How To Install PC Case Fans With The Best Results

Want to give your computer a breath of fresh air? Learning how to install your PC case fans is one of the easiest and most important ways to do just that. It seems simple enough to screw a fan in, but do it wrong, and you can cause heat issues that will result in an unstable or slow computer.

There are a few minor things to consider as well, such as fan type, cost, speed, noise level and more. The first step in learning how to install a PC case fan is finding the right one for your situation. You should also know how it functions.

Here’s a simple definition:

” A fan is a hardware device that keeps the overall computer or a computer device cool by circulating air to or from the computer or component.”

Read the full article by Computer Hope.

Choosing The Right Fans For Your PC (Price, Size, Shape, Noise, RPMs, and Lighting)

Most fan options to consider include RGB lighting, maglev (magnetic levitation) motors, blade shape, and high vs. low RPMs. While LED lighting will only affect appearance; maglev will impact sound levels (and your wallet).

The first step in choosing a fan for your PC is deciding how much you want to spend. Prices vary, but if you’re on a budget, you can still get by with a lower end fan. Besides, higher priced options usually have more to do with noise reduction than with an increase in performance.

Note, RPMs don’t define the fans ability to move air alone, as the number and shape of blades can also determine how much air the fan pushes. Also, when looking at specs, make sure always to check the CFM (Cubic Feet per Minute), which is the fans measure of air flow.

Reasons To Install A New PC Case Fan

The most straightforward reason is that you’re building a new PC or upgrading an old one. If you’re starting from scratch, look for a case that has fans already installed. That way if you want to replace them with your own, you’ll already know their size and locations.

But, why would anyone choose to upgrade preinstalled fans?

One reason could be CPU overheating from poor air flow thru the case. Second, is a buzzing or grinding fan that indicates possible damage. Whether it’s age related or just broken, it isn’t working at max capacity and needs replacing.

The last reason is that the preinstalled fans may not look pleasing to the eye. Upgrading is a great way to improve your PCs overall look and feel too.

Pro Tip: To identify a faulty fan, isolate it by listening for a buzzing or humming noise as it spins. If it makes any unusual noises, it’s best to replace it.

What Power Connectors Do You Need?

When learning how to choose and install pc case fans, it’s essential to understand the different connector types.

The main types of connectors for PC case fans are a 3 and 4 pin analog or 3 and 4 pin MOLEX.

4 pin analog fan connector
A 4 pin analog connector allows for total control over the pc case fan.

Analog is always preferable, as it allows you to control fan speed via BIOS by plugging directly into the headers on the motherboard. Analog connectors also enable the use of fan speed controllers to set the RPMs manually.

4 pin molex power connector
A MOLEX connector provides power to the pc case fan, but not much else.

The MOLEX connectors will be useful if you have more fans than analog connectors. If your fan isn’t compatible with a MOLEX connector, they make adapters that remedy this. Note, that if using a MOLEX, you can’t control the speed of a fan, as it’s sole use is only to provide power to a component.

To connect a case fan to the motherboard, slide the plastic friction clip onto the fan header. To remove the connector, squeeze the clip until the small latch releases from the header, and gently pull.

Note: Some friction clips simply slide on and off without using a clip to hold it in place.

Power Connector Labels And What They Mean

When looking at the fan headers on your motherboard, you’ll notice the following labels:


The labels are meant as a mean of letting you know what goes where, but, can still come across as confusing.

For example, CPU_FAN is the header that connects to the fan on your CPU heatsink. CPU_OPT is used if you have more than one fan cooling your processor. The CHA_FAN header is the location where you’ll be connecting your case or “Chassis” fans. Last, the AIO_PUMP header is used to power and monitor an AIO (all in one) liquid cooling pump.

cpue fan header input
See two labels and only one input? In this situation it will accept either.

If you use a 3 pin analog connector, you can still use the 4 pin headers on the motherboard. Doing this will allow the fan to run, but you’ll lose the ability to fine-tune the settings.

Pro Tip: Have too many fans and not enough headers on your motherboard? Consider using a splitter to attach and control multiple fans with a single header.

Prep Your PC Case Before Fan Installation

Most modern cases use a combination of 80mm, 120mm, and 140mm. Always opt for the larger fan size when you can. A bigger fan is going to not only be quieter, but it’s also going to move more air.

Determine how many fans your case can support. Since not all fans are created equal, you need to find out what size each needs to be. To quickly find this info, refer to your case manual to see the supported size and placements.

Don’t forget to identify all of the fan mount locations around your PC case prior to installation.

How To Install A PC Case Fan

There are usually four main roles of PC fans. An intake fan that brings in cold air, an exhaust fan that expels hot air, a PSU fan that vents your power supply unit and a CPU cooling fan that keeps your core temps down when combined with a heatsink.

All fans move air in one direction, indicated by a small arrow that you can find on the top of the fan. If you can’t see this arrow, or your fan doesn’t have one, then look for a label on the motor housing. Air is forced out to the sticker side of the fan. If You don’t have a sticker or an arrow, then use the side of the fan where the wiring is visible.

labeled image showing case fan airflow direction
The sticker and wiring indicating the direction of airflow.

After you get the direction figured out, it’s as easy as putting the screws in. Take care that you don’t over tighten the screws since you never know when you’ll need to take them out again. Don’t worry the fan isn’t going to fly away.

To reduce any unwanted fan noise, try eliminating rattling by inserting the screws with rubber rings around them. These rubber rings usually are included with your fan. Also, you can get them off of Amazon or Newegg for a few bucks.

Pro Tip: Are you having trouble holding your fan in place? Painters (aka Masking) tape works great to keep it still while you set the screws in place.

Check Your PC Temps After Install

To make sure your pc case fans are set up and working as they should, it’s a good idea to download temperature monitoring software such as CPUID’s HWMONITOR. A lousy configuration will cause an increase in CPU temps and a decrease in performance.

HWMONITOR gives you a run down of temperature and system performance.

For the best results, you want a neutral air pressure inside the case to strike that perfect balance between the intake and exhaust fans.

Getting The Air Pressure Right In Your Case

The rate at which case fans move air is CFM (Cubic Feet per Minute). When selecting a fan, it’s better to look at higher CFM vs. only looking at RPMs. A fan can have high RPMs, but won’t move the same amount of air compared to a fan with high CFM and low RPM.

Note: Higher RPMs also mean increased dBA (Decibels Weighted-A) commonly known as noise.

It’s important to arrange your fans in a way that maintain constant static pressure. Having a high static pressure means that your case expels more air than it takes in. Having low static pressure means that your case is taking in more air than it can vent. Neutral static pressure is when your case is taking in the same amount of air that is being forced out.

direction of air flow in pc case
An even balance of pc case fans, provides neutral static pressure and maximizes cooling.

You want neutral static pressure for two reasons. It keeps a constant flow of air moving thru your case, which makes reducing temperatures more efficient. Second, it prevents the accumulation of dust by maintaining a continuous stream of air moving across the surfaces where dust would otherwise fall and collect.

Positive vs Negative Air Pressure as Fast As Possible
PC Case Air Pressure as explained by Linus Sebastian at Techquickie

An excellent way to obtain neutral pressure is to have the exhaust fans equal the same amount in mm (millimeters) of your intake fans. For example, if two front intake fans are 80mm for a total of 160mm and your exhaust fans are two 120mm fans at 240mm, you’ll lose air faster than you get it. The ‘wind tunnel’ effect only works if both intake and exhaust fans share the same amount of space (and air).

Effective Fan Placement: Intake vs. Exhaust

You’ll typically find intake fans at the front or bottom of the case and exhaust fans at the top and back. This configuration works best as hot air rises and cold air falls.

When it comes to installing fans over a radiator for closed loop water cooling system, there are two configurations you need to consider.

The first being the standard ‘push’ configuration, where you mount the radiator to the inside of the case. The fans are then screw directly to the radiator on the inside. This way the fans push air thru the heat absorbing metal fins and out of the computer.

The second is a ‘push/pull’ config using a fan on each side of the radiator. Everything is set up the same way as the push method, but additional fans are mounted on the outside of the radiator to pull air thru to the outside of the case. It’s often debated whether this works or not, but you can decide that for yourself.

Pro Tip: Never install your radiator with the intake fans, as this will cause heat from the metal fins to enter the PC case (you want hot air to exit).

Avoid These Common Issues

These are just some of the issue you might run into when figuring out how to install pc case fans.

If You get a fan that is too small, it may not move enough air to keep the temperature low. If it’s too big, it may not fit in your case. Though there is some wiggle room with larger fans, it may entail you screwing new holes in your case to accommodate it.

Question: Do you want to screw holes thru your PC case to install a fan?

Answer: Probably not.

Performing proper cable management can save your fans and cables from damage by getting them out of the way. The fans can get jammed up, or the fan can impact and break the cable; neither is a good scenario. You’ll be greeted by a loud ‘buzzing’ sound if one of your fans become obstructed by a wire.

Also, make sure that you connect your fan to the nearest header. By doing this, you expose less wiring to any moving parts and reduce the risk of damage.

Using Hardware or Software To Control Fan Speed

After you figure out how to install pc case fans, you can learn to control RPMs manually by using a fan controller. You’ll usually find one of these mounted on the front of your case in one of the drive bays. They have knobs or sliders, that when turned or slid up, increase fan speed.

A fan controller is convenient if you hate fan noise and only want them going full blast when gaming or watching a video.

If you don’t have a physical fan controller, you can adjust your fan speed by using your BIOS settings or other downloadable free software such as Almico’s SpeedFan.

Pro Tip: You must use a 4 pin analog connector to control fan speed manually. If using a 3 pin analog or a MOLEX connector, you won’t be able to adjust RPMs using BIOS or any other software.

How To Adjust Fan Speed In BIOS

By default, your PC case fan speed is set to auto in BIOS. This way your PC adjusts the RPMs under different loads so that your fans aren’t spinning away at full blast 24/7. If you want your fans to run at a set speed, try the following:

  1. Restart your computer
  2. Start pressing the ‘F2’ or ‘Delete’ keys to enter BIOS
  3. In BIOS, Select “Monitor” or “Status”
  4. Select “Fan Speed Settings” or “Fan Speed Controller” (or similar)
  5. Adjust the RPMs up or down
  6. Choose “Save and Exit”

How To Use ‘SpeedFan’ Freeware

Assuming you’ve already downloaded and installed the software, we’re going to jump right into using the program. Setting up the program may seem complicated at first, but it’s not, so don’t panic. To set your PC fan speed do the following:

  1. Open the ‘SpeedFan’ Program
  2. Choose ‘Configure’
  3. Next, select the ‘Advanced’ tab
  4. Click the ‘Chip’ dropdown
  5. Pick the option that ends in “$A40 on ISA” (or similar)
  6. Find ‘PWM 1 Mode’ and select it
  7. Select ‘Set to’ at the bottom and change ‘On/Off’ to ‘Manual’ or ‘Software Controlled’ (or similar)
  8. Check off ‘Remember’ before you click ‘Okay.’
  9. If not already on the home screen, select ‘Readings.’
  10. Change ‘PWM1’ percentage (%) up or down to adjust fan speed (0% stops the fan completely)
  11. Repeat to do the same to your other PC fans (PWM 2, 3, etc.)

And that’s all there is to it.

Need More Info?

We hope we were able to help! If you think we left anything out or if you have any additional tips, feel free to contact us. We’d love to hear from you.