Should My PSU Fan Be Up or Down?


We often get asked ‘should my PSU fan be up or down?

Your computer is a powerhouse of productivity, but only if you keep it cooled down. One of the most important ways to do that is by making sure your power supply unit (PSU) fan is in good condition. In this post, we’ll explore the benefits of keeping your PSU fan up and down, and how to tell if it’s not working right.

1. What is a PSU fan and what does it do?

A PSU fan is a cooling fan installed in a computer power supply unit. Its purpose is to keep the components inside the PSU from overheating by circulating cool air. Many PSUs have multiple fans, which work together to provide effective cooling. The size and number of fans varies depending on the size and power of the PSU.

Most PSUs have at least one 120mm fan, but some higher-end models may have two or even three. Some PSUs also include a built-in fan controller, which allows the user to adjust the speed of the fans based on their needs. By keeping the components of a computer cool, a PSU fan helps to ensure optimal performance and longevity.

2. The benefits of keeping your PSU fan up

One of the most important parts of any computer is the power supply unit (PSU). The PSU provides power to all of the other components in the system, and it is responsible for converting AC power from the wall into DC power that can be used by the motherboard and other components. One of the key features of a PSU is its fan.

The fan helps to keep the PSU cool, and it is an important part of maintaining the longevity of the unit. In general, it is best to keep the fan running at full speed. By doing so, you can ensure that the PSU stays cool and operating properly.

Additionally, keeping the fan up can help to reduce noise levels from the PSU, as well as improve overall airflow within the system. This configuration is recommended if your PSU is located at the bottom part of your case.

3. The benefits of keeping your PSU fan down

Keeping the PSU fan down has several benefits.

  • For one, it helps to prolong the life of the PSU by preventing overheating.
  • Additionally, it can help to improve the stability of the PSU, as well as reducing noise levels.

This configuration is recommended if your PSU is located at the top part of your case.

When choosing a PSU, it is important to select one with a high-quality fan that can be easily controlled.

A good PSU should also have ample ventilation to ensure that air can flow freely through the unit. By following these simple tips, you can help to ensure that your PSU will provide years of trouble-free operation.

4. How to tell if your PSU fan is up or down?

There are a few ways to tell if your PSU fan is up or down.

  • One way is to look at the fins on the fan. If the fins are pointing up, then the fan is likely mounted upside down.
  • Another way to tell is by looking at the direction of airflow. If the airflow is coming out of the bottom of the PSU, then the fan is mounted upside down.
  • Finally, you can also check the manufacturer’s documentation to see how they recommend installing the PSU fan.

In most cases, it will be clearly indicated whether the fan should be installed facing up or down.

However, if you are still unsure, you can always contact customer support for assistance.

5. How to change the direction of your PSU fan?

Most computer cases have at least one fan mounted on them to help keep the internal components cool. These fans typically draw air in from the front of the case and exhaust it out the back or topside. However, there may be times when you need to change the direction of the airflow, such as when mounting the case in an upside-down orientation. Fortunately, it is usually fairly easy to change the direction of a case fan.

  • First, locate the fan in question and identify which way it is currently configured.
  • Then, depending on the type of fan, you will either need to remove the entire assembly and reverse it or simply flip a switch located on the fan itself.
  • Once you have made the necessary changes, reassemble the case and power on your computer to test that the fan is now functioning correctly.

With a little bit of effort, you can easily change the direction of your case fan and ensure that your computer continues to run cool and efficient.

6. Tips for keeping your PSU fan in good condition

  • Keep it clean – Over time, your PSU fan will inevitably accumulate dust and dirt. This can lead to reduced airflow and increased noise levels. To keep your fan running smoothly, simply remove the dust and dirt on a regular basis.
  • Lubricate the bearings – Just like any other type of fan, your PSU fan has bearings that require lubrication. If the bearings are not properly lubricated, they will wear out quickly, leading to increased noise and vibration. Fortunately, lubricating the bearings is a simple task that can be easily performed at home.
  • Replace the impeller – The impeller is the blades that move the air through the PSU fan. Over time, these blades can become worn or damaged, reducing the fan’s efficiency. If you notice a decrease in airflow, it may be time to replace the impeller.
  • Check for bent blades – Bent blades can also cause decreased airflow and increased noise levels. Inspect the blades on a regular basis to make sure they are straight. If you notice any bends, simply straighten them out with a pair of pliers.
  • Check for obstructions – Obstructions in the airflow path can also cause decreased airflow and increased noise levels.

Alternatively get a computer technician to do the above.


Keeping your PSU fan in good condition is essential for ensuring that your computer runs cool and efficiently. By following these simple tips, you can help to extend the life of your PSU fan and keep your computer running at its best.

I am a computer engineer holding a bachelor's degree in Computer Science, complemented by a Master's in Business Administration from University of Strathclyde, Scotland. I currently work as a Senior IT Consultant in Melbourne, Australia. With over 15 years of...