I've received alot of queries on how to choose parts for a DIY watercooling setup and what kind of cooling performance is expected. I've decided to write a quick guide for the benefit of everyone who wants to make a foray into watercooling and here it is.
1.1 - The Basics:
For most watercooling setups, the basics required are the same. You need a pump, a reservoir, a radiator and a CPU waterblock. On top of these, you will require some accessories like fittings (nozzles or barbs to some people) and also tubing as well. Finally, while you can run straight distilled water in your watercooling loop, it is generally recommended to add anti microbial additives to prevent the growth of algae, fungus and other nasties. These will be covered in detail in later sections.
1.2 - The Not So Basics:
Other parts including the motherboard (Northbridge, Southbridge, Mosfets, etc), the GPU, and even every other component you can think of like the HDD, RAM, PSU can also be watercooled. Most people don't go so far though, usually only to the extend of cooling the motherboard and GPU. These will be covered in detail in later sections.
2.0 - The Parts:
This section deals with the parts involved in watercooling.
2.1 - Pumps:
The pump is the heart of any watercooling system, which pumps the liquid around the entire loop. The movement of liquid helps the water to pick up heat from the CPU block carrying it to the radiator where the heat is removed. There are very few pumps in use in watercooling loops and virtually any watercooling setup I know of uses the same 2 pumps (though there are alternatives of course). The Laing D5 and the Laing DDC. Swiftech also rebrands these pumps as the MCP-655 and the MCP-355 respectively. These 2 pumps utilize a simple spin impeller design that takes in water from 1 outlet and spins the water out from another. In some situations, it is not uncommon for 2 or even 3 pumps to be present in a system to overcome the restrictions from multiple blocks (CPU/Mobo/GPU/etc).
Commonly used with pumps are pump tops meant to replace the original tops of the pumps. Generally these pump tops provide better flow rate or pressure, especially in the case of the MCP355. Aftermarket pump tops can improve flow rate by as much as 100% and is a worthy investment for any loop. Some replacement pump tops are integrated with reservoirs such as the very popular XSPC Reservoir Top for the MCP355. Costing around half as much as a MCP355, it greatly improves pump performance and doubles up as an extremely space effective reservoir.
2.2 - Radiators:
The radiator is where heat is removed from the liquid in your watercooling system. In many ways it is similar to heatsinks used in aircooling systems, heat is transferred to the fins and air (usually a fan is used) then flows through the fins carrying heat away. In most radiators, water flows from one inlet/outlet to another via various narrow channels which are covered in fins. These fins absorb the heat from the channels directly, cooling the liquid within the channel. In most radiators, there is no distinction between inlets and outlets and you can therefore use them in any configuration. The most common radiators utilize 120mm fans and can therefore be mounted directly onto most casings without any modifications. Other radiators are also available that utilize 80mm or 140mm fans instead.
Push or Pull? While fans in pull were thought to be better for a long time, it was recently revealed that pull is only better for slow or undervolted fans (up to around 1000 RPM). Beyond that push has a significant advantage. Adding a shroud also always significantly improves performance and yield the following results in descending order:
BEST
Push(w/Shroud) + Pull (w/Shroud)
Push(w/Shroud) + Pull
Push + Pull
Push(w/Shroud)
Push
Pull
WORST
2.3 - CPU Blocks:
The CPU block replaces your aircoolers on top of your CPU and its primary purpose is to transfer heat from the CPU to the liquid in your watercooling loop. CPU blocks tend to be the most restrictive components in your loop, greatly reducing the flow rate of the liquid. This is however only a concern in complex loops where multiple blocks (like GPU/Mobos/etc) are used.
2.4 - Reservoirs:
The Reservoir's primary purpose is to provide easy access to fill or even drain the loop as well as an important show piece since the liquid in it is highly visible in most setups. Most reservoirs feature both top and bottom caps to allow a user to fill and drain a loop. At least 2 threaded holes are also usually present to be used as an inlet and outlet. Some radiators also feature integrated reservoirs so you are able to fill the loop directly from the radiator. However, it is usually not possible to fill a loop fully through the radiator and will result commonly in trapped air that is undesirable but such reservoirs/radiators combos are very useful when space is a concern. Another alternative is the use of a T line to fill a loop, essentially using a section of tubing as a mini reservoir. Some reservoirs in the market can also be mounted in the 5.25" bays such as the EK Spin Bay Reservoir.
2.5 - Motherboard Blocks:
Motherboard full-face blocks are like CPU blocks but are far less restrictive. The exact components they cool depends on the block itself but usually cover at least the Northbridge and part of the mosfets areas. Additionally, the Southbridge might be cooled together as well for the sake of a complete look though usually only passive air cooling is required for it. Also available are generic Northbridge cooling blocks that fit most motherboards that have somewhat fallen out of favour these days as they are usually lacking in the visual department.
2.6 - GPU Blocks:
GPU blocks cool your graphics card and there are 2 main types widely used.
The first (and more expensive option) is a full face GPU block. It covers nearly the entire length of the card cooling the GPU core, RAM, VRMs etc. These blocks can also be chained using special fittings in the case of a multi-GPU setup.
The second is using a generic GPU block which fit most cards and can be used in combination with either generic or custom made heatsinks that fit over the non-covered areas. It is important not to neglect cooling the non-covered areas which can easily lead to damaged cards.
2.7 - Tubings:
Tubings are a continued source of confusion for most people new to watercooling but the concept behind it is a simple one. Every tubing has 2 important dimensions that you should worry about. The first is the internal diameter, this is the diameter that the water flows through. The second is the external diameter, this is the diameter after adding the thickness of the walls of the tubings.
For example, a 3/8" inner diameter tubing with 1/8" walls would have an external diameter of 5/8". This is because when you view the cross section of a tubing, you'll have to count the walls on either side of the tubing. Thus 1/8" + 3/8" + 1/8" gives you a total of 5/8". If this confuses you, then simply concern yourself with 2 numbers instead: the inner diameter which is 3/8" in this case and the outer diameter which is 5/8".
In choosing your tubes, a couple of factors are usually considered. First of all, a larger inner diameter tubing will result in better flow rates. However, the downside is that these tubings usually require a larger turning radius so as not to kink. The brand and model of these tubings also affect the likelihood of kinks and is an important consideration. Aesthetics also play a part with colored and UV reactive tubings available and even clear tubings with varying characteristics like their tint, likelihood to yellow or cloud over time and so on.
2.8 - Fittings:
There are more fittings that I can list here but the most important fittings are the ones that allow the connection of your tubings to the other parts like radiators, blocks and so on.
The most basic fitting, which acts as a nozzle for your parts is straight forward. The tubings slip on top of the outside of the fittings so the outer diameter of the fitting must match the inner diameter of the tubings. However, it is sometimes popular to use smaller diameter tubings to secure a tighter fit over the nozzles. Hence it is not uncommon to see setups which utilize 7/16" ID tubings with 1/2" fittings. Also after tubings are put in place, most people will use a tiny clamp meant for tubings to clamp the tubings onto the nozzles to prevent leaks. These clamps are commonly known as worm clamps, herbie clamps and various other types are available as well. The widespread usage of these clamps led to another type of fitting discussed below.
Compression fittings which featured an integrated clamp featured an extra ring that screws onto the fittings over the tubings. Compression fittings ensure a leak free connection where your tubings join the nozzles. However, compression fittings have very specific tubing requirements as compared to regular nozzles. In particular, it has a specific requirement for both the inner and outer diameter for your tubings which must match up exactly. That is to say, a compression fitting meant for 3/8" ID, 1/2" OD tubings will not work on 3/8" ID 5/8" OD tubings. This is in contrast to regular 3/8" nozzles which fit any tubing of 3/8" ID.
Also, there are many various other kinds of fittings like SLI connectors which allow you to chain up your GPU blocks, 45 degree adapters to allow better routing of tubings. In the future I will list down the common ones and what they're used for.
2.9 - Coolants / Additives:
There are 2 main options when it comes to choice of liquid for watercooling
Option 1: Distilled water + biocide. Distilled water is one of the best known liquid conductors of heat (other than the highly toxic mercury) and if used pure can give one of the best performance in a liquid cooling system. However, growth of algae or fungus is not uncommon when the loop runs for several months untouched hence it is recommended that some form of a biocide be used. These can range from silver coils left in the loop, to a few drops of certain chemicals very toxic to micro organisms. There are also concentrated bottles of biocide/coloring agents that you can add to your loop like the Swiftech HydrX.
Option 2: Using pre-mixed coolants that usually come in a litre bottle which you add to your loop directly without the need for other additives. These pre-mixed coolants come in both clear and colored (and UV reactive) variants and are sometimes touted to be non conductive so your hardware is safe in case of leaks. Take these claims with a pinch of salt however as even if they're perfectly safe out of the bottle, any contaminants can easily make them conductive. Its best to not have to deal with a leak on your hardware in the first place.
There also are reports of both pre-mixed and concentrated additives losing their color over time and these coloring tend to be deposited all over the loop, especially in the waterblocks. If regular (every couple of months) maintenance is not your thing, distilled water would be a smarter if less aesthetically pleasing solution.
3.0 - Loop Configuration
There has been much debate over loop configuration but from experience as long as the reservoir is placed directly before the pump, the placement of the rest of the components do not have a great impact on overall temperatures.
Popular recommendations include placing high restriction parts closer to the pump and in most cases that would be the CPU waterblock.
4.0 - Buying Guide:
This section will contain approximate reference prices from my store. In some cases it might be cheaper to order directly from overseas for certain components, warranty issues and waiting time not withstanding.
Watercooling Kits:
There are kits from companies like Swiftech (~$400) & XSPC ($150~$190) which comes with everything you need to setup a full WC system including tubes, biocides, waterblocks, radiators, reservoirs, pumps and fittings. These kits often offer similar performance to parts available separately yet cost only a fraction of the total cost, the only downside being you can't choose the exact components you want.
5.0 - Common issues:
5.1 - Bleeding:
Bleeding refers to the process in which air is removed from a watercooling loop, usually by running the pump for several hours up to several days. During this time, air trapped in components like the CPU block, radiator will be pushed towards the reservoir where it can bubble up, gradually reducing the amount of air present in the loop. During bleeding, it is common for the loop to be noisy or gurgles to be heard.
Some loop configurations are inherently harder to bleed (like a top mounted radiator) and it will sometimes help to tilt the casing in different orientation to hasten the bleeding process.
5.2 - Corrosion:
6.0 - Common terms encountered in watercooling:
TO BE CONTINUED
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