FAQ: Is Liquid Cooling for Me? - Overclock.net

OC'ing Noob · 10-26-08

Recently there has been a lot of new members interested in water cooling their computers. Problem is, there seems to be a lot of misconceptions of what liquid cooling is, how it works, and what it does. There is a huge amount of resources available of working with liquid cooling, but next to none helping people decide if they want it.

What liquid cooling is, it is a system of cooling that involves using water as the medium for heat transfer. Normally, computer components in need of active cooling usually have a chunk of copper slapped on to it with a fan mounted in some way. However, air is not that efficient as a thermal transfer medium and one may witness spikes in their temperatures. As overclocking becomes more mainstream and even normal consumers begin to push the boundaries, we find that conventional cooling simply is no longer enough. Here we bring in water or any other type of thermal transfer medium.

First of all, how exactly does liquid cooling work? Liquid cooling involves using thermal conductive liquid (usually water) to absorb the heat from blocks mounted on system components and carry it to some sort of heat exchanger to cool it. There is also some kind of pump involved as well, to drive the liquid coolant through the system so that heated water is constantly moved to the heat exchanger. Here is a diagram of how it actually works:

Pump -> Drives liquid to the heat exchanger -> Heat Exchanger -> Heat exchanger cools the liquid down and drives cooled water into the water block -> Water Block -> Water block transfer heat from CPU to water -> Warmed water is pulled from pump -> Pump -> Drives liquid to the heat exchanger

Now some of you may be wondering, “Where is the reservoir?” since you have no doubt seen the myriad of liquid containers in many of our systems. Well the simple answer is, you don’t actually need one. All you need is some sort of method to fill and bleed the system. A reservoir simply makes the process incredibly easier.

Here are some definitions of the components I listed in the diagram:
1. Pump – A machine that drives the liquid coolant, meaning it sucks liquid coolant in one way and shoots it out the other. Now that I think about it, humans can be considered a huge walking pump.
2. Waterblock – A low level heat exchanger that transfers heat from your system component to the liquid coolant.
3. Heat Exchanger – Any sort of device that transfers heat from one medium to another. This is usually a heater core or a radiator being cooled by computer fans.
4. Reservoir – To put it simply, it is a water tank. It contains liquid for the pump to feed upon.

Now you are probably wondering what liquid to use at this point in time. To be honest, any liquid that is an efficient conductor of heat will work. The most commonly used liquid coolant is a homemade mixture of distilled water, antifreeze, and biocide, but there is a huge variety of 3rd party coolants. Someone had also used beer to great success, so cheers!

By this time, you guys are probably nervous at the sheer difference between liquid cooling and air cooling. Hell, for air cooling you just stuck it on there and it worked. So that leads us to the big question, who in the right mind would want something like this?

The answer to that question is in one of the three following reasons:
1. Cool your system at as low a noise level as possible. This is especially valid when dealing with HTPC’s where one does not need to overclock.
2. Achieve as low a delta T (change in temperature from idle to load) as possible to maximize your overclock. Here we use obnoxiously loud fans to keep temps as low as possible so when we are overclocking our CPU’s we are no longer limited by the temperature factor.
3. Achieve an acceptable level of overclock at a low noise level. This is a compromise between the first to reasons to use liquid cooling, where we achieve as high an overclock as possible without torturing our eardrums.

With those fabulous reasons, why wouldn’t we want liquid cooling? Well, unfortunately we will now move on to reasons why we would NOT want to use liquid cooling:
1. It can get very expensive if you are doing it right and you purchase everything new. Cheap liquid cooling kits from Thermaltake, Koolance, and Zalman are generally trash and no better than high end air cooling. Good news is for the most part, most liquid cooling components last forever and unless you are a liquid cooling junky, you don’t need to ever change it out.
2. Liquid and computers generally do not get along. While some companies do make non-conductive coolants, those will eventually become conductive over time. Now if you properly leak tested your loop for at least 24 hours before using it with your system, you should be completely safe. Not properly leak testing is the equivalent of putting an open cup of orange juice in your computer case and hoping nothing happens. The inner walls of tubing are pretty thick and will never get punctured by liquid. Leaks usually happen either becomes something broke, barbs were not tightly screwed in, or proper leak testing had not taken place.
3. Liquid is heavier than air. There is just no way around this unfortunate fact of nature. A computer with an internal liquid cooling system will generally add about 10 lbs or so extra weight.

As far as maintenance goes, liquid cooling requires very little maintenance beyond the initial leak testing, annual changing of coolant (kind of like an oil change), blowing out the dust from the radiator with a a dust can every now and then, and every now and then, adding a couple of drops of UV dye to keep it glowing bright.

Liquid cooling is not the end all be all of cooling. It will not help you achieve miraculous temperatures or sub ambient temperatures. It is however, the best option available without having to modify your motherboard to protect it from condensation. Is it for everyone? Absolutely not! However, if by the time you read this and decide that you still want to give it a shot, chances are, liquid cooling is meant for you.

Hondacity · 10-26-08

idle to load temps....

intel procs are known to have problems with idle temps...

why not ambient to load temps?

OC'ing Noob · 10-26-08

Ambient temperatures do not tell us the idle temperature of the CPU is at all. The CPU idle will always be a bit higher than ambient.

**mortimersnerd** · 10-26-08

Nice FAQ

omaryunus · 10-26-08

good job with that OC'ing Noob

OC'ing Noob · 10-26-08

Quote:

Originally Posted by mortimersnerd

Nice FAQ

Quote:

Originally Posted by omaryunus

good job with that OC'ing Noob

Much thanks!

Thingamajig · 10-26-08

Quote:

Originally Posted by OC'ing Noob

As far as maintenance goes, liquid cooling requires very little maintenance beyond the initial leak testing, annual changing of coolant (kind of like an oil change), and every now and then, adding a couple of drops of UV dye to keep it glowing bright.

I think you should include regular cleaning of the radiator as dust easily collects in there and drastically effects temps, especially if you run a finely tuned and very hot system.

Apart from this, well done. I can imagine how much time you spent on this and i'm sure the OCN community appreciate your efforts.

OC'ing Noob · 10-26-08

Quote:

Originally Posted by Thingamajig

I think you should include regular cleaning of the radiator as dust easily collects in there and drastically effects temps, especially if you run a finely tuned and very hot system.

Apart from this, well done. I can imagine how much time you spent on this and i'm sure the OCN community appreciate your efforts.

Good idea and added! Thanks for both the suggestion and the sentiments!

Tricky · 10-26-08

Excellent FAQ. Too bad I'm so scared of a WC leak.. I would of had a WC setup.

underdog1425 · 10-27-08

Great faq

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FAQ: Is Liquid Cooling for Me?

10-26-08	#4 (permalink)
mortimersnerd Fear the penguin Join Date: Mar 2008 Location: Michigan, United States Posts: 7,342 Hardware Reviews: 4 Trader Rating: 49	Nice FAQ

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