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Goodday all,

I was recently reading up on a few projects that might be of interest to me when I found "CPU Bong water coolers", there isn't much online on them so I figure I would ask y'all.

If you do a quick google search you can see what this thing actually is.

They get a length of PVC and orient it vertially, at they bottom they attach a 45 split with the 45 open end facing up. The very bottom of the pipe sets in a bucket with water.

Water from the bucket is pumped through a CPU waterblock and collects heat. The water continues to a shower head situated at the top of the PVC pipe. The water flows through the shower head and strait down the tube into the bucket. While the water is falling through the tube air is forced over it via a fan over the open end of the 45 split.

I think the idea is that the air gonig over the small droplets of water will strip off molecules that are close to evaporation. When they evaporate they pull heat from the last of the water in that drop, cooling the drop. All the drops are cooled this way.

Is this how this thing works?

How could I get a rough estimate the size I would need to remove lets say 300 watts from the incoming water? (I know I will get people who quote "But what if the butterfly flaps its wings in Europe, that thing will then only cool 299.4553456 watts; I just need something generic. Should I get a 10foot PVC pipe or a 6in pipe?)

Does it scale? If a 1ft pipe can effectively remove 10 watts, does a 10ft pipe remove 100 watts?

If you think it depends on to many factors to tell me, what are the factors? Humidty, ambient, CFM of the fans, how small the drops are from the shower head, etc and which should be maximized and which should be minimized.

share|improve this question
    
A quick search shows most people who play around with building these just test them empirically, and I can see why. You need to know all sorts of variables to do the a priori calculation, like flow rates, droplet size distributions, humidity (your whole room will need to be de-humidified somehow, or else the exhaust will need to be vented to the outdoors, lest you reach saturation and evaporation no longer takes place), etc. –  Chris White May 10 '13 at 17:23
    
20 foot it is!! I'll make a sauna and a water cooler this weekend! –  BumSkeeter May 10 '13 at 17:37
    
Hmmmm, I've heard of similar devices used to cool people (I maintained and used one at Burning Man). I would be weary of such a setup if you want to leave your computer on for a long period of time as the water will eventually dissipate into the atmosphere, leaving you nothing to cool with and burning out your CPU. –  Adrian Aug 24 '13 at 16:24

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