How to Build a Water-Cooled PC

PC Parts

If you want to play the latest PC games at the highest resolution or use your workstation for intensive tasks, then your PC needs to be able to handle high temperatures. Computers use a lot of energy and get hot, which is why most PC towers and laptops come equipped with a built-in fan.

Unfortunately, a simple fan unit is not enough to cool down a high-end PC build running the latest hardware. The average high-end gaming PC can emit up to 400W of energy, which can produce surface temperatures over100 degrees-F. If you have ever felt your computer after a long session, you know that it gets pretty toasty.

That is why water-cooled PC builds exist. As the name implies, these kinds of PC builds use water to cool the internal components when running hot. A water-cooled PC unit can handle much higher temperatures and keep your internal components safe from damage.

So today, we are going to talk about how to build a water-cooled PC. We will cover the difference between water-cooled and fan-cooled PCs, talk about the different components of a water-cooled PC, and provide a guide on how to build one.

PC Parts
Why Use Water?

Water-cooled towers take advantage of the unique thermal properties of water. If you remember your high school chemistry, water has a very high specific heat. The specific heat of a substance is how much energy it takes to increase the temperature of the substance by 1-degree Celsius. Water has a high specific heat, meaning it can absorb a lot of energy without itself getting hot.

So with a water-cooled PC, you can overclock your hardware components without fear of damage. Liquid-cooled PC builds are not only more efficient at cooling, but they also reduce and can straight-up eliminate noise from fans. With a cooled PC build, you can also get more out of your components.

PC Parts
How Do WaterCooled PCs Work?

Different PC components can be cooled in different ways. So to explain the difference between air-cooled and water-cooled systems, we will consider the case of cooling one of the more important pieces of hardware, the CPU.

With a standard air-cooled PC, a device called a heat sink absorbs heat from the components. The fans pull cool air from outside and pass it over the sink. The fans then expel the heated air out through vents.

A water-cooled gaming PC, in contrast, works by pumping water (or some other liquid) through tubes that connect to a water block. The water block is essentially a big sink and transfers the heat radiating from the machinery to the water. The liquid then gets pumped into a radiator, and the liquid coolers are cooled by internal fans. The liquid then moves back to the water block, and the cooling cycle continues on and on.

Air-cooling is still more common than water-cooled PCs simply because they are easier and cheaper to make. But a water-cooled gaming PC is far superior at absorbing heat, and they are becoming more common. As time goes on, you might see water-cooled gaming PC towers become the standard rather than a luxury.

PC Parts
Open vs Closed LoopWater Cooling System

There is also a distinction between open and closed-loop water coolers. In a nutshell, an open-loop water cooling system travels all around your PC in a loop and cools everything. A closed-loop system, in contrast, cools a single component. Most of the time, closed-loops are used to cool CPUs and GPUs.

Closed-loops are usually cheaper and much easier to install because they are modular and localized around a single part. The NZXT Kraken range and Corsair's Hydro Series, for example, use closed-loop cooling. Generally speaking, a closed-loop system is better than a fan-cooled system, though some high-end fans can compete. A closed-loop liquid cooling system will also allow you to squeeze more work out of your components like the GPU and CPU.

Open-loops are extremely effective but difficult to set up because they must be custom-built. Open-loops are superior to any other kind of cooling system in terms of cooling, efficiency, and noise, as you can design it in whatever way you want. You can cool your RAM, motherboard, processor, GPU, and even your hard drive(s) if you want.

So if you are embarking on your first liquid-cooling PC build, we would recommend going with a closed-loop cooling system first. They are just cheaper and easier to incorporate into your existing rig without making huge modifications.

PC Parts
What Components I Need foran Open Loop Cooling System?

Since every computer is different, we will not recommend specific parts of brands here. But if you want to make your own open-loop cooling system, then you will at least need the following components:

- Water block
- Radiator
- Pump
- Reservoir
- Tubing
- Fittings
- Coolant type (e.g., liquid with additives or a special coolant substance)

Water Block

The water block is the main unit that picks up the heat from your hardware components and transfers it to the liquid. The part you want to cool needs to be directly attached to water blocks. Water block eat transfer is determined by total surface area, so all other things being equal, water blocks with a larger surface area are a better idea.

There are water blocks for different PC components (i.e. CPU, GPU, RAM, etc.), but they all share the same basic design and function.


The radiator works to keep the liquid cool after it transfers heat from the water block. Most radiators have a fan that cools the liquid as it flows through the copper fins on the side. As is the case with the water block, radiators with a larger surface area will transfer heat better.

If you are cooling multiple components, then you will need more than one radiator. A good rule of thumb to follow is that you should have about 140mm of surface area for each component that you want to cool. You also need to consider fins per inch (FPI), which is basically a measure of how powerful the fan for the radiator needs to be.


The pump works to circulate the coolant to the different parts of the computer. The larger your cooling system, the stronger the pump needs to be. The amount of liquid the pump can move is determined by the flow rate. Keep in mind that flow rates assume zero static pressure, so the actual rating will be a bit lower.

DC pumps are the most common for cooling systems and consist of a single moving piston that pumps liquid. There are also more complex pumps with more-involved mechanisms.


The reservoir is the part that holds the liquid and removes air bubbles as it cycles through. The reservoir is also the part where you physically add coolant to the system. Most pumps mount inside your PC case, but there are some that have an external container. There are also reservoir/pump combos, but there are optional and not necessary to make an open-loop build.

PC Parts

Tubing is pretty basic and carries the liquid through the loop. The main division here is soft and hard tubes, which are pretty self-explanatory based on the names. Tubing is designated by its inner diameter (ID), outer diameter (OD), and wall thickness (OD minus ID). Most open-loop setups require anywhere between 5-10 feet of tubes.

Common tubing materials include Vinyl, Clearflex, and Tygon. Vinyl is the most economical option but makes kinks. We would recommend a good Clearflex to start and premium tubing if you want to upgrade. Otherwise, tubes are up to personal preference.

Fittings attach the tubes to the other nodes of your cooling system so there is no leaking. Each tube needs two fittings, and the kind of fitting you need depends on the kind of tubes (soft or hard). The best kind of fittings to get are compression fittings, which have a barbed end to fit the tube then a compression ring around the exterior. The fitting size needs to be matched with the tubing ID and OD.

Most liquid cooling setups use distilled water that has additives that prevent bacterial growth and corrosion. You can buy coolants separately or make your own. Coolants also come in a huge range of colours, so you will have lots of options to match your style (personally, we like blue and purple).

Instead of additives, you can also use what is called a kill coil. Kill coils are made out of metal (usually silver) and are placed in the loop. The metal kills bacteria and other growths. Keep in mind that if your loop uses multiple kinds of metal (copper and aluminium, for example), then you will need to add some anti-corrosive material as well.

PC Parts
How to Install aWater Cooling Loop?

Here is a quick list of the tools you will need to install a loop.

- Screwdriver
- Allen wrench (aka hex wrench)
- Measuring tape
- Flashlight
- Towels or rags (for potential spills)
- Pliers
- Funnel (for feeding coolant)

Most of the tools are common enough that you probably already have them or can buy them for cheap at a local hardware store.

1. Plan the Loop

The first thing to do is plan how you want to loop set up in your tower. You need to know exactly where your water blocks are going to go, the loop order, and how the tubes will connect them with the coolant. You do not want to just eyeball the form as you go, so take some time to draw out a rough schematic of the system you want.

Loop order can be flexible but at the very least, make sure the reservoir and the pump are right next to each other. Water blocks normally connect directly to the part they are meant to cool. Loop order does not generally affect performance unless you are trying to squeeze every ounce of efficiency out of it.

Also, make sure all other non-cooling components are situated correctly, such as casings, wiring, cables, etc. Thoroughly clean all loop components like the tubes, reservoir, pump, water blocks, etc.

2. Install the Water Blocks

The next step is to install the water blocks on the components. Most water blocks work the same, but there might be small variations depending on the type you get. Line up the holes on the water block with the holes on the component, and put the screws in. You may have to remove/move some internal components to situate the water blocks.

Before attaching the water blocks, you also might want to apply some thermal paste on the components where they connect. Make sure that you do not put the screws in too tight, or that the water block does not put too much pressure on raised structures like transistors, or you can damage your hardware.

3. Install the Radiator and Reservoir

The next step is to put in the radiator and reservoir. Typically, the radiator should be put near the vent that your fans usually occupy. You can also attach them to the bottom of your case or set them up externally outside the case. Like the water block, don't put the screws in too tight.

The best place for the reservoir is in the case where extra HDDs are supposed to go. You can mount the reservoir however you want. If the holes in your case are not spaced correctly to attach the reservoir, you can make extra holds very carefully by using a drill.

PC Parts

4.Install the Pump

The next thing to do is place the pump. Like we said earlier, the pump location doesn't really matter, as long as it's next to any radiators in the loop. Pump installation varies from model to model, but most of the time, they can be screwed on or attached with a Velcro strap. The pump will also have to connect to the motherboard for its power supply.

5.Install Tubing and Fittings

Now it's time to place all the tubes and fittings. Cut the tubings so they fit between the components and attach them to the water blocks inlet ports with the fittings. If you cut the tubing, make sure it's a straight cut, or else it will not seal properly. Most components have a designated "inlet" and "outlet" port so line the tubing up appropriately based on the loop order. Make sure that there are no sharp turns or kinks in the tubing.

6.Fill and Test Loop

Do a final check to make sure all components are snug and secure, and disconnect all power supply cables from your computer. The trick here is to test the cooling system without having the PC actually on. You can do this through a lot of ways, such as using a separate power supply for the pump or a tool called a "bridge connector" that many liquid cooling kits come with.

Next, open the reservoir and start to add your coolant liquid of choice. A funnel is handy for this but not necessary. Carefully pour the coolant into the reservoir, making sure it remains above the pump. Turn the pump on once it has some water in it, and check how the water flows through your system, taking notice of any leaks. Let the loop run for about 12 hours, then check on it later to see if there are any problems with leaks or fittings.

From there, it's not just a matter of turning your PC on and testing the coolant system. There are programs to help monitor the temperature of your components. If a part is overheating, it could mean a problem with your loop connections or setup.

Maintaining a liquid-cooled PC is also easy. You just need to replace the water every so often as it gets dirty. Also, you should try to drain and clean the components of your loop once every 6 months or so.

A water-cooled PC build is a great alternative to an air-cooled PC and can help you get more performance out of your rig. So do your research, follow our guide, and you will have a high-end liquid-cooled PC for hardcore gaming.