120mm vs 140mm Case Fans – A Clear Winner For Most Cases

Fans between 120 mm and140 mm, which size case fan is best for you?

This is the question I hope to answer in this article. It will walk you through all you need to know about these popular forms of expression.

Understanding Case Fan Sizes

Case fans are generally measured by the dimensions of the fan enclosure in a square shape. This is the length of the side.

A 120mm fan might seem small, but it is about the same size as an adult’s hand.

A 140mm case fan can sound and look very similar but have so many different characteristics. The extra 20mm of surface area per side makes it even more appealing.

120 mm Case Fans

The most popular case fan size is 120mm and they are compatible with a wide range of build types.

Even larger cases with more space for 120mm fans will still work. Many consumers choose to buy a 120mm fan even though their case might actually be able to accommodate a larger fan.

It’s not just about familiarity. 120mm case fans are generally more expensive than their more specific 140mm or larger counterparts.

140 mm Case Fans

The best 140mm case fans are the second most common size, but they are more expensive and less compatible than 120mm fans. Due to the popularity of HTPC, Mini ITX, and Micro ATX cases, 140 mm fans may not always be compatible if you are planning to build an SFF (Small Form Factor) computer build.

The larger fan size has its advantages, however. For most Micro ATX and ATX cases, a 140mm fan in the same spot as a 120mm fan can produce better results.

Other case fan sizes

It’s worth noting that other fan sizes are available than the most popular.

As a way of increasing airflow in some SFF cases (or bold ATX cases), 200mm fans are more popular than ever.

Some users might also be pushed to smaller fan sizes, such as 80mm or lower.

These fans are great for low-profile builds. Sometimes, they are even used in places not intended for them. After the internals have been removed and replaced by a Mini ITX, an exhaust vent from a large VCR can be used to mount a fan at 80mm.

Let’s compare our two rivals now that we have an understanding of the different fan sizes.

Why 120 mm fans are the best

Compatibility and Ubiquity

A 120mm fan has the obvious advantage of being compatible with any build.

Even the smallest HTPC and Mini ITX cases have at most one or two 120 mm fan mounts. Large Extended Tower cases can still be mounted with plenty of 120 mm fans.

Lower Cost

Cost is another factor. You can fit a 140mm fan in the same spot, but sometimes customers prefer to save money by choosing 120mm.

This is not something we would recommend as a deciding factor for 140 mm, but it is a valid pro for 120 mm fans.

Read Also: Ryzen 5 Motherboard Best Am4

Why 140mm fans are the best

Quieter Operation

It turns out that you can run two fans at the same RPM and the smaller fan will actually be louder.

A lot of small fans won’t be enough to reduce the noise generated by your computer.

When running at the same RPM, 140 mm fans are significantly quieter than 120 mm fans.

This means that you will get better cooling with less noise, especially if the fans are quiet.

More cooling power

140mm fans have a larger surface area than 120mm fans, which allows them to have greater cooling power.

This point is not without nuance. It will all depend on the fans you are actually purchasing.

A larger fan will push more air and run at a slower speed than a smaller fan.

How to Choose

Choose A 120 mm Fan if…

• You are building in a Mini ITX or HTPC case
• If the price savings over getting 140mm are worth it in a larger case
• Your fans want you to transfer them to a new PC eventually
• You have a messy Case and require high static pressure

Choose A 140 mm Fan if…

• Your fans should be quieter, especially if they are large air coolers or radiators.
• You’re building in a compatible Micro ATX case
• You are building in an extended ATX or standard ATX case

FAQ

How many case fans do I need for my computer?

It depends on what you mean, and we’ve covered this extensively elsewhere on the website.

You should aim for at least 3. You want at least 2 for intake and 1 for exhaust.

To maintain a positive pressure environment, it is important to have more intake than exhaust as you grow your case fans.

A positive pressure configuration will allow you to minimize dust buildup in your computer while still allowing for maximum airflow.

Do I need a different fan size for my case?

If your case can accept both 140 mm and 120 mm fans, then you will want the 140 mm.

You will want to use the 200mm fans compatible slot(s) in your case. Cases with 200mm fan mounts are often optimized to fit 200mm fans.

You might consider smaller fan sizes, such as 80mm or smaller for your case or mod project.

You may not see the same cooling effects with such small fans. So be aware of these thermal limitations. For SFF PC builders, might I recommend a blower-style graphics card?

What are the Best Case Fans for My PC?

Last but not the least, Where can you find the best case fans for your computer?

You’ll find a number of recommendations in that article, as well as the link I just provided to more detail on that topic.

The Noctua HTML12 redux is a great choice for 120mm fan users. This 120mm fan has full support for PWM (fan controls), and speeds up to 1700 RPM.

It is balanced for high airflow and high pressure. This means that it can be mounted anywhere on your computer, even on a cooler.

I recommend the be still! Silent Wings 3. This fan is a 140mm case fan with PWM support. It can run at speeds up to 1600 RPM.

It is also very quiet under load, as the name suggests. This makes it perfect for liquid cooling radiators and quiet case fans. Although it is more suited for cooling, it can also be used as an intake or exhaust.

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