Liquid Cooling: A Beginner's Guide

March 1, 2022

Liquid cooling is a great way to keep your PC running smoothly, while minimizing noise. It also just plain looks cool. But is it the best solution for you?

We'll walk you through the basics of liquid cooling, so you can make the best decision for your build, and feel confident when buying coolers.

What is Liquid Cooling?

Before talking about the types of coolers you might want to purchase, it's important to understand what liquid cooling is, and how it works.

Liquid cooling, also known as water cooling, refers to any cooling system that relies on fluid to efficiently transfer heat away from components in your PC, such as your CPU and GPU.

No matter what cooling system you use, you'll still need to know some air cooling principles, including how to select and set up case fans, in order to make sure your system runs efficiently.

You can check out our case fan guide, as well as our basics of air cooling guide, in order to give you a better understanding of PC cooling best practices.

Types of Liquid Cooling Systems

Liquid cooling is not a one size fits all solution, and different types of cooling setups work better in different cases.

There are three main types of liquid cooling setups:

AIO coolers

An AIO cooler, or all-in-one cooler, is a common system used for cooling the CPU. AIOs are a closed loop system containing a water block, radiator, pump, and soft tubing.

This is one of the most common types of liquid cooling systems, because they are easier to install than custom liquid loops. A lot of first-time builders will opt to cool their CPU using an AIO, and then air cool their GPU.

You'll want to make sure that your water block is correctly positioned so that your pump is not overtaxed when pushing fluid through the system.

  • If you’ve mounted your radiator to the top of your case, make sure the tubes connect to your water block from the bottom.
  • If you’re mounting your radiator to the side of your case, make sure the tubes connect to the radiator at the bottom of your case.

If not properly installed, it can lead to pump noise, increased wear, and even premature failure of the AIO.

Liquid Cooling Kits

Some manufacturers will make kits designed to help you create your first liquid cooling loop.

Working with a kit is great for first-time builders, because it ensures inherent compatibility across all parts of your loop. If you're looking for even more customization, however, you may find a fully custom solution to be far more appealing in your PC Case.

Custom Loop

If you're somebody that enjoys tinkering with their PC, or you want a very specific look and feel to your liquid cooling setup, a fully custom liquid cooling loop is the best solution for you.

When not working with a kit, you'll want to do extra research to make sure all of your parts are compatible. That being said, you'll have full control over all of the finishes, materials, techniques, and aesthetics of your loop.

How Does Liquid Cooling Work?

If you've never built a liquid cooled system before, you might be wondering how this process works, and what is involved in keeping PC parts cool using a liquid system. We’ll break down each individual part in a custom loop, and walk you through what each part does.

Coolant

It would be silly to discuss liquid cooling without first addressing coolant. What is so special about liquid cooling anyway?

Liquid cooling gained popularity due to the concept of heat capacity - how much heat a substance can absorb before it changes temperature.

Simply put, water has a far higher heat capacity than air, due to its molecular structure.

Higher temperatures are a direct result of higher molecular movement. Water is composed of both hydrogen and oxygen molecules, but the oxygen molecule in water is very electronegative, meaning that it will naturally attract the electrons of molecules around it.

Hydrogen molecules “stick” very strongly to the oxygen molecule in water, and this magnetism keeps molecules from moving around too much.

This gives water higher resistance to temperature changes than air, and is the reason why people cite liquid cooling as more efficient than air cooling.

Pump Types

In order to circulate coolant throughout your system, your setup will need a pump. AIOs have one installed already, but custom loops give you plenty to choose from.

Liquid cooling pumps are water lubricated, so it is not a good idea to run any pump without liquid, even for a few seconds. This can degrade your loop prematurely, and may result in poor performance or pump failure.

Sometimes pumps will come as a combo unit with a reservoir on top.

There are two main types of liquid cooling pumps: D5, or DDC.

Take note: some manufacturers will slightly tweak designs or replace parts with lower quality ones in order to save money in production, while still referring to their pump as a D5 or DDC. You'll want to do a little research on the manufacturer of your liquid cooling pump, to make sure you're getting a high quality component that will last.

DDC Pumps

  • DDC pumps are hallmarked by their square design. 
  • While these pumps tend to have a lower flow rate, they also boast higher head pressure. This means that they are more able to push fluid through tighter spaces, like a restricted water block.
  • DDC pumps are also more compact than D5 pumps, but they do also tend to run warmer, and with more noise. 
  • If heat is an issue for you, DDC heat sinks are also available on the market. These heat sinks may help improve the longevity of your pump, and can reduce wear.

D5 Pumps

  • D5s are hallmarked by their round design.
  • They tend to be a more popular selection than DDC pumps among builders.
  • D5s run with less noise, generally. 
  • However, they have lower head pressure than a DDC pump, and a higher flow rate.

Installing Your Pump

You'll want to see if your pump requires a topper. These channel coolant to the pump, and typically allow for fittings to be installed to complete your loop.

Always place your pump at the lowest point in your liquid cooling loop. This will ensure that fluid is moved efficiently through your system, and your pump isn't working harder than it needs to.

Reservoir

The sole purpose of your reservoir in your liquid cooling loop is to feed coolant to the pump for recirculation. It also is key in the filling stage, so that your pump never runs without water to lubricate it.

The size of your reservoir doesn't really matter in terms of performance, but you might find that larger reservoirs are more convenient when topping off your loop at the filling stage.

A lot of builders will select larger reservoirs purely for aesthetic purposes. Regardless of your selection, you'll always want to make sure that your reservoir is placed directly above your pump.

Some liquid cooling manufacturers will offer combination units that contain both a reservoir and a pump together. Distro plates are a common variant of this, where the plate will function as a combo unit, and also contain waterways that allow coolant to be distributed throughout your system.

Water Block

A water block refers to the component that directly touches the hardware you're looking to cool; this is the place where heat is transferred to the liquid in your loop. On an AIO, this is the block that sits on your CPU, but for custom loops, you can buy separate units for both CPU and/or GPU setup.

Radiators

Where air coolers contain a heatsink in order to dissipate heat from your CPU, any liquid cooling system you use will require a radiator.

As liquid is pushed through your system, it passes through a radiator in order to offload the heat it has taken on.

While a traditional air cooling heatsink relies on your case and fan setup to fully dissipate heat from your system, a radiator can stand nearly completely independently of the rest of your components.

Generally speaking, it is best practice to select a radiator that is at least 120 mm for every part of the system you are looking to keep cool. You can always go bigger than you need, but it is a bad idea to go smaller.

A Note on Radiator Placement

Where you place your radiator in your case matters. You'll still need to rely on fans to help remove heat from the radiator, and having the best fans for the job helps too.

If you can, opt for at least one radiator at the top of your case. Heat rises, so offloading that heat from the top of your case will ensure that it doesn't interfere with any other component.

Case Fans

Even though you're setting up a liquid cooling system, you will still need to utilize case fans in order to make sure that your PC runs efficiently.

The type of fans you select, especially the ones you place on top of your radiator, will be a primary factor in determining how efficient your liquid cooling system runs. Static pressure fans are the best for this job, because they are designed to push air through places in your case that resist free air flow.

Tubing

There are plenty of material options when it comes to tubing for custom liquid cooling systems, but for our purposes, we'll be focusing on hard tubing and soft tubing.

Hard tubing is typically made out of acrylic (plexiglass) or PETG (polyethylene terephthalate), and requires either a kit with pre-bent tubes or custom bending that you will have to do yourself.

Bending kits can help here, but if you're attempting a custom loop for the first time, you'll want to make sure that you've bought more tubing than you need for your loop. You may have to practice your beds in order to set up your loop the way you need it to be.

Soft tubing by contrast is much easier to manipulate within your case. AIOs rely on soft tubing, for example. However, this does not produce as clean a look as a custom hard tubing cooling loop.

Fittings

Whether you're using hard tubing or soft tubing when constructing your liquid cooling loop, the fittings you choose will also assist in the construction.

Make sure you are selecting the correct fittings for the type of tubing that you're using, and they are sized correctly as well.

Fittings also come at several different preset angles; if you're not eager to make a ton of bends in your first custom loop, fittings would help with that. Just be aware of the increased risk of leaking

Common Questions About Liquid Cooling

Is liquid cooling better than air cooling?

Liquid cooling fans often assume that it is always better than air cooling. However, with recent improvements to CPU efficiency, more and more people have come to find that in most use cases, there is not much difference in performance.

CPU core counts and clocks continue to increase as manufacturers continue to innovate and improve prior designs. However, despite these increases, overall TDP (Thermal Design Power: the maximum amount of heat a chip can generate, that a cooling system can dissipate under any workload) has not changed as much.

Air coolers do rely somewhat on fluid transfer as well; there is fluid in the heat pipes that carry away heat from your CPU to the heat sink.

Where liquid cooling really shines is in cases where you are overclocking your system. Generally, liquid cooling allows for fewer dramatic swings in temperature during periods where your PC may be working harder or “sprinting.” This will help extend the life of your hardware.

Do I need to liquid cool my PC?

Again, this is going to depend heavily on your use case for your system. You likely will never need a fully custom liquid cooling loop. However, if you're looking for an efficient cooling system for a high performance PC, that also looks good and runs quiet, liquid cooling is probably the solution for you.

What kind of liquid is used for PC cooling?

The primary ingredient in any PC coolant is water; specifically, distilled water. You don't want regular old tap water in your system loop. The minerals, salt, and other impurities contained within non-distilled water will cause faster deterioration and corrosion.

While water alone can be enough to cool your system, additives are often included to help improve heart capacity, and also protect against freezing.

Many coolants will also contain a glycol variant. This helps to improve the coolant’s heat capacity and will regulate temperature more efficiently. Common versions of glycol include ethylene glycol and propylene glycol.

Some coolants will use deionized water; this makes the water less conductive for electricity, making it slightly safer in your PC in the case of a leak. However, this can also make the fluid more corrosive over time.

Finally, you might find dialectic fluid in your PC coolant. This is another non-conductive fluid that is slightly less corrosive than deionized water.

How often should I refill my liquid cooling loop?

You should be performing regular maintenance on your liquid cooling loop in your PC every 6 to 12 months on average. This includes cleaning and refilling your loop, in addition to the normal dust removal required for PC maintenance.

If you do not perform regular maintenance on your loop, there's an increased chance that algae, bacteria, or other impurities will grow in your liquid cooling system. This can lead to higher temperatures, poor performance, and even total system failure if you're very negligent.

Check and see if your AIO cooler has the ability to be refilled as well; this will ensure the cooler lasts a lot longer.

What are the risks or drawbacks of liquid cooling?

The most obvious risk you take when constructing a liquid cooling system is leaks. It goes without saying that water and hardware typically don't mix.

As you construct your system, you want to ensure that there are no leaks contained within your liquid cooling loop. One wrong move, and you could end up with a very expensive paper weight instead of a PC.

Liquid cooling is also going to result in:

  • Increased build time
  • A slightly higher cost than an air cooling system
  • Increased time spent when both upgrading and maintaining your system.

In story, it's a bigger investment of time and money, period. If you're okay with that investment, great! But if you're looking for something that will save time in the long run, liquid cooling is a high-maintenance option you don't have to choose.

Benefits of Liquid Cooling

We've gone over some of the drawbacks of liquid cooling, as well as the reasons why air cooling might also be a good option for you and your PC. But let's break down the benefits of liquid cooling too; there are specific cases where liquid cooling will really shine.

Overclocking

When you are looking to overclock your PC, your CPU will work that much harder, and go through more dramatic swings in temperature as it is working through processing game graphics, rendering video files, and more.

Generally, liquid cooling systems will help regulate these temperatures during these periods of hard work much better than an air cooler can.

Space Saving

We've talked a lot about performance, but there are some practical aspects to liquid cooling outside of just temperatures.

Air coolers can get massive. When you're building a PC, you have to keep in mind how your air cooler will fit alongside both your RAM and your GPU in order to function well in your system. If you select an AIO instead, you don't have to worry at all about saving space around these components.

Transports Better

If you move your PC around a lot between homes, your college dorm, or LAN parties, it's probably a good idea to select an AIO over an air cooler. Why?

An AIO will have 16 points of contact on average in your system. An air cooler will have just four, with a lot more weight hanging on those four points.

As you transport your system around, you increase the risk of movement and/or damage to your PC components. Overall, an AIO will be safer to transport generally than an air cooler in your PC.

Better Performance in Warm Climates

If you live in a place with higher ambient temperatures for most of the year, liquid cooling will serve you better than air cooling.

PC temperatures will be directly correlated to the ambient temperature in the room around the system. This is where the efficiency of liquid cooling will really come in handy for you.

You will also likely experience better noise reduction than an air cooling system in your PC.

Conclusion

Once you've weighed all the pros and cons for your PC, and the ways you'll use it, you should have a much better idea of what cooling system will work best for you.

Your choice of case is going to matter just as much in your journey to perfect PC temperatures. Luckily, we've got ITX cases and ATX cases that will do the job, look great, and even travel with you.

Check out our latest product offerings, and good luck on your next build!

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