Question Using a 120mm fan in a 92mm opening? Custom airflow opinions

gremlin3378

Honorable
Jul 27, 2015
22
0
10,510
0
I'm currently making a custom build using a strong case with fixed dimensions that don't offer that much flexibility. I'm asking for opinions on which design would offer the best cooling performance. I would prefer to use the 120mm fans that I already own unless using 92mm fans would provide near identical performance. Due to the size constraints of the case, 92mm openings are the largest I can make on the sides of the case. However, there is room for a two 120mm openings on the top of the case. Unfortunately, the airflow couldn't be a direct and straight path. There may or may not be that much difference in cooling performance with each of the designs. It makes sense to me to have a more direct path that lessens the amount of unnecessary turbulence. Additionally, I'm concerned about the CPU cooler fan's influence on the push and pull airflow path in the case. I would consider an alternative cooler (like a Scythe Big Shuriken 3) that offers a bit more vertical clearance if necessary. I would test it myself but I was planning on cutting only once. Any opinions from those who have tested similar designs or have experience with aerodynamics would be greatly appreciated. Understand that this is just rough concept for the sole purpose of optimizing airflow. The PSU will be in a separate section of the case along with GPU. Thank you

Here is the link to the images.
View: https://imgur.com/a/YttOG1j
 
Last edited:

ScrewySqrl

Champion
Moderator
teh 120mm fan will be choked on the 92mm hole, so you should be better using the 92mm fan there, though due to size they'll be noisier than a 120mm fan in a 120mm hole, but less than the choked fan.

an alternative would be the 120s on top and more 120s on the bottom with a bottom-to-top airflow build. if you do that, you can reorient the cpu fan (if its the elevated heat pipe sink that usually blows toward the back of the case)) to blow toward the top of the case
 
Last edited:

gremlin3378

Honorable
Jul 27, 2015
22
0
10,510
0
teh 120mm fan will be choked on the 92mm hole, so you should be better using the 92mm fan there, though due to size they'll be noisier than a 120mm fan in a 120mm hole, but less than the choked fan.

an alternative would be the 120s on top and more 120s on the bottom with a bottom-to-top airflow build. if you do that, you can reorient the cpu fan (if its the elevated heat pipe sink that usually blows toward the back of the case)) to blow toward the top of the case
I appreciate the suggestions. However, I just need to know if the larger 120mm fans rated at 50CSM used in the case to create "U" shaped airflow will offer better cooling performance than the 92mm fans rated at 35 CSM positioned horizontally on opposite ends of the case to create a straight path for airflow. This is assuming the 120mm fans would have a 120mm opening and the 92mm fans would have a 92mm opening (design A2 vs design B). Cutting the case from the bottom isn't an option.
 
Last edited:

Mtop

Notable
Nov 21, 2019
618
62
1,040
31
Ignoring speeds and noise levels 50 is greater than 35, I would go with the 50's.
I would not put the 120 in front of 92mm holes. I like B except I would not exaust where the intake can suck some of the hot air.
Me I'd do A2/B - 120 intake at top 120 exaust at rear.
Just my thoughts
 

ASK THE COMMUNITY

TRENDING THREADS