loading
Fog machines are great for Halloween... but fog tends to rise up into the air, spread out, and disappear. If you do not have a very powerful fog machine, this can ruin the whole effect.

The solution to this is to build a fog chiller. The fog chiller cools the hot fog from the machine, causing it to stay low and billow along the ground.

This is a small fog chiller, which works well and is cheap. It takes an hour or two to build.

Step 1: Design and Theory

About Fog
The principles behind a fog chiller are the ideal gas laws. The warmer air is, the less dense it is, and therefore is pushed upwards by sinking cold air. Simply put, warm air rises, cool air sinks.

Fog machines work by pumping fog liquid onto a very hot "heat exchanger", which flash-vaporizes the liquid. This expansion pushes it out of the nozzle. The fog exiting the machine is very hot, and will rise up.

This device cools the air in which the fog is suspended, therefore causing it to sink to the ground.

Design
I designed this chiller myself, and I think the design is unique.

Fog enters the device at the top. At the top, there is a large expansion chamber, so that the fog can properly mix with the air.

Below this expansion area, there is ice. This cools the fog. Once the fog is cool, it will sink down below the ice into another chamber.

On one end of this chamber, there is a fan to blow the fog. On the other end, there is a hole for the fog to exit. This further mixes the fog with the air, and blows it out.

The theory is that the fog will expand in the first chamber, as well as cool. Once the hot fog has cooled enough to sink below normal air, it drops below the ice and is blown out.

If the amount of incoming fog is too fast for the cooling, then the fog will not cool as much, but will still be forced through the layer of ice, most likely resulting in enough cooling to retain the effect.

The whole device is fairly small, only about twice the size of a fog machine, and can be built with easily obtainable materials for not much money.
wow awsome if and any way you could change the color of the fog als could i use dry ice for a longer time running than normal ice
<p>If I may add my $5.00 worth of advice....</p><p>The way I used to change the color of the dry ice fog was with the <br>fountain lights that were/are 3 LED lights that would take turns <br>switching on and off illuminating the water as it flowed from the <br>fountain. It worked like a charm with the dry ice fog! But, be careful not to <br> add too much dry ice that you don't freeze up the fountain, For this reason, you might <br>want to put a screen around the fountain's bottom side so that water can <br> get in but the ice particles can't. I accidentally fried one of my wife's fountains up <br> that way. (4 years ago and I am still hearing about it every October 12th when we start setting up for Halloween on the dot!) But the effect was SO much worth the $15.00 (at any aquarium supply store) to replace it. at any aquarium supply store. However, you can get them cheaper now <br>especially at stores like Marc's when you purchase something that already has the <br>darn thing in it like their pumpkins! Hey! $5.00 for fountains is <br>nothing to sneeze at buddy! Buy the pumpkin and use it once a year but <br>the fountain all year for everything else!</p><p>Hope this helps you, if not maybe it will help another person. Sorry it was so late in reading your post, you could say I've been on quite a bedrest per doctor's orders.</p>
Try using led lights, spot lights with removable color gels, black lights or pin lights with color gels up underneath the fog like Dj Lights that shine up at trees to show a colored fog effect. However, if you want to try something different, fun, with a short lived, yet awesome colored display of creeping fog, drop dry ice in a cauldron or glass of water with colored glow sticks and watch the awesome spectacle of fog bubbling and boiling over the top like a low lying fog of witches brew.
hey all u out there i was wondering if there is a way to make a fog machine. not a chiller but the machine. if u can help tell me
<p>Why? They are really cheap and ready to go. They have a tank, and pump, a heating element, and are self contained. Why reinvent the wheel?</p>
Could you substitute regular ice for dry ice? I'm just thinking this way you could eliminate the melting of the ice...
<br>If you have dry ice and enough of it, then you may not need a fog machine? I suppose you could substitute dry ice for regular ice, but I wouldn't recommend, since placing dry ice is tricky and might not work as well with this particular construction? But if you do have dry ice and prefer to use it as a fog effect, here's what I've seen: When you add dry ice to water, you get a similar type of fog effect, except its much more volatile and much more fun, when used safely and appropriately. (The First Rule to Remember, When Using Dry Ice is Handle With Care and Always Use Protective Wear. Since Dry Ice Is Actually the Solid Form of Carbon Dioxide, in This State Its Much Lower in Temperature than Frozen H2O, It Can Burn the Skin.) Depending on amount of dry ice, amount of water, temperature of water, and type of container used, determines how long, how fast, and how much liquid fog is produced. Lets say you have an 8oz glass of water at room temperature approximately one inch from the top and you drop one to two cubes or chunks of dry ice, what you get is an immediate chain reaction like a bubbling boiled effect which rushes a liquid fog over and down the glass.If you use a much larger or longer tub, container, or cauldron of water filled almost to the top, but not to deep, you'll need several bricks of dry ice to continue adding through the night, because it can go fast. As the dry ice or carbon dioxide is added to water, it changes to its gaseous state creating a bubbling boiling fog over the top and down along the ground effect. The hotter the water, the faster and quicker the effect. Also, you can drop colorful glow sticks as the dry ice is added and watch the amazing flare of colors look like they are boiling over. Some clubs safely use this effect on their specialty drinks with color, once evaporated. With enough Dry Ice you can create a low lying thicker fog, but may or may not produce as much, as fast a fog as a machine. To each is own. Some local grocery store chains carry dry ice, since its used for shipping cold items. t seems like you can never buy enough, sometimes, so plan wisely. It can be costly, too. Keep frozen until use, eventually it will dissipate into a safe gas, since a regular freezer is warmer than dry ice at 32 degrees. <br> <br>I'm glad to see a smaller way to create a fog chiller and with the small fan, its genius! I'm gonna try it out. I'm a DJ who uses Fog and tons of lights every year at Halloween. Its a curse, I'm mean a calling to decorate my house and street during the holidays. Halloween and Christmas are a DJ's favorite time of year. Of course I'm the kind of girl who probably goes a little over the top, but at least I have fun. <br> <br>Maybe, If you want to try different materials for your chiller, perhaps using a wider tube such as an aluminum dryer tube attached to the fog machine via aluminum tape, while running the tube through a fitted hole down or through the top of the lid of a larger bucket (painters bucket), tub, tote, or small 13 gallon garbage container through the interior and then out the side, instead and sealed with the aluminum tape. Add regular ice as needed. The pressure of the fog machine should be great enough to create a low flow of fog with out the extra fan, to create the same effect, though a fan may definitely help if the night is too still? If the tube is wider, made of metal or aluminum, with the right amount of regular ice, it should keep nice and chilled like a bartender's tumbler, as the fog machine blows the hot fog through the frosty aluminum tunnel it will instantly react and create a spectacle of low moving fog across a multitude of colored lights or gravely scenes. <br> <br>Just saying&acirc;€&brvbar;.Sorry So Long&acirc;€&brvbar;.
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
This sounds completely reasonable. I see two potential complications: <br> <br>1) The dry ice may be so cold that it re-condenses the vaporized gasses out of the air. I am not familiar with the exact physical explanation for fog, so this may not be a problem at all. <br> <br>2) The cold CO2 generated by subliming dry ice will sink and displace the oxygen in a confined space. Don't put large amounts of dry ice in a confined space. The small amounts used here would not be a concern to me. <br> <br>I recommend you try it out, it has the potential to work much better than regular ice. <br>
You could use this to make a fog screen display. I am currently working on one. Great bile'
just finished making this but my new 9V battery gets weak after a few minutes. is there another battery i can use with better results? my fan is 12V, it says.<br /> <br /> do i need a few batteries in series?<br /> <br /> thanks
use AA batteries, D or C these batteries will last much longer as the have many more milliamp hours (MAh) than a 9v
where did ya ghet your smoke machine from?<br>
I think I got it from walmart. You can find them everywhere about this time of year (Halloween)
I'm not sure if I put enough ice in, but I realized room temperatureaffects it a LOT. Essentially, the cold fog will sing through warm air,so keeping the room warm will do it.<br /><br />I'll try more ice and a low circulating fan.<br />
v Me too! I have the same one. Only that it cost 40 bucks, but I got it for 20.
I have the exact same machine! I am so going to make this. im just wondering, could you have the fan where the fog exits, or will it dissapate too much?
I don't anticipate it being a problem. Try it!
well i am a dj and i have a 200$ DMX and all that industrial party strenth fogger and i was wondering if this would work for that too mine shoots about 20 feet and it about 3 times bigger than his
I wouldnt use a 9v battery with a 12v fan. You'l wear out the battery real quick and the fanwill under-perform. Try useing a proper 12V supply or battery
I wouldnt worry about under-voltage on a cpu fan that much; they are pretty tolerant, and simply (as you say) lose speed. If you underpower it too much, it will just stop. I built the other one - super cheap version, and I love the results. I imagine this has a very similar effect, but a constant flow - the fanless one 'billows' more.
you're battery is gonna die in about half aan hour if you left it on
You could replace the 9v with a variable power supply
good idea though, i'd make one of them if I had a fog machine
I really this idea. I think i'm gonna cool it with a PC watercooling system. Just that i'm gonna use the radiator to cool the air. Then for CPU cooler i'm gonna add a thermoelectric cooler to it, with an "aircooler" for CPUs on the other side. I think that could get cold enough. Well if not, i still can use it to chill a PC :)
I like this, but the problem is that this unit would be in the wings of my stage, and with the lighting and actors, it gets very warm in this area. So blowing warm air into a box of ice is not the best thing for me. Would it be possible to have the fan fixed internaly and blowing out through a hole? Then no unnecesary warm air would melt the ice.
You could probably mount the fan inside the box (or, as others have suggested, the exit hole) and eliminate the warm air intake. But if you want to put it inside the box, be sure to use dry ice so there is no water that could short out the fan.
or could i put a piece of plastic or something like a hood on the fan, and have a small hole below the smoke outlet for water drainage
sure, nothing wrong with that
if you have a drainage hole you wont have to worry about the water.
well, i had the same fog machine as you do. i also have one from the same company, with an ice chamber built in, made specifically for ground level fog. i like your way though, much more creative.
Make this and attach it to your fog machine with the ready ice chamber for extra low fog!!!
hahaha yeah
It might make frost not smoke! lol
maybe snow! lol
It might make frost not smoke! lol
I'm reminded of a basic "Swamp cooler" design. Cool, good job.
You should use dry ice in the cooler to give extra fog off.
Yes, dry ice works great in fog chillers, and there's no water to drain away.
i was thinking, instead of ice maye you could use some form of liquid cooling, like a fridge, with cold water being,. say, pumped out of bucket (with a electric pump) with water and ice, and into the chiller with all the pipes arranged for lots of surface area, then you could refill the water quickly. but i worried about the noise, im a filmmaker and i need a quiet mist/fog machine
This is how the commercial fog chillers work. If you're going for silence, look into using a liquid cooling system for a PC. They will be quieter than a large cooling unit. I can't say how effective the liquid cooling unit may be since it is intended for cooling by conduction instead of convection.
Liquid cooling was an excellent thought, but doesn't chill, just cools to room temperature. For the fog to stay low, it has to be below air temp.
Hey guys, I work in the theatrical industry and have a few praises and a few suggestions. Excellent job breaking it down. this is basically how a pro-grade unit works. -Dry Ice (frozen CO2) is a must to get a good heavy fog. Its cheap and as long as you wear safety gear, easy to work with. Plus you won't have any water to worry about. You can buy it at some grocery stores, an oxygen supplier or some party stores will have it. -If you run a drier hose between the fogger and the chiller, you won't have to worry about the height. - If you are using dry ice, it will be more effective if you build an interior compartment with a 3in pipe (drain spout pipe with all the holes works best) and lower it to the bottom of the chiller. Then place the fan at the exit instead of the entrance. The fogger's "blast" will push the fog into the chiller fine and the fan will pull the chilled fog out nicely. This will only work with dry ice though as the water will short out the fan otherwise. One other thing, if you use the dry ice, put a blanket on top if you don't fill it to the lid. that will keep as much oxygen away from the dry ice as possible and it won't evaporate as quickly. Good job with a nice, inexpensive chiller!
I have the same fogger. i got mine at Michael's and it is so awesome i added a timer controller.
I know there is already a fog chiller on Instructables, but this one is a different design. His is cheaper and easier to build, but I will claim that mine works better. I suggest you look at both and decide which one is best for you.<br/><br/><a rel="nofollow" href="http://www.instructables.com/id/Super-Cheap-and-Easy-Fog-Chiller/">Super-Cheap-and-Easy-Fog-Chiller</a><br/>
ya, I like yours too! Good job!

About This Instructable

178,819views

201favorites

License:

Bio: http://www.awesomelicious.com/about/me.htm
More by T3Hprogrammer:Hack your House: Run both ethernet and phone over existing Cat-5 cableMake a Fog Chiller for $10Shock your Trick-or-Treaters
Add instructable to: