Air Cooling Buyers Guide

What is a CPU cooler and why it’s important

CPUs, also known as processors, consume a lot of energy and without a cooler will overheat will shut down or could even be damaged. It’s critical therefore to choose an appropriate cooler for your CPU. This guide will show you what to look out for when buying a CPU cooler.

Before we get started it’s important to note that many Intel and AMD processors do ship with a cooler included in the box. You can check if a cooler is included in the Specifications tab of the CPU on the Scan website. As a general rule these boxed coolers do an adequate job, but are built to a budget so can be pretty noisy, especially those included with Intel CPUs. It’s therefore a good idea to consider buying a third-party CPU cooler as it should provide better cooling and be quieter than the boxed cooler. What’s more, if you’re planning on overclocking the CPU to eek more performance from your PC then these boxed coolers really aren’t suitable and you have to buy a higher-grade CPU cooler.

Pictured here are some typical AMD and Intel coolers that you’ll find included in the box with some CPUs.

The three types of CPU cooler

There are three main types of CPU cooler available, air-coolers, all-in-one hydrocoolers and custom watercooling loops. The guide will cover the first two types as they are simple plug and play upgrades that don’t require any particular skills to install. We have created a separate guide for custom watercooling as it’s a far more complex topic that requires many more decisions and buying multiple components to make up the loop. The table gives a quick summary of the pros and cons of each of these types of cooler.



Air Cooler


Hydrocooler


Custom Watercooling
Cooling Good Good Best
NOISE Good Good Best
Complexity to install Easy Medium Hard
Cost Low Medium High

How does an air cooler work?

Air coolers are the traditional and lowest cost way of keeping a CPU cool. While you’ll find air coolers in all sorts of shapes and sizes, they all comprise two main elements, a large metal heatsink that conducts heat up and away from the CPU and one or more fans that blow air across the heatsink, transferring the heat into the air inside the case. High-end air coolers have heat pipes, two phase heat transfer devices, embedded in the heatsink that conduct air even more effectively to the fins above, aiding cooling.

Air coolers are comparatively cheap to manufacture and generally very easy to install as they simply clip onto or bolt through pre-cut holes in the motherboard around the CPU socket. The downside is that they only move heat off the CPU, so a PC with an air-cooled CPU still requires case fans to exhaust hot air from around the air-cooler outside the case.

How does a hydrocooler work?

Hydrocoolers are a costlier alternative to a traditional air cooler. A hydrocooler comprises several elements: a waterblock with an integrated pump which conducts heat away from the CPU into a fluid which passes through a tube into a radiator, which is in turn cooled by one or more fans. Finally the cooled water passes pack through another tube back to the waterblock to start the process again. This is exactly the same principal used in custom watercooling loops, but hydrocoolers are far simpler to install as they are pre-filled at the factory with water, so you don’t have to worry about component compatibility, filling and bleeding or leaks.

While hydrocoolers are typically more expensive than air coolers and provide similar cooling, they are much cheaper than a custom watercooling loop and much easier to install. The main advantage hydrocoolers have over air coolers is they free up the interior of the case, improving airflow and directing heat away from the CPU, so you may be able to get away with fewer case fans.

Typically the combination waterblock/pump clips onto or bolts through pre-cut holes in the motherboard around the CPU socket. After that you need to screw the radiator onto a suitable free fan mount on the case, so make sure your case has suitable space available.

How to pick the perfect air cooler or hydrocooler

Whether you’ve chosen to go with an air cooler or hydrocooler here are other things you need to know before clicking the buy button.

CPU socket

The first and most important consideration is to make sure you choose a cooler that is compatible with your CPU. AMD and Intel produce CPUs in a variety of ranges, each with their own socket, which has its own unique dimensions. You can check which sockets a cooler supports on the product page of the cooler on the Scan website and clicking on the Specifications tab. Here are the list of the most common AMD and Intel CPU ranges and their associated sockets. These tables aren’t exhaustive, so check carefully if you’re looking for a cooler for an older CPU.

Processor Type Socket
Ryzen 9, Ryzen 7, Ryzen 5, Ryzen 3, Athlon AM4
Ryzen Threadripper TRX4
EPYC SP3
Processor Type Socket
Core i9, Core i7, Core i5, Core i3, Celeron, Pentium, Xeon W-1200 S1200
Core i9 X-Series, Xeon W-2200 S2666
Xeon W-3200, Xeon Scalable S3647

CPU TDP

As already mentioned CPUs emit waste energy as heat, which needs to moved away by the CPU cooler. This energy is referred to as the Thermal Design Power (TDP) of the CPU. While AMD and Intel measure TDP slightly differently, it’s still the best estimate of how much energy the cooler needs to dissipate.

The higher the TDP of the CPU the more powerful cooler you will need to purchase, so it’s important to cross reference this value against the maximum TDP of the cooler. You can find this information on the product page of the cooler on the Scan website and clicking on the Specifications tab. There’s no downside to choosing a cooler with a higher TDP rating than your CPU, in fact the opposite is true, as an overrated cooler will help to cool the CPU even more effectively.

Size Considerations for Air Coolers

The vast majority of air coolers will fit in most ATX cases. However, it’s still a good idea to check the height of the cooler versus the width of your case, particularly if you’re building a small form factor Micro-ATX or Mini-ITX PC. This can be checked by comparing the values listed product pages of the cooler and case on the Scan website and clicking on the Specifications tab.

Check the height of the CPU cooler (A) against the width of the case (B) before buying an air cooler.

Some large air coolers can also restrict access to the DIMM slots on the motherboard. This means you might have to temporarily remove the cooler or fan(s) if you want to change or upgrade the system RAM. Particularly large coolers may even limit the height of the DIMMs you can install, so it’s worth bearing this in mind if you planning on using particularly tall DIMMs with large heatsinks or RGB lighting strips. Some coolers even block access to all the DIMM slots. It’s not always easy to work out in advance whether an air-cooler will limit access to DIMMs, better brands such as Be Quiet! provide a cooler compatibility checker.

Size Considerations for Hydrocoolers

Hydrocoolers come in three main size groups, 120/140mm hydrocoolers with a single fan, 240/280mm hydrocoolers with two fans and 360/420mm hydrocoolers with three fans. You can check what each case supports on the product page of the case on the Scan website and clicking on the Specifications tab which will list what size radiators the case supports.

Managing CPU Cooler Noise

Regardless whether you buy an air cooler or hydrocooler it will be cooled by one or more fans. These will typically be either 3-pin standard fans or 4-pin PWM fans, either way, there are multiple ways to control the fan speed. The easiest way is via the motherboard, with basic boards providing fan control via the BIOS and higher end boards being bundled with Windows software that provides the same capabilities but with greater convenience.

Corsair hydrocoolers stand out in this regard as you can control them and their RGB lighting (if present) via the iCUE application in Windows.

Finally, as most coolers use industry standard 120 or 140mm fans, you can often replace the fans if you want something quieter or more powerful. Just make sure to keep an eye on the CPU temperature to make sure it doesn’t get too loud as you tweak or swap the fans.

Time for TIM

The last thing to bear in mind when choosing a CPU cooler is Thermal Interface Material (TIM). This is a thin layer of paste that you spread out between the top of the CPU and the bottom of the heatsink of the aircooler or waterblock of the hydrocooler. TIM helps conduct heat out of the CPU by smoothing out imperfections in the surface on either side and is essential for good cooling.

Many coolers come with TIM pre-applied or packaged in a small syringe for you to apply, but its worth checking before ordering. You can check for the presence of TIM on the product page of the cooler on the Scan website and clicking on the Specifications tab.

If there no TIM included, or you want to invest in better TIM, which might help lower the CPU temperature. We stock a wide variety of TIM brands.

The best CPU coolers

There you have it, everything you need to know when choosing a CPU cooler. We hope you've found this buyers guide helpful. Don't hesitate to contact one of our friendly advisors for more advice if you still have questions on how to select the perfect CPU cooler. If you’re all set to go we recommend checking out coolers from these top brands.