PC Case Fans For Beginners: Everything You Need To Know

PC case fans have become a LOT more complicated in the last decade ago or so. Previously you would just connect a Molex or 3-pin fan to your PSU or motherboard, and they would run. Okay so they WOULD run very loudly (most of the time), but it WAS fairly easy.

Nowadays, though, there are just so. many. different. options. There are 3 and 4 pin fans, daisy chained fans, interlocking fans, RGB LED fans, PWM fans and more. Why are there so many options? And are there pros and cons to each option, especially in terms of wiring them all up?

Well YES, RGB fans are certainly a bit harder to install and wire up due to the extra cables (for the RGB support). But I cover everything you need to know about PC case/chassis fans in this video – from purchasing decisions, to their actual installation, and also their post-install maintenance (such as cleaning your fans).

https://www.youtube.com/watch?v=zq33aY4mqkY

If you prefer text over video, please read on for the guide/transcript version of this video.

Video Transcript And Guide

Hey everyone, building computers one or even two decades ago was EASY – case fans either had a simple Molex connection that plugged into your PSU like this, OR they were “3 pin fans” and you could either plug them into your motherboard OR use a Molex adapter and continue to use the PSU to power them. Oh, the good old times. But now… NOW everything is “PWM this” and “ARGB that”. There’s 4 pin fans and 6 pin fans, and then there’s daisychained fans, magnetic fans and interlocking fans. When did it all get SO COMPLICATED?

Luckily, I’m here. My friends call me Tristan “The Fan Guru” Perry. Actually no-one calls me that… cos I don’t have any friends. But I DO know a lot about PC case fans, so here’s EVERYTHING that you need to know.

This guide is split into three sections: I’ll firstly cover any questions you might have BEFORE you buy your case fans. If you already have them though, feel free to skip straight to the second section which will cover actually INSTALLING your case fans – how to wire them up, cable manage them, how to avoid overloading the motherboard fan headers, all that fun stuff. I’ll then cover some post-install things you need to know in the final section: things like how to check that the fans are working well, and when to clean your fans. So let’s get started.

Section 1: Pre-Purchase

Okay, so you’re planning your new PC build – or maybe you’re doing some upgrades – and you’re not sure what case fans to buy. The FIRST thing you’ll need to work out is whether to go for RGB fans or not. That’s because RGB fans look great, of course, BUT they do require a LOT of extra cables. That’s because RGB fans have one cable that controls how fast the fan should run, and another cable for the PRETTY LIGHTS. And so this will ‘kinda make your job harder but of course if you want a flashy RGB build, you just need to be aware that you will have a little extra complexity. I’ll discuss how to connect your fans to your computer later on, but the next factor to consider is the BRAND of case fan.

Now if you’re going for RGB fans then I would probably recommend buying from a company like Lian Li, Corsair, NZXT or Thermaltake because they all offer “solutions” for your case fans where you can get an RGB fan hub that takes care of all the pesky extra wiring. Lian Li are particularly strong here, with their Infinity fans using only a single cable from the RGB fan to the Uni Hub, and many of Lian Li’s cases offer some pretty nice cable management features too so your cable management doesn’t end up looking like this guy’s:

The fact that this is still the standard in 2024 is mind blowing.
byu/TrippySubie inpcmasterrace

But if you don’t want RGB fans, can you just buy any old make of case fan? Well no, ideally you’ll still want to stick to a reputable main brand such as Noctua, Arctic – or some of the other companies I mentioned previously. You don’t need to spend a fortune here though – I recently picked up some Arctic P12 fans and they cost me just over £5 each. They work REALLY well too – I combined this with a fan hub (which I’ll discuss later on) and my system is ultra quiet most of the time. Noctua fans also offer some great performance but this comes at a big cost – and do they really need to be 6 times the price of some other perfectly good fans? There’s probably a “style premium” here to be honest – Noctua fans have a distinctive design (along with pretty great performance, of course). I actually purchased a Noctua cooler for my CPU because I liked the design, performance and look of it:

But for my case fans, I just wanted something simple looking that would blend in – meaning black Arctic fans for my black Corsair Carbide case.

There are, however, four other important things you should check before buying a case fan. Well, five if you count.. y’know, checking the reviews, but it kinda goes without saying that you shouldn’t buy some 2/5 rated fan. You should always consider how fast the fan runs (its RPM in other words), whether the case fan supports PWM – pulse width modulation, whether it has daisy chain support, and what type of fan bearing it has.

So turning back to the RPM rate: this stands for rotations per minute and it’s literally how many times each minute that the fan will spin round. Woah. The faster the fan spins, the more air it can move through it. In other words, a 3,000 RPM fan will bring more cold air into your case (or expel more warm air OUT) than an 800 RPM fan. BUT the faster they spin, the more noise they make. Bigger isn’t always better… when it comes to fan speeds. I typically like fans that have a max RPM of 1,800 to 2,000. That seems to strike the right balance between effectively cooling your system at peak, versus not being TOO noisy.

Of course, the advertised RPM rate will just be the HIGHEST rate that it MIGHT run at. If you buy a 4 pin fan – also called PWM – this will run at a variable speed. So when your system is barely doing anything, the fans will spin really slowly (and quietly). Fan speeds will then automatically ramp up when you start heating up your computer – by gaming, video editing, doing 3D modelling, or whatever. Nowadays I would always recommend buying a 4 pin, Power Width Modulation fan because they don’t really cost more than the older 3 pin variants, and you’ll have a LOT more flexibility of their speeds. You can TECHNICALLY change the speed of 3 pin fans if your motherboard supports it, but I wouldn’t really bother with DC control. Just buy a PWM fan and move on with your life, in my opinion.

The third factor to consider when buying case fans is whether they support daisy chaining or not. I’ll get onto HOW to install your fans in the next section, but some fans like the Arctic P12s support something known as “daisy chaining”. This is where each fan’s cable actually has two connectors on it, not just one. This allows you to connect all your fans together in a chain, and then only plug the last fan into the motherboard’s chassis fan header. This can help with cable management, and it’s useful because many motherboards only have 1 or 2 case fan headers, which doesn’t help much if you have 4 or 5 case fans! Daisy chained fans can be a nice benefit as a result.

The final factor is the design of the fan – or more specifically, its fan bearing system. This is the thing in the middle of the fan, it helps the fan spin round in a way that minimizes friction and maximizes the fan’s performance and lifespan. There are LOADS of different types of bearings, but essentially fluid dynamic bearings (or hydraulic bearings) are probably worth buying nowadays – they prolong your fan’s lifespans and it’s what many of the higher end fans use, too.

So that wraps up the main factors to consider but I should also quickly mention your motherboard and case. If you plan on buying 6 case fans (for example), it’s unlikely that your motherboard will have 6 chassis fan headers – which is where you need to plug the fans in to. What you’ll need to do instead is either buy some fan splitters that allow you to connect a few fans to the same header OR you should buy a fan hub. I discuss this point a LOT in the next section but without buying either of these, you’ll end up with all your computer parts and then realize at the VERY start of your build that you’re stuck because you can’t power all your fans. So it is worth considering HOW you’ll connect up your fans BEFORE you start building your PC.

Finally you should double check that your case can physically support all your fans. Most cases support 120 millimetre fans so make sure that you haven’t accidentally purchased 80mm fans or something. Equally some higher end PC cases support some 140mm fans and so it’s worth buying some of these because they can move a LOT more air while running at a slower speed – meaning that your computer runs cooler but is also quieter.

I should also quickly point out that just because your case has space for 15 case fans, it doesn’t actually mean that you MUST BUY 15 case fans. Unless your fans are a key part of your build’s aesthetics, you only need case fans for effective cooling and many people find that having two or three intake and exhaust fans (so, 5 or 6 fans in total) is often enough. Once you start getting more than this, your system becomes a LOT more noisy, and it has a LOT more wires too – even daisy chained fans will require multiple runs of cables to multiple fan headers or hubs, because you can’t stick 15 fans on a single header, for example.

So do think carefully about how many fans you actually need – and remember that you can always add more later. You could start off with 2 intake and 2 exhaust fans, and only buy more if you NEED more. Or, y’know, you could spend almost $500 on 15 Corsair RGB fans and two fan hubs if you’d like. Both options work fine.

Section #2: Installing

Okay, you have your case fans – congrats. Sooo… how do you install them? And why are there just so many wires?

The first thing you’ll need to decide is the orientation of your fans. Fan blades have a particular curve shape because in one direction they will draw air through them: basically they will act as an intake, and bring fresh air into your PC case. In the other direction, they blow air OUT of them – which we call exhaust fans. Many fans actually have arrows on their side to show the direction that the fan will blow, but if it doesn’t have this, check out the manual OR simply plug the fan in (as I’ll discuss in a second) and put a bit of tissue near it and see if the fan blows the tissue away or sucks it towards the fan.

This is importsnt to know because a “healthy” PC build will usually have some exhaust fans and some intake fans. Basically you want a constant supply of colder air from the room (via your intake fans) and then any warm air (from your CPU and GPU) will be expelled out your case through your exhaust fans. Some people disagree with this and even recommend having ALL exhaust fans to have a negative pressure set-up, but the majority of people prefer having some exhaust and some intake fans so that’s what I’ll cover in this video. Right, now the LOCATION of these exhaust and intake fans is crucial. You can’t just randomly have intake and exhaust fans right now to each other, for example. I tend to recommend that because hot air rises, it’s best to have the front case fans (and any bottom ones) act as intakes so that they bring in NEW air, and then any back and top fans act as exhausts. This also ensures a constant supply of air through the case, and it’s probably the most popular way of configuring your fans.

With that decided, how should you connect your fans to the case? I mean, they USUALLY come with simple metal screws – aren’t they good enough? Well YES in many cases, screws are fine but if you had a super fast 3000 RPM fan (for example), it might vibrate around too much if you just use screws. As a result, some people rely on anti-vibration “screws” (basically rubber sticks) instead of using metal screws because these rubber screws will dampen any vibration noise. It’s up to you although many modern fans ARE quite quiet and minimize vibrations so I’d probably just stick to screws to begin with.

Okay, so at this point you can mount your fans onto your case – and you’re left with the “simple” task of wiring everything up. Joy. 

If you simply have ONE case fan and you purchased it in the last decade, your job is easy: just fine the 3 or 4 pin fan header on your motherboard, and plug the fan in there. Usually the header is labelled as “CHA_FAN” meaning chassis fan, or it might just say “FAN 1” or similar, but do double check your motherboard’s manual if you aren’t sure. Since you have plugged it into the motherboard, you’re done – thanks for watching this video. But of course, it’s not that easy. We don’t just have ONE fan – we often have 5, 6 or even more. You might also have an RGB fan which has TWO cables: one for the fan header of course, but the other will go into your motherboard’s RGB fan header.

To make matters worse, many motherboards only have one or two fan and RGB headers to plug our fans into. So, what do we do? Well there’s three main options here: you can buy a fan splitter, you can buy daisy chained fans OR you can look at a fan hub.

In some ways those first two options ARE actually very similar, but let’s look at Y splitters first: these have a single end that will plug into your motherboard, and then they have two or more ends that you plug your fans in to. This means that if you had a 6-way splitter, you could plug SIX fans into this and then plug THAT into your motherboard’s fan header, right? Well yes – physically that would work. BUT many motherboard fan headers can supply up to 1 amp of power. Some fans only use minimal amounts of power so you MIGHT be able to split 6 or 7 fans and then plug this into the header HOWEVER this is really pushing it. General advice is to only plug around 2 or 3 fans into each motherboard header. This means that if you had six case fans, you should have TWO fan splitters and then plug into TWO motherboard fan headers.

The same is true for the LED light aspect: you can purchase ARGB splitter cables, for example, that allow you to plug multiple RGB cables ultimately into the same motherboard RGB header. You should continue to avoid plugging too many fans into the same RGB header though: you should always check your motherboard’s specs for the total power output on that header, and calculate things accordingly.

Using splitters CAN work fine, but some fans actually have daisy chain support – this is where they have TWO ends to their cable. One end plugs into your motherboard’s fan header as normal BUT you can instead choose to use the other end and plug THIS into the next fan’s cable. This chains the fans together, and it gets rid of the need to buy separate fan splitters. It also makes cable management a bit neater because Y splitters ain’t exactly pretty. I recently purchased Arctic P12 fans and while I didn’t use the daisy chain feature, I really like that they offer this functionality.

The OTHER option of powering your fans is via a fan hub and I’ll discuss that in a minute, but I firstly wanted to cover a few questions people might have about their motherboard fan headers. Many modern motherboards have 4 pins and as I mentioned earlier, this gives you more control of your fan speeds due to PWM. BUT what happens if you purchased a 3 pin fan by mistake? Well this is actually fine (sort of): you CAN plug it into the 4 pin header, but you just won’t have the PWM control: the fan will probably run at full speed.

Equally if your motherboard only has 3 pin headers but you have 4 pin fans, you can ALSO plug this in okay – essentially the fan’s plug will overhang the motherboard header a bit because one of the pins is unused, but this won’t cause a major problem (apart from the fact that the fan will again run at max speeds).

This is all true for splitters (or adapters) too: you can purchase 4 to 3 pin fan adapters, for example, that will act as splitters but also “downgrade” your 4 pin fans to 3 pins to make it easier to plug these into your motherboard (or an older fan hub).

Before I discuss fan hubs, I wanted to cover one other quick point. You might have noticed that when you have a 4 pin splitter, only one of the “ends” has 4 pins. All the rest have 3 pins. This isn’t a faulty cable though: it’s by design. The tach signal is the thing that helps control the PWM fan speeds, and only one of these can be “passed” to the motherboard (essentially). So a 4 pin splitter will always have one “true” 4 pin end to “pass” on the tach signal, and then the rest will just be 3 pins.

Okay, so will all that said, you COULD approach your fan cable management by using a ton of splitters or daisy chained cables but this will quickly resemble Medusa’s hair after a nap. It won’t be pretty. That’s where fan hubs come in and these are sometimes “mandatory” for RGB fans due to all the extra wires that are required, but they are often fairly useful for standard fans too.

Fan hubs allow you to run all the fan cables to them, and you plug each 3 or 4 pin fan plug into the fan hub. This might look a bit messy but you can always hide this in the back of your case, behind your motherboard. Once you have plugged all the fans in, you can then run just a SINGLE fan header wire from the fan hub to your motherboard. This means that you don’t need to worry about having Y splitters everywhere, and trying to plug wires into a chassis fan header  that might be located in a really awkward position.

Now you might be wondering how you can plug 10 fans into a fan hub, when I’ve said a bunch of times that the fan header on your motherboard only has limited power output? Well that’s where SATA power comes in. The SATA wire from your power supply unit isn’t just for old style hard drives and SSDs, it ALSO allows us to power peripherals like this extra USB hub at the front of my case – but ALSO my Arctic fan hub. Some fan hubs accept a standard SATA power plug, while others require a smaller SATA 12 volt connection – in which case you’ll need to buy one of these SATA adapters and plug one end into your PSU SATA cable and the other into the fan hub.

Either way though, this extra SATA power gives the fan hub everything it needs to run LOADS of case fans. THAT’s the awesome thing about fan hubs. Then when you come to control your fan speed’s (as I’ll explore in the next section), you just have a single “thing” to control. It’s so much easier.

Everything I’ve said so far applies to “standard” fan hubs, but also RGB fan hubs. There’s really only two differences that I can think of: firstly, RGB fan (and hubs) will have MORE wires everywhere. And secondly many RGB fan hubs are essentially “mandatory” and they are tied to your specific RGB fans. In other words, you can’t buy RGB fans from loads of different companies and expect them to work with your Corsair RGB fan hub. If you go with 1 Corsair RGB fan, you’re kinda tied into Corsair from that point. Unless, of course, you have SOME RGB fans and then some “normal” fans – and you can then do whatever you want with those other fans. Plug them into a 4-pin Y splitter, then into a 4-way 3-pin splitter and finally into a fan Molex adapter that then plugs into your PSU. That will work. Heck, if actually WILL work but it naturally wouldn’t be a good idea!

So that pretty much wraps up this section, but I wanted to wrap up with some advice about cable management. Even if you use a fan hub, you’ll still have LOTS of wires around your case. It’s often best to try and tuck any wires behind other fans, or behind your motherboard tray. This will make them effectively hidden. You might also want to use cable ties – especially behind your case – to tidy up all of the fan wires. I often bundle them together and also clip them onto the case via the small hoops that cases often have.

Before wrapping up this section, there’s one other cable management point I wanted to discuss. BEFORE you run any of your fan wires, you should double check where your motherboard fan headers are located. My Asus B550M motherboard has one in the middle of the board, and another sandwiched awkwardly between my graphics card and PSU. For simplicity it would probably have been easiest just to run my fan hub’s 4-pin cable to this middle one. BUT that would have looked quite messy, even if it was a black wire and a black motherboard. So I actually opted to REMOVE my graphics card so that I could access this “hidden away” chassis fan header, because THIS led to the cleanest wiring set-up. In other words, try and plan out where your fan wires will run before you install everything – but please don’t worry too much if you get it “wrong” because it’s easy enough to change later on.

Section #3: Post-Purchase

With your fans installed, you can FINALLY boot up and see all your fans spinning – noice. BUT if they aren’t spinning after booting up, don’t worry, it’s almost certainly the case that either the fan header isn’t fully plugged into the motherboard OR the fan hub’s SATA power cable isn’t fully plugged in. Double check these and try again, and they should run fine.

At this point, boot up into Windows and I would probably run HwInfo and click Sensors only which will show you a BUNCH of data. Scroll down until you see the motherboard section, and there should be one (or more) entries in there for chassis fans. This will tell you how quickly they’re running, and at idle they might run at under 1000 RPM but once you start using your system (especially for gaming, video editing or whatever) you’ll THEN probably see your fan speeds ramp up. That’s because your CPU and GPU are heating up, and the sensors in your PC will detect this and tell your fans to run faster so that more cold air is bought in (through the intake fans) and more warm air is expelled (via the exhaust fans).

That’s all great BUT some motherboards have quite harsh “fan curves”. A fan curve is basically how quickly your fans should run based on your PC’s internal temperatures. Some systems will run your fans at 100% speed – which is NOISY – even when your CPU is at just 70 degrees celsius or so. That’s not ideal, and it’s where fan control software comes in because these allow you to change your fan speeds.

There are a bunch of ways of doing this: your motherboard might come with software for it, like the Asus Armory Crate that allows you to set your fans to be “quiet” (in other words, running at a low RPM) or at max speeds to cool your PC down more:

There’s also software like SpeedFan and this can work fairly well, especially because it can automatically control your fans speed OR you can take manual control of them. But right now I think that FanControl is probably the best option – it’s entirely free and you download it from their website, but it might also prompt you to download some extra packages from Microsoft’s website. Once this is installed, it runs through a full calibration process where it works out exactly what fans your computer has, and how they can best be controlled. It’ll do this by setting them to 100% fan speeds and then slowly lowering it down, and seeing how your computer’s temps react to this. It then “decides” the best option for them. However you CAN override this and choose manual fan speeds, or you can create customized fan curves that will ramp up fan speeds according to certain temperature points. FanControl is a pretty useful bit of software and it’s free, so it’s definitely worth checking out.

Before finishing off, there’s two other quick points that I need to discuss: how to prevent (and clean) dust build-up off your fans, and when to change your fans entirely. Some PC fans have little grills or filters on the outside of your case and these help to prevent dust from getting through your fans, and inside your PC. These can work well but if your case doesn’t have them, you can either buy third party ones OR just leave them off and see if dust IS actually a real problem for you. Some parts of the world have a lot more dust than others, plus environmental factors like whether there’s a smoker in the house can also contribute to dust build-up.

If you DO end up adding dust filters though, you should probably leave them OFF your exhaust fans – it’s often best to just add filters to your intake fans because this is where the dust will come in from.

In terms of cleaning dust off your fans, it’s not really difficult. Turn your PC off and open up the case. If you can easily touch the fan blades, get a cloth or similar and just wipe the dust off. However you can’t always quite reach the fans, and in this case, a can of compressed air can work wonders – just point it at the fan blades and it’ll blow all the dust away.

And now the final point of this video: when should you change your fans? Well I actually covered this in detail in another video but case fans CAN actually last for well over a decade. So I would only really change them if I wanted a new style or color theme in my case OR if a fan started rattling or making lots of noise – this is a sign that the fan’s bearing is shot, and there’s no simple fix for this. Just buy a replacement fan.