Does have two exhausts like this mess up airflow?

thedream829

Weaksauce
Joined
Jul 22, 2021
Messages
75
So I have an NXZT H400 and when I have both exhausts (top, and back) it makes a loud noise, like some sort of turbulence noise. Would this also effect performance? I'm thinking about just having the back fan and no top.
 

ncjoe

Limp Gawd
Joined
Feb 16, 2016
Messages
213
you sure you have the fans facing the correct way ?

I have 10 total fans in pc... and case is very quiet .. at least to me...
 

hititnquitit

[H]ard|Gawd
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So I have an NXZT H400 and when I have both exhausts (top, and back) it makes a loud noise, like some sort of turbulence noise. Would this also effect performance? I'm thinking about just having the back fan and no top.
Try it and see what happens (with both your temps and noise).
What are you using as a heatsink?
 

SmokeRngs

[H]ard|DCer of the Month - April 2008
Joined
Aug 9, 2001
Messages
17,672
Having two exhausts in a setup like yours can technically mess up airflow but it's not likely to do so. The amount of air the fans would have to be pushing would need to be quite high and above what computer fans typically flow to have a noticeable effect above and beyond margin of error.

As for noise, it's highly unlikely a couple of exhaust fans could cause a loud noise. It's possible at least one of the fans has a mounting issue and causing vibration and noise because of it. It's also possible one of the fans isn't balanced correctly and has an issue with being either vertically or horizontally mounted. I've run into both issues. I was going to replace an exhaust fan in a system a while back and it caused some horrible noise and vibration. That fan mounting point used a plastic frame to hold the fan in place without screws so I removed that and screwed it into the case directly but the noise and vibration persisted. It turns out that specific fan did not like being mounted vertically at that specific place in the case. There was no trouble with the fan if mounted horizontally, not mounted at all or even mounted vertically in another case or in a different spot in the case.

Some weird things can happen with fans but it's highly unlikely your issue has anything to do with airflow issues.
 

doyll

[H]ard|Gawd
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So I have an NXZT H400 and when I have both exhausts (top, and back) it makes a loud noise, like some sort of turbulence noise. Would this also effect performance? I'm thinking about just having the back fan and no top.
Assuming your CPU and GPU are air cooled fan in top vent will most likely hurt rather than help case airflow. Best is likely 2x 140mm front intakes (hi-pressure fans) with all openings not covered by them on their mounting panel sealed off so air they flow into case has to flow thru case and out, not leak in front and into fan to end up going in circles cooling nothing.

You might find below link to basic guide of how airflow works and how to optimize case airflow of interest:
https://hardforum.com/threads/basic-guide-to-improving-case-airflow.1987938/
 
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