensation all over the stage. Also, to second what others said, you probably don't want this effect running the entire show. I'd go with the fogger + fan option, because the vertical-shooting foggers are not going to disperse enough to provide the wispy steam coming out. I'd go with a DMX-controlled fogger with quick dissipating fluid, as mentioned, with a fan under the nozzle pointing straight up. That would probably work pretty well. You don't want to put the fogger on a dimmer, even one that is switched - run it to straight power and control it via DMX. Aside from the obvious issues of putting a device with a heater block and fluid pump on a dimmer, foggers have heat-up time - you wouldn't know when it was going to turn on.

[len]

You'll probably have to play around with the design a little to get the combination right. Putting the fan under the output nozzle makes sense, but may not be the best place to go. Depends on a lot of factors.

[icewolf08]

A couple things. First off, I agree with everyone who mentioned not using a humidifier. It won't do what you want. Also, you don't want a fogger because they are not designed for long duration releases. You will burn through fluid like crazy and you won't want to pay for that. Even with a quick-dissipating fluid you would end up with tons of unwanted fog either coming up for the effect or trapped under your stage.

A hazer will work and can run for the entirety of the show, though as was mentioned, you have to ask if you really want to do that. As for those that mentioned that haze is not easy to see, if you look right at the source, which is what you would be doing in this case, you will see it, because that is where it is the most dense. Haze is perfect for this effect, but you just need to decide if you really want to see it for the whole show. I have run many a hazer for an entire show to create atmosphere in the space, once you hit critical levels you don't see it except for where light hits it.

[FatherMurphy]

You might want to consider noise vs. proximity to audience, too... most foggers make hissing noises as they release the smoke, and DF-50 type hazers produce some low rumbles as they run. MDG makes a CO2 propelled hazer that is almost silent, if one is available in your area.

[skienblack]

You might want to consider noise vs. proximity to audience, too... most foggers make hissing noises as they release the smoke, and DF-50 type hazers produce some low rumbles as they run. MDG makes a CO2 propelled hazer that is almost silent, if one is available in your area.

Sound is the least of my worries. We will be running any equipment besides a humidifer from our trap room, which this drops into. Is there anything like a quick dispersing haze fluid?

[Tex]

Is there anything like a quick dispersing haze fluid?

I don't think so. To me, that would be the exact opposite of the intended use of a hazer. Most people want to extend the hang time as long as possible.
There is, however quick dispersing fog fluid:
Fog Machines - Buy Le Maitre Quick / Extra Quick Dispersing Fog Fluid

[kicknargel]

I'd talk to your LD. When I light this show, I want haze in the air anyway, so this plan might kill two birds with one hazer.

[Brother]

We are doing Rent and would like to have a "steam" effect coming from a manhole in the stage. We considered using a hazer and some ducting but have decided to go with 3 humidifiers since it will run the whole show. Would a hazer work better or would running it for 2.5 hours straight be to much?

How do humidifiers work?

[Brother]

I think the rate that the haze is determined by the cfm and energy of the unit. The length and particle size, and weight of the specialty liquid droplets, oil based or water solution used, determine the persisistance of the "haze" in the atmosphere and its duration and hight reached. The oil based being more stable, would most likely last longer. (Stability Factor). This is my rational from the physical chemistry I picked up in chemistry grad school.

[lwinters630]

Yeah, wispy steam. We have access to beneath the space.

I made this effect for a pot belly stove chimney in a newspaper stand on a cold street corner scene.

connect the dmx smoke unit into a large box 4'x4'x4'. Then take 3" flex steel dryer vent hose up to the manhole. Insert a small variable speed PC type fan into the vent about 12" or so before the output hole.

What happens is that the large box acts as a holding bin for the smoke so you can turn on and off the smoke unit to keep the box full without it surging like most smoke machines. The variable speed PC fan allows you to keep a trickle of smoke drawing up and out the manhole at whatever rate you like. You may also "Y" in some clean air to get it wispier.

I hope this helps.

[spong8]

One way that we made steam effects is through the use of a pnumatics mixed with a fog machine. Basically we had a fog chamber where the fog machine pumped into. We had pvc pipe that lead from the box of fog and had drilled holes through and through the pipe where we wanted steam to appear. One was only large enough to fix an air nozzle to, the other was slightly larger, where the fog would exit. Basically when we fired the air it created a vaccume in the pvc which syphoned the fog out of the chamber and out of the hole in a whispy way.

You could use this at a simpler scale as well by using ducting and hoses. The trick IMO would not have a fan directly syphoning on the supply of fog but allow it to naturally make its way to the fan as it blows. I think the principle being used is air moving from a low pressure to a high pressured area. Highpressure being the air being blown by the fan.

[len]

Any atmospheric CAN activate a fire alarm. But it's impossible to say that a particular unit or type of atmospheric will trigger the alarm after X minutes. It depends on the output, airflow in the building, the type of alarm, how it is set, etc.

If you use an atmospheric (fog/haze), I'd find a way to control the building/space HVAC and turn the fans on to run constant during the show. It may get a little chilly, but you can turn up the temp a degree or two to compensate. Having the building hvac fans running constantly will help push air through the filters and decrease the particulate in the air. I don't think an off-the-shelf humidifier or 2 will give you the forced look you want. Remember that those steam trunks in big cities push the steam at over 70 mph, so there's a good deal of force behind them. A good hazer/fogger that can be vented to point up through the hole in the stage is probably the best bet. But I'd go with haze because most foggers are noisier.