Chicago
Track Your Order
0
Does it matter how many case fans you use inside a PC?
PC components produce heat and the primary way of handling this is by pulling cool air inside the chassis and exhausting the waste heat. That's where the trusty case fan comes into play. A case fan can be installed on a chassis where mounting points are located, ranging between 120 x 120 mm to 200 x 200 mm. 120 mm and 140 mm fans are the most popular, but how many should you install inside your PC? Is it best to use all available slots and will your PC overheat if you don't install any?
More fans will equate to better airflow
The more the merrier
Each fan installed is rated by how much air can be moved through its spinning blades. By adding more fans, you're essentially increasing the maximum airflow possible, resulting in more air being forced through the PC case. This air is important as it's used by heatsinks to pass heat from components such as a CPU. The faster we can move it, the better the thermal performance. But there's a flip side to adding more fans than you believe you require.
Instead of having a single intake and exhaust fan installed and running at 2,000 RPM, why not double them to two each and lower speeds to 1,500 RPM? Not only will you still be moving more air through the PC case (depending on the fan specs), you'll emit less noise. Fans are the number one source of sound from within the desktop PC. Be it a CPU cooler or case fans, you'll hear a combination of motor whine and air turbulence. Throw in an AIO liquid cooler pump and it's quite the orchestra.
But how does all this affect temperatures?
PC airflow guide: How to strategically set up your case fans
You'll need to set up proper airflow inside your PC case for optimal cooling. This guide will show you how.
Looking at the numbers
Measuring the differences (if any)
Not all PC cases come with fans. Some may come with one or two, others may come fully populated and some require you to BYOF (bring your own fans). Generally speaking, your hardware should perform well enough with limited cooling. So long as there's adequate cooling strapped to your processor, you shouldn't have any issues with heat. Two fans, one for exhaust and the other for intaking cool air would be sufficient for systems under sustained loads.
For reference, I used the NZXT H7 Flow, an Nvidia GeForce RTX 4070, and an Intel Core i9-12600K. Five test runs were completed for each configuration and delta temperature readings (room set to 21C) were taken during 3D Mark.
|
Case fans |
CPU |
GPU |
|---|---|---|
|
0 |
55C |
52C |
|
1 (1 rear) |
52C |
49C |
|
2 (1 rear, 1 front) |
46C |
43C |
|
3 (1 rear, 2 front) |
44C |
40C |
|
4 (1 rear, 3 front) |
42C |
39C |
|
4 (1 rear, 2 front, 1 top) |
41C |
39C |
|
5 (1 rear, 3 front, 1 top) |
40C |
38C |
|
6 (1 rear, 3 front, 2 top) |
40C |
38C |
As you can see from the data, using more fans helps lower system temperatures, be it the GPU, CPU, storage drives, or motherboard components. This is especially evident with the voltage regulator modules (VRMs) that are passively cooled using heatsinks next to the CPU socket. When using an AIO liquid cooler and limited case cooling, the VRM temperatures will increase due to the lack of directed airflow across the heatsinks. Having more air pushed through the case, more heat can be exhausted.
That said, if you have just one intake or exhaust fan, your PC won't melt. Modern hardware is more efficient than previous generations and the GPU and CPU will only run as fast as their thermal management allows. If you don't have enough cool air passing through your system, your hardware will simply run hotter at best or thermal throttle at worst. Before I installed two front fans inside my Mac Pro conversion project PC, I had just one exhaust fan on the rear.
Temperatures were pretty solid on the AMD Ryzen 9 7900 and RTX 4070. They weren't running cool by any stretch but barely passed 47C and 46C (delta temperature readings) playing games, respectively. Installing the two front fans increased airflow through the G5 lowered temperatures considerably (36C and 39C) and allowed the Arctic Freezer 36 A-RGB CPU cooler to slow down.
Airflow vs. static pressure
It doesn't really matter
There are two types of fans, airflow and static pressure. The former is designed for pushing air through chassis grills and the latter is mainly used on radiators or instances with more resistance. When it comes down to it, you can use either or for both applications, so long as their sizes match up (120mm or 140mm). Using static pressure fans on your PC case won't cause temperatures to rise uncontrollably. Airflow fans on a radiator may need to work harder, however.
If your PC case comes with a fan or two, using them without buying more will work well enough for general computing and gaming. Should you desire cooler temperatures, add a few more fans in strategic positions to match intake and exhaust to create positive pressure. The best part is high-quality case fans can be bought for as little as $10.
