# Fog Chiller - Theory and Practice



## Hellvin

I am attempting to build my first fog chiller and having viewed several how-to tutorials, videos, etc., I see some commonality but still have a few questions regarding the basic theory.

I intend to use a typical (40 litre / 10 gallon) polystyrene cooler. I live in climate that will be cool on Halloween (last year we had snow) but still need to pre-cool the fog from my Chauvet 1200.

For example, if I see some setups run the fog into the chamber (via PVC or ABS pipe), across an "open" section (wire mesh or other perforated section), and then back into an outlet section.

But this would seem to be too short a time frame to expose the hot fog to the cool air. Is it not better to circulate the fog more?

In other setups, I see the use of coiled/wound dryer vent in say a garbage can. I suspect this is an attempt to get more contact time between the two sides (cold ice vs hot fog). But I want to keep to a smaller more compact chiller set up with the ice box.

Can I, for example, allow the hot fog to pass directly over/through the ice mass and then let it filter down to the bottom of the chest and flow out through an outlet port at the bottom?

I guess some experimentation is in order, but just wanted to pick some brains along the way too. Maybe I should also post some sketches of what I am contemplating too.


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## Lunatic

Yes, exactly.
What most of us have found is that the vortex style chiller works best. The whole idea is to push the hot fog through the ice wall where it rapidly cools and condenses the fog. The fog picks up some moisture as well which helps give it some weight. That is the most important point in the concept.

There may be some room for improvement but the concept works quite well and I'm sticking with it.


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## Hippofeet

Mine goes in the chiller, out the top, and down through about 18 inches of cubes, with a port (no riser) at the very bottom, with a small section of screen to keep the ice cubes from falling out of the bottom port. its a 20 liter square bucket with a hinged lid. I like more ice, and a little more distance from the fogger to the chiller if possible, but I have had good results with the fogger right up against the bucket.


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## Hellvin

OK - thanks guys. I swung by HD at lunch hour today and found a nifty little "coupler" which until today, I did not know existed. It is an ABS fitting which takes 1.5" ABS on one end and has threaded 3/4" at the other.

I am going to try fitting a threaded 3/4" copper end into that piece and then run 3/4" copper through the ice bath/mass and continue using the 3/4" copper as the outlet end as well. I am thinking that copper is many many times more thermally conductive* that either PVC or ABS, so I will use that in the "heat transfer" section (rather than ABS) but may also try the "open air" style too.

Perhaps I will get a test section up and running here this week.

* assuming a delta-T (temperature) of 25C from the "hot" fog to the "cold" ice/water, the expected heat transmissions would be approx:

Copper (0.8mm wall thickness) = 12,500 W/m2
ABS (2.0mm wall thickness) = 2.4 W/m2

Determining an air-to-air heat transmission is beyond my limited engineering skills!


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## oldpro

Of course if you can't get the fog lower than ambient temp I 
Suppose it still won't fall very well.... Correct me if I am wrong


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## Hellvin

The idea with a chiller of course it to take the "hot" fog from it's temperature at dispersal down as low as you can get it. If you are using ice (or ice water) you should be able to get it down to that temperature provided you are able to give it enough time to do so.

If your ambient temperature *is* freezing or lower (which is not impossible here at 51N on October 31st!), then it would be an interesting experiment to see how the "cold" fog behaves when it gets expelled... will it still sit low to the ground, or will it float higher?!


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## RoxyBlue

If it gets that cold where you are, Hellvin, you might want to add some dry ice to the mix. If the fog temperature is higher than ambient, it's going to rise.


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## Hellvin

Last year it snowed here and was pretty flippin' cold indeed!

I didn't run the fogger at all, but in hindsight, I should have just to see how different the fog would have behaved under the circumstances... ;-)

And correct me if I'm wrong, adding dry ice to the water-ice mix would produce some secondary fog as well as the two ices mix.


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## MurrayTX

I am wildly overbudget due to my prop impulse spending and wanting to go full walkthrough for the first time this year. SO one corner I am cutting is in making a chiller, but am still attempting a chiller effect. The target area will be a 8 x 12 "room" constructed between a 4ft rock wall and my house going through my sideyard, with a floor of sandy dirt and wood mulch. I will go low tech by putting chingos of ice in front of the fogger and with a small row cover acting as a tunnel of sorts to force the fog to pass over it before exiting and hopefully hanging like a bog. Since it is on mulch and sand, there are no worries regarding the melt off. I will report back after the haunt ends as to its success/failure. Maybe there won't be a need to build a big chiller to then have to store year-round.


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## Hippofeet

Hellvin,

I've done something like what you are talking about, but not exactly, I like the idea of the coil in the ice, and the only issue I had with running the fog into a long length of copper tubing was the fog condensing inside the tube, and having a thin brown liquid run back towards the fogger. I ended up drilling a small hole in the bottom of the tube (I put in a small bend between the chiller and the fogger, with the hole at the bottom) to allow the condensed liquid to drip out into a bucket. I was using an up fogger, and there was maybe 3 feet of rise on the tube, but even with other chiller setups I have the problem with the liquid running back towards fogger. I would love to see some pics.


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## Hellvin

Murry - I tried something similar your technique one year. I simply shot the exhaust fog through a 1.5" ABS pipe (10') and placed three bags of ice over the tube hoping that would be enough to do the job. It was my first year using a machine and was a last minute attempt to make a chiller on the fly. The fog shot through the tube so fast and the tube was so thermally insulative that the ice didn't have much effect. Still, in your case where the exhaust fog is moving slower it will have more contact time. Is there any way you can get the fog to get in under the ice? Cold air sinks and hot air rises, so you want to try and reverse your layers (hot gas under cold mass) to make thermal transfer more effective.

Hippofeet - It sounds like your chiller is at max efficiency so too speak! what is the length of your copper in contact with the cold mass? What size pipe? I hadn't cosidered the possibility of condensate forming but I guess it is a real concern. One avenue is to adjust pipe diam. and/or length to keep from over-cooling the gas. And at what temp does fog condense anyway?! 

I am assuming/hoping that a smaller diameter pipe will force the gas to flow faster.

So many questions!!


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## MurrayTX

AM thinking of having my ice on the mulch without a pipe and the fog blowing over it sort of like the stunt where a guy walks on hot coals. Am thinking a gardening row cover to slow its dispersal...with the hope that the fog continues over the ice a bit before breathing through the row cover cloth. But your suggestion may be do-able too... I will just need to figure out a way to drape a lot of ice over the row cover. if I can reinforce the structure underneath.


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## Hippofeet

Hellvin,

The pipe is 3/4 inch copper, I don't have an exact measurement on the length of the coil, but I would GUESS the total length as 6-8 feet. There is an air gap at the fogger nozzle, it does not fit tight. . I think (again not sure) that its not the temp of the fog, but the difference in temperature of the air vs the heated vapor? If anyone knows, please correct me. 

As far as the speed of the vapor of in the pipe, I'm not sure at all, and I would need to do some testing to figure that out. 

Honestly, I really wish it wouldn't condense. But it has happened in a few chillers I've put together.


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## Tokwik

Wasn't Niblique working on a copper coil design a ways back?

I am interested in the theory side of your discussion. Right now I am currently running a "reverse vortex" design and some rough dimensions based upon findings in the monster chiller thread.

I'm using the 1/3 space design with an air gap from the fogger.
Top 1/3 of space is air for expansion.
Middle 1/3 of space is ice.
Lower 1/3 of space holds the chilled fog and directs it towards the exit.

What I have is about 2-3 inches of space before the fog enters about 14 inches of 3" PVC and is directed to the top of the chiller. Expanded fog settles down through about 100lbs of ice then exits out through another 3" PVC tube out the bottom.
Now my bottom tube is about 5' long, so I do get a bit on condensation here, but it doubles as the ice melt drain so I don't really know the extent.

The numbers I got last year were
Ambient air temp: 50-55*F
Ground temp: About 40*F
Exit PVC tube temp: 8-12*F (shot at the pipe, through the fog)
About 100lbs of ice, 5 lbs dry ice, and salt mixture.

Now these weren't exactly perfect numbers, but I was using an IR thermometer from anywhere between 2-6 feet away.


I'm definitely interested in what you guys come up with. I hope my numbers can help some with the theory.


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## Hippofeet

Let me revise that length in contact with the cold mass, it would be about 5 feet of copper tube. I gave the total length of the tube.


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## Hellvin

Hippofeet said:


> ...
> I think (again not sure) that its not the temp of the fog, but the difference in temperature of the air vs the heated vapor? If anyone knows, please correct me.
> ...


That is correct - in order to calculate the heat loss, you need to make reference to the difference in temperature (e.g. delta-T) between the hot and cold sides.

Per my previous figures, if the k-value (thermal conductivity) of copper is 400 W/mK (Watt per metre*degreeC), then the heat loss is found, using a delta-T, as:

delta-E = delta-T * k / t, where t is the thickness of material separating the two sides.

Some common k values:

k = 400 W/mC for copper
k = 200 W/mC for aluminium
k = 60 W/mC for tin
k = 2.2 W/mC for ice
k = 0.6 W/mC for water
k = 0.2 W/mC for PVC, ABS, plastics
k = 0.03 for expanded/extruded polystyrene (e.g. "styrofoam")
k = 0.02 W/mC for air


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## Tokwik

Not sure if it will help or not, but I found the thread where Niblique was working on a copper pipe design. I believe he was trying to get the same effect as a vortex-style chiller with less ice.

Not sure how his final results came out, but it's an interesting read.

http://www.hauntforum.com/showthread.php?t=25849


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## Hippofeet

Hellvin,

You swam out into some deep water right up there! ^^

But I understand, in some sort of vague, blurry way.

Are you looking to calculate the ideal ice mass/tubing material/time in ice to get the best chiller possible? 'Cause if that's what you are doing, heck, we can even play with the fogger heat exchanger temperature (depending on the fogger) and then calculate to get the fastest heat loss through the smallest cold mass possible.

Can't we? This is fun, I like this.


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## TNathe

you guys are already putting more thought into this than the manufacturers of fog machines with built in chillers i bet . I am following this thread intently.


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## Tokwik

Okay, I've got a question.

*What is the end result that you are looking for? *
The mathematics has me very interested but I'm lost in what you are after.

I'd be more than happy to contribute with raw data if I can. I'm thinking I can set up a digital thermometer at the fogger nozzle to get a better reading if Hippofeet doesn't already have that number. Combine that with another thermometer at the chiller exit for your delta for my sized chiller.

Which brings up another question. Wouldn't the overall volume of the chiller affect your numbers?

Yep, I'm confused since I'm not sure what the end result is supposed to be, but still highly interested.

*subscribed*


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## Hellvin

Yes! We know we know the variables (pressure, flow rate, temperature, mass of ice, exposure/contact time, etc) and it is a seemingly simple thing but actually a complex process. As has been pointed out in the super-fogger thread, even just changing the outflow conduit to a corrugated dryer hose could induce turbulent flows in the out-flowing fog (but is that true and do we necessarily only want laminar flows?).

But in the end we can often solve for a workable solution by instinct and a few guesses.

I guess the engineer in me just wants to to think about ways to understand the truly critical components, then optimize or improve the process.

I'm going to see if I can get a pseudo-chiller up and running tonight (very warm evening @ 26C/79F ambient and 36% RH)...


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## Lunatic

Pushing the hot fog through the ice is the most critical factor found so far. Everything else appears to be minor in comparison. There's always room for improvement but I haven't seen one in years. I got burnt out thinking about it. I hope you see some good results.


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## Hippofeet

It will be a while before I burn out on this. This is the part of these things I really like, I mean yeah, I've got a great big TRUE 3000 watt handmade fogger with a built in chiller that runs non stop at 100% percent output, but I had to really dig in deep to figure out how to change the heat exchanger temperature, control the amount and duration of fog fluid, and vary warm up/cool down cycles of the two heat exchangers. And then, I basically said, ok, lot's of room here, throw in some screens, drop in 100 pounds of ice, and blammo, built in chiller. It works great. But. My goal (at least on this subject in this thread) is to know exactly why it works, what are the best conditions for it to work (and I just ran into this at a haunt Im working at, the temperature difference from a month ago during the day, to cold and at night totally screwed up my ground effect indoors) and what I need to build into the fogger to be able to adjust for those things on the fly. Sometimes, just turning up the output doesn't do it. 

For sure, lots of people are going to be like "YAWN" lol, but they stopped reading this post already. I get that. But I think sometimes approaching things from a real engineering, mathy perspective can garner good things down the road.

Plainly stated, my goal is to understand the mechanics, chemistry and atmosphere interaction so maybe next year I can build a fogger I can adjust for more than just duration, interval, and output (which is really cheating anyway, the output knob, its not "turning up or down" that AC pump, I gwarruntee).

Im building foggers. Might at well know what the heck Im doing.


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## Hippofeet

Also, as far as turbulence, I was taught to leave the inside curve of an intake port "rough" when grinding and gasket matching heads for performance. It was supposed to improve fuel atomization. I would be up to using metal flex tube in lieu of smooth copper tubing, strictly as an experiment. It would still have a great heat transfer, and would sure be easier to bend.


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## Hellvin

Lunitic - yes, I noticed the same thing last night (fog on ice). Originally I set up my planned ABS-to-copper run (about 3' length of each) and pushed the fog through unimpeded with a bag of ice laying on top of the copper. That in itself didn't do much (so I think I would have to get much more ice and much more contact area on the pipe).

So, in the second iteration, I dismantled the copper and added another 4' of ABS (7' total) and just slid the raw ice cubes into the length (1.5" dia). At first, it was really working well - the "warm" fog was coming through noticeably cooler (sorry I dont have a heat gun to measure) and laying low. But then I noticed that within 20 to 25 minutes, the cubes were being spit out the end under the pressure of the flowing gas/fog. Also, the cubes were much smaller - most had been "cored out" (i.e. the centre had melted away but the outer perimeter was still there). It got to the point where I couldn't shove the cube back in before another got spit out.

I guess my lesson learned there is that, like you say, fog shot directly onto or in line with an ice mass will do the job rapidly and efficiently. But the corollary observation might be that the process ends up putting a lot of heat into the ice. So I guess regardless of how you chill it, just be prepared to replenishing the ice!!

I think I am still moving toward using the copper, but immersing it in as big an ice-water mix as my cooler will hold. All of the heat lost by the fog has to end up being "stored" in the ice water, so (just extrapolating what I saw last night) a huge mass will be required if I run the fogger all night.

I like the idea of the ice/water "bath" as water, I think, is a deeper heat sink -- that is to say it can store more heat and still stay cold. Still, I think I will have to plan on reloading the ice over the course of the day...

****

Hippofeet - Your 100 lb ice mass kind of ties in with what I was getting at above, but you are obviously running a stronger machine (3000W vs my 1250W). But a 100 lbs!! That's a lot of ice! It also sounds like you are tinkering with an AC unit to either deal with the massive cooling demand directly or at least keeping the ice mass cool(er) over the duration (e.g. rather than retaining the lost heat in the ice, pull it off into an infinitely deep heat sink).

How big is you set up space-wise?


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## RoxyBlue

If salt water weren't the bane of existence for plants and metal, adding rock salt to your water/ice mix would certainly help with keeping temperatures low.


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## Hippofeet

Its built into an aluminum truck toolbox, about 2 foot wide by 16 inches tall by 5 foot long. Right now, the fog sprays into a space under the ice, moves up and through the ice, and back down and out an opening near the bottom front. 

Its just ice, no refrigeration, but full of ice it last a while. There is a drain at the bottom to release the water buildup.

Its two 1500 watt heat elements, both on at warmup, then left heater on, there is an overlap where both are on, then one shuts off to warm up, then there is another overlap, then the other shuts off to warm up, repeat on a loop. I used a push button controller for all the functions. I have plans to make a new one the same way, but running through a modified air conditioning unit. Problem is, the air-con may not get as cold as the ice, so I may need a freezer cooler unit or something. Im looking at a meat locker freezer across town, to get an idea on size and temp. I have a couple digital thermostats, I can use them to turn on fans, or switch on and off heat exchangers if I need to, but Im thinking of ways to control the speed of the fog through the unit, to get it as cold as possible. 

On the copper tubing, I have found that you need some feet of COIL in the ice mass, just like making a still condenser, to give it time to cool down. It wont re-condense completely like it will in a still, and I cant see a difference in fog output from the little bit that does condense. You need to make sure that all parts of the coil flow downhill, so that liquid cant gather in a low loop of coil, and impede the flow, and make it "spit". In this case, the fog would enter the chiller at the top, and exit at the bottom. It would be pretty easy to use a five gallon bucket, drop in the coil, fill it with ice and done. Or, run cold flowing water with the outlet at the bottom run to a drain, but that's pretty inconvenient, and not something I'm looking at.

Honestly, vortex chiller is tried and true, I have 3 right over there, small medium and large, and they work great. Fog gets cold, fog stays on the ground, put in new ice every once in a while, easy. I also have a fog machine with a built in ice compartment, not one I made, and it works the same, its just one thing instead of two. Still, maybe something new can be done. I will have a few beers and stare at some parts later, maybe Lady Inspiration will visit me, and plant a tender kiss on my troubled brow.


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## oldpro

You guys are making my head hurt. 
What about spraying a very fine mist ( vapor) of 
Almost freezing water into the fog then run it thru the chiller to the point where 
It's almost snow but not.

Just thought


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## Hellvin

Hippo - I agree, there shouldn't be any low points in any set up to avoid trapping any potential condensate.

Just so I am clear though - what is meant by the term "vortex chiller"? Is it a particular style fashioned after or popularized by the name-brand?

http://www.vortexchillers.com/lowfog/chillers/coldfusion.html

Is the "vortex" style to push the fog through in direct contact with the ice?

One final question: in your big box set up, it sounds like you have two open air spaces sandwiching the ice layer. The hot fog first rises up through the ice mass and cools off, but how do you collect it from the "upper chamber" and siphon it out? I'm thinking perhaps a large diameter drain (3" or 4" PVC) sitting flush with the top of the ice mass that cool fog would sink into then drop back down and out of the box. Also - it must be a bit of trial-and-error to get just the right thickness of ice. Too thick and the cool fog would not rise high enough to get to the drain, too think and the fog won't get cool enough.

Oldpro - now you are making a snow-making machine! Old Saint Skellington would be very proud! ;-)


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## Lunatic

Hellvin said:


> Lunitic - yes, I noticed the same thing last night (fog on ice).
> 
> I guess my lesson learned there is that, like you say, fog shot directly onto or in line with an ice mass will do the job rapidly and efficiently. But the corollary observation might be that the process ends up putting a lot of heat into the ice. So I guess regardless of how you chill it, just be prepared to replenishing the ice!!


Just to be clear, my chiller pushes the hot fog into the top of the cooler and down through the ice wall and exits out the bottom. An older design "Fog on the Rocks" (I think that's what it was called) pushed the hot fog horizontally into one side of the ice cooler, across and on top of the ice and then exits on the opposite side. Pushing the fog through the ice is better.

Yes, the hot fog melts the ice but I never have to replenish the ice during Halloween night. However, my foggers are only 800 watts so I would guess that using a bigger boy would blow through ice much quicker.

I can't wait to see what you and Hippofeet come up with. I still share the same passion but I'll sit back and ride the coat tails of your successes. Thanks for keeping the passion alive! Now go make some fog!!!!


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## Hellvin

OK - here is a sketch for what I am going to try:










I think I may have drawn the fogger unit too short (meaning I dont think that the beast will actually sit full on the cooler lid and still have room to provide the ABS run down into the cavity).

The idea is too carry the fog through 1.5" ABS into the cavity, transition to 0.75" copper which then drops into an ice bath and comes back to the air layer at the top. Then there is just an open length of ABS at the end to draw off the cooled fog. I think I get the best effects of efficient chilling (through the copper) and direct contact (after being expelled from the copper, it can linger over the floating bed of ice).

It has drawbacks as discussed elsewhere in this thread (potential condensate accumulating in the copper at the bottom), but it is water tight, and I think, thermally efficient.


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## niblique71

Tokwik said:


> Not sure if it will help or not, but I found the thread where Niblique was working on a copper pipe design. I believe he was trying to get the same effect as a vortex-style chiller with less ice.
> 
> Not sure how his final results came out, but it's an interesting read.
> 
> http://www.hauntforum.com/showthread.php?t=25849


I haven't done anything new with the design other than test it with Just ice and Ice water. The principal is sound and the unit works. I just never got to test it with dry ice at the final chamber as designed. This unit taught me the final lesson which is "surface area" = good transfer of thermal energy. Unfortunately for us home haunters, Ice cubes have the absolute most surface area to transfer "Cold" in the shortest amount of time. Add the evaporation factor in and ICE cubes still are the most efficient method of chilling fog. Especially true nowadays since copper prices have hit an all time high. If copper wasn't so expensive now, I had a great idea to improve my original Copper pipe water/ice bath design.

EDIT: If you look closely at the design in the thread above you'll see that it is an Ice bath design, with copper pipes to transfer the chill. It is somewhat hard to understand since it isn't enclosed yet. It's difficult to envision the different cooling chambers in those pictures.


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## Lunatic

Hey Helvin, 
Oh I see what your doing. I like the idea of chilling the copper like that. I wonder about the fog quality and weight without picking up moisture from direct contact with ice. I wonder if it would be worth it to take the chilled fog coming out and then push it through some ice to super chill it?

Liking the process


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## Tokwik

Hellvin said:


> OK - here is a sketch for what I am going to try:


Couple observations.

You are planning on going from a larger to smaller tubing. The velocity of the gas (fog) will increase. In addition, the gas should compress adding to the heat factor.

Once it re-enters the upper chamber, it will re-expand dropping the pressure and temperature, but it is now past your chiller part.

I don't know enough about physics and thermodynamics, but Bernoulli is a good first place to start. The thermal equations I'm not even going near. Since you are also dealing with a compressable gas, you need to take that into account. So maybe Boyle's Law would be the proper place to start.



> The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system


Then consider Bernoulli.



> Bernoulli's equation is sometimes valid for the flow of gases: provided that there is no transfer of kinetic or potential energy from the gas flow to the compression or expansion of the gas. If both the gas pressure and volume change simultaneously, then work will be done on or by the gas. In this case, Bernoulli's equation - in its incompressible flow form - can not be assumed to be valid. However if the gas process is entirely isobaric, or isochoric, then no work is done on or by the gas, (so the simple energy balance is not upset). According to the gas law, an isobaric or isochoric process is ordinarily the only way to ensure constant density in a gas. Also the gas density will be proportional to the ratio of pressure and absolute temperature, however this ratio will vary upon compression or expansion, no matter what non-zero quantity of heat is added or removed. The only exception is if the net heat transfer is zero, as in a complete thermodynamic cycle, or in an individual isentropic (frictionless adiabatic) process, and even then this reversible process must be reversed, to restore the gas to the original pressure and specific volume, and thus density. Only then is the original, unmodified Bernoulli equation applicable. In this case the equation can be used if the flow speed of the gas is sufficiently below the speed of sound, such that the variation in density of the gas (due to this effect) along each streamline can be ignored. Adiabatic flow at less than Mach 0.3 is generally considered to be slow enough.


Then you will need to dive into the Venturi effect.



> The Venturi effect is a jet effect; as with a funnel the velocity of the fluid increases as the cross sectional area decreases, with the static pressure correspondingly decreasing. According to the laws governing fluid dynamics, a fluid's velocity must _increase_ as it passes through a constriction to satisfy the principle of continuity, while its pressure must _decrease_ to satisfy the principle of conservation of mechanical energy. Thus any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is negated by a drop in pressure.
> When a fluid such as water flows through a tube that narrows to a smaller diameter, the partial restriction causes a higher pressure at the inlet than that at the narrow end. This pressure difference causes the fluid to accelerate toward the low pressure narrow section, in which it thus maintains a higher speed. .


That ends my Wikipedia quoting for the night, but as I'm still a bit confused about what exactly you are looking for, I'll just leave it at that.

And there is no way in HELL I'm doing the math. No way, no how.

Looking forward to how this thread develops.


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## oldpro

Will the 3/4 diameter copper flow enough to supply 
Fog fast enough to your yard haunt.
And is the surface area of the copper tube 
Large enough to cool the fog if it pushed thru fast by a large fog machine?


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## niblique71

oldpro said:


> Will the 3/4 diameter copper flow enough to supply
> Fog fast enough to your yard haunt.
> And is the surface area of the copper tube
> Large enough to cool the fog if it pushed thru fast by a large fog machine?


Probably Not... When I did my copper pipe matrix I calculated the diameter of the 20 or so pipes to equal a 2" pipe I think. It really should equal a 3" diameter pipe for less restriction and compressive behavior. I just couldn't afford the extra copper pipe at that time. You'd likely need at least that much surface area even with an ice bath concept to cool the fog adequately. The Ice bath concept DOES WORK. You just need a "Radiator" type setup to efficiently exchange heat/cool.


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## Hippofeet

Hellvin said:


> One final question: in your big box set up, it sounds like you have two open air spaces sandwiching the ice layer. The hot fog first rises up through the ice mass and cools off, but how do you collect it from the "upper chamber" and siphon it out? I'm thinking perhaps a large diameter drain (3" or 4" PVC) sitting flush with the top of the ice mass that cool fog would sink into then drop back down and out of the box. Also - it must be a bit of trial-and-error to get just the right thickness of ice. Too thick and the cool fog would not rise high enough to get to the drain, too think and the fog won't get cool enough.


The heating elements blow into the first air space, and the force coming out of the heating elements force it up and through, then down into the second air space and out a port at the bottom. I enlarged the port as the first time the fog was very slow coming out. The force of the fog coming out of the heat exchangers is enough to force it through the ice and down and out the port, the entire unit is sealed except for the exit port. I could add a DC fan, and I may, but I'm pretty happy with it now.

No trial and error with the ice. I could possibly do better, one of the reasons I'm still tinkering with it. I think I could get the same results with less ice, so Im going to build an identical set-up in a smaller box, with half as much ice. 50 lbs is still a lot, even for 3000 watts.

With a 1500 watt machine, I'm not sure your drawing will allow enough time for the fog to cool down enough. I mean, definitely try it, but I'm with Niblique, going that route I would use a way big pipe, or better yet a radiator set-up. Like a couple radiators off a 4 cycle motorcycle or something. Or make one. Hmmm. I may do that this week. Depends, we just got really busy.

Im sure the fog is coming out around 250 to 300 degrees, what's the math on cooling that down to below ambient air temp?


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## gmacted

Hellvin said:


> Just so I am clear though - what is meant by the term "vortex chiller"? Is it a particular style fashioned after or popularized by the name-brand?
> 
> http://www.vortexchillers.com/lowfog/chillers/coldfusion.html
> 
> Is the "vortex" style to push the fog through in direct contact with the ice?


There is an entire thread dedicated to the "Vortex Chiller".

The first post in the thread has a link to an interesting document that shows detailed pictures of the original Vortex chiller designed by "deathlord.net".

Here's another interesting link that talks about the history of the Vortex Chiller.

I just found this thread and am very interested and willing to share my knowledge/experience. I'm in!


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## Hippofeet

Testing a very small vortex chiller (5 gallon square) with a very forceful 1500 watt today. It works surprising well. It seems to work best when I time the fogger for small, but steady puffs, rather than one long blast, although i was surprised just how well it worked run all out. Just eats ice faster that way. Just one bag of ice in the chiller.

I'll try to pick up some copper tubing (or suitable metal) later today to make a coil, and try running that through the same sized container with the same amount of ice, see how it works.

So far, I like the small vortex with the 1500, but running a lot I will turn a bag of ice to water in an hour easy, maybe less looks like. after lunch I will leave it on, and see how long before it just gets useless, but still has some ice.


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## Lunatic

Just for the info.
My chillers are made out of 60 quart Igloo cubes. Configured as the "reverse Vortex" and I use about 35 lbs of whole ice cubes in it. I push an 800 watt Martin fogger through it and it lasts me Halloween night. It does cycle and that gives me more ice life. If I had a continuous fogger I would fog out the neighborhood!


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## gmacted

Just for the info.

My chiller is made from a 120 quart rectangular cooler. It can be configured as a "vortex" or "reverse vortex". I also use a "pseudo venturi" input along with a 1300 Watt VEI V950 continuous fogger.

The "pseudo venturi" input was originally used but eventually removed from the Vortex design. I personally think the Venturi input help with the expansion of the fog.

I followed the design of the original Vortex chiller on deathlord.net. To this day, I still think it's the best, simplest and most effective design.


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## discozombie

Im planning on sitting my fog machine on top of a standard plastic igloo cooler I just trash picked. Im concerned about the heat generated from the fog machine in regards to it sitting on top of the cooler. Has anyone experienced melting their cooler or a fire?


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## Lunatic

I always sit my fogger on the top of my chiller and never have a problem with excess heat melting the plastic.


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## Hippofeet

No problems with plastic, styrofoam, well.... I would put a board under the fogger.


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## discozombie

thanks for the info.


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## ATLfun

Tokwik said:


> Not sure if it will help or not, but I found the thread where Niblique was working on a copper pipe design. I believe he was trying to get the same effect as a vortex-style chiller with less ice.
> 
> Not sure how his final results came out, but it's an interesting read.
> 
> http://www.hauntforum.com/showthread.php?t=25849


I made my first chiller last year in the Coleman Extreme 120 quart cooler.

http://www.walmart.com/ip/Coleman-Xtreme-120-Quart-Cooler-Green/21270184

The dark hunter green really blended well with props. It was mid 60's last Halloween night and the chiller worked great. I never had to replace the ice all night.

I really believe that the best "secret method" is to use ice cream salt. I bought two boxes at the grocery store and spread it over the top of the ice.

Brian


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## oldpro

Have any of you used 3" thin walled aluminum tubing? 
I am going to rework my trash can cooler and make it a vortex style as suggested,
But I will tig weld the aluminum tubing together.
Then the thin wall aluminum will transfer cold to the fog better than than PVC 
Or the smaller copper. I will put up pics when finished.


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## Hippofeet

I'm still hoping to see the pics. I just love TIG welds. TIG stainless is art.


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## mudbugntx

Hellvin, go to page one in the thread below and look for my post. You are wanting to do something like the one I made.

http://www.hauntforum.com/showthread.php?t=34661


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## Schizodeluxe

I had a crack at customising a smoke machine I just bought. Like what most people seem to be doing, I attached a hose from the smoke machine into a cheap esky/ice box and fed the other end through the other end of the esky, filled with ice and tried it out. Works really nice, the smoke stays low to the ground and lingers around a lot longer instead of diappearing quickly.


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