Question about PSU fan direction

szvwxcszxc

Senior member
Nov 29, 2012
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I read,

Standard and recommended configuration, though, is with the lid closed, having the PSU take in air from the bottom of the case, through the supplied filter. Source

However, I'm pretty sure that on the PSU manual it mentioned the fan is intended to face upward. Moreover, my PSU while fthe fan is facing upward has the text upright, implying it's in the correct way.

My case has the filter below the PSU, which I assume is meant for the PSU fan.

So which way is it supposed to be? I am unlikely to change it anytime soon, seeing as I spent a lot of time organizing the case wires since my PSU is not modular. But it would be good to know if I ever have spare time or am bored and want to do something then I might flip it around if that's how it's supposed to be.

Picture of my case and PSU:
IMG_1062sm.jpg
 

Deders

Platinum Member
Oct 14, 2012
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I've never seen a PSU facing upward in a case before, but I guess it's an option. I'm sure the case designers intended it to be facing down, which way up would the text on the other side be if the fan was facing down?
 
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szvwxcszxc

Senior member
Nov 29, 2012
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I've never seen a PSU facing upward in a case before, but I guess it's an option. I'm sure the case designers intended it to be facing down, which way up would the text be if it were the right way around.

please rephrase that last sentence? thanks lol
 

szvwxcszxc

Senior member
Nov 29, 2012
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Lol, done

Thanks lol

ok, that's a good question. I believe it would be facing up also the same way (so if flipped would be upside-down) but I cannot be certain. UPDATE: It faces upwards on both sides. So the text would be upside-down if flipped.
 

Zap

Elite Member
Oct 13, 1999
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I've never seen a PSU facing upward in a case before

The original Antec 900 had a solid bottom with no vent, so if you placed the PSU with the fan facing down, it would overheat.
 

tracerbullet

Golden Member
Feb 22, 2001
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Up / Down doesn't matter for the PSU itself. There's nothing inside the PSU that moves or cares about what orientation it's in. There are parts in it, so over a hundred years gravity might bend and break something, but of course that's not something to really even consider.

It all comes down to airflow and how your case is set up for fans and such. Where they are, what direction they point. In the setup in the picture, PSU fan down will pull outside air right through the PSU and leave the case air alone. Fan up will pull air outwards from the case itself. That can be good or bad depending on the airflow thing.

Looks like you've got a pretty good divider in the middle of the case w/ the 2 long video cards, so you might think in terms of top / bottom halves of the case. As long as each half has some air coming in and going out you'll be fine.
 

crazymonkeyzero

Senior member
Feb 25, 2012
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Some older cases didn't have psu vents, in which it would be bad to mount it upside down (as Zap mentioned) .Realistically in most modern cases have filtered vents on the bottom for that reason, so it doesn't really matter whether or not the psu is mounted up or down. I personally prefer to mount mine downward to intake cool air though a filter, but some prefer the fans on top for aesthetic purposes.Completely up to you, both choices are fine. Just make sure you have filter if you do pick the upsidedown orientation.
 

szvwxcszxc

Senior member
Nov 29, 2012
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Some older cases didn't have psu vents, in which it would be bad to mount it upside down (as Zap mentioned) .Realistically in most modern cases have filtered vents on the bottom for that reason, so it doesn't really matter whether or not the psu is mounted up or down. I personally prefer to mount mine downward to intake cool air though a filter, but some prefer the fans on top for aesthetic purposes.Completely up to you, both choices are fine. Just make sure you have filter if you do pick the upsidedown orientation.

Would there be any performance increase for flipping it upside-down?
 

tracerbullet

Golden Member
Feb 22, 2001
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Would there be any performance increase for flipping it upside-down?

It all comes down to airflow and how your case is set up for fans and such. Where they are, what direction they point. In the setup in the picture, PSU fan down will pull outside air right through the PSU and leave the case air alone. Fan up will pull air outwards from the case itself. That can be good or bad depending on the airflow thing.

Depends on how your other fans are set up. How are your other fans set up?
 

Eureka

Diamond Member
Sep 6, 2005
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The correct answer would be to check the bottom of the case for a PSU vent. The PSU fan is an intake fan that blows air into the PSU and out the rear. The Rosewill Challenger does look like it has vents at the bottom of the case, so the PSU fan should be on the bottom. This way it gets its air from the cold air outside the case and independent of the rest of the case.

You face it upwards if there are no bottom vents because, well, there's no place to get air from the bottom.
 

tracerbullet

Golden Member
Feb 22, 2001
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I got curious about this as I had the same question myself recently, spent a few minutes hitting up a few manufacturer's sites. Checked on their power supplies and pulled up any FAQ's and / or manuals.

BeQuiet - doesn't mention mounting direction
Corsair - doesn't mention
PC Power & Cooling - doesn't mention
Antec - can't pull up any manuals, links dead
Seasonic - "Depending on the type of computer case, correct mounting of the power supply will result with the fan side top cover facing the mainboard. This does not apply to all types of cases".

I'd have thought one or more would have something to say about it, other than "face the fan inside the case, maybe".
 

Deders

Platinum Member
Oct 14, 2012
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The beQuiet's have fans that are shaped in a way that they spin faster as hot air rises, but will also spin up if it gets too hot.

I think for PSU's in general it doesn't really matter which way up it goes. it's better to have the dust filter to avoid clogging, and not having hot air going into it is going to be better for it, possibly lengthening the lifespan.
 

pauldun170

Diamond Member
Sep 26, 2011
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Case has PSU vent on bottom?
true= PSU mounted intake fan down
false= PSU mounted intake up
 

szvwxcszxc

Senior member
Nov 29, 2012
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The beQuiet's have fans that are shaped in a way that they spin faster as hot air rises, but will also spin up if it gets too hot.

I think for PSU's in general it doesn't really matter which way up it goes. it's better to have the dust filter to avoid clogging, and not having hot air going into it is going to be better for it, possibly lengthening the lifespan.

Case has PSU vent on bottom?
true= PSU mounted intake fan down
false= PSU mounted intake up

ok then whenever I get the time I will flip it upside-down.
 

flish

Junior Member
Jul 14, 2011
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mine was facing down, it acts like a vacume cleaner, I'm doing a new build right now.
New cpu, ram, mobo, and cpu fan. Turned it on and got exactly the same problem, it turns on, fans start and after 30 ish seconds shuts down and then restarts and loops this pattern. there are no bios on the screen.
My conclusion (hopefully) it was the PSU. This was the only part I didn't renew. I just hope this knackered PSU didn't screw up my new kit???