PC airflow discussion

[smut]

Hello everyone, One year ago I built my first PC.

I wanted to discuss about airflow in my case because I don’t think it’s the best configuration but I have to say the temperatures are just fine.

I basically have 3 front intake fans: two 120mm fans and one 140mm fan.

And total of 4 exhaust fans: One 140mm top fan One 140mm rear fan

RTX 3060ti founder edition which has 2 fans (one facing up and one exhausts through the IO)

And the PSU which is facing up and exhausts air out of the system to prevent dust buildup underneath the case.

I know negative airflow is bad, but I’m still not sure whether I should achieve positive or neutral airflow and what I currently have in my system.

I added a simple diagram of my build’s airflow plus some technical data about the fans, and I’d appreciate if some of you can analyze it and tell me what airflow I actually have, if it’s bad or not, and how can I make it better. Thanks in advance!

 

[Naijin]

20 minutes ago, smut said:

Hello everyone, One year ago I built my first PC.

I wanted to discuss about airflow in my case because I don’t think it’s the best configuration but I have to say the temperatures are just fine.

I basically have 3 front intake fans: two 120mm fans and one 140mm fan.

And total of 4 exhaust fans: One 140mm top fan One 140mm rear fan

RTX 3060ti founder edition which has 2 fans (one facing up and one exhausts through the IO)

And the PSU which is facing up and exhausts air out of the system to prevent dust buildup underneath the case.

I know negative airflow is bad, but I’m still not sure whether I should achieve positive or neutral airflow and what I currently have in my system.

I added a link of a simple illustration of my build’s airflow plus some technical data about the fans, and I’d appreciate if some of you can analyze it and tell me what airflow I actually have, if it’s bad or not, and how can I make it better. Thanks in advance!

 

https://pasteboard.co/jFKHx7q7AR5H.png

Maybe list your specs? What case are you using? You could already flip your PSU as intake from the bottom and if possible, move the 140mm fans to the front and use the 120mm fans as exhaust.

 

Negative pressure isn't necessarily bad, it just allows more dust to come in through small cracks/crevices instead of being stopped by a dust filter.

If temperatures and sound are fine, you can just leave it

[Tegneren]

The GPU fan is quite restricted and only some of the air from the rear fan goes out through the rear IO the rest goes out the side of the heat sink. The PSU fan usually dont run at all or quite slow unless you are pushing it close to its limit, so I think overall you have a slight positive pressure or quite balanced depending on whats happening. 

You can do a smoke test with some incense or something while running a stress test to check if there are air being pulled in to the case where its not supposed to

[smut]

1 hour ago, Naijin said:

Maybe list your specs? What case are you using? You could already flip your PSU as intake from the bottom and if possible, move the 140mm fans to the front and use the 120mm fans as exhaust.

 

Negative pressure isn't necessarily bad, it just allows more dust to come in through small cracks/crevices instead of being stopped by a dust filter.

If temperatures and sound are fine, you can just leave it

Thank you for your response!

Here are the relevant specs:

Case - be quiet! Pure Base 500DX (front panel is only supported by 2 x 140mm or 3 x 120mm. I managed to fit 2x120mm and 1x140mm )

i5 12600k with Cooler Master Hyper 212 Black Edition CPU Air Cooler

RTX 3060ti founder edition as already mentioned.

 

Temperatures and sound are fantastic so far, but I'm afraid about the dust build up while at high utilization of the fans..

I'll try the smoke test while stress testing as suggested by Tegneren

[smut]

1 hour ago, Tegneren said:

The GPU fan is quite restricted and only some of the air from the rear fan goes out through the rear IO the rest goes out the side of the heat sink. The PSU fan usually dont run at all or quite slow unless you are pushing it close to its limit, so I think overall you have a slight positive pressure or quite balanced depending on whats happening. 

You can do a smoke test with some incense or something while running a stress test to check if there are air being pulled in to the case where its not supposed to

That is exactly what was bothering me. Because at idle the GPU and PSU fans won't work at all but at high utilization the GPU will exhaust some, and the PSU will be at ~80% load so I guess it will start exhausting as well. So I have little positive airflow until the setup is running high, then I guess it has a slight negative airflow.

I will try the smoke test, thank you for the advice!

[Naijin]

29 minutes ago, smut said:

Thank you for your response!

Here are the relevant specs:

Case - be quiet! Pure Base 500DX (front panel is only supported by 2 x 140mm or 3 x 120mm. I managed to fit 2x120mm and 1x140mm )

i5 12600k with Cooler Master Hyper 212 Black Edition CPU Air Cooler

RTX 3060ti founder edition as already mentioned.

 

Temperatures and sound are fantastic so far, but I'm afraid about the dust build up while at high utilization of the fans..

I'll try the smoke test while stress testing as suggested by Tegneren

I had a 500DX as a previous build, was a great case and I just used the stock fans. I put the 2 140mm fans in the front as intake and 1 140mm as exhaust. Nothing extra added and sound/temperatures were perfect.

 

Flip your power supply to intake from the bottom, as it's got its own dust filter.

[TPCEA]

2 hours ago, smut said:

Thank you for your response!

Here are the relevant specs:

Case - be quiet! Pure Base 500DX (front panel is only supported by 2 x 140mm or 3 x 120mm. I managed to fit 2x120mm and 1x140mm )

i5 12600k with Cooler Master Hyper 212 Black Edition CPU Air Cooler

RTX 3060ti founder edition as already mentioned.

 

Temperatures and sound are fantastic so far, but I'm afraid about the dust build up while at high utilization of the fans..

I'll try the smoke test while stress testing as suggested by Tegneren

Dust, if you are willing to deal with it regularly and aren't forgetful like me (I just about forgot the anniversary breakfast at work today!), is not a big deal. However, it's better just to have positive pressure. If I understand correctly, you probably have positive pressure. A photo or diagram might help. 

[smut]

4 hours ago, RevGAM said:

Dust, if you are willing to deal with it regularly and aren't forgetful like me (I just about forgot the anniversary breakfast at work today!), is not a big deal. However, it's better just to have positive pressure. If I understand correctly, you probably have positive pressure. A photo or diagram might help. 

Living with pets is another level of dust, not in this build! 

I've uploaded a simple diagram of my build - https://pasteboard.co/jFKHx7q7AR5H.png

[TPCEA]

7 minutes ago, smut said:

Living with pets is another level of dust, not in this build! 

I've uploaded a simple diagram of my build - https://pasteboard.co/jFKHx7q7AR5H.png

I totally understand!

 

That is either slightly positive or neutral,  imho.

[Whatisthis]

5 hours ago, smut said:

That is exactly what was bothering me. Because at idle the GPU and PSU fans won't work at all but at high utilization the GPU will exhaust some, and the PSU will be at ~80% load so I guess it will start exhausting as well. So I have little positive airflow until the setup is running high, then I guess it has a slight negative airflow.

I will try the smoke test, thank you for the advice!

If you can put the exhaust fans on a separate header, you can run them slightly slower to maintain positive pressure.

 

You could also take out the top fan - natural convection will push hot air out, especially with a positive pressure case.

 

looks fairly balanced as-is. I would just monitor for dust issues and make a change if you notice it necessary.