You recently spent a significant chunk of money building the perfect PC, and you don’t want the parts to get damaged due to overheating.
You probably also want a few RGB fans to show off your master creation.
The question is, how many fans should you get?
How many are too many?
What’s the bare minimum to get you adequate cooling?
How Many Fans Do You Need In A PC?
Ideally, you need one exhaust fan in the back and two intake fans in the front of your case to create the perfect airflow.
Install the two intake fans in the top and bottom slots (i.e., leave the middle slot empty) to maximize airflow to your CPU, GPU, and motherboard chipset.
At the bare minimum, you should install one exhaust fan in the back to draw heat from your case and an intake fan in the front to pull cold air in.
It’s not a good idea to only include exhaust fans because it doesn’t create a sufficient airflow to push out the heat.
The worst combination is to have three intake fans in the front because CPU heat doesn’t have a way to exit the case.
If you only have one fan, putting it in the front of the case will be more effective for cooling your GPU, while putting it in the back will cool your CPU more effectively.
You can also put the single fan in the top slot in your case if you’re looking for the middle ground for cooling both the CPU and GPU.
However, make sure that the top fan is an exhaust because if it blows air into your case, the airflow will collide with the GPU exhaust airflow, dampening the GPU’s cooling.
Having more than three fans in your case won’t give you much extra cooling as the law of diminishing returns will kick in.
You can save some money by avoiding more than three fans in your case.
If you insist on filling up all the fan slots in your case, install three intake fans in the front with two exhaust fans in the top panel and another exhaust in the back.
You should also consider that multi-fan setups can become extremely noisy.
Sometimes, a fan’s noise level outweighs its thermal benefits, especially if you install it in the top panel.
Your CPU, graphics card, and power supply should come with dedicated coolers—and in most cases, you can upgrade the CPU cooler.
To optimize the airflow in your PC, you need to consider the tower’s layout as well as the sizes and positions of the components, especially the graphics card and CPU heatsink.
Then choose the best location and spin directions for the fans in your case accordingly.
The case’s design and materials also significantly impact how you can implement cooling.
Below, we’ll discuss the various types of fans you can use on your computer and how they’ll impact your cooling and noise.
Types Of PC Fans
PC fans come in various forms and sizes.
You can divide them into different categories based on their blades, size, and bearing technology.
Let’s go over each factor and consider the different options.
1. Blade Design
Fan blades come in three main varieties:
A. Static Pressure (SP)
These fans are excellent for cooling radiators and heat sinks because there’s only a small gap between the blades, and the blades are thicker and flat.
As a result, the air will enter the case with much more force.
SP fans are also a more effective option for passing the air through a thick filter.
Another advantage of these fans is that they have minimal splashback, the air that hits an obstacle after passing the blades and slips back in the opposite direction.
B. Air Flow (AF)
These fans are characterized by the large gaps between the blades, allowing a larger air volume to pass through.
However, the air will be pushed through with less force, making these fans less optimal for cooling radiators and heat sinks.
These fans have more splashback, given the large gaps between the blades.
Hybrid designs give you the best of both worlds:
- Swept blades that scoop the air more efficiently and increase air velocity.
- Excellent airflow due to the relatively large gaps between the blades.
These fans also operate very quietly because their blades are less flat and have a lower density, which reduces turbulence and noise.
Hybrid fans aren’t optimized for a single application, but they work adequately in most scenarios, which is why they’ve become ubiquitous in recent years.
As a rule of thumb, smaller fans generate more static pressure even if their RPM is lower.
That’s why it’s best to cool a radiator with a smaller fan.
On the other hand, larger fans tend to have less RPM because turning larger blades requires more torque, which puts more strain on the motor.
The three most common diameters for PC fans are 120 mm, 140 mm, and 200 mm.
A. 120 mm
The main advantage of these fans is their ability to direct a focused cone of air at high pressure.
As mentioned, they’re excellent for cooling radiators.
However, they’re notoriously noisy because of their high RPM unless you spend a few more dollars to buy silent fans.
B. 140 mm
One hundred forty millimeter fans are the middle ground between noise and performance.
You get excellent cooling because more air passes through without significantly reducing pressure.
However, larger fans typically generate more noise.
You can’t expect the silent operation you get from 120 mm fans, but these fans won’t be as noisy as 200 mm fans either.
If you intend to install fewer than three fans, 120 mm fans are the superior choice because they create a more focused flow of air.
As you increase the number of fans in your PC, 140 mm fans pull ahead in terms of cooling, but they generate more noise.
A compromise would be to reduce the RPM on these fans to make them less noisy, but that also reduces their cooling effectiveness.
C. 200 mm
Spinning a 200 mm blade requires considerable force, which means you’ll get lower RPM and higher power consumption.
However, these fans cover a much larger area than smaller fans.
You’ll get unmatched airflow with these large fans.
You can put two of these in the front of the case to create a constant flow of high-volume air slowly passing through your chassis.
Large fans come with a serious disadvantage, though.
They have a limited lifespan because the motor has to work harder to spin the blades and the bearings tend to fail after a while.
The fan bearing is the most critical component determining a fan’s lifespan.
To understand why you need to understand how a fan operates.
The fan blades are attached to a shaft that rotates to spin the blades.
This shaft is inside a cylinder which has a mechanism to reduce friction and allow the shaft to rotate more smoothly.
This cylinder is called a bearing.
Fan bearings use different mechanisms to lubricate the shaft and allow it to run more smoothly, but the main ones are fluid bearing and ball bearing.
A. Fluid Bearing
Fluid bearing is simply a small amount of lubricant that reduces the surface contact between the shaft and the fan hub.
Fluid-bearing fans are cheap, but they have the shortest lifespan as they’re notoriously prone to dust and leaks.
It’s easy to identify dust buildup inside the bearing as it prevents the fan from spinning efficiently.
Your fan will spin for a couple of seconds but suddenly stops.
Leaks are also easy to detect because the fan makes rattling noises.
Fortunately, these problems are easy to solve.
All you have to do is pop the hub off, clean it, and refill it with mineral oil.
It’s best to install fluid-bearing fans vertically to reduce the chances of leakage and rattling noises.
In contrast to the previous type, ball-bearing fans are the most durable and expensive.
The mechanism uses a ring of balls around the shaft to reduce friction.
These fans can withstand higher temperatures and aren’t prone to leakage or dust buildup.
You can also install them in any orientation without worrying about longevity.
However, regardless of the bearing mechanism, vertically installed fans tend to fail more quickly due to gravity.
The main problem with ball-bearing fans is their high noise level, but highly silent fans are available at slightly higher prices.
C. Maglev Bearing
Magnetic levitation (maglev) bearings use magnets to levitate the shaft and allow it to spin without coming into contact with the hub.
These fans operate entirely without any fluids, meaning they’ll have extremely long lifespans.
However, maglev is a relatively new technology for PC fans.
Therefore, it’s naturally more expensive, but longevity can save you money in the long term.
Choosing The Right Fans For Your PC
Many people obsess over the number and types of fans they want to put in their rigs.
As you’ve seen, there’s no shortage of options when it comes to fans.
The choice doesn’t have to be difficult because cooling technology has come a long way, and you can get adequate cooling with almost any fan.
As a rule of thumb, choose fans that fit your budget and give you the appearance you want.
If you want to dig deeper, here are a few factors you need to consider when selecting fans for your PC build.
PC fans are designed for specific use cases with specific features at specific price points.
You can spend anywhere from around $12 to $35 on a fan.
High-end fans usually feature switchable RPM profiles, cord extensions, and anti-vibration pads.
They’re optimized for silent operation and provide better airflow and static pressure.
Budget products come with bare-bones functionality, lower RPM, and may even make some noise.
Overspending on fans isn’t a wise decision because the law of diminishing returns kicks in as you buy more fans with heftier price tags.
A thirty-dollar fan won’t necessarily give you twice as much airflow as a fifteen-dollar one.
Check out the manufacturer’s numbers for cubic feet per minute (CFM) and noise levels (dB) at different RPMs to find the sweet spot between noise and cooling.
A fan running at around 2000 RPM is more than enough for most gaming PCs, but if you have a system with excessive heat, you can go with 3000 RPM options.
If you have no budget restrictions, you can go with the Phanteks T30, which features a thick 30 mm frame that maximizes airflow.
Gaming hardware manufacturers like Corsair and Cooler Master have gone to great lengths to design cool-looking fans.
RGB fans allow you to customize the appearance of your rig, but they have a few disadvantages:
- They cost more.
- You need special software and controllers for true customization.
- Depending on the number and type of fans you use, they may require complicated wiring.
- Some RGB fans come with proprietary connectors that may not be compatible with your motherboard.
Despite these disadvantages, there’s no denying that RGB fans take your rig’s appearance to a whole new level.
Not all fans can operate in dusty or humid environments.
If you live in an area with lots of dust or you have to keep your PC in a basement with excessive dust buildup, fluid-bearing fans aren’t a great choice as the dust will quickly mix with the fluid and prevent the fan from spinning.
Instead, you should buy sealed, dust-proof fans which are IP55-rated.
These fans are also relatively waterproof, meaning they’ll last longer in humid areas.
If your dust or humidity problem is more severe, you can opt for an IP67 rating, which costs more but gives you total protection against dust and airborne particles.
You can configure your fans to pull air into the case (aka intake) and push it out (aka exhaust).
Before getting into the details, note that fans don’t create air.
They just move it around.
If you have all your fans set to exhaust, they’ll counteract each other’s efficiency because they work against each other.
Moreover, since the exhaust fans push out all the air inside the case, fresh air has to penetrate through the case side panels.
That air carries dust particles that accumulate in all the nooks and crannies of your case and suffocate the airflow.
The opposite situation isn’t all that effective either.
Intake fans also cancel each other out, but the slight advantage is that they blow the dust particles out of your case instead of drawing them in.
The optimal layout is to have both kinds of fans with slightly stronger intake fans that send out dust from your system.
You should also have dust filters on the intake fans to prevent excess dust from entering in the first place.
How To Determine Fan Airflow Direction
It can be confusing to determine which way a fan pushes air, but fortunately, manufacturers make it easy.
There are usually two arrows on the outside rim of the fan that indicate which way the fan pushes the air and which way it spins.
If you can’t find the arrows, you can turn the fan on for a few seconds and determine the direction by putting your hand in front or behind the fan.
You can also find the direction by seeing which side is the front and which side is the back.
Fans usually pull air in from the front and push it out from the back.
The backside has four brackets that form an X shape, whereas the front is unrestricted.