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October 13, 2023

How to Know Which Way a PC Fan Blows

If you spend enough time on PC building forums, it doesn't take long to learn that the orientation of a case fan matters. It's important to get it right, so you can create a nice airflow through the case that pushes cool air in and exhausts hot air out. Getting it wrong can lead to overheating, which can damage components and shorten their lifespans.

It's also a good idea to dust the fans every six months or so, particularly if you live in a dusty environment. The more dust that builds up, the less efficiently the fans will work. It's a good idea to use compressed air to blow the dust out of the fans, which will keep them working at full capacity.

The easiest way to determine which direction a fan blows is to look at the arrow indicators on the casing. If a fan has a clear arrow pointing in one direction, that's the side of the case that the air will blow toward. If the arrow isn't present, or if you want to evaluate a case fan that is already mounted and you don't feel like unmounting it to look for an arrow, you can simply look at the shape of the blades. If the curve of the blades is away from you, it's an intake fan; if they resemble a bowl shape and curl towards you, it's an exhaust fan.

Knowing which way a fan blows helps you to properly mount them, which is a big part of creating and maintaining proper airflow through the case. It will ensure that cool air is being pushed through the CPU, GPU and other heat-generating components, keeping them from overheating, which can cause damage to them and reduce their lifespans.