Water Cooling Loop: Closed vs Open

Closed Loop vs Open Loop Cooling, Which should you get?

WEPC Closed loop vs open loop 01
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When it comes to a water cooling loop, we often see many people comparing closed loop vs open loop cooling. Now, the two are widely different in quite a few areas, although share the basic principle of using liquid to cool components. To clear things up and share some insight into both open and closed loop water cooling, we are going to be going over exactly what closed and open are, and take a look at what you can expect from both. We will also explain which cooling solution makes the most sense for you and your particular PC build plans.

What is Open Loop Water Cooling?

An open loop, sometimes referred to as open loop liquid cooling, is a water loop you create yourself with the individual parts that combine to provide a cooling solution. Open loop water cooling is quite an expensive hobby and is usually reserved for the enthusiast but manufacturers are slowly but surely bringing out new and improved ways to make life easier for the beginner. 

To complete a water cooling loop, you are going to need several different parts, which can become quite elaborate depending on the variety of components you need to cool. 

What Do You Need For A Basic Water Loop?

  • CPU Block
  • GPU Block
  • Fittings
  • Tubing
  • Reservoir/ Pump (with fill port)
  • Compatible Case
  • Coolant
  • Tools

What Else Would You Need For More Elaborate Loops?

  • Monoblock
  • RAM Block
  • Flow Fittings
  • Drain/ Fill Fittings

Custom water cooling is one of the best ways to not only chill your components but also adds some of the best aesthetics money can buy. Sure your PC may look superb with all those RGB fans and a closed loop cooler but the creativity and style that comes with a custom water cooling loop is unrivaled.

Open loop liquid cooling can be used to cool your CPU, GPU, motherboard VRMs, and RAM, enabling you to push the entire system to its limits.

When it comes to compatibility and form factor with an open loop it is somewhat complicated vs closed loop coolers. Radiators come in similar sizes for an open loop system but come in sizes as large as 480mm. There is also a rule that you need about 120mm of radiator per cooled component as a minimum. Luckily there are radiators for almost any build and the same goes for reservoirs and pumps too, giving enthusiasts more options to build custom open loop systems in small mini-ITX cases.

What is Closed Loop Water Cooling?

Closed loop water cooling, otherwise known as closed loop liquid cooling or all-in-one (AIO) is a simplified version of custom open loops making it easier for the general consumer to include water cooling into their build. It is called “closed-loop” because these units come built with coolant inside that goes from the cooling block to the radiator.

What Comes Included?

  • Water Block/ Pump Combo
  • Radiator
  • Tubing

(Everything above is all one unit)

You will also receive brackets to help install on both AMD or Intel motherboards.

Closed loop solutions are primarily used as CPU coolers but manufacturers also produce GPU and RAM closed loop solutions. These types of loops come from all the biggest names in the gaming PC world, such as Corsair, Thermaltake, and NZXT

Closed loop cooling comes in similar sizes to open loop options but they are compatible in a wider selection of cases as it is only the radiator you have to worry about. Sizes vary from 120mm all the way up to 420mm but the main difference to open loops is how easy these are to install. That’s right, as the loop is already assembled, you are just left with the task of screwing the radiator in place and securing the water block to the component. Everything is done, so there is no chance of the consumer spilling coolant inside the system (unless there is some sort of disaster), making these a safer bet for the majority of PC builders.

Water Cooling Loop: Closed Loop vs Open Loop Cooling

Even though the blocks are probably the most expensive part, there are still many other components that go into making an open loop. Fittings, tubing, coolant, and everything else is going to put your budget through the roof, so be prepared to splash the cash.

Cheaper closed loop coolers are considered overpriced for many but serve as a nice middle man between air cooling and a full custom open loop. With a closed loop you can spend your cash on the important stuff like more powerful coponents and still get a relatively cool CPU/GPU too. 


It is widely known that an open loop will generally yield greater results. This statement, however, is only true on a loop-by-loop basis though. Closed loop coolers only have one component to cool and so they produce consistently similar results across the board from manufacturer to manufacturer. On the other hand, open loop cooling can vary between a tiny elaborate loop that cools several components, which can in some instances heat up a component quicker due to the small amount of coolant in the loop. 

The flip side is those extra-large elaborate loops, these cool multiple systems and feature plenty of coolant, leaving the average temperature lower for longer. 


For those with little experience in open loop cooling, you may not be aware that you are going to need quite a few tools in comparison with a closed loop cooler. A closed loop simply requires a screwdriver to install the radiator to the case and the block to the motherboard.

Tools for open loop cooling, however, require a few extras. You are going to need accurate measurements for your tubing, so a tape measure and some pipe cleaners are a good place to start there. You are also going to need cutting tools for your tubing. Soft tubing can be cut with any sharp knife but you will need a specific tool or a saw for hardline tubing. Glass and other specialized materials like metals are another step beyond this but you can buy pre-cut bent options that can be directly installed into your loop. You may also need a deburring tool to get any shavings from the rim of your tubing. Drills, sand-paper, clamps, and other nice-to-haves like leak testing kits are also great to have.

It is worth noting that you are going to need a bit extra room when doing an open loop, whereas a closed loop can be done in the smallest of work areas.


Aesthetically, a closed loop is just never going to compare with the beauty of an open loop but what you go for is all down to how much you can afford. Open loop cooling takes a lot of planning, time, and effort to get right, with the maintenance sometimes being a bit of a hassle.

One thing we can all agree on with open loop cooling is how incredible it looks. There is no better way to make your PC look aesthetically impressive. The combination of tubing, fittings, and RGB lit blocks, makes for an internal spectacle that you just cannot take your eyes away from.

Final Word

With a water cooling loop, there is technically no better way to cool your components. When it comes to the question of closed loop vs open loop cooling, most PC builders are probably going to opt for the easy to install AIO closed option. There is an ever-growing small percentage of PC enthusiasts that wish to ascend to custom open loops and benefit from the best aesthetics you can possibly get out of a PC.

So, open loops are harder, more expensive, and less compatible while a closed loop is cheaper, easier to work with, and yields decent performance results, so what should you get? What you go for depends mostly on your budget, even if you really want to take the plunge and learn how to watercool your PC. The risks involved with an open loop may not seem worth it but wow do they look spectacular.

What is closed loop cooling?

Closed loop cooling is essentially a prebuilt water cooling loop that is simply fitted into your system. You don’t need to sort any tubing out, connect fittings, or worry about leaks, these are pre-assembled in a factory and pre-filled.

Is open loop cooling better?

Whether or not an open loop is better depends on the loop. If everything is correct and you have the required amount of radiators, then yes open loop cooling is going to be better for performance.

Is closed loop water cooling worth it?

Closed loop cooling doesn’t really improve temps all that much. If you are running a high TDP CPU then sure, you are going to see differences, and your system will benefit from a closed loop but air is just as capable.

Does water cooling loop order matter?

The order of your loop only starts o t matter if your flow rate is slow enough to let heat start to pool.  You don’t need to worry about which component should run where but there are best practices that experienced water cool builders will stick to.

Do closed loop water coolers leak?

Closed loop water coolers can leak but ti usually very rare. The tubing will degrade over time which can sprout a leak after years of service.

How long do closed loop water coolers last?

A closed loop cooler should generally last around 5 years. Closed loop coolers can last longer and require no maintenance, unlike open loop cooling which can require constant maintaining.

The Author Who Worked On This Article

Product Specialist - Gaming PC, Prebuilt Gaming PC, GPUs, CPUs,
Shaun is a gaming enthusiast and computer science graduate who has been working with computers for the last 15 years. He took a shine to competitive FPS back in the mid-2000s and hasn’t looked back since.

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