• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Building your First evaporative cooling tower!

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

Pro*Banshee

Member
Joined
Mar 27, 2004
Location
Pittsburgh Pennsylvania
Building your own Bong (for evaporative cooling purposes on a computer)

Cheap!
Powerful!
Low-Maintenance!

Materials needed:

5' section of 4" PVC Pipe
1 Sanitary Wyee fitting
10' of 1/2" tubing (optional ATM)
Showerhead
1/2" fitting to match showerhead thread
1/8" plywood or popsicle sticks or hard wood
PVC glue
Krylon Fusion Vhynl paint (I chose blue, completley optional :cool: )

1. Take your 5' section and cut off roughly an 8" section of it. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/8cut.jpg

2. PVC glue (as per instructions on can), this piece into your Wyee fitting and let dry (1/2 hour) http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/wyee.jpg

3. Glue on the end cap (as per instructions on can), onto the 8" section http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/endglue.jpg

4. Drill a 1/2" fitting sized hole into the bottom section of the 8" piece of connection pipe at the bottom. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/holedriller.jpg

5. Take a pair of vice grips, grab the fitting, and screw it into the 1/2" hole you drilled. Strength (or a set of thread cutting tools) can help a lot here. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/barbin.jpg

6. Liberally apply PVC glue around the fitting to seal the PVC against it.
(no picture here)

7. cut another 8" section out of your remaining piece of the 5' pipe, leaving you with a 3'8" section of it http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/8cut2.jpg

8. Glue this piece into the Y part of the Wyee fitting you glued the end cap/extension part to. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/wyee2.jpg

9. Create this wooden piece to hold the showerhead in place on top of the pipe. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/woodenpiece.jpg

take the showerhead and 1/2" fitting for it, and sandwich the wood between them when you screw them together.


10. Take the remaining piece of PVC pipe not glued to anything and cut these L-shaped marks into it (no dimensions provided) http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/cuts.jpg
Make two of these, on opposide sides of the pipe, facing opposite directions. When the wooden piece is inserted and twisted, it will lock into place.

11. take the final piece of L-cut PVC pipe and PVC glue it into place on the only remaining Wyee connection. this is the bong. http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/bongcomplete.jpg

There you go :)

Im pretty sure a device could be made to lash it to a pole (I tied mine to the side of my desk with shoe laces, just make sure it's nearly straight up and down, you can tell by the loudness of the sound of the water hitting the bottom in the tank), or you could make a big heavy wooden block about the size of the end cap and glue it in place.

If you were to use this in a computer, you would need a water pump with at least a 6' head (height the pump can pump up to) and a decent CPU waterblock. The way the watercooling loop would go is as follows:

Bong-->Pump inlet-->Filter-->CPU waterblock-->Bong.

[Geeky theory explanation]
The theory behind bongs is one of evaporation. Making a substance change state requires immense energy, and what better source than a CPU putting out perhaps 100 watts of heat? This heats up the water and allows it to evaporate faster (like a puddle on a sunny day). The showerhead and height of the bong allow the water to be broken up into smaller droplets, and be cooled faster. The cooled water then drops down into the reservior at the bottom of the bong, where it's cycled along the loop again.
Since the cooling is so efficent, it isn't unreasonable to power 4 or 5 computers off of one bong loop, the pump being the only issue.
[/Geek]

Maintenance: My bong burns off about 8 oz of water a day (about 1/2" of the pipe reservior). A cupfull of water in the morning with a capful of rubbing alcohol (helps keep living things out of the bong) is as far as mintenance goes.

Hope this helps anyone looking to bong cool.

-Additives-
this topic comes up ALL THE TIME, so here's the straight dope:

*The Cheap*
-Rubbing Alcohol
-Hydrogen Peroxide
Both of the additives work very well in keeping living slime out of my bong after a months usage, the only downside was a slight slimy buildup on the side of the bong wall, the tubing got cloudy, but it always does on a count of me using Tap water.

*The Moderatley agitating (to the lungs, depends on sensitivity)
-Bleach
-Bleach Tablets
I've tried both of these additives in my bucket as well as my bong cooler, and they both work marvelously. The Key is not putting too much in though, you want perhaps 1/2 oz per every 16 ounces of water, and even that is overkill.
Make sure you keep a window open though. While it DOES leave a fresh, clean smell in my room, huffing bleach and agitating the smokers in the house doesn't bode well for this additive.

*The Expensive but Ideal
-Humidifier Biocide
This stuff is MADE for evaporation, I would provide some information, but I was always too cheap to buy it, so just assume it works good if you have the means to aquire it.

------------------------------------------------------------------------------------------
Improved Design
------------------------------------------------------------------------------------------

http://img.photobucket.com/albums/v314/Pro*Banshee/improvedbong.jpg
This design makes use of the misting heads that some have suggested instead of shower heads. Since misting heads are so restrictive, many of them would have to be used to get a half-decent flow, along with a pump with lots of pressure, or two put serially.

So, on with the explanation!
Water enters in through the hot water lines (D) and makes its way to the misting heads (C). The misting heads spray the water into the main chamber and are cooled off by the water being forced in by a moderatley strong blower (A). The Gasket (B) keeps the air/water mixture from leaving through the top (heated anything rises). The cooled droplets are further forced down into the Sponge/Brillo pad (E) and collect on it and form drops which drip down into the main chamber, allowing for a cold water return (F). The Moist air leaves through the Wye Exit (G).

------------------------------------------------------------------------------------------
Improved Design
------------------------------------------------------------------------------------------


(Edit) Here's my bong, completed if anyone'd like to see. (3/25/05)
http://img.photobucket.com/albums/v314/Pro*Banshee/Bong/DSC00001.jpg
(Edit) Fixed pictures, added additives section (5/23/05)
 
Last edited:
Nice guide. If you can come up with pictures in addition to the diagrams, I'll add it to the sticky section. We get questions about bongs every once in a while, and this would be the perfect thread to point them to. :thup:
 
And for the Theroy of operation:

~A body of water will evaporate with air moving past it.
~Heated water will evaporate easier than cold water.
~A CPU supplies a large ammount of heat

the showerhead and large falling distance only make the water into smaller droplets, helping it to cool+evaporate faster.

Cooler temps could be achieved if there was a fan blowing into the 45o part of the pipe, but water loss would increase exponentially. I also net very very nice temps in my room (70% humidity is a fair estimate). for you on the south-west part of the US, consider this superior to a Radiator setup :D .
 
Do you use ditilled water? I would think that using tap water would provide extremely high amounts of mineral residue due to the fact that the water evaporates.

I'm not quite sure if I understand correctly, the shower head sprays directly down from the top off the bong then the heat is dissipated from the water to the air then to what? the sides of the bong? or does the hot air go out through the 45* at the bottom?
 
Alright, here goes again :p
http://img.photobucket.com/albums/v314/Pro*Banshee/diagram.jpg
~A body of water will evaporate with air moving past it.
~Heated water will evaporate easier than cold water.
~A CPU supplies a large ammount of heat

Pretend we're inside a heated drop of water inside my bong, just coming from the CPU waterblock, being sprayed out of the shower head.
We have lots of thermal energy, which we need to get rid of. Since air that isn't at 100% humidity will take some water with it when it moves past us, we'll get rid of this heat by passing it off to a few suckers and letting them drift off the rest of the molecule and out the top of the bong. Since the water drop got cooler and loss some of its mass, a slight vacumn is created inside which draws air in through the 45o pipe. The cooled droplet of water then falls down to the bottom of the bong, where it waits to be cycled again.

Yeah, you could use distilled water, but Tap water works great too, not to mention it's also cheaper. As long as you have a decent filter in line with the hose (I don't, shame shame), then no crud would build up in your block.

I suppose there would be mineral deposits, but I havent tested long enough to confirm this. The farthest I've gotten was the tubing got cloudy, and the lucite on the block fogged up. Big deal, right?


------------------

only prob with bongs is evaporation

this IS the desired effect you know. My design just cuts down on the evaporation compared to some of the other beasts I've seen (a half a gallon a day isnt unreasonable).
 
C'mon man! No props to the guy who expained this to you? heh

What about maintance, pal?

Pro*Banshee said:
Bong-->Pump inlet-->Filter-->CPU waterblock-->Bong.

Almost - the filter goes between the bong and the pump so any minerals or impurities don't screw with my pump - either of them.
 
Depends on the humidity of the area you live in.

A dry area? Definatley, Subambient temps aren't out of the question.

In a moderate climate like mine (60%+ humidity all the time), temps are better than a rad (around 40c peak as opposed to 57c peak with rad)
 
I agree about the fan. Wouldnt a lower powered fan pushing hair up through it remove more heat? And what about a misting noozle or 2? Kinda like they have a grocery stores for the veggies. I think the sound of a shower running 24/7 would drive me insane. Maybe cut the remaining sections into 12 inch section and use connecting peices. Cut a round peice of screen. So instead of large drops hitting the bottom straight they hit levels and spread apart. Would also slow the decent giving more time to cool.

|*|
|=|
|=| <--- Screen and joint
|=|
|=|
|=| ..
|=|/*/ <-fan WITH FILTER!!!
|..|../
|..../
|_/

Lol do yourself a favor and buy a water distiller. They arnt too expensive.

JT
 
I agree with Jtanczos because a shower runnin 24/7 by my computer would drive me crazy. An idea has been running through my head and I wanted to know what everyone thought about it. Instead of having the bong upright, how about laying it at a 30* angle instead? it wouldnt be as efficient, and it would take up more space, but it wouldnt drive me crazy.

Heres a (bad) pic I did in paint
http://www2.freepichosting.com/Images/421471017/16.jpg
 
efficency = 0 on that bong, the water would only be cooled on the small section that's touching air.

If the man peeing noise is too much, then I suppose either a sponge (one of the big poofy kind made out of the preforated fabric), or a couple of ping-pong balls should muffle the noise
 
The noise isn't as bad as everyone makes it out to be. I've been over there helping build it, testing it, etc and it's actually rather soothing - like rain. It's also about the same volume as my y.s. tech 120mm fan (39 db I think) 7volted. If you are really concerned about the noise, put some music on...

A fan will help but for a larger bong like this one, it's unneeded. I'm sure you all saw the post about the uberbong? The guy said he could cool 8 or 12 computers off of it with one fan blowing out, not in - correct me on this one Pro*Banshee, you talked to him. Anyway, a 2' bong with a fan should be sufficient for a cpu if you run with a fan. Anything over 4' could do cpu, gpu, and northbridge with a fan easy or possibly passivly. It probably would be able to do multiple computers.

The possible problem with misting heads is that I doubt they will allow enough flow through them. You have to remember that the showerhead will add a lot of restriction to the loop. I actually modded the head that Pro*Banshee uses by drilling holes inside to allow more water to flow through it. I haven't done any tests with misting heads but I just don't have a good feeling about them. Also, you want the water to fall as straight as possible down the bong.

Jtanczos said:
Would also slow the decent giving more time to cool.
Please correct me if I'm wrong but I believe that the faster they travel through the bong, the better cooled they get. I'm assuming this becasue of the way radiators work - more flow = better cooling. If they fall faster, they end up touching more air - like water to rad. This would also explain why adding a fan pushing up aids in cooling as it forces more air to touch the water.

sterVin, the pic doesn't work.
 
Slow the Descent yes, but not expose enough surface area to make evaporation useful.

If you want a truly noiseless evaporative cooler, build something like the fountain-cooler, it's a bunch of tubes sticking up with an absorbant material wrapped around them (about 40). The water is pushed up all 40 tubes and dribbles down slowly. A fan pushing on it can net truly below subambient temps.
 
I don't have any experiance with evaporative cooling towers, but ive had an idea in my head for while now and figured I would see what experienced individuals think.

Attached below is a picture (a very poor quick job in paint I might add) of my idea. Basically, instead of having the water shower straight down, the water flows onto a flat surface angled slightly downward, onto another similar surface and this continues to the bottom of the cooler, with these surfaces (ill call them flaps) overlapping each other. The flaps would be quite large (as would the cooler) to allow the water to spread out as thinly as possible across the surface. A fan would force air cool up through the cooler. The air would be pushed through the water as it flowed over the edges of the flaps, and would blow over the surface of the water as it flowed over the flaps. This would (in my unproven unsubstantiated researchless theory of course) expose more of the water's surface area to the cool air, over a longer period of time compared to the shower method, cooling the water more. This idea is sort of like a radiator (the idea being to expose the most surface area to the cool air as in a radiator), but with less flow loss (since the water flows free from the tubing) and with (at least some) of the benefits of an evaporative cooler.

Any thoughts, comments, suggestions, etc would be appreciated.

Mike
 

Attachments

  • cooling_tower.GIF
    cooling_tower.GIF
    4.6 KB · Views: 17,996
That probably wouldn't work as well as a straight decent because the air would just travel over the top of the water, not through it (smaller size). For that to work correctly, it would have to be massive. Something you have to realize is that the flow in a bong system isn't that much lower than that of a normal watercooling system. With Pro*Banshee's ~5' bong, a hydor l30 1, and a maze 3, he was getting about .75-1gpm through the head. Unless the flaps in your design are massivly large, the water won't spread thin enough - it'll just gush through. The only way to find out though is to try it.

Also, something you have to realize is this: bong's are super-efficient in terms of reducing and removing heat in water. A 5' bong could cool at least two computers with three blocks each (cpu,gpu,nb). I saw an article a long time ago on the front page where a 4' (I believe) bong was used to cool four rackmount computers and their video cards... all in parallel. For a standard computer, a 2-2.5' bong should be more than sufficient.
 
Back