Reverse-flow OEM Tower Cooling?

CDR_Xavier · June 15, 2023

Hello, this is Xavier.

We (our club) have a few OEM towers in our lab (a old ThinkCentre and a Optiplex 7020). Both computers come with a single 92mm rear exhaust, no intake and no mesh.

I have found out that the Thinkcentre have a front 80mm fan mount, so I added a 80mm server fan for some positive pressure -- mainly because I put a GTS8800 in it, which ran quite hot.

The GTS8800 is of blower-style cooler, so I think increasing the internal pressure (of the case) will help, so I also reversed the direction of the 92mm exhaust, so now it points inward. The GPU temp is now lower (by about 5 degrees), but I'm not quite satisfied with that.

The CPU cooler is, for all purposes, a Intel stock (except it's a Lenovo-made Intel Stock, since it's a OEM case and blah blah)

The Dell doesn't have a high-power graphics card (a RX460), thus it doesn't run as hot. However, I also reversed the exhaust fan to be the intake, and I plan on upgrading it with a 50W (12V 4.32A) server axial, because I reasoned that dust management will be easier if all the air enters through filters at few easy-to-access areas, and also because the Optiplex don't have front fan mounts. I'm mildly concerned that the motherboard can't handle it, but on the other hand the fan also only come with a single positive wire, so I think it might be able to manage. If not I will purchase separate ~20-30W axials.

Also for both computers, I am considering adding a fan filter, however I am unsure of what rating of the filter (I believe they are in ppi, or ppo) I should choose. I have seen PPO~200 filters around industrial machinery, but I'm not sure.

I don't care if hot air exits the front of the computer. I want the temps to be controlled, and that the machine won't be filled with dust in half a year.