In recent years, "water cooling PC's" are more and more common. Water cooling replaces noisy and low performance air fans and delivers efficient cooling solution for processors, video cards, motherboard chipsets, memory, power supplies and hard drives in personal computers. Water cooling allow extremely high overclocking and can make computer much quieter, some "water cooling systems" even silent! "Water cooling systems" were up until the late 90's homemade. They were put together using car radiators and aquarium pumps and home made water blocks. Today, a growing number of companies are manufacturing premade, specialized components, allowing water cooling to be compact enough to fit inside a computer case. Water is some twenty five times more efficient than air at conducting heat, which makes it an obvious choice for cooling all manner of hot running computer components. Water cooling is getting cheaper, safer, increasingly compact and more aesthetically pleasing by every day. The whole premise of liquid cooling your PC is now more viable than ever before, and with the trend for ever-increasing cooling requirements showing no signs of abating, it might be a case of when rather than if you make the switch to the "water cooling PC".
CPU Water Block - very important part of "water cooling PC". CPU (central processor unit) creates most of the heat in the system and most of the power of the computer rely on the processor. Heavy load on the CPU, like compiling DVD or working with huge size photographs in Adobe Photoshop will increase temperature of the unit and will increase temperature of whole machine generally. The waterblock is mounted to your CPU in order to remove the heat it is creating. It is very important to buy a good waterblock.
Pump - an aquarium pump was OK a few years back, but fortunately we have more options lately. Instead of running another 110/220 Volt power cord near or inside the "water cooling PC", we can use 12V DC pump specially designed to fit and work inside computer, taking power from computer's power supply. The pump will circulate the cooling water in your system. The pump’s gallons per hour (GPH) rating and its life span are very important things to look at. Also pump's maximum head rating (MHR) is what we can't overlook. GPH is a measure of flow rate. This is used as the measure of the amount of fluid flowing through a tube or emitter in one hour if nothing is restricting the flow of the cooling water, and the pump is not pumping the water against gravity. MHR refers to gains or losses in pressure caused by gravity and friction as water moves through the system. It can be measured in lbs/in2 (PSI) but is most commonly listed in feet of water the pump is able to push above the pump.
Radiator - or heat exchanger in other words. It's a device that cools the liquid in the "water cooling system" by allowing it to circulate through a series of water channels.
GPU Water Block - does the same job as the CPU water block, but is used to cool the graphics card.
HDD Water Block - again does the same job as the CPU & GPU water block, but is used to cool the hard disk drive.
Coolant - a fluid agent that produces cooling; especially one used to cool a system by transferring heat away from one part to another, in our case transfer heat from water blocks to the radiator. In "water cooling PC" we use distilled or de-ionized cooling water.
Tubing - makes a road for coolant transfer between the water blocks and other parts used in "water cooling PC". Commercially sold tubing comes in three different materials. PVC, Silicone, and Tygon. Tygon is the most expensive, and is a very clear in color. It is very strong, and very kink resistant. Silicone tubing is a milky color, and extremely flexible. It's made of very soft rubbery material, which is ultra flexible, and can be bent into very tight curves without it trying to spring out again. Silicone tubing is by far the easiest material to work with, and is highly recommended for your "water cooling system". PVC is the cheapest tubing that is sold specifically for water cooling. It is very strong, but very inflexible. PVC tubing is not recommended for "water cooling systems" that will need tight curves in the hose, and it can sometimes make it very difficult to install the waterblock.
Clamps & Fittings - used to connect tubing to water blocks, pump and radiator. You may need adapters to make, for example, a 1/2 inch hose fit on a 3/8 inch waterblock or vice versa.
Reservoir - a water cooling reservoir is essential for a properly built "water cooling system". A reservoir will increase the cooling power of your system by increasing the amount of water in the system, and therefore the amount of heat the system can dissipate.