How to Choose the Best PC Fan Direction for Optimal Cooling

Modern PCs can easily consume upwards of several hundred watts of power to push as many frames as possible. With this power, comes a lot of heat which inevitably has to be dissipated somewhere.

Mapping out the best possible and most efficient airflow direction and fan placement can be hectic. Especially since the complex jargon thrown here and there by enthusiasts can easily confuse new PC builders. So, what is your PC’s best possible fan configuration to achieve optimum airflow and cooling? Follow this guide for more details.

Basics of PC Fans

PC cooling works based on a very simple rule, cold air in, hot air out. If any one of these two checks is not satisfied, you will not achieve the desired temperatures. Staying on topic, PC fans mostly come pre-installed in cases nowadays. The quality and quantity as well vary a lot, though you can always go for aftermarket options.

1) Fan Size

If you’re out shopping for PC fans, you must’ve come to know that PC fans, like clothes come in different shapes and sizes. Larger fans at around 200mm can push through more air, however, most PC cases top out at say 120–140mm.

READ MORE: Case Fan Bearing Types – Differences And Comparison ➜

2) CFM (Cubic Feet per Minute)

CFM stands for Cubic Feet per Minute and is used to measure the volume of air that a fan can push through within 1 minute. A higher number means more volume filled, with most decent fans offering upwards of 50 CFM for 120mm.

3) RPM (Revolutions Per Minute)

RPM determines the number of times your fan spins in 1 minute. More RPM is normally better, though it can cause extra noise which is measured in Decibels (dB). RPM doesn’t really matter since CFM is a better measure of the fan’s performance. It is best to balance sound (dB) and CFM.

4) Difference Between Static and Airflow Fans

There are two types of fans based on how they circulate air. Static fans are commonly used when there are a lot of obstacles that may hinder airflow, say a radiator or a bulky CPU cooler. Aim for high mm-H2O values if you’re out to purchase a static fan.

If you want to save the extra cash, airflow fans are all about the air volume pushed. If your PC has a lot of free volume and air can pass through unrestricted, airflow fans may be just what you need. It is important to watch some reviews about the particular fan you’re purchasing to see if the claims are borne out by real-world performance.

READ MORE: 5 Best High CFM Case Fans For Efficient Cooling ➜

The Two Airflow Paths

What system parts do you need to cool? Generally, your priority should be to pass as much cool air as possible through your CPU and GPU since they tend to consume the most power. In this regard, we have two types of airflow directions;

1) Intake Fans

As the name suggests, intake fans supply cold air into your PC and dispel the hot air upwards. They provide a cooling effect that lowers the temperatures of your PC components.

2) Exhaust Fans

Hot air rises. The air around your GPU and CPU is heated and rises in your PC. Therefore, people generally install a fan at the rear end of their PC to drive off the unwanted heat.

To determine in which way your fan throws air, look for markings on the fan itself. A small arrow should indicate the direction in which the fan blows air. Likewise, if no such indications exist, inspect the curves of the blades. If the fan curves towards you, that’s the exhaust side.

READ MORE: How to Optimize and Maintain Positive Airflow in Your Gaming PC ➜

Types of Air Pressure

Typically, there are 3 kinds of air pressure, each having its own flaws and benefits. Ideally, there should be a minimal difference between these types of air pressure at any given time. However, we must go over them to get an idea of what a balanced configuration looks like.

1) Positive Air Pressure

To achieve positive air pressure inside your PC’s case, there should exist more intake fans than exhaust fans. This leads to the air pressure in your case being higher than the surroundings.

• Less Dust.
• Steady/Larger flow of cool air over components.
• Inadequate exhaust airflow.

2) Negative Air Pressure

Negative air pressure effectively means more exhaust fans than intake fans. This creates a net negative air pressure in your case, which does attract more dust since air flows from high -> low air pressure. However, it has the added benefit of removing excess hot air.

• Efficient removal of exhaust.
• Increased dust accumulation.
• Potential cooling imbalance if not configured properly.

3) Neutral Air Pressure

The ideal configuration should be neutral, wherein the number of intake fans is equal to the number of exhaust fans. The only caveat in this scenario would be the placement of these fans which we shall touch on in the next section.

• A balance between positive and negative air pressure.
• Theoretically, the amount of air taken in will be equal to the amount of air pushed out.
• Is slightly harder to achieve.

READ MORE: Effective way to improve Fan Curve of Over-Heating GPU [Guide] ➜

Different Types of Fan Configurations

Achieving the lowest temperatures for your PC is a game of min-maxing. There is no mathematical formula or one-size-fits-all solution in this case. You can, however, be within the margin of error of the best cooling possible should you attain a balanced configuration. What exactly does a balanced configuration mean then?

1) Single Fan Configurations

Most commonly found in OEM solutions, a single fan exhaust solution can only cool low-end desktops. If you use an old system or components that use less wattage, you can make do with this setup though it would be preferable to have at least one intake fan as well.

On the flip side, a single intake fan could be a disaster for your PC. Unless you use very low-power components, the hot air will just accumulate inside, basking every other component in its heat.

↪ When to Use This Config?

If you have a low-power CPU and GPU, this could be a decent configuration for your PC. Provided your case has the option, we strongly recommend getting 1 intake and 1 exhaust fan to get the best of both worlds.

2) Dual/Triple Fan Configurations

A dual fan configuration with a rear and a front fan is a perfect example of neutral air pressure. The air moves from the front to the back, straightforwardly flowing over the main components. If you prefer, you may install another intake fan at the front for enhanced airflow.

Most pre-built gaming PCs arrive in a triple fan setup with 2 intakes and 1 exhaust fan. If you run a mid-ranged setup, this should be perfect for your needs. The second fan at the front will provide ample cooling to the GPU within say 150W.

However, make sure that the airflow is not obstructed by meshes and poor design choices, which most budget PC cases are victims of.

↪ When to Use this Config?

This setup aims towards neutral to positive air pressure and is suitable for budget/mid-ranged setups. Do note that you should keep the size and wattage of your components in check. If your CPU cooler is very large, airflow might be obstructed and the same goes for the GPU.

READ MORE: 7 Best Coolers For Intel Core i9-14900K in 2024 ➜

3) Multi-Fan Configurations

A setup with 2 front intakes, and 1 top and 1 rear exhaust could be a worthy upgrade over the triple fan configuration we discussed above. The air pressure is neutral in this scenario, however, your mileage may vary since the air from the lower intake fan at the front still needs some push to move up towards the exhaust.

Alternatively, you could opt for a bottom intake fan. This will create significantly positive air pressure, however, if your case design allows for unobstructed airflow thanks to the absence of a bottom-mounted PSU, this setup efficiently circulates air around your GPU.

If you have the budget and the appropriate case, a front, rear, bottom, and top setup could do you and your GPU and CPU wonders. While the aim for neutrality continues, it is hard to find flaws within this setup.

↪ When to Use this Config?

If you have a decent rig and don’t want to dabble into AIO territory, these multi-fan configurations will do just fine. However, if you run unlocked 250W+ CPUs, you will need very strong air cooling or preferably a good AIO unit which we’ll discuss below.

4) All-in-Ones (AIOs)

AIOs are most often placed at the top of your PC, rather than the front. The fans can be set into push or pull mode, with the former pushing out heat, from the radiator, and simultaneously, from the PC. Similarly, the pull configuration, although rare, pulls in air which of course heats up since it passes through the already-hot radiator.

The most common AIO configuration is a top-mounted push layout. The CPU generates heat, this heat travels in the form of a liquid to the radiator (in red). The fans (in green) push out the heat from the radiators and create an exhaust at the same time.

A top-mounted pull design can lead to even lower CPU temperatures, however, it may increase the overall case temperature. Likewise, this decision will require some changes to your fan setup to achieve a balance between intake and exhaust fans.

↪ When to Use AIOs?

AIOs are more aesthetically pleasing than a normal air cooler. They can be costly and if are satisfied with your current cooler’s performance you should not burn money on an expensive AIO, unless you’re really compelled by the looks.

READ MORE: Best AiO Coolers – 120, 240 and 360mm ➜

Which Fan Setup Suits You the Most?

Depending on your PC’s specifications and power consumption, you first want to make sure whether you want to use a normal air cooler or an AIO. Afterward, based on your PC’s case and budget, decide on the number of PC fans you can purchase.

You must choose your GPU accordingly. In a particular case, Linus found that his RTX 3090 ran at higher temperatures with two intake fans and one exhaust fan compared to having just one exhaust fan.

That video was debunked and the conclusion came out to be that the GPU was benefitting more from a negative air pressure. While installing two intake fans at the front would seem beneficial to anyone, even according to us, that specific build required a bottom intake fan as well to push the GPU’s hot air upwards.

Long story short, the GPU was too large, the case was too small and there should’ve been a bottom intake fan for the GPU. Select a case that allows you to install a fan at the bottom and make sure it’s not on a carpeted surface if you do so.

Budget cases cover the front intake fans with unnecessary plastic, hindering the airflow significantly. Whatever you do, avoid PCs with a solid front panel like the plague. It is also necessary to make sure your CPU cooler is appropriate for your processor; you wouldn’t want to pair an i9-14900KS with the stock Intel cooler.

READ MORE: How To Control The Fan Speeds Of Your Newly Built Gaming PC ➜

Conclusion

To achieve the perfect airflow, determine and re-evaluate your requirements. You may need to upgrade your casing or fan set if your components are power-hungry. Avoid dust build-up and perform routine maintenance on your system.

Fan orientation and pressure types don’t really matter as long as you maintain a balanced setup. Likewise, if you think you have the best possible orientation, try upgrading your fans based on the CFM / mm-H2O values.

The ambient temperature can also affect your PC’s performance a lot. Since this factor is not under your control, try undervolting your GPU and CPU, which can sometimes give better performance and even prolong your GPU’s lifespan.