How Does a Computer Case Fan Work? | Different Types Explained

You have fans on CPU coolers, inside power supplies, and graphics cards. But are there any for RAM, motherboard chipset, VRMs, storage devices, and PCIe cards? Apparently, most of them rely on the computer case fan to cool them down by controlling the ambient air temperature inside the PC chassis.

Understanding how PC case fans work can lead to a better installation strategy and an educated purchase decision. This article will explore all the different types of case fans based on their size and design intent. Let's begin with the basics.

The Core Function of Computer Case Fans

Computer case fans move the hot air from the chassis, which can build up due to the presence of heat-producing components. In fact, liquid CPU coolers with front-mounted radiators can push hot air inside, which needs to be moved out. Similarly, CPU air coolers can heat up air inside the chassis, which needs to be effectively moved out, and fresh air needs to be brought in.

The computer case fans play a vital role in ensuring your PC thermals stay at a lower value. Lower operating temperature means that critical components like RAM, SSDs, and other performance-oriented parts do not thermal throttle. It also enhances their operational life. In simple terms, computer case fans keep the ambient temperature inside the chassis low. Here are the installation strategies and setups that play a role in the core function of chassis fans:

Airflow Dynamics: Intake vs. Exhaust

The installation orientation of the fan can create intake or exhaust. Remember that there are no separate types of computer case fans that are designed for intake or exhaust specifically. Typically, the aesthetic side of the fan is the pull side. You want the air to flow from the front and exhaust at the back to prevent recirculation of hot air.

Front or bottom fans act as intake, pulling cool air inside the chassis. They are also the least visible. You can install the exhaust at the rear and top. As hot air tends to move upwards, it helps the chassis achieve better heat transfer with lower effort.

Positive, Negative, and Neutral Air Pressure

There are different pressure conditions you can create inside the PC case using computer case fans.

• Positive Pressure: It is the best configuration. There is high pressure inside the case, which causes the clean air from the intake to escape from gaps rather than coming in. This configuration reduces dust accumulation. It is achieved by fans pushing more air inside than exhaust fans take out.
• Negative Pressure: For cooling, it's the best configuration, but not for dust. The dust can enter through gaps and accumulate in the PC case. It's done by using more exhaust than intake using computer case fans.
• Neutral Air Pressure: For moderate conditions, intake and exhaust to the computer case fans are balanced.

The Mechanics: How Does a Computer Case Fan Work?

There are mechanical and electronic aspects that make a computer case fan work. It needs to have cables providing electronic signals for control and power to the motor. Here are the electromechanical component details:

The Role of the Motor and Bearings

Motors and bearings are the key components that directly impact the longevity of computer case fans. Manufacturers use premium technologies to ensure that they offer a longer lifespan. Typically, all fans are DC-based with a brushless motor. It rotates the shaft on which the fan blades are also mounted, and they rotate at the same RPM. However, the shaft needs to be supported, which brings us to the most vulnerable part of a fan, i.e., the bearing. There are three main types:

• Sleeve: It is the most inexpensive bearing that uses a shaft that rotates inside a sleeve with some lubrication. These wear out the fastest due to dryness and heat.
• Ball: Instead of direct contact of the sleeve and shaft, there are balls in between that reduce the contact area. It improves lifespan and makes it resilient. Orientation of the fan doesn't affect its performance.
• Fluid Dynamic Bearing (FDB): The internal shaft rotates on a cushion of pressurized fluid. There is no metal-to-metal contact. It offers the longest lifespan but costs the most.

Fan Blades: Static Pressure vs. Airflow (CFM)

The fan blades are made with a specific output in mind. There are fans that are made to increase the static pressure, and then there are those that increase airflow.

• Static Pressure Fans: Static pressure fans will have lower operating RPM but have a high pressure difference between the inlet and outlet. These are ideal for cases with high obstruction. The blades are wide, low-pitch, and tightly packed.
• Airflow Fans: These produce a massive flow rate, but there should be no obstruction at their inlet or outlet. They have thin, highly curved, and widely spaced blades.

PWM (Pulse Width Modulation) vs. DC Speed Control

The traditional DC speed control PC case fans use a 3-pin connector for power supply and control. The motherboard simply drops the voltages to decrease or increase the fan's speed.

Modern PWM computer case fans use 4-pin connectors. They use 12V constant but send pulses of on and off cycles so fast that it impacts the fan speed. PWM fans are superior in terms of their noise levels and very low achievable speeds.

Different Types of Computer Case Fans Explained

When we have an in-depth idea of what PC case fans are, we can move towards understanding the three main categories:

Airflow Fans (High CFM)

As we mentioned earlier, the airflow fans are ideal for conditions where the intake and exhaust have no obstruction. They are ideal for pushing air into the chassis where the air path is clear to the exhaust. They can move larger volumes of hot air out of the chassis.

Static Pressure Fans

In case you need fans to push air across a fin, like in a CPU air cooler or the radiator of a CPU liquid cooler. Pushing air and pulling from the fins requires more pressure. The friction that comes with moving air over large surfaces and tight spaces between fins, especially in radiators, requires higher static pressure. If a fan has high pressure at low RPM, then it is considered premium.

RGB and ARGB Case Fans

Owing to the massive drive of computers being more aesthetic, RGB and ARGB case fans are the go-to choice for most. Whether you are gaming, doing productivity work, or streaming, the lively feeling that comes with lighting can change the mood. The latest ARGB allows individual LED control and is considered the most premium with sync options.

Standard Case Fan Sizes and Form Factors

Depending on the provision in the PC case, computer case fan manufacturers produce different sizes. The most popular are the 120 and 140 mm dimensions. However, there are specialty sizes that are designed to fit inside smaller and niche cases.

120mm vs. 140mm: Which is Better?

The bigger the better for performance. 140mm pushes more air at low RPMs, which means better air flow with a quieter system. In comparison, 120mm gives a more balanced approach, taking up less space inside the PC case. 120 mm runs quietly at low load, but when the boost is needed, it can cool the dense radiator of a high TDP CPU cooler.

Specialty Sizes (80mm, 92mm, and 200mm)

If you are aiming for a small form factor (SFF) PC build, then you may need the specialty sizes, including the 80mm, 92mm, and 200mm. Using a single large fan or multiple small fans to flow the air across a jam-packed HTPC or console-like gaming PC build.

Conclusion

The computer case fans are designed to push or pull air inside the PC chassis. The purpose is to circulate fresh air for heat control. You can install computer case fans in different orientations and configurations to achieve varying pressure inside the chassis. However, it's important that you pick the right fan size compatible with your PC and go for the fluid dynamic bearing (FDP) for longevity. Finally, use ARGB fans for control over aesthetics.

If you are looking for all the types of fans under a single roof, then consider ESGAMING. They produce static pressure and flow fans with ARGB for aesthetics. Founded in 2017, ESGAMING has quickly become a recognized emerging brand in high-performance computer components and accessories. From PC cases and power supplies to cooling systems, ESGAMING is dedicated to delivering creative, reliable, and well-crafted E-sport solutions for gamers, creators, and PC builders around the world.

For more information, visit www.esgamingpc.com.