Question How to achieve positive air pressure and keep temps low?

[wizkid96]

Hello everyone,

I recently discovered undervolting for GPUs and have been extremely happy with the results I got, but this led me down a pretty deep rabbit hole of optimization. I’m not experienced at all, so this is why I’m writing here. I was trying to set custom curves on my fans to achieve positive pressure inside the case to minimize dust, as it collects quite easily where I am. Unfortunately, I’m not sure if I’m doing this right. I have 3x120mm fans on the front as intake, 1x120mm on the back as exhaust, and a Cooler Master 240mm Lite AIO on the top as exhaust. The fan on the side of the case is off since it never did much to help with cooling or airflow anyway.

I plan on buying a better fan for the back since this one is pretty cheap. Additionally, I am planning on getting a Deepcool LT720 360mm AIO since the temps on the Ryzen 5950x get a bit high under load.

This is a picture of the fan setup:

https://imgur.com/D2OuqIs

View: https://i.imgur.com/D2OuqIs.jpeg


This is a picture of relative idle temps in a room with an ambient temp of around 31°C:

https://imgur.com/k3eV00c

View: https://i.imgur.com/k3eV00c.jpeg


And these are the curves I’ve set in the BIOS for the fans and pump.

Front fans -

https://imgur.com/4Tfs6QC

View: https://i.imgur.com/4Tfs6QC.jpeg

Back fan -

https://imgur.com/js4QUAC

View: https://i.imgur.com/js4QUAC.jpeg

Pump -

https://imgur.com/w9mWbfS

View: https://i.imgur.com/w9mWbfS.jpeg

Radiator fans -https://i.imgur.com/3HUNDYb.jpeg

If anyone can tell me how to go about setting fans for the best airflow, I would greatly appreciate it.

These are my specs:

• Case: Corsair iCue 5000X RGB
• Motherboard: MSI MAG X570 TOMAHAWK WIFI
• Video Card: Palit GeForce RTX 3090 GamingPro 24 GB
• CPU: AMD Ryzen 9 5950x
• CPU Cooler: Cooler Master MasterLiquid Lite 240, 2x120 mm
• RAM: Corsair VENGEANCE RGB PRO DDR4 32 GB (2x16 GB) 3600 MHz
• Power Supply: Cooler Master MWE 850 Gold V2

 

[SkyNetRising]

How to achieve positive air pressure and keep temps low?

Put radiator in side position. Radiator fans oriented as intake.

 

[wizkid96]

Put radiator in side position. Radiator fans oriented as intake.

Wouldn’t this put more hot air into the system ?

 

[SkyNetRising]

Wouldn’t this put more hot air into the system ?

Yes. Slightly.
But cpu temperatures would be lower and you get positive air pressure.

 

[JohnBonhamsGhost]

plan on buying a better fan for the back since this one is pretty cheap

i would change all fans to higher quality.

a Cooler Master 240mm Lite AIO on the top as exhaust...planning on getting a Deepcool LT720 360mm

this should make quite a difference for you.
even moving from a 280mm to a 360mm with similar quality fans lowered CPU temperatures ~6° across the board for me.

whether the AIO should be mounted on the side as intake or top as exhaust really depends on the overall setup.
i would install the 360mm in the top as exhaust and add 3x more side fans as intake.
this way fan RPMs can be significantly lowered to cut quite a bit of noise and offer much better temperatures system-wide.

 

[wizkid96]

i would change all fans to higher quality.


this should make quite a difference for you.
even moving from a 280mm to a 360mm with similar quality fans lowered CPU temperatures ~6° across the board for me.

whether the AIO should be mounted on the side as intake or top as exhaust really depends on the overall setup.
i would install the 360mm in the top as exhaust and add 3x more side fans as intake.
this way fan RPMs can be significantly lowered to cut quite a bit of noise and offer much better temperatures system-wide.

What fans would you recommend I get if I were to replace all of them? (I thought the 3 Corsair ones on the front were good, but judging by what you said, I guess they aren’t.)

 

[Eximo]

Are you having noise or temperature problems? A few degrees here and there isn't going to make much difference unless you are trying to max out a 24/7 overclock or something.

To get positive pressure you just need more intake than exhaust. You seem to already have that. Increase fan intake speed, decrease fan exhaust speed for even more positive pressure. Since you also have a lot of potential exhaust locations you may also need to cover some of them up.

Even with a positive pressure arrangement you will still want to have filters on all the intakes. The idea to keep dust out is to make sure that no air comes in through an unfiltered opening, thus the positive pressure. If you can't establish such a pressure, you may need to consider a different chassis.

 

[JohnBonhamsGhost]

What fans would you recommend I get if I were to replace all of them?

that depends on what aesthetic options you'd be looking for(RGB LEDs, fan itself's color, etc),
where you would be shopping,
and what budget you have available.

there are lots of nicer options these days.
compare
the airflow (CFM or m³/H),
the air pressure (mm/H2O),
and the noise produced (bB(A))
to what you have now, and see what better options are available to you.

your current fan specs should be available on the manufacturer product support pages for the hardware.

 

[Phaaze88]

Best Case/Heatsink/Radiator Fan Picks 2024 – Hardware Busters - Hardware Busters

Hardware Busters - Best Case/Heatsink/Radiator Fan Picks 2024 – Hardware Busters - Best Picks

hwbusters.com

The fan on the side of the case is off since it never did much to help with cooling or airflow anyway.

The fan in the picture is positioned as exhaust... even if it were flipped, it's one stream crashing into another. The more straightforward the air stream is, the more efficient it's going to be. In past threads, I was advising owners of 4000/5000/7000/etc cases to leave the side sealed, except if it were going to be used for a distro plate or pump/reservoir.

I was trying to set custom curves on my fans to achieve positive pressure inside the case to minimize dust, as it collects quite easily where I am.

1)You have the 5000X instead of the D-Airflow. Front panel on the former is more restrictive than the latter.
The front panel may be the biggest obstacle present.

2)Radiators are themselves a source of flow restriction, so keep in mind where you install one.
3)Exhausts should NOT be filtered. They reduce airflow too, albeit slightly.
There's a filter at the top, yes? It keeps dust out when the PC is off, but while it is running, it just helps to trap it inside, such as between the filter and a radiator.

4)There's no one way to set up fan curves. They don't even have to be curves; they can be flat.
Speaking of - the pump rpm should always be max, or close to it, because: LINK
5)A fan's performance doesn't scale linearly.
You are going to have to trial and error #4 & 5, tuning fans to your own comfort zone and as you need time to compare and examine how much and where the dust accumulates.

The above is also assuming the case doesn't have too many open seams/gaps to the point of making the pressure thing moot(some cases really are like this).
So, how frequently do you clean/dust out the PC?



TL;DR: 5000X front panel is screwing this up. It, or the entire case needs to go.
Install AIO radiator in roof, and remove dust filter up above. Cover/seal the side fan area.
Max out pump rpm, and play around with fan curves.

 

[js2]

Get magnetic dust filters for the intake fans, give the front of the filter a light rub down with fabric softener for extra kick. Also might be a good idea to replace all thermal paste/pads if it has been there for a few years.

Case looks like it could do with a dust out in general. Without dust filters u will be blowing dust more than air.

 

[wizkid96]

Best Case/Heatsink/Radiator Fan Picks 2024 – Hardware Busters - Hardware Busters

Hardware Busters - Best Case/Heatsink/Radiator Fan Picks 2024 – Hardware Busters - Best Picks

hwbusters.com

The fan in the picture is positioned as exhaust... even if it were flipped, it's one stream crashing into another. The more straightforward the air stream is, the more efficient it's going to be. In past threads, I was advising owners of 4000/5000/7000/etc cases to leave the side sealed, except if it were going to be used for a distro plate or pump/reservoir.




1)You have the 5000X instead of the D-Airflow. Front panel on the former is more restrictive than the latter.
The front panel may be the biggest obstacle present.

2)Radiators are themselves a source of flow restriction, so keep in mind where you install one.
3)Exhausts should NOT be filtered. They reduce airflow too, albeit slightly.
There's a filter at the top, yes? It keeps dust out when the PC is off, but while it is running, it just helps to trap it inside, such as between the filter and a radiator.

4)There's no one way to set up fan curves. They don't even have to be curves; they can be flat.
Speaking of - the pump rpm should always be max, or close to it, because: LINK
5)A fan's performance doesn't scale linearly.
You are going to have to trial and error #4 & 5, tuning fans to your own comfort zone and as you need time to compare and examine how much and where the dust accumulates.

The above is also assuming the case doesn't have too many open seams/gaps to the point of making the pressure thing moot(some cases really are like this).
So, how frequently do you clean/dust out the PC?



TL;DR: 5000X front panel is screwing this up. It, or the entire case needs to go.
Install AIO radiator in roof, and remove dust filter up above. Cover/seal the side fan area.
Max out pump rpm, and play around with fan curves.

Thank you for the awesome advice. I was actually thinking about the side fans and was wondering exactly this: if I were to install 3 intake fans there, wouldn’t that cause the air from the front panel to be disturbed? Which you basically said. So maybe what I would do is get the 360mm AIO, install it on the top, get a better fan for the back exhaust, remove the top filter when the PC is in use, and possibly check if there is a replacement for the front panel. Even if there isn’t, I can always detach it. One thing I was not able to figure out was whether I should swap the front fans because the ones that came with the case are optimized for static pressure and from the reading I did, it seems they need to be for airflow. Or does this not matter all that much?

 

[Phaaze88]

One thing I was not able to figure out was whether I should swap the front fans because the ones that came with the case are optimized for static pressure and from the reading I did, it seems they need to be for airflow. Or does this not matter all that much?

That would require some trial and error. Now, you may find after the testing that it doesn't matter much, but it's not possible to know before that.

 

[Silas Sanchez]

As far as dust goes it never ceases to amaze me how much builds up even with very balanced air flow, to fight natures evil I just periodically take off the side cases and give it a quick blast with my datavac. Dont be fooled, dust is gonna get in no matter what.

 

[JohnBonhamsGhost]

if I were to install 3 intake fans there, wouldn’t that cause the air from the front panel to be disturbed?

if air just dissipated that way, yes.
but because it combines to cause an equilateral stream, no.

the more air coming in through intake vents, the more that will be finding it's way out through exhaust vents/cracks/separations in the case material.
all of this exiting air will be taking internal heat with it.
you may still find pockets with circulating air that tend to stay warmer than others, but the less heat making it to these sections, the less heat there is to remain there.