Reversing PSU Fan to Exhaust

maklabouhlel · 16 Jun 2022 at 22:05

Hi there, I just bought an Asrock DeskMeet barebone PC and I want to replace the existing PSU which is a standard ATX PSU but the fan exhausts air onto the CPU fan. I have a Seasonic PSU for the job but I'm going to have to reverse the fan and void the warranty. That's not too much of an issue but I was more concerned about the PSU overheating if I did this. Any advice welcome?

maklabouhlel · 16 Jun 2022 at 22:32

Zefan said:
Can you clarify the issue? Why are you replacing the PSU, because it has a different airflow configuration or because you want to upgrade to a different unit regardless? With this new PSU, do you really need to reverse the fan? I'm sure it will work fine, if you want to increase positive pressure I'd just swap another fan's direction so you don't need to go messing inside a PSU.

I just want a better PSU that is very quiet and better quality. The PSU is directly above the CPU. If I don't reverse the fan, the CPU fan will blow down and the the PSU will blow upwards. Asrock has designed it so fresh air enters the rear of the PSU and exhausts it onto the CPU fan.

maklabouhlel · 17 Jun 2022 at 15:00

JollyJamma said:
I would not change the direction. There might be a good reason for the direction ie pushing air over the components instead of creating a vacuum where air can enter from the sides and not actually provide cooling.

That an unless you're a professional, DO NOT OPEN A PSU. Even if it's unplugged, there's enough charge stored up in the capacitors to injure or kill you.

Just make do with the slightly inefficient airflow mate. It should be a problem.

I've opened many PSUs and replaced fans so that's not to much of an issue. The included PSU, CWT GPT500S-A, is widely available from other retailers and actually has an intake fan so Asrock obviously reversed the fan to exhaust to help cool the CPU.

maklabouhlel · 17 Jun 2022 at 22:22

pastymuncher said:
I have just read a review on your barebones and that psu has been customised for that case, including much shorter cables. I really wouldn't switch the psu fan around on any other psu as psu's are normally designed to have the airflow go through the unit in one direction so switching the fan around could lead to hotspots and potential failure. There's also the extra cable length that you would have to find somewhere to hide and in that very tight case there isn't many places to hide them. My wifes case has a similar layout with the psu sitting directly over the cpu leading to a conflict in airflow when using a ATX psu. What I did last year was to ditch the ATX psu and fitted a Seasonic SSP-300SFB SFX psu. At the time it was only £37 but has increased to just under £45 now. It's 80 plus bronze rated and is a decent little unit that runs nice and quiet. A 300w psu is plenty for her pc as she only has a Ryzen 4300GE. Swapping to this smaller psu has improved her cpu temps by quite a margin as the cpu cooler can now breathe freely without fitting the psu for air. Switching to a higher output SFX psu would probably work well for your case as well as not messing around with psu fans.

Sounds like a great idea which would allow a taller cpu cooler.