How to Watercooling -
Watercooling, it is something that just about any PC enthusiast envies and
admires but few are willing to take the plunge and get it. It is cold, it is
quiet, and it looks awesome. To the general population either Watercooling seems
too complicated and risky, or so expensive that you would never consider
spending that money on anything other than a new video card. Times have changed
since the days of “experimental Watercooling” and this guide hopes to help you
put together your own Watercooling system in words and explanations that just
about anyone can understand. To spark your interest note that water is ~30 times
more efficient than air at transferring heat!
I will assume that you know about air cooling, and the principles of general
heat transfer associated with running a stable PC. The CPU (and GPU) of a
computer generate a lot of heat, these days it is so much heat that without
something actively taking that heat away it is very possible that the computer
will lock up, or in the case of AMD processors melt into wasted computer goo.
You need a heatsink to absorb and dissipate that heat, and the more heat you
take away, the cooler and more stable the CPU is. Typically people utilize a
heatsink made of aluminum or copper with some sort of fan attached to get the
air inside the computers case to carry excess heat away from the CPU or GPU.
However, air cooling has its limits and anyone who owns a quality heatsink and a
fan so loud that you can’t sleep in the same house as it knows what I am talking
about. With air you can only go so cold, or so loud before you have to call it
quits. Remember that uncanny ability of water to efficiently transfer heat? Why
not apply those principles in the same ways as air cooling? Watercooling has
been so successful and appealing that many manufacturers have made it easy to
get started with everything from custom radiators to completely assembled
Watercooling systems. The common features between water and air cooling end
there, to cool with water you need to start playing a whole new game (a game
with rules that are quite easy to learn).
You will need some basic elements to put together a water cooling system, one of
which is a computer that isn’t “micro ATX” format ;). These following components
are pretty much shared in all systems but their appearance and application often
times varies greatly.
-Water pump: there are in-line pumps that often also work as “in-reservoir”
pumps. Try to find one that does at least 100 gallons per hour (GPH)
|In-Line pump w/ water flow
-Waterblock: the “heatsink”, get one that is fit for your processor (AMD or P4
|Simpler CPU Waterblock
|CPU Waterblock cut-away
|The internals of another Waterblock
-Radiator: Cools the water, (many
types, shapes and sizes)
|160mm X 80mm Radiator
|Cut away of radiator
- Reservoir: Stores water, (only if you are making a reservoir system)
reservoir w/ UV sensitive liquid
-Tubing: comes usually with an internal diameter of 3/8”, ½” (or sometimes ¾”)
Vinyl and Silicone make the best tubing.
- Clamps and Barbs: these prevent leaks and hold tubing in
|90 degree brass barb
- Distilled water: Does not conduct electricity or contain added minerals. Make
sure to also get something like “Purple Ice” or “Water Wetter” to prevent
corrosion. Water wetter cleans the inside of the system, makes heat transfer
more efficient and also prevents corrosion (it is designed for race-car
radiators!) I do not recommend anti-freeze because to refill you would need to
dispose of all your liquid at some sort of car garage to be safe. Many companies
sell various types of coolants to add to your water. In addition to this there
are cosmetic additives which can change the color of your liquid, or make it
“glow” in UV light. These should not replace other additives to prevent
corrosion unless specifically noted by the manufacturer.
|UV sensitive dye
- Tools: You will want screwdrivers, something to cut hose and an outlet. Other
things you may need or want are sealants, a bucket and potentially some towels
Basic Principles of water
Diagrams of watercooling setups
There are only a few relatively simple components of water cooling, and the rest
are just details. The most important component is the CPU or GPU water block.
This acts just like a heatsink, cool water flows into the Waterblock and takes
away heat and then flows back out into the pump or reservoir. The Waterblock
usually has some sort of internal “water maze” that the water flows through in
order to maximize heat exchange. The maze pattern, or internal structure varies
from manufacturer to manufacturer. The best Waterblocks are made of silver but
they are ultra rare, copper and aluminum Waterblocks are more common and they
seem to get the job done (copper slightly better than aluminum since it is
better at transferring heat.)
Warm water flowing out of the Waterblock makes its way to either a water
reservoir or an inline pump. The pump pushes this water to the radiator. The
radiator is composed of many thin metal fins much like a typical heatsink.
Through these fins travels a winding tube made of some metal, the water flows
through this tube and gives its heat to the fins. The fins are usually then
cooled by air being pushed or pulled (pulling is more efficient) through the
radiator by some sort of fan. From the radiator the freshly cooled water flows
back to the Waterblock. The entire process is actually rather simple; it is the
details that make water cooling appear complicated.
There are two main schools of thought when it comes to water cooling. The
reservoir system and the inline pump system. I will start with the inline pump
system. In the “inline” system there is no water reservoir, all of the water
used in the unit is contained within either the tubing (usually ½” internal
diameter), the Waterblock, the radiator, or the pump. The water is constantly
being circulated throughout these components. One benefit of this is the space;
without a bulky water reservoir all you have to fit in your case is the
radiator, Waterblock, tubing and pump. Pumps are typically smaller than
reservoirs (which are often designed to actually contain pumps). There are two
main drawbacks to this method. One con is the noise, submersible pumps are
typically quieter. Although being “inline” doesn’t necessarily mean that the
system will be loud (it depends on the quality of the pump used).
Another drawback is the “bleeding procedure”. In order to have a self contained
water cooling system without a reservoir you have to have the ENTIRE system “air
free”. Everything must be air tight in order to prevent air from getting in.
This is where the bleeding procedure and the bleeding line come into play. To
fill the system you need to initially fill it under water for some time, in
order to ensure that all of the air bubbles are completely ejected from the
tubes and other components. The bleed tube is an extra length of tube at the
highest point in the system designed to collect the gasses that will eventually
dissociate from the liquid. It also acts as a small extra source of coolant in
the case of evaporation (which if you did a good job you hopefully won’t have!)
To use one you simply have to use a “T” or “Y” tube connector and attach a
length of tube that just contains extra coolant with a plug on the end. This
length of tube ,as you will see later, should be located between the pump and
the reservoir. The point of this entire procedure is to eliminate traveling
bubbles, think of them as blood clots. If they collect in your Waterblock (brain)
then your CPU will potentially overheat, or in the case of your brain, die.
Reservoir systems approach Watercooling differently. First of all, there really
isn’t much of a bleeding procedure. In fact if you want to you don’t have to do
any bleeding at all. You simply immerse the pump within the reservoir and fill
it up with coolant. Before closing off the reservoir it is recommended that you
run the system for a while, adding water until the block is completely full and
you cap it off (this procedure will be discussed in detail later in the guide).
This way air bubbles will really be eliminated or minimized. The last thing you
want is a pocket of air traveling through your tubes, if this were to happen it
would most likely just displace in the reservoir, unlike inline systems where
that pocket of air could potentially be circulated over and over again.
|Notice the pump submerged and
contained within the reservoir unit
You must match components, in several
dimensions. The first step is to find tubing that matches the hookups (or barbs)
as far as internal diameter goes. You will want to match a Waterblock with ½”
barbs to tubing, a radiator and a pump/ reservoir that all share this same ½”
diameter standard. If you were to attach different sized tubing or another
component somehow it would not benefit the entire system; a chain is only as
strong as its weakest link. If a component is of a smaller diameter chances are
your overall flow rate will decline as a result of that bottleneck.
Another factor to be aware of is corrosion. If you have a copper radiator and an
aluminum Waterblock chances are that the electromagnet value of the copper will
steal electrons from your aluminum Waterblock through the water. You don’t need
to know the details of it, just know that there will be deposits and corrosion
throughout the system as a result of the imbalance. However; there are ways
around this. There are chemicals that you can add to the water that prevent this
from happening. You should add some sort of special PC water cooling coolant
additive, water wetter, purple ice or some combination that you see fit. Keep in
mind this applies to your y-splitters and barbs, if they are brass they contain
copper and WILL corrode with time!
People who are into Watercooling have varying opinions about what to use to
actually cool the water. Some people believe in using old radiators from cars,
some people believe in using thick, clunky heater cores and others just use
special radiators designed to work well for Watercooling systems. I will focus
on radiators in this guide for one simple reason. Heater cores and car parts are
often times big, clunky ugly things to have sitting in or around a PC. In these
days of “computer fashion” I believe it is social suicide to plop some big ugly
component right along side your cathodes and LED fans. Although some contend
they may cool slightly “worse” than these other options often times you can find
nice looking radiators that will fit right on an 80mm fan port, or other
standard computer sizes like 120mm or 80x2mm fan ports. Since you will most
likely want to show off your new Watercooling kit to pick up some fine ladies
you don’t want them gawking at your 86 Corvette radiator stuffed in place using
rubber bands and zip-ties!
Powering the Watercooling pump can
accomplished in 1 of 2 ways. Either it will have its own plug that you can run
out of the back of your case, or you will have to Molex it (or wire it directly
into your power supply). What method you use is up to you since they both have
their benefits, that mostly being convenience. Remember: ground your setup in
some sort of surge protector, de-ionized water is not supposed to conduct
electricity but at that wattage there could be some measure of electric transfer
between block and CPU/GPU (this would not be good).
|This reservoir houses it’s own pump.
Note that the plug would be difficult to squeeze out the back of a case.
Some pumps come with plugs that you install once the wire has cleared the
rear of your case.
|Notice how the power cord exits the
rear of the case through a slot
The method of fastening the Waterblock varies, and I recommend only ONE method.
The method I endorse is one that is either designed to specifically fit onto the
socket like a normal air heatsink, or one that screws into the motherboard via
the 4 screw holes surrounding most modern CPU sockets (many utilize a plexi
glass plate and cushion springs for the screws). Other methods involving
brackets and other “sandwiching” devices all too often are fastened unevenly,
break, or apply uneven pressure. For these reasons I recommend you get a
pre-made reliable water block that fastens in a tried and true method. If you
decide to use a sloppy bracket method or something similar do not be surprised
if you crack your core, or worse discover that it has fallen off and your system
is fried. Lastly, use a CPU shim on AMD systems and some form of “arctic silver
thermal compound”. Using a cheap thermal pad or toothpaste will just do to
negate the effects you are trying to achieve by using Watercooling in the first
You will need to avoid the growth of microorganisms. If you are using simply
de-ionized water you aren’t protecting yourself from microorganisms. You might
be laughing now but look at this image taken from the Hard forums (this image
posted by user “Dyrewolfe”). While looking for information on coolants I came
across this gem. The lesson; unless you want nasty stuff like this in your PC
add some coolant or a product like Water Wetter (Incidentally Dyrewolfe noted
that this was the result of “well water”).
What details you deem valuable depend on your personal preference, financial
situation and space to work with. All of the methods work well and you won’t be
disappointed at the upgrade if you work carefully. If you have a little amount
of space yet you want a reservoir system there are products like the “Bay-Res”
that fit a full sized reservoir within a 5.25” bay, likewise if you are tight on
space there are radiators specifically designed to be fit over normal fan bays,
so you sacrifice very little in way of internal case room. Whatever system you
use be careful in putting it together, and remember to test it before you
actually fit it inside your PC.
Deciding What To Buy
Decide on a tubing size, I recommend ½”, you may get better water flow and to be
honest the big thick tubes just look cool! Remember to match all of the
components with this size. You can use silicone or clear vinyl tubing which are
usually both available readily at your local hardware store.
I think a good idea to start with next when putting together a water cooling
system is the radiator. You want to find a radiator that will fit your
application. I use a radiator that is 160mm x 80mm, it fits directly over a dual
80mm air intake. If you don’t have space like this you should find a place where
you can find a ~80mmx80mm radiator. This would preferably be on an intake, so
you are cooling with fresh air. If you mount the radiator on the exhaust you
will use warmer air, although you won’t add slightly heated air to your internal
case temps. The choice lies between a cooler CPU or slightly warmer internal
ambient air temperatures, if you ask me the choice is clear!
|Notice the radiator will be receiving
exhaust type air.
|My radiator fits directly behind this
dual 80mm fan intake
Now that you have a radiator
picked out, and a spot for it you will need to decide between an inline system
and a reservoir solution. Find where you will locate your reservoir, and find an
appropriate pump. I recommend that the pump be at least 100GPH, and remember to
match up the tubing diameter! If the pump is submersible then simply make sure
it fits inside your reservoir, and that the reservoir has the proper openings
for the pump and all of the necessary tubing. If you use something like a bay
reservoir then make sure you have a small enough pump to fit inside, or room
elsewhere in your case to house the pump. The two most recommended pump brands
are Eheim and Danner. Both of these come in many models etc, but you shouldn’t
buy one with more than 300GPH pumping capacity, since given the nature of the
system the bottleneck of the water flow is likely not the pump itself.
Find fasteners and clamps for every junction made between tubing and component.
You will want to close off every single one to prevent leakage. The two basic
types of clamps are pictured below.
|Note: there are other types of clamps
to be found, these I find are the most common and easy to use.
Whatever water block you want is
likely to fit on your motherboard. Some motherboards do not contain screw holes,
and others are blocked off by capacitors etc. You will want to check your
motherboard for compatibility. You will want to find a block that is made of the
same material as your radiator and fittings (if made of metal). Copper blocks
seem to perform the best, but I use an aluminum block coated in silver and it
also performs fairly well. Whatever you do get make sure it has the following
three things: a good method of connecting the block to the motherboard, the
internal metal matches that of your other parts, the fittings match the diameter
of your other parts. For the performance of individual Waterblocks you will
probably need to hit the forums or individual product reviews. Keep in mind you
will see some very basic waterblocks, and you will see much more complicated
expensive blocks: rely on ratings not simply appearances! Another feature to
look for is a smooth surface on the block for the CPU to make contact with, if
it is anything less than a mirror shine you want to look into one with a cleaner
|This Waterblock fastens on using the
usual “push and clip” method common for AMD processors.
There are other ways of mounting radiators and reservoirs. You can mount some
radiators and reservoirs externally, in fact you might go so far as to store
your reservoir in a fridge. As I said before, I am biased towards clean, nice
looking, practical and reliable systems so I don’t usually go for such a huge
mess of tubes and wires. This system is completely externally mounted and
manufactured by a company called “Koolance”.
If you choose to buy a complete kit, this section of the quest will become
rather self explanatory. The kit will likely contain directions, or the
manufacturer will provide them online. My first system was a complete kit and it
took next to no time to put together, test and get installed. And it completely
blew my air cooling set up (Alpha PAL8045 W/ Delta 38 screamer) out of the
water. If you do not have a complete kit, or your manufacturer provided poor
directions then the following should help guide you in the necessary steps and
precautions. Just remember; be careful, and test, test, test!
Since you have an idea of where you want your individual components to go you
will want to cut your tube to fit the application. Remember; cut the tubing a
little long so you don’t come up short. Cut the ends at 90 degree angles, and
when fastening make sure they fit on nice and clean (fastening can be a struggle
at times but it is a necessary evil). The following section will describe
basically where your tubing optimally should go.
Bleeding and Filling
Do not install any of the components into the system yet; simply figure out how
you will attach them, given that the system will be preassembled when you do
finally mount it in the case. Start with the length of tube going from the
output of the pump to the top of the reservoir. The bleed line is optional, but
it should be between the radiator and the pump connected by a T-splitter. Once
that is solidly in place take the output from the bleed and run it into the
radiator. You will want to put the clamps on the tube before you fit them onto
the barbs. Clamp both of these tubes down. From the output of the reservoir run
tubing to the Waterblock, there is a specific way to attach this tubing. Make
the cool water input either to the center barb on the block or to the lowest
barb if the block is horizontal (in that order of importance, if there is a
center barb choose that for the input over the lower barb!) Clamp both of those
down. Next attach the output of the Waterblock to the tubing that will input on
the reservoir or pump. DO NOT CLAMP THIS DOWN YET! This way you ensure that the
freshly chilled water from the radiator goes straight to the CPU. By attaching
the hoses this way I found results several degrees Celsius lower than I did with
the radiator before the reservoir. I also had better results with the radiator
attached to an intake air source versus an exhaust port.
|A close-up of the pump output
connecting to the top of the reservoir
|The input and output tubes from the
*Note: If you are installing a GPU or chipset cooler in addition to the CPU
simply split the cool radiator output into enough lines to transfer cool water
to your GPU or chipset cooler. Run the exhaust from this into the input of the
pump or reservoir by means of reverse Y or W-splitters.
If this is the first time running your
system you will want to flush out all of the components. Submerge the reservoir
and the pump into a vessel containing water (de-ionized or tap will work here).
Now make sure that the input to the reservoir is pointed into a sink to drain
the “dirty water”. Suck on the bleed tube until it fills with water and cap it.
Turn the pump on and you should see that the system completely fills up with
water and pumps it out through what will be going into the reservoir or pump
input. Run it until the water is clear, and then run it a little while longer.
Turn off the pump and drain the system of the tap water.
Now repeat these steps in some vessel containing your distilled water. I
recommend you measure out the amount of water so you can approximate how much
coolant to add to the mix. Make sure the pump input is draining into the vessel
this time so you keep all of the liquid in place. Once you have shaken all of
those pesky air bubbles out and the water is flowing evenly you can think about
adding your coolant to the mix (this will be after about ~15 minutes or so of
component shaking and turning of the pump off and on). Mix in the coolant so
that it flows in the desired concentration. Now making sure that no air gets in
connect the input of the pump/ reservoir under water. Make sure everything is
still copasetic and there are no air bubbles. If this is the case then you are
set for testing! You should dry off everything and run the closed system for at
least a few hours to test for leaks. If everything is fine then you can install
it in your case. Attach everything as you previously planned (making sure to
keep the bleed line elevated if you have one) and then run the system with the
computer off. Test this for a few hours or overnight and see if there are any
leaks, dead pumps or kinks. When installing the components make sure not to rest
tubing on hot objects, or twist and bend them in such a way that they kink. A
kink would seriously impede your water flow and effect cooling and is more
common in 3/8” tubing.
If everything appears to be working correctly do another check.
Do you have thermal compound on the Waterblock, is it fastened correctly?
Are there any kinks or leaks?
Is everything hooked up as you like?
If so it is time to power up. Immediately check your bios for your CPU temp. If
the temperature readout seems reasonable then go ahead and boot into windows.
Using Motherboard Monitor check your temps, do they seem correct? If so it is
time to really test the Watercooling. I recommend Prime 95 to max out the CPU
and get results that really push the Watercooling to its limits. Once you are
satisfied that everything is working well feel free to experiment in
overclocking or whatever else you see fit!
You are probably wondering what sort of results to expect. If your system is
really maximally efficient you should expect idle CPU temperatures to reflect
the ambient air temperature in your room. I have seen steady idles as low as 13
degrees Celsius in my set up, and this is probably due to some of the cold air
my intake sucks from the winter outside. However, these temps don’t stay that
low and will rise with CPU activity. Expect your max temps to drop significantly,
as mine are typically lower than 45 degrees Celsius even when overclocked.
Expect an average CPU temperature that reflects an average ambient room
temperature (or slightly warmer if your radiator is hooked up to exhaust air).
If your radiator is hooked up to an exhaust then you should expect your CPU
temperatures to reflect that of your internal case environment. This can be
drastically warmer and is the reason why I recommend cool air intake for the
radiator. If your results are not like this then chances are you are doing
something wrong. In my experience if you take your time and do things right you
can expect very good results like this from a system with 3/8” tubing, a
reservoir and aluminum block. Make sure you are monitoring from on socket
sources, and not diodes. Diodes typically are not as accurate as on socket
sources, and will typically display a temperature that is cooler than the actual
core by a few degrees. While it may not matter for the average user, it can
become rather important if you are overclocking! On a similar note, be aware of
mechanical failure. Just as a CPU fan can die, a pump could potentially die. Use
precautions against disaster. By using a program like
CPU idle you can not only
lower your overall temps but you can make sure that if your CPU reaches a
certain temperature it will shut down the computer. Be safe, have fun and don’t
go frying too many CPUs.