How to tell if a PC fan is intake or exhaust

The fan orientation of your computer is a critical consideration. You need to pay attention to the direction of the airflow of your fan if you want to prevent your system from overheating or avoid other hardware malfunctions.

If your fan is intake, it will pull cool air in, and when it is positioned as an exhaust fan, it will direct hot airflow away from your CPU or case.

However, if you are not a seasoned PC builder, you may have a hard time assessing if you have an intake fan or exhaust fan. The good news is we are here to help. Continue reading as we offer helpful tips to determine the airflow direction of your CPU or case fans.

Find the arrow points

Most computer fans have small arrow points indicating the airflow direction. Where the arrow points, air will blow from that side. This trick may only work if the fan has noticeable arrows.

Observe the fan blades

If the fan does not have arrows or is mounted on a CPU cooler or within the case, and you do not want to go through the trouble of unmounting it to find the arrow, you can simply observe how the fan blades spin.

The convex side of blades is the intake side and vice versa. If the fan blades appear rounded, it implies they are curving away from you, hence the intake side.

However, if the fan blades curve towards you and appear like a bowl, it is the exhaust side. At times it so happens that the exhaust fans have crosshatch supports for the fan’s frame. You may also find a circular sticker in the center reflecting the brand logo and name on the exhaust side.

Once you know in which direction the fan blades rotate, you may easily be able to determine in which direction the fan blows air.

Why is it important to know the direction of fan airflow

Knowing the fan airflow direction is important as it can help you determine where to mount the fan, particularly if mounting it on a case. It will also help you determine the correct airflow setting for case fans.

Here is what you need to consider when setting up your computer fans. It is preferable to have a positive pressure instead of a negative pressure setting. When you configure the fans for positive pressure, it implies that more fans are set up as intake fan and blowing cool air in instead of pushing hot air out. Hence, it is important to ensure that your computer is provided with sufficient cool air so that the components of the computer are kept cold.

If your fans are too loud, check out the post on how to control case fan speeds.

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Tracy C.
Tracy C.

Hi! I'm Tracy and I am the owner of this little website. I build it as a resource center to troubleshoot common tech, hardware and software issues.

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