Read on what a bong is, how it works, and many other questions answered in this thorough guide!
Ok, so who wants to know about bong cooling? By "bong" I don't mean an actual bong, I mean a piece of PVC pipe. (I've been told by some of my.......more enlightened friends that it IS possible to use it as a bong.) Moving on..........
Most watercooling uses the principle of the transfer of heat through a closed medium. Since energy cannot be created or destroyed, but only transferred, this is exactly what it does. Simple H2O loop:
The pump pumps the water, the radiator transfers the heat in the water to the metal on the radiator, and then the fan that's attached onto the radiator blows the heat off, and into the ambient air. The cool water then goes to the waterblock, picks up some heat, and then completes the loop. If I can remember correctly, this cooling by conduction. (one object directly touching another. If I'm wrong, tell me! ) This is a great way to cool your computer since water can hold many more times the heat than air. But, if you want to do some serious cooling/overclocking, using a bong cooler could be better.
I believe that this was the first article about bong cooling. (correct me if I'm wrong) Go read it, it's good.
Before we go any further, a computer bong (if you didn't read the article) is a piece of PVC pipe. It can be different diameters (mine is 4 inches) and different lengths. (mine is about 3 feet tall) It has a showerhead (or something to spread the water out) at the top. It has a "sanitary tee" about 2/3's of the way down. This is there so you can put a fan inside. (which will be explained later)
The idea of using a bong to transfer heat is a little bit different, and is a little more complex, but isn't that bad to understand. Instead of using conduction, we're going to use evaporative cooling. Ever get out of a pool and have the wind blow on you, and you get really cold all the sudden? That's evaporative cooling! When water evaporates, it changes states from a liquid to a gas. Gases have more every than liquids do, and as such, they have to get this energy from somewhere, since they couldn't just make. [sidebar]Heat travels from areas of high heat to areas of low heat to achieve equilibrium.[/sidebar] The heat is supplied by the surroundings, which in this case, would be your body. The heat energy from your body goes to the cooler water, and the cooler water heats up and gets enough energy to evaporate, but leaves you without that heat energy, which is why you see people standing beside pools chattering their teeth off.
The good thing about using a bong cooler is that the water temp can actually go lower than the ambient temp of the room, which is good for us overclockers. The first time I ran my bong, I poured steaming hot water from the faucet into it and let it sit for a while, probably not longer than......3 hours max. I checked it about every 45 minutes, and you could feel it getting colder each time. When I came back the last time, the water was chilly. That's how good they work.
Here's the "loop" (it's not closed) for a bong:
The pump pumps the water to the waterblock, which picks up the heat from the CPU (or whatever). The water goes to the bong. It's pumped up to the showerhead, and falls down the bong. When this happens, the air from the fan that's inside the sanitary tee is being pushed up past the falling air, helping it to evaporate. [note: bongs will work without fans, but not that well. I know from experience, lol] The pump is sitting in either the bottom of the bong or the bottom of a reservoir that the bong is sitting in, and the water goes through the cycle once more.
Q: Isn't this....loud?
A: It can be, but there are several ways to take care of this. I personally use a piece of foam in the bottom of my bong, and that works pretty well. I've heard of some people filling their bongs up with ping pong balls to help with evaporation (more surface area for the water to evaporate off of) and and noise. It all depends on your preference.
Q: Don't you have to worry about all the water evaporating away???
A: YES!! Always check the water level of your bong!! I cannot stress this enough. The water evaporates quickly, and before you know it, it'll be time to refill. I know when mine's about to run out of water when I hear my pump grabbing a little air with the water.
Q:Can I use antifreeze/water wetter in a bong?
A: I've never used water wetter, but I've heard that it smells horrible. So I wouldn't recommend it. Antifreeze: unless you have this yearning to breath antifreeze fumes, I don't suggest it.
Q: Can I recondense the water and use it again?
A: You can, but it would be using more energy that the bong is taking away from the CPU, so it's not worth it. If you tried to make a closed bong, it wouldn't work at all. (this is known as perpetual motion, which doesn't happen)
Q: How much does all this cost?
A: Depends on the hardware store in your area, but the bong itself shouldn't be more than around $20-$30USD.
Several things to remember:
Use a powerful pump---some pumps just don't have enough juice to get the water up to the top of the bong.
Always check your water level! [Disclaimer: I am not responsible for any fried computers out there if you do this.]
Have fun while doing this!!