Deafboy's Water Cooling FAQ and Information

[deafboy]

Watercooling FAQ and Information

Figure we should have a thread that discusses water cooling as a whole, what to look for, and answers to frequently asked questions.

I am by no means an expert when it comes to water cooling but thought I would at least try to share some of the information that I have come across over the years. Please feel free to correct me if I am wrong. I AM NOT AN EXPERT, WATER COOLING CAN BE DANGEROUS AND CAN DAMAGE COMPONENTS, DO SO AT YOUR OWN RISK. I AM NOT RESPONSIBLE IF SOMETHING HAPPENS.

This is simply a start, I will try and add things as things go. I am hoping the whole, editing post issue, will be fixed soon so I can keep the posts up to date. If there is anything you think I am missing or should add, please let me know and I will do what I can.

Firstly I suppose I should start out with what water cooling is. Water cooling is just that, cooling using water. Simply it is using the flow of water to move heat away from components.

Watercooling Jargon:

Will go into more detail about each later on.

Water block: Pieces of metal used to transfer heat from the computer component to the water. Often made of copper or brass and can be found plated in various metals such as nickel.

Thermal Interface Material (TIM): TIM, often called Thermal Paste, is a solution used between two components to aid in transferring heat between both surfaces. It’s sole job is to fill imperfections on the chip and the water block.

Radiator: Essentially a collection of tubing with fins on the outside to generate surface area to dissipate heat.

Fins Per Inch (FPI): FPI refers to the number of fins found per inch on a radiator. More fins the more surface area the more heat can be transferred.

Static Pressure: is the resistance to flow, often measured in inches of water. Used to describe the energy added by a fan. Measured perpendicular to airflow.

Pump: Device used to move water via an impeller.

Fitting: Object that allows all the objects in the system to connect, often via tubing or pipe. There are many types, such as barbs, compression, push lock, and so on.

Reservoir: Object that holds the liquid in the system.

Pump Top: Object to improve or add features to a pump.

Flow Rate: The rate in which water is moving through the system.

Restriction: Is often used to describe how restrictive certain objects are in the loop, ie how objects affect the flow rate and other metrics.

Series: Often used to describe multiple pump setups, where a series setup is pumps running in serial (back to back) with one another. ie. one pumps out port is feeding into another pumps inlet port. Essentially combining their head while maintaining the same flow rate

Parallel: Often used to describe multiple pump setups as well as water blocks, where a collection of objects (pump, water block, etc) are arranged in parallel, ie one reservoir is feeding into both pumps simultaneously or feeding multiple waterblocks at the same time. Essentially combining their flow rate but maintaining the same head.

Loop: Is used to describe a collection of water cooling parts. ie reservoir -> pump -> water block -> radiator -> reservoir.

Thermal Capacity: Thermal capacity is often used to describe the amount of heat a system can sustain, ie, how much a radiator can dissipate.

Delta: Used to describe the difference between temperatures in the system. ie, the difference in water temperature over the ambient temperature of the room or the difference in temperature from idle to load.

Bleeding: Term to describe the process of removing air from the loop.

Fill Port: An object used to add fluids to the loop.

Quick Disconnect (QDC): A type of fitting that can be connected/removed without having to drain the loop.

Figuring out what you need:

This one is almost impossible to give a generic answer to as it depends heavily on what you want out of your loop, both in terms of performance but also aesthetics. If you are just starting out there are many kits available that come with everything you need to make a loop.

I am just going to give a general description what you should look for.

First thing you should pick out for your loop are the water blocks. What waterblocks you chose will help you narrow down what pump and fittings you should get. Some blocks are more restrictive than others and require a stronger pump to maintain effective flow rates. For most loops, this won’t be a main concern. The only time you really need to worry about restriction are on big loops with multiple blocks. Some people say you need to keep it in mind for radiators but most radiators these days aren’t very restrictive. When looking for a block, you should try and find reviews about the blocks you are looking at. It’s hard to judge a block by it’s cover as the internal provide the most information about how it transfers heat and how restrictive it is. Generally speaking, it’s safer to avoid blocks that have plated materials as plating (if done poorly) can flake and cause issues within the loop.

Next thing to look for are radiators. Depending on how much you need to cool, you will need more/less radiator space. More space is certainly better but there is a threshold where gains will greatly reduce. There are many things to consider when looking at radiators, firstly you will want to be away of the FPI. The greater FPI the better static pressure you will want and often the louder your system will be but the greater FPI the more heat can potentially be transferred. This can often be made up for radiators that have a lower FPI count but thicker. These types of rads don’t require as high of static pressure and can often be ran with slower fans, making them a quieter solution. Next thing to consider is the size itself, often described by the size of fan used on it. The larger the radiator the bigger the thermal capacity of the system but leads to issues of fitting in the case.

Next up, fans. Now that you know what kind of radiator you are using now you can chose fans that best match that type of radiator. You will want something with good static pressure regardless of the FPI count as the fans still need to push air through something. Unfortunately I don’t know of any tried and true method of picking the best fan, you best bet is to read reviews and see what works best with your type of radiator. You’ll need to find what has good static pressure while fitting your price point, your noise level acceptance, and overall performance. Scythe Gentle Typhoon AP-15’s are generally accepted as the best all around performer at lower noise levels while Yate Loons are often accepted as the best budget static pressure fan, be aware though, there are knock off’s out there.

Last major thing to consider is pumps. For most it comes down to a handful of pumps. It’s generally accepted that the Laing D5 and it’s variants are the best quiet pump and built to last. The D5 is a repurposed pump used in other applications and incorporated into PC water cooling. It’s a great pump that is for those with a small loop and want silence. The D5 isn’t great with larger, more restrictive loops though, which is where the 35x and 35x2 (2 35x pumps with combined pump top) comes in. They are smaller and better for more restrictive loops. The D5 is cooled by the loop while the 35x/35x2 essentially require additional cooling via heatsinks/fans. There is also the PMP-500 (what I use) and others but those two are the main contenders that most people are familiar with and are known performers.

Lastly we come to tubing, fittings, and reservoir. These come down to personal preference. I always tell people though if they are going to go with tubing to use tubing that is slightly smaller than their fittings to ensure a tighter fit. Example, use 7/16 tubing on ½ fittings. It’s often a snug fit, sometimes requiring the tubing to be warmed up to slide over, but the benefit is it’s almost guaranteed to never leak or accidently pull off.

For reviews, it would suggest checking out martinsliquidlab.org however, xtremerigs.net recently has done a very extensive review on CPU waterblocks.

Planning your loop:

Loop order: Reservoir -> Pump -> everything else -> Reservoir.

I’m sure you’ve noticed the everything else and maybe a little confused. It’s been discussed over and over again, and it’s pretty much been proven every time that what happens in the middle doesn’t really matter much. Once you’re done you’ll have a closed loop and the temperatures will come to an equilibrium in a short amount of time. There is no need to do something like (1) if you can have something like (2) that is shorter/cleaner:

(1) reservoir -> pump -> water block -> radiator -> water block -> radiator -> reservoir

(2) reservoir -> pump -> water block -> water block -> radiator -> radiator -> reservoir

Your goal should to have a clean short loop. Having a short tidy loop will help performance because your pump can only do so much because it’s has a limited amount of head. The longer your loop the more your pump has to work and you’re simply adding restriction while lowering the flow rate (you want 1 GPM, anything beyond 1.5 or so is excessive and can actually worsen temps in some cases).

[deafboy]

Flush your parts!

You might be tempted to put your parts together right away, but fight that urge! You need to make sure your parts are clean first.

You’re thinking to yourself, “But deafboy, how can by parts be dirty? They are brand new! What happened to them?!?!â€

The main components you need to worry about here are your radiators. While they might be new they are often not clean. This is because of how the radiators are produced, there can be left of flux/solder from the manufacturing process. For this I am just going to reference martin’s website since it’s the exact process I use.

http://martinsliquidlab.org/2011/02/26/flushing-your-block-rads-clean/

Leak Testing:

Once you have all your parts together, be sure to leak test. What is leak testing? Exactly like it sounds, you’re testing for leaks in your system!

What should you fill your loop with? This can go back and forth all day. The main part of your coolant should be pure distilled water. Don’t use tap or drinking water. You can use biocide, dye, kill coils, or whatever you want. I personally only use distilled water and a kill coil.

Slowly fill your reservoir with your coolant, generally I tell people to fill the reservoir about 75% full and then turn on the pump to let the water circulate. BUT WAIT!

Before you start leak testing, be sure nothing is plugged in except for the pump. You don’t want your motherboard, gpus, hard drives, etc plugged in just in case there is indeed a leak in your system. Plugging in the rest of the components is pretty much the very last step.

Alright, now that is covered, back to leak testing. Place some paper towel throught the case near fittings, blocks, and radiator. These will be used to help find leaks if there are any and keep as much water away from the components as possible. Once you have paper towels laid out and you have water in the reservoir you are going to do an initial check for leaks. Gravity is going to do some of the filling for you so just keep an open eye for any water coming out of the system. Presuming you don’t have any leaks you are going to start a process of turning the pump on, turning it off, filling the reservoir, and repeating. While doing all of this, keep an eye out for leaks. Turning this process you might think your pump is broken as any air in the pump causes them to be quite loud. This is perfectly normal and don’t freak out. Just be sure that the pump has water and isn’t running dry. RUNNING THE PUMP WITHOUT WATER WILL DAMAGE THE PUMP!

Repeat the process until the water level somewhat stabilizes. When you can no longer add water, close the fill port/reservoir and let the system run for a while. If you can gently move the entire computer side to side, back and forth, to help knock some of the air bubbles out all the while keeping an eye out for leaks. If your pump has the ability to change speeds, turn the pump up and down to help change the flow rate. If you can’t adjust the speed, turning it on letting it run and then turning it off can have the same effect. We simply want to help work the air bubbles out of the system.

Once you have gotten all the big air bubbles out, let the pump run for a while to let itself work out the smaller bubbles, be sure to check on it every now and then for leaks.

After the system has been running for a while and you haven’t had any leaks, it’s time to plug the rest of the computer components in and turn it on. I generally leak test for 12-24 hours before plugging in and powering the computer.

ENJOY!

Words of Warning:

Do not mix metals without researching. If you have any copper/brass parts in the loop you should not have any aluminum parts in the loop, these metals do not like one another and can speed up galvanic corrosion.

If you have parts that are plated, be sure to keep an eye on them as parts as of the past several years have had plating issues causing the plating to flake off the base metal.

[Optimus Prime]

Very informative, definitely an article I'm going to refer to when I build my loop later this year.

Just a quick question in relation for FPI of rads and rpm of fans, any chance you could add a section talking about for example rads with a fpi of 10 or less are suited for fans of xxxx rpm with good static pressure?

[deafboy]

Very informative, definitely an article I'm going to refer to when I build my loop later this year.

Just a quick question in relation for FPI of rads and rpm of fans, any chance you could add a section talking about for example rads with a fpi of 10 or less are suited for fans of xxxx rpm with good static pressure?

It's not quite that simple but I can certainly discuss that if you'd like. Will get that written up and added when I can :)

[Helltech]

Oh you're on these forums also? You have helped a lot on OCN. Thanks for the informative guide.

[deafboy]

Oh you're on these forums also? You have helped a lot on OCN. Thanks for the informative guide.

Figured I might as well join here, lol. Thanks :)

[MalenskiiPC]

Awesome guide, this deserves a sticky. :D

[Leviathan7895]

@deafboy; Nice to see you on these forums as well as OCN. I been following your build log on your TJ07, and it's looking great, keep it up! Your 670 blocks will get there sooner or later :)

[deafboy]

@deafboy; Nice to see you on these forums as well as OCN. I been following your build log on your TJ07, and it's looking great, keep it up! Your 670 blocks will get there sooner or later :)

Thanks :) If the blocks aren't here tomorrow USPS will have a raging giant to deal with, lol.