Choosing the Best Case Fans For Your Air Cooling Needs

In order to attain the best possible air cooled system, you’re going to require some pretty decent aftermarket case fans. The stock case fans that comes with your case are probably not going to give you the best performance boost when it comes to reducing the heat level in your PC.
So how does one go about choosing the best aftermarket case fan to improve their PC for air cooling?

Well, there are lots of different case fans to choose from, and picking the right one can be quite difficult for beginner PC builders. Fans come in different sizes, shapes, design, and even specifications which can make your decision even harder.

But don’t worry too much because this guide is here to help you understand more about case fans for your air cooling needs.

Why Do We Need Aftermarket Case Fans?

ID-COOLING LED 120mmMost PC builder will go with air cooling instead of water cooling which is why fans are slightly more important. Fans are used to move the heat that your PC components generate when under load. Not properly removing the heat, or having the heat build up inside your case can cause serious problems to all your precious PC components.

That’s why using good quality aftermarket case fans are essential to properly air cooling your PC.

Here are some reasons for you to replace your stock fans:

  • You’re upgrading your PC.
  • You plan on doing some light overclocking.
  • You’re PC is generating a lot of heat and tends to overheat (PC is probably under performing).
  • You want to achieve the best performance boost.
  • You’re worried about the longevity of your components.
  • Lastly, you’re a freak for aesthetics and love making your PC look great, like me 😉 .

Those are probably the most simplest reasons I can come up with and I might of missed some but you probably know your own reason for wanting to change your case fans.

Case Fan’s Size, Power, and Cosmetics

The first order of business is finding out what case fan you want and need. Understanding these three things are the simple basics of buying a fan, and once you know what you want and need than you’ll have a easier time choosing the best case fan.

Knowing the Case Fan Sizes

Case fans come in all sorts of different sizes ranging between 25mm to 250mm. But the most commonly used fan sizes are 80mm, 120mm, and 140mm. The important thing to remember is that you have to find the right fan size that your case is able to support. You don’t want to be buying a fan that doesn’t fit in your case.

If you can’t tell what fan size your case supports, you can look at the manual that comes with your case and there probably is a diagram of all the fan mounts that are on your case. Or you can bust out a ruler and just roughly measure the stock fans.

case fan sizes

Does size matter?

Well… They sorta do. I’m talking about fan sizes of course.

When it comes to different fan sizes, there are two things that the size has an affect on – air flow and noise (which I cover on later down below).

But for now, you just need to know that the bigger the fan size, the more air the fan can push with less noise, and the smaller the fan, the less air but more noise. And that is because big fans don’t have to rotate as much to move the air but smaller fans have to rotate a lot faster to move the same amount of air.

Types of Power Connector for Fans

All the fans run on 12 volts that is either supplied by the motherboard or power supply. Most case fans you buy do come with adapters that allow you to either choose between the two. Fans connecting to the Motherboard are usually small Molex connectors with 2 Pins. The 3 Pin fans have tachometer signal that allows the motherboard to read the fan’s RPM, and the 4 Pin connectors fans with PWM signal for speed control.

Fans with 4 Pin connectors tend to be slightly more expensive than then the other two types. I personally recommend fans with PWM signal because controlling the speed of the fan affects the loudness of the noise the fan creates. But you don’t have to buy fans with PWM in order to control the speed, you can buy speed controllers or cases with simple fan controller hubs (more on this later).

Fans can also be powered by using the 2 Pin large Molex connector which connects to the power supply. This is an option for those who don’t have enough fan plugs on the motherboard for all your fans. However, you have to be understand that plugging it in this way will make the fan spin at it’s regular 12 volt rotation (RPM) which could be really loud for some fans.

Fan Cosmetics

Corsair Air Series AF120 LED

Now here is the part where you will be most tempted by – Cosmetics or aesthetics. Most fans come with different designs and lighting features that make them eye-catching for most people. You don’t want to buy a fan that looks nice but performs horribly.

Always check out the specifications for the fan before you consider the cosmetic part. Yes, LED’s look cool but LED’s don’t help move the heat inside your case. And there are some great case fans that don’t have LED’s so it’s really down to what you want.

But just know that cosmetics comes with extra expense so you can actually find a fan without the cosmetics that performs well for cheaper price.

Fan’s Air flow and Noise

When you’re picking out your case fan for your PC, these two are probably the two things you have to consider the most. The questions you should really ask yourself is how much air the fan can push and how much noise does it make when doing so?

Determining Air flow of the Fan

Air flow of the fan is measured in CFM (cubic feet per minute) which determines how much air the fan can fill up within a minute. The higher the CFM of the fan, the better the fan is because it’s able to push a lot more air. CFM can also help you understand air pressure for your PC.

However, when you look at the CFM you have to also consider the RPM (revolutions per minute) because it can have an affect on the noise and performance of the fan.

To make things easier, here is a scenario. Lets say you have two fans:

Fan 1: 70 CFM at 1000 RPM

Fan 2: 75 CFM at 1500 RPM

(Note: these are just examples to help you understand better)

Which fan do you think is better? You might think that fan 2 is better because it has higher CFM, but really the fan 1 is a lot better because it’s able to generate as much air as close to fan 2 with less RPM. Meaning that the fan 1 rotates slower but generates as much air as the fan 2. So fan 1 doesn’t have to work as hard.

What About The Noise?

Fan noise is rated in decibels (dB, dBA, etc) and almost all case fan manufactures provide you with the noise level of the fan that they are selling. Generally, fans dB ranges between 10 dB to 36 dB. You want the fan to have the least amount of dB (noise) because nobody likes loud fans.

There many things that factor in the noise of the fan like:

  • The design of the blades.
  • How close the blades are to each other or the outer ring.
  • Different types of bearings for the fans.
  • And other different factors

So to make your life easier, just go with the dB that the manufacture provides and maybe add in a dB or two for reading errors when they tested it.

Fan Speed Control

case fan controllersIf you’re worried about the noise of the fans then you should really consider getting yourself a fan speed controller which will allow you to control the RPM of the fans.
And if speed controllers are too expensive then you should buy a case that comes with a simple fan controller hub.

They can really make a life changing difference on the noise and over fan performance.



That really is the basics of PC case fans and what you really need to know. Once you understand all that then you’re pretty much set to building the best air cooling system for yourself.

You should also checkout my guide for setting your case up for best air cooling if you haven’t already.

Let me know if you have any questions or concerns below. I’ll be more than happy to personally help you out. Happy building and gaming to all. 🙂

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