PC & Peripheral Reviews

Under The Hood: The Beginner's Guide To Water Cooling Computers

I used to think a truly high-performance computer meant lots of fans, lots of noise and limited speed. Then I discovered water cooling. If you really want to overclock your PC and push it to the brink of its power, water cooling is the best way to make that happen while keeping it whisper quiet.

Music by Eric Skiff.

Why Water Cooling?

Water has a high thermal conductivity, which means it absorbs heat very easily. That makes it a great candidate for cooling your system.

Water cooling works by running water over each of your components, transferring heat from each part to a radiator that dissipates the heat and keeps the water cool — almost exactly as your car’s radiator does. This lets you cool your processor, graphics card and other hardware more effectively.

We’ve talked a bit about water cooling before, but prebuilt systems like the Corsair Hyrdo Series can only take you so far. They’re certainly quieter than most air coolers, and they’ll definitely give you lower temperatures than your PC’s stock fan, but if you really want silence and low temperatures, a homebrew water loop is the best way to do it.

Water cooling is particularly useful for people who perform resource-intensive tasks such as video editing and gaming. Not only will it keep your hardware cooler during heavy loads, it offers lots of headroom if you decide to overclock your system, giving you the most power possible out of your components.

Water cooling isn’t without downsides. It has long been an enthusiast-only endeavour, mostly because of its high cost and complexity. However, you can buy all-in-one kits that cut your cost in half, and eliminate the hours of research you’d otherwise have to do finding compatible parts. Below, we’ll show you all the parts you need for a water-cooling setup as well as how to put it all together. Check out the video above if you want to see it in action, then head to the how-to below for more detailed instructions.

What You’ll Need

We’re using this XSPC Raystorm RS240 all-in-one kit. You can buy your components separately if you choose, but the cost can jump quite a bit. The parts you’ll need include:

  • Waterblock: This is the block that you mount on the hardware to be cooled. In this guide, we’ll just be cooling our processor, but you can also find waterblocks for your graphics card, chipset and other components. Note that while waterblocks for RAM and hard drives exist, they’re not really necessary and won’t give them much of a performance boost — water cooling is most useful for the processor and graphics card.

  • Radiator and Fans: The radiator, coupled with its attached fans, is what actually keeps the water cool as it flows through your loop. Radiators come in multiple sizes, usually designed for a certain number of fans. The larger and thicker the radiator, the more effectively it will be able to dissipate heat. Our radiator is a 240mm fan (meaning you can attach two 120mm fans to it), but you can get smaller one-fan radiators or large four-fan radiators. If you have a large enough case, you can mount them inside your computer, but smaller cases will usually require you to mount them externally.
  • Reservoir: Your reservoir is what holds the liquid in the loop, and makes bleeding out bubbles easy. Most reservoirs require you to mount them inside your case using provided hardware, though some (like the one we’re using) are designed to mount inside your 5.25-inch external drive bays.
  • Pump: Your pump is, obviously, what pumps the water in your loop. You can buy an external pump or a pump that attaches to certain reservoirs. In our case, we’re using a pump that’s built-in.
  • Fittings: You’ll need two fittings for each component in your loop — the waterblock(s), the radiator(s) and the reservoir. These are what actually allow you to connect them to one another with tubing. You can use barb fittings, which are just a spout, or compression fittings, which contain a second piece you screw on for a super tight fit. Compression fittings are better looking but more expensive.
  • Tubing: Your tubing is what connects each component together, and it comes in multiple shapes and colours. When you buy tubing, make sure its inner diameter (ID) and outer diameter (OD) are compatible with the inner diameter and outer diameter of your fittings. Usually this means they should be the same size, but in some cases your tubing can be slightly smaller than your fittings if you want a tight fit.
  • Coolant and Additives: Lastly, you’ll need a coolant, and you’ll have to buy this separately even if you get a kit like the one mentioned above. You can buy all sorts of coolants with different properties, but we’re partial to distilled water. It’s just as effective as anything else, but it’s super-cheap and has less of a chance of causing problems. You’ll also want some additives for your coolant, which can include but are not limited to:
    • A biocide, which keeps algae and other gunk from growing in your loop. PT Nuke is a popular brand. Alternatively, you can use a small piece of silver called a kill coil, since silver acts as a natural biocide. This is nice because it doesn’t require you to add extra liquid to your coolant.
    • An anti-corrosive, which is only necessary if you have multiple metals in your loop. Our loop contains a copper waterblock and a copper radiator, so we don’t need this. But if you used a copper block with an aluminium radiator, for example, you’d want an anti-corrosive like Fesser Base in your coolant.
    • A drop or two of dishwashing liquid, which acts as a surfactant and can help you get rid of bubbles in your loop.
    • Colouring, which we don’t recommend using. Colour additives have a tendency to gum up the works, so if you want colour, we recommend getting some coloured tubing instead.

If you’re buying all your parts separately, make sure to triple-check that everything is compatible. If you’re unsure, ask around on forums like Tom’s Hardware or Overclock.net. I also highly recommend checking out DazMode’s complete guide to water cooling on YouTube, as it’s incredibly informative on the finer points of each component.

How To Put It All Together

Once you’ve decided on all your parts, it’s time to put everything together. The process is a little involved and can be pretty scary at first — but as long as you go slow and follow the instructions, you should have a safe water loop running in no time. Again, to see the process in action, check out the video at the top of this post.

Step 1: Plan Out Your Loop

Before you do anything, look inside your case and plan out how your loop is going to work. Figure out where you can mount your reservoir and pump using the included hardware, decide where your radiator is going to sit, and in what order you’ll connect all the parts.

Your reservoir should sit right before your pump in the loop, so the pump never runs dry. If your reservoir isn’t built for a drive bay like ours is, you’ll need to either mount it on your case with the included hardware, or find a spot to velcro it in place. The hard drive cage is often a good candidate for this.

Once you’ve figured out where all the parts go, decide how you’re going to run your tubing. From the pump, you can go to your radiator, then your waterblock, then back to the reservoir. Alternatively, you can go to the waterblock first, then to your radiator and back. Neither provides a clear performance improvement over the other, so do whatever looks good to you and fits easily.

Keep in mind you may have to tweak this setup once you actually start connecting your tubing, but at least get a good idea of where you expect everything to go.

Step Two: Rinse Out Each Component

Next, collect all your hardware and rinse it out. For your waterblock, tubing and reservoir, this is as simple as just running some distilled water through it and dumping it out. Your radiator, however, is a bit more complicated. Radiators can often come with a bit of debris left over from manufacturing inside, so you’ll want to give it a very thorough rinse before you hook it up.

To do this, heat up some distilled water and pour it into your radiator, filling it up about two thirds of the way. Plug up the holes, and then shake it vigorously for a minute or two. Dump the water back out into a bowl, and you may find that a lot of debris comes out with the water. Repeat this process until the water comes out clear.

<3>Step 3: Install Your Hardware

Now that everything’s clean and ready to go, install your main components. The waterblock will mount to your CPU the same way any other cooler would: add a dab of thermal paste to the CPU, set the cooler on top, attach the backplate to the back of your motherboard, and screw it into place. When you screw it in, make sure to only give each screw a few twists at a time, moving in a star pattern so that pressure is applied evenly to your processor.

If you have a big enough case, you can mount the radiator just by mounting it on the vent where your fans usually go, then screwing the fan to the radiator itself. If you have a larger case, you’ll likely mount it in the bottom. If neither of those are an option, you’ll need to mount it externally using the brackets that come with it.

Mount your reservoir and pump using velcro or the mounting hardware that come with them. If you have a bay reservoir like the one we’re using, just slide it into place and screw it into the sides like you would a DVD drive.

Step 4: Connect Your Tubing

Now that everything’s in place, it’s time to connect it all with your tubing. Screw your fittings into each component, making sure they’re good and tight before you continue so you don’t spring a leak. I like to screw them in finger-tight, then give them a small turn with a spanner or pair of pliers to make sure they’re snug.

Now, start connecting your tubing. Slide one end of your tubing over a fitting, then measure how much tubing you’ll need to connect it to the subsequent component in the loop. Mark it with your finger, and cut the tubing with a pair of scissors. Cut it as straight as you can. Connect that end of the tubing to the next component, and repeat this process with each piece of hardware. Make sure you’re connecting the tubing to the correct fitting each time — your blocks, pump and reservoir should each have a designated inlet and outlet. It won’t matter which holes you use on your radiator.

You may find during this step that the tubing makes too sharp a turn, and kinks. This is bad for your water flow, so you need to return to the planning stage and see if there’s a way to make that bend without a kink — sometimes giving yourself some extra tubing solves the problem, but you may need to connect your components in a different order. To disconnect tubing from your fitting, you may need to slice it with a razor blade where the two connect — pulling them off is often very hard to do.

Step 5: Fill Up Your Loop

Once everything’s connected, it’s time to fill up the loop. Some people recommend removing the loop from your case and testing it on its own, but I prefer to test it inside the case. If you test it outside the case, you can still spring leaks by moving it back in, so it doesn’t give you a lot of extra security against leaks. As long as you do everything slowly and correctly, you shouldn’t have a problem — just make sure to put some paper towels down inside your computer, and if you do spring a leak, plug it up, empty out your loop, and give your computer 24 hours to dry off. Most of your hardware will be fine, even if you get a little water on it.

Before you fill up, you’ll need to jump your power supply. This lets you test the pump and the fans without actually turning on the computer itself. Disconnect the 24-pin cable from your motherboard, and connect the green wire to the black wire using a paper clip, as shown above. Some kits also come with a small adaptor to serve this purpose.

Next, add your liquid additives to your water, if applicable. Grab a funnel and put it in the reservoir’s fill port. Carefully pour your water in, filling the reservoir almost to the top. Some may empty into the tubing, which is OK. Once the reservoir is filled up, flip the power switch on the back of your computer and let it run for a second. When your reservoir gets about halfway down (one-third of the way if you’re using the XSPC pump/reservoir combo), turn the computer off before the pump runs dry. It’s very important to make sure your pump never runs dry, as this can permanently damage your pump in a matter of seconds. Once you’ve let a little water out of the reservoir, fill it up to the top again. Repeat this process until the water level in your reservoir stays constant. Double check your loop for any leaks, and if everything’s OK, you have yourself a working water loop!

Step 6: Test for Leaks and Bleed Out Air Bubbles

The last step is to let the entire loop leak test for 24 hours. Let it run and check back frequently to make sure it isn’t leaking anywhere. During these 24 hours, you should also find that a lot of the bubbles in your loop will bleed out. You may need to tip, shake or jiggle the case to help this process along, as well as tap or pinch the tubing. Don’t worry if you have a few small bubbles left over, they’ll go away in time. Again, a drop or two of dishwashing liquid can help bleed out the bubbles as well.

Once the system proves to be leak-free, you can turn it off, reconnect your 24-pin motherboard cable, close everything up, and start using your computer. You should find that your computer’s temperatures are much lower, and that you can run the fans at much lower speeds, keeping everything much quieter. You’ll need to empty out the loop and rinse out the hardware about every six months, but or now, you’re ready to overclock your processor, do some serious gaming, or just bask in the silent hum of your computer’s new cooling system.

Further Reading

If you’re ready to give water cooling a try, that’s great! I highly recommend doing a bit of extra research, so you know everything backwards and forwards before you start. Here are some other great guides that should help you learn more about the process:

I also high recommend these two video guides:

And, of course, we have a few water cooling gurus around here that know their stuff, so feel free to ask questions in the comments below.

Originally published on Lifehacker Australia


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