How To Tell Which Way Do CPU Fans Blow

How To Tell Which Way Do CPU Fans Blow? Proven Guide 2023

This article, we’re just going to focus on How To Tell Which Way Do CPU Fans Blow? If you spend enough time around PC builders and sites about building PCs, you’ll quickly learn that the direction of a case or CPU cooler fan is essential.

When a fan is set up to take in air, the goal is to bring in cool air. But when a fan is set as an exhaust fan, the goal is to get hot air out of the case or cooler. Both choices are helpful depending on where the fan is in the build.

How can you tell at a glance which way the fan is going, especially since even experienced PC builders sometimes have to think about it? Even if the maker of your fan doesn’t make it clear, it’s pretty easy.

Look for the arrow

Some fans have a small sign on the outside that shows which way the air is going. The air will blow toward the side where the arrow is pointing.

Look at the fan blades

Some fans don’t have arrows, or you’re trying to judge a fan already mounted in a case or on a CPU cooler and don’t want to take it off to look for an arrow. You don’t need the arrow to tell you which way the air is going. Instead, look at the blades of the fan.

If the fan blades look rounding away from you, they are on the input side. (The side of the fan blades that curve outward is the side that lets air in.)

If the fan blades curve toward you like the inside of a dish or bowl, that is the vent side. (In other words, air comes out of the hole on the side that isn’t flat.) Most of the time, the crosshatch supports for the fan’s frame are also on the exhaust side, with a circular sticker in the middle that says the brand and type.

Remembering the shapes of the fan blades is the best way to figure out which way the fan is blowing. This way, you can tell right away which way the fan is blowing.

Why this matters

As we’ve already said, the movement of a fan affects how air moves. Especially for a case, the best place to mount it will depend on which way it goes. It also ensures you set the right temperature for your needs.

Most PCs use positive pressure to get enough cool air through the system, so you need more fans set to intake than output. In some cases, a builder might choose a negative pressure setup, in which more fans push air out of the box than pull it in.

Both ensure your machine doesn’t overheat from the hot air its parts make. But if you ignore how the fans are installed or how the case was set up when you bought it, you could end up with a different setup than you wanted.

Read our tips on installing fans and setting up fans for positive or negative pressure to learn everything you need to know to cool your PC as well as possible.

What fan should you use?

Air can be moved with a cheap fan. So will one that costs a lot. How loud they are and how well they move air makes them different. Also, they look so pretty.

But that doesn’t mean you should never buy fans. The type of fan you choose (airflow vs. static pressure) can help you get the best cooling out of your case.

When the speed increases, it’s easier to hear fans that are either more efficient, more prominent, or both. And if you’re building a fancier PC, the fan’s materials (and lighting choices) can make it look better.

Try one of the suggestions below to change your stock fans or add some to your build. All of them are well-liked by people who build PCs, and the PCWorld team has used them more than once. Of course, our list is one of many terrific choices; there are many others. But these ideas are an excellent place to start.

Arctic P12 PWM 120mm fan (5 pack)

Which Way Do CPU Fans Blow

These are always popular because they move air well, aren’t too loud, and come in packs of five for about $30 to $35. You’ll only pay $6 to $7 per fan, which is a great deal given how well they work. (They also come in 140mm if you need a bigger size.) Their only drawback is a lighter, less premium frame, but if you’re making a more expensive PC where materials and looks matter, you probably aren’t trying to buy in bulk.

be quiet! Pure Wings 2 120mm PWM (BL039) Cooling Fan

Untitled 1

Can’t afford Noctua but want a good worker with a quieter, more pleasing sound? Be quiet! made these fans. strike a great mix between higher performance, solid build quality, and low cost. And they’re much cheaper than Noctua’s black fans, which cost more than the company’s normal brown fans. (There is also a 140mm version.)

Noctua NF-A12x25 120mm fan

Noctua NF A12x25 120mm fan

At $35 each, these fans aren’t cheap, but they’re still very popular because they work well and aren’t too loud. If you don’t like the company’s typical tan and brown patterns, you can check out their Chromax line, which has a more traditional black. Noctua makes fans of different sizes and ones that are better for static air, but these are the best all-around choice.

Lian Li UNI Fan V2 SL120

Lian Li UNI Fan V2 SL120

Other RGB fans may have brighter lights, but few can beat how easy these Lian Li fans are to build with. Usually, when you use more than a couple of RGB fans, the wires get all tangled up. The cleanest way to connect these fans is to physically join them together and then connect just one of them to a controller or your motherboard. We like how these fans’ light effects are more modest and elegant, but since the first one came out in 2020, other versions have come out as well. You can adjust static pressure, airflow, or RGB. Whatever you want, you can do it.

How to Tell Which Way Do CPU Fans Blow?

In short, here’s how to figure out which direction your fan will blow:

  • Look for lines on the fan that show airflow.
  • Check how the fan’s blades are bent. If they are turned toward you, that’s the exhaust.
  • Check by putting a piece of paper or your hand in front of it while the fan is running. You can usually tell how the air is moving.
  • See what the fan’s sticker says. Most of the time, the side with the sticker is the side with the exhaust, but this isn’t always the case.

Follow our guide to fixing How to Fix CPU Cooler Not Screwing In


In conclusion, gaining an awareness of the direction in which the fans on your CPU blow is vital for achieving proper cooling and preserving the performance of your CPU.

You may extend the life of your computer system and make it more stable by ensuring that it has adequate airflow and that heat can be dissipated.

Do check our latest post on the Does CPU Affect FPS

As a result, if you want correct information regarding the airflow direction of your particular CPU fan, it is strongly advised that you consult the instructions or documentation provided by the manufacturer.


Which way is a computer fan blowing?

If the fan blades look like they are rounding away from you, that means they are on the input side. The side of the fan blades that curves outward is the side that lets air in.) Curved fan blades coming at you? The exhaust is on that side.

Does CPU fan go clockwise or anticlockwise?

Most computer fans move from front to back () and spin in the opposite direction of the clock. Most fans have the crossbars and wires on the back, which is the part that lets air out. Another quick way to tell which side is the intake is to see if you can see the whole blade.

What direction should fans be on CPU cooler?

Make sure the front of your CPU fan is facing the back of the heatsink so it can push cooler air between the blades of the HS and out the back. Here is where the exhaust fan(s) will take over and pull this hot air out of the case.

Are CPU coolers intake or exhaust?

Do CPU air cooler fans bring air in or let it out? Most stock CPU coolers have fans that pull air in. They pull air from inside the case and force it down through the heat sink. If the stock CPU coolers had exhaust fans, they would have to pull air through the heat sink and blow it into the case.

Which way should AIO fans face?

If you’re putting the fan on the “front side” of the case, the fan’s “convex side” should face the water cooling row. The fan should then be put on the front side of the case.