The possibilities for a water-cooling set-up are virtually endless but for the most basic of set-ups here is the stuff you would need (I'll probably miss something out but I’m sure someone will fill in the gaps for me!!
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One of the first things you must decide on when planning a water-cooling set-up will be the internal diameter of the pipes you want to use on the system (most commonly 1/2" or 3/8") 1/2" will give you a better flow rate (discussed further under pumps) but will mean larger pipes obviously which are harder to bend around corners without kinking. 3/8" pipe is easier to route around corners looks less obtrusive but provides a slightly reduced flow rate. Serious water-coolers swear by and only by 1/2" tubing or above. Unless you want to water-cool everything in your computer (CPU, MEM, PSU, HDD, Northbridge) then personally I think 3/8" is fine however as with everything it is personal choice, use which ever suits your needs better. This decision will affect what components you choose for the rest of your system. 1/2" components can but do not always cost more and may or may not be worth the extra money/hassle for you.
Pipe: And yes there is still more on pipe, having chosen the diameter you want you must now decide about some of the following. Wall thickness, the thicker the wall the less likely the pipe is to kink (causing a blockage) but the more difficult it is to bend around corners. What do you want the pipe made from, if you want to colour the water then it will have to be clear, you must also take into consideration the effect of any chemicals you might want to add to the water upon the pipe (you don’t want the chemicals to eat through the pipe) As I know some people who have had trouble with additives such as redlines water wetter turning their pipes cloudy (additives are discussed further down). So you must choose a material that will resist the chemicals whilst still being clear (if you wanted a clear tube).
A waterblock: This is the bit that sits directly on the CPU, it replaces the common heatsink & fan. They come in all shapes and sizes and can be made from copper, aluminium, copper & aluminium (having both does add some further complications but I will save this for another time) these are the most common metals in use are they are the most efficient at shifting heat away from the CPU core. Below is a picture of a fairly standard waterblock (and in fact the one I use myself!):
^^ Its a z4 aqua sink
^^Viewed from underneath
The waterblock usually has 2 hose connectors (some have 3 or even more depending on the design) and the block must be water tight (else electrical bits get wet, and they don’t like it!! :shock:)
Inside the main body of the waterblock there is a path from one hose connector to the other, this can be as simple as just an empty space joining the two of can be in the style of a channel for the water to flow through from one to the other, as shown below.
Any design that joins the two connectors in some way is possible and there are many designs out there.
With the design shown above the cool water enters in the centre of the block right above the main die of the CPU, this way the coolest water is present right above the hottest part of the chip. It then spirals from the centre until it reaches the other hose connector.
To put it simply the CPU heats the waterblock (don’t forget your arctic silver though, just like a heatsink and fan) the waterblock then heats the water, but the water is flowing so the heat is effectively taken away.
The waterblock is held onto the CPU in much the same way any heatsink & Fan is, although they generally use the holes present around the processor for mounting purposes.
Fittings must be used on the waterblock, which will fit your choice of pipe
Think that just about covers the waterblock.
Pump: This is the main work horse of the water-cooled set-up its job is to well... pump
(sorry but its the truth!!). Again these come in all shapes, sizes colours and yes prices. Firstly there are a couple of different types of pump, you have submerged pumps which have to physically sit in the water they are pumping, you have inline pumps where the outside of the pump never gets wet and it is just hooked up to an inlet & outlet pipe, and you have pumps that can run as either inline or submerged. Inline pumps tend to be favoured by the more serious water coolers as with any pump there will be a certain amount of heat produced and if the pump is sitting in the water you are using to cool your CPU it will be heating this water up while it sits in it, thus this means that you wont be able to cool your CPU quite as much. This effect is minimal and dependant on the pump you are using but it is still something to consider. If you are using a submerged pump then you have to use a reservoir (something i will cover shortly). There are pro's and cons to both types of pump, but in the end inline pumps win for most people.
Next in the pump debate is the supply you will run it from, them can either be run from 12v or mains (230v for me in the UK and 110v for those in the US). Again there are good and bad points for each, 12v pumps can be directly powered from you computers power supply and so will always be turned on when the computer is, however they tend to be noisier, less reliable and run hotter than the equivalent mains run pump. This said, it's not everyone's idea of fun to fiddle around too much with mains voltages.
Mains voltage pumps are usually more reliable in the long run, run quieter and cooler than their low voltage counterparts however :? (you knew that was coming didn't you) As they run from mains voltage there comes a complication, switching the pump on. Many people swear by running their pumps 24 ours a day 7 days a week even when the computer is switched off, fine, so long as you are sure its switched on and plugged in and that your girlfriend didn't unplug it to use her hairdryer (or and not wanting to be sexist here in any way, your boyfriend didn't unplug it to plug his stereo in (just thought i would comer my bases there
). If the pump did get unplugged its not the end of the world the processor will get hot yes but fairly slowly, over the course of a couple of minutes if you have temperature monitoring software running you will be made aware of this soon enough and you can turn the pump back on and all is well and good. If you aren't in the room but have said software set up to shut down your computer if the CPU starts to get too hot, all is still well and good. But if your not in the room and have no software in place then CPU damage could occur given enough time. A lot of ifs there I know but hey these things happen.
The next way to do it is to have a switch mounted in your case to turn the pump on and off manually, but this has a similar flaw to the method above, you could forget to turn it on. Thirdly you can use a relay to turn the pump on (for those not electronically minded a relay is an electronically operated switch, you hook one part to the 12v supply from your computer, and the other part to your mains supply and to the pump) when the computer turns on the switch is operated and the pump turns on, when the computer is turned off the switch is de-activated and the pump turns off (this is the method i personally use) but as even it has its drawbacks. Relays can and may fail especially over time (a long time) they don’t fail very often but it can happen, you are then in a similar situation as described above, except that you would have to change the relay out for a new one. Also not everyone is electronically minded and would know how to set this up (Although if you are seriously thinking about H2O cooling then you could probably find out or get a friend in the know to help).
And yes there is still more to a pump, there are two main styles of pump that will be suitable for this project, These are Mag-Drive or Shaft-Drive. These are explained below:
Shaft-Drive: As the name implies the impeller (this does the pumping of the water) is driven by a solid shaft which links the motor to it, as such the impeller which is in the water and the motor which must be kept totally dry are separated by a rubber seal around the shaft. These seals can and do fail resulting in water in the motor and a dead pump. Shaft driven pumps are generally cheaper, but noisier and more likely to fail when compared to Mag-Drive pumps. There is more to a shaft drive pump but this about all that is needed for our purposes.
Mag Drive: As the name implies this type of pump relies on the power of magnetism. All of the electronics of the pump is completely sealed from the rest of the pump, there is no way the electronics can get wet unless you hand physically damaged the pump and cracked the housing or something like that. The electronics generate a continuously rotating electromagnetic field inside the pump housing. Sitting in the middle of the pump housing there is an impeller (again this does the pumping) mounted to a round magnetic rotor and this whole unit sits on a shaft (usually made from ceramic in the better pumps) and in turn this whole assembly is sealed with a water entry connector, and a water exit connector. Mag-Drives are usually more expensive, run quieter, will last longer and are a safer design to use. They rarely fail and if they do it usually requires the replacement of the magnetic portion of the impeller rather than the whole pump. Mag-drives are the type of pump i personally use.
^^My Mag Drive Eheim 1250
There are a few specifications to consider when choosing a pump, the most important of which is its rated l/h (litres per hour) Or G/h (gallons per hour) depending on the specs provided by the manufacturer. This is as the measurement implies the amount of water the pump would shift if there was no back pressure applied to it (I.E no resistance due to pipes or waterblocks etc) when looking at this figure you can expect it to take a hefty drop once all of the pipes waterblocks etc have been linked to it, but its a good indication. A higher flow rate will increase your systems cooling capacity to a point so its just a case of finding the sweet spot as the higher the flow rate of the pump the louder the pump will run. Louder is a bit of an overstatement as unless you try a huge pump you will not be able to hear it running over the noise of a spinning hard drive. Especially if the pump is well mounted (I used anti vibration rubber mounts to help).
There is only one thing to be wary of when using Mag-drive pumps don’t be tempted to buy a really cheap one if you are going to place it inside your system, as I said above they rely on a rotating magnetic field and magnetic fields and hard-drives don’t really mix too well. Some cheap Mag-drive pumps are not shielded very well and could cause you problems if placed too close to hard-drives or cables running around in your system. Better makes of Mag-drive pumps are well shielded and produce very little if any magnetic field outside of their casing however I still wouldn’t place one of these pumps unnecessarily close to any cables or drives.
Fittings must be used on the pump which will fit your choice of pipe
That just about covers all the vital aspects of pumps
Radiator: Right so you have taken the heat away from the CPU (explained under "Waterblock") and it has heated up the water in your carefully chosen pipes (see "pipes") and this now warmer water is moving thanks to the efforts of your reliable pump (see "pump"). Next important component is a radiator, this is used to help cool the water back down a bit. It must have connector that will again fit your chosen pipe. Designs of radiators vary from model to model but they all have one thing in common, they all consist of a pipe (or many pipes) which are connected to a large number of fins (thin pieces of metal used to increase the radiators surface area) the more fins the greater the surface area of the radiator. The warm water in the pipes heats up the fins and these fins are in turn cooled either by just letting the heat "radiate" away from them, or more commonly by using fans to pass air over them. These fans can usually be low volume quiet running ones as long as you have a good radiator and aren't trying to cool a ridiculous amount of equipment with one water rig.
^^A typical radiator used in watercooled pc’s.
Reservoir: A res as it will now be referred to is not a necessity when making a water-cooling set-up it is again a case of use one if it suits your requirements so I thought I would just add a bit about them. Res's are used to hold a small (Or even sometimes large) amount of water. Contrary to some peoples beliefs normal pumps will
NOT suck water they will only push water and so they must be "primed" this means that they must have a supply of water fed to them by gravity. Having a res placed higher than the pump is one easy way of doing this as gravity will be pushing a large body of water to the lowest point (I.e. towards the pump) It is also true that a system without a res will have the same system but its just easier to set-up with a res. Also having a large body of water means that there is a lot of water for the CPU to heat up before the temperature of the whole system will rise by any amount, if the res is made of metal then it will also act as a radiator in its own right further cooling the water so long as it has a fresh supply of air if it is housed in you systems case. A res can also act as an air-trap, any air in the system will collect in the res and not in other places (remember the whole idea of this is to remove air from the equation until you reach the radiator) if you were to get a bubble of air trapped in the waterblock for instance this could cause you CPU temps to rise considerably.
However having a large body of water in your case can have its bad points, it can take up vital space, finding space for my 1.5 Litre res even in my Lian-Li pc70 was a bit of a squeeze where I put it, but hey it fits and looks cool. Any amount of water in your case will add weight to the whole system remember every litre of water will add 1Kg of weight to the system. So systems can be built both with and without, weigh up the pro's and cons for yourself and see which you want.
^^My custom made copper 1.5 Litre reservoir
Additives: Additives can be used in the water you are using for many different reasons, to make the water coloured or even glow under UV light. You can get additives that will improve the thermal conductivity between the metal surfaces and the water (by reducing the surface tension of the water, the water will "wet" better to the metal surfaces and thus conduct the heat away better) The two main products used for this are Purple Ice, and Redline Water Wetter, these products also help to prevent corrosion of the metal components in the system as well as helping to prevent biological growth such as algae which could really mess things up!!
But wait I hear you say, I’m still relying on fans to cool my system so why is this idea any better. Well I say listen in... The waterblock removes the heat from the CPU much like a normal heatsink this is in turn cooled by the water flowing through it, water is much more thermally conductive than air which is used to cool a normal heatsink and as such it will remove the heat from the waterblock much more effectively you then take this warm water and pass it to the radiator this is very similar to a heatsink. It cools the water by using moving air, but (and this is a big but) the radiator has a MUCH greater surface area than any heatsink and fan you may use and so it can cool the heat taken from the CPU much more effectively. This means you can have a system running more quietly and cooler than a system running just a heatsink and fan.
Misc Parts: There are a few other parts that are totally optional but highly advised, these are some form of clips to tighten around the ends of the pipes whenever they join onto something so that you can ensure a watertight seal. Another nice addition in my mind is an inline temperature probe that can be put in the path of the water so that you can keep an eye on the temperature of the water flowing round your system.
Order of components: There are many schools of thought around the internet as to which is the best order to place components in a water-cooling set-up:
Res->Rad->Cpu->Pump
Res->Cpu->Rad->Pump
Res->Pump->Cpu->Rad
Res->Pump->Rad->Cpu
Those are just a few of them, within a little it doesn’t make much difference once all of the water has been heated a little the temperature of the water in the system will be roughly the same at most points in the system, Usually just go for the route most suitable for your circumstances. Mine is personally set up using method 4 as listed above but all of them are valid routes to go.
For those physics minded amongst us here are some thermal conductivity figures for materials often used in water-cooling (for those not so physics minded just trust me that a bigger number is better, and you will still be able to see what im on about!! Trust me
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So as you can probably work out, in theory a copper waterblock and copper radiator should be the best things to go with (although it also depends upon the design of these units as well, not just what they are made from. A well made aluminium waterblock will out perform a poorly designed copper one, and the same is true for radiators).
All in one or separate: So you have gotten this far, now do you want to build everything inside your case or have the bulk of the equipment outside of the system. Having everything inside is more aesthetically pleasing but may not be possible due to space constraints, having everything inside is also a must if you are a regular LAN partygoer. Having things outside can allow a larger reservoir and better overall cooling especially if you live in the colder climates of the world you could put your res and radiator outside for some really chilly water, however this will seriously affect portability and would require a more powerful pump. You could just settle for having it in a different room or just next to your case on the floor if you like. It all depends on your situation!!
Well I think that covers most of the basics and some not so basic points of watercooling, hope this helps you out Sky and everyone else.
I was only going to post a short piece, than an hour or so later I guess I got a little carried away with myself. Any questions or comments feel free to post them or message/e-mail me, please excuse any spelling or gramatical errors but hey its late... erm i mean early (2:22am :? ). Just as a little extra below is a picture of my water cooled rig glowing nicely in the dark
I don't have any "interesting" facts on air because it doesn't have any fun properties... 
