Optimal airflow for my setup (BeQuiet 802)

Kashinoda · 6 May 2021 at 21:14

Trying to work out the best use of my existing case fans in this case before building.

I have
4x Noctua NF-12 120MM
3x Arctic P14 140MM
2x BeQuiet Pure Wings 2 140MM

I've had a best guess at proportions here:

I'll remove a portion of the bottom panel so the lower 140mm isn't wasted. My main concern is on the top-right exhaust diverting air away from the CPU Cooler, am I over thinking that?

I note a fan can also be mounted at the bottom if all the PSU shroud is removed, but is that worth doing?

defoerate · 6 May 2021 at 22:52

If you don't put fans on the floor and you have good front air intake I guess the air will move a bit like this video.

https://www.fractal-design.com/wp-content/uploads/2021/02/Meshify-2-Compact-Airflow-Loop-4K-1-HB.m4v

ninjag · 10 May 2021 at 22:52

This is why my OCD airflow adventures have gotten me so far!

I found that using the top fans as exhausts wasn't working out as expected and I was also worried about losing airflow from the top front intake so I changed them to intakes (mesh filtered as well) and it seemed to work better.

The fans don't push a huge amount of air under normal conditions as they now sit around 670rpm. If the CPU goes above 60°C then they start to crank up and this is when I get a lot of airflow but unfortunately a lot of noise as well.

My CPU (5600X) sits in the 30's when idle. I'll need to grab a screenshot after some gaming with the new fan setup. It's more the GPU which gets hot (1660 Super), especially when clocked, so I added that extra fan just before it and have yet to test it out.

My case fans are Corsair ML140
The one on the CPU Heatsink and in front of the GPU are 140mm Alpenföhn fans.

One thing I've noticed with these Corsair ML140 fans is that there's no direct airflow from the centre of the fans and it all seems to come from the edges and goes out at a bit of an angle. Airflow doesn't feel great when running at low rpms. When cranked up to 100% they are awesome, but also very loud.

The spare 140mm Alpenföhn fan from my CPU cooler seems to be much better at having direct airflow straight from the fan (could be the fin design?) and definitely pushes out more airflow at lower rpms and therefore much quieter. I'm tempted to replace my Corsairs with a few of these: link

I'm starting to wonder just how effective air cooling is, or perhaps more accurately how variable it is. I think once you have a decent airflow system in place then the actual power of the airflow doesn't seem to have a huge impact unless it's at full blast, just so long as the air is moving. I reckon if I reduced my rpms to 300rpm it probably wouldn't make much difference, so long as they crank up when under load.

ninjag · 11 May 2021 at 00:33

After an hour and a half of Shadow Tactics "Blades of the Shogun" which surprisingly hammers my GPU, these are my temps.

The GPU is overclocked, MSI Afterburner keeps increasing the power to 100% on reboot, and temps would normally be high 80's with the GPU and about 91-93°C with the hotspot. It would seem the fan in front of the GPU is helping a little bit, not huge but enough to keep things more comfortable.

Shame I can set fan profiles in BIOS against the GPU temp. There's a PCI-E temp sensor, but that's not the same and they've remove the option to set against it now anyway

EsaT · 11 May 2021 at 18:04

ninjag said:
One thing I've noticed with these Corsair ML140 fans is that there's no direct airflow from the centre of the fans and it all seems to come from the edges and goes out at a bit of an angle. Airflow doesn't feel great when running at low rpms. When cranked up to 100% they are awesome, but also very loud.

The spare 140mm Alpenföhn fan from my CPU cooler seems to be much better at having direct airflow straight from the fan (could be the fin design?) and definitely pushes out more airflow at lower rpms and therefore much quieter. I'm tempted to replace my Corsairs with a few of these: link

Big motor hub obviously creates big airflow "shadow" and decreases area swept by blades lowering airflow per RPM.
And that traditional (high speed optimized?) blade design isn't good for trying to push air in focused fashion.

While also Alpenfohn has big motor hub, it has more blades and at bigger angle helping at lower RPMs.
With more forward swept blade design helping to produce more "coherent"/laminar airflow.