Would it make sense if I reversed the airflow on a enclosed PC ?

PDifolco · March 2, 2022

Hi

I've got a fully watercooled PC (specs below) in a near fully enclosed desk (see pic), that is directly mounted to the wall, so no space or any possibility to put outside fans somewhere

Only openings are on the right side by the wall power plug (with the blue USB adaptor) and on the top to pass cables (between the Highlander figurine and the Bose mini speakers)

So not much air going in there...

Currently I have

Front 360mm rad (GPU AIO) with 3x120mm Alphacool Aurora fans on intake, at 50% constant speed (the GPU don't ever get past 60C)

Top 280mm rad (CPU AIO) with 2x140mm Arctic P14s fans on exhaust (towards the drawer...), running 40 to 95%

One 140mm BQ Silent Wings 3 (I think!) rear exhaust fan

I had a 3900X previously, and it didn't really get hot (75C max), but I've now a 5900X, tweaked it a bit with PBO to get some more boost, and this thing jumps right up to 75C+ when gaming, and 85-90C on torture tests/benchmarks (CBR23)

I know that those temps aren't really an issue with a 5900X, yet the whole area gets hot over time and I can see that in gaming it slowly rises to 80C+ as well after 1h or more...

Obviously the restricted airflow is an issue, hot air can't get out of the enclosure, so I was wondering if it could make sense to reverse the flow by putting the rear fan on intake at 80+% speed, and the front fans on exhaust still at 50% speed, letting the top ones to exhaust

This would maybe create significant negative pressure, but it seems that hot air will at least get out more efficiently then..

What do you think ? Did some of you tried this on an enclosed case ?

Eigenvektor · March 2, 2022

The one thing I'd be worried about with this would be dust. The rear fan typically has no dust cover, since it is exhaust, rather than intake. You'd have to take it out semi-regularly to clean it, otherwise you'll never see how much dust buildup there is.