A cooler PC will run smoother, faster and more quietly. Applying cooling components is fiddly, but worth doing. PC Advisor shows you how to liquid cool a PC.

The components inside your PC generate heat. The standard heatsink-and-fan combo is sufficient for normal use, but components run hotter when you push them harder.

If you're overclocking your PC, building a liquid-cooling system will prevent your components burning out.

Below is a list of equipment we used for our setup. Note, however, that we chose each part for a specific reason.


We arranged our components in the Antec P180 Advanced Super Mid Tower (£128 inc VAT). It's an older case, but roomy. Most cases will suffice, but keep your space constraints in mind. You'll need plenty of room for the components, tubing and reservoir. The P180 sports a few 120mm fans; we'll be using the one on the rear.


For this setup, we'll need a radiator. Warm liquid is pumped through the radiator while the fan pulls air through its grille, transferring heat and then expelling it from the case. We decided on a 120mm Black Ice GT Stealth radiator (£27 inc VAT) because it fits with the fan mounted to the top of our chassis. Pick a radiator that fits your particular PC case.

Cooling block

Our Intel Core i7-990X Extreme Edition processor demands a CPU cooling block that fits the 1366 socket. We used the Danger Den MC-TDX (£48 inc VAT). Select the block that's right for your PC's processor, but don't mix metals or you could risk galvanic corrosion. Mixed metals in an electrolyte (in our case, water) will swap ions more readily than parts of one metal.

All our components are made of brass.


The pump is responsible for circulating the liquid through the chassis. The goal is to cool only the CPU, so you don't need anything too impressive. We went with the Danger Den DD-CPX1 (£35 inc VAT).


The reservoir holds the liquid used for cooling, and it provides a spot for quickly checking the liquid levels. We selected the XSPC 5.25in Bay Reservoir (£36 inc VAT). Bay Reservoirs fit into the same slot as a DVD drive. This is convenient as there's no need to pry off the case walls to check the liquid levels. Our chassis had plenty of 5.25in bays to spare.

Barb fittings

Barbs are fittings that attach to various components. Tubing, in turn, attaches to the barbs. Barbs come in a variety of sizes. Bigger barbs allow larger tubing, which improves the flow of liquid, but they also take up more space in the case. The barbs we chose had an outer diameter of 1/2in.


There are a dizzying number of tubing options, but we wanted to economise.

In general, the tubing size is tied to the barb size. For 1/2in barbs, you'll usually want 1/2in tubing, for example, but we opted for slightly smaller 7/16in tubing. The smaller tubing requires more effort and care to fit, but it's flexible and inexpensive, and it wraps tightly around the 1/2in barbs to form a perfect seal.


If you'd prefer to use the larger, 1/2in tubing or a different size altogether, use clamps to ensure your tubes stay in place. These are inexpensive, but make sure you get the size that matches your tubing and barbs.


Faced with an array of liquid options, we stuck with the simplest, and the cheapest: distilled water. Make sure that you're using nothing else. Tap water is full of impurities that could permit algae and the like to grow in your system, clogging tubes and corroding the water blocks.

Putting the pieces together

Planning is critical, so sketch a diagram before you begin assembling your liquid-cooled system.

The water is at its coolest temperature as it leaves the radiator, so we want it to pass over the CPU first. The warm water that's transferred away from the CPU will then be routed back into the reservoir. From there it will head through the pump and back through the radiator, completing the cycle.

First, attach the reservoir, radiator, pump and motherboard to the empty case. (Screws for mounting came with our parts.) Mount the reservoir in an empty 5.25in drive bay, then position the radiator to straddle the 120mm fan on the case's roof. The pump is small, but it lacks mounting screws; we used some Velcro tape to secure it.

Next, attach the tubing to the CPU water block before you mount it on to the motherboard. The 7/16in tubing we chose for our 1/2in barbs will prove its worth here. After attaching the 1/2in barbs to the block, you'll need to slide the tubing on to the protruding ends. If you can't get the tubing around the barb, try heating the end with a hairdryer. Once you have a tight seal, mount the CPU block on to your motherboard.

The next step is to connect the tubing to the pump. Attach a pair of barbs to the inlet and outlet ends of the pump (consult the manual for advice).

Next, guide the tubing from the CPU water block down to the pump, bending the tubing as little as possible. Once you've gauged a length that leaves some flexing room, use a sharp blade to cut the tubing and then attach it to one end of the pump. Repeat this step to connect the pump to the reservoir, the reservoir to the radiator, and then back to the CPU.

Now for the most important part: leak testing. With everything mounted in the case and the tubing firmly attached, you need to jump-start your power supply to give your liquid-cooling system a ‘dry' run.

Pick up your PC's power supply and look at its large 24- or 20-pin ATX connector. We're interested only in the solitary green wire and one of the black ones (it doesn't matter which). You'll be closing the circuit, much like the motherboard switch would, but you'll instead be using a paper clip.

Fill your reservoir with distilled water.

To prevent spillage, you may need to slide the reservoir out of the case a short distance or use a funnel.

Take care that the only thing connected to the power supply is the pump. Bend a paper clip into a U shape. Slide one end into the green wire's connector and the other end into that of a black wire.

Turn on the power supply to start the pump. Turn it off at the reservoir's halfway point, then refill the chamber. Eliminate any air bubbles in the loop to optimise circulation. Turn on the power supply again. If water is circulating and your parts remain dry, your efforts have been successful.