Seasonic ... fan up or fan down?

[tony ennis]

If the "top" of a PSU is determined by when the English is rightside up, then my Seasonic X-series PSU has its fan on top.

My case (Cooler Master HAF 912) wants the PSU on the bottom. The case has a filtered port right below the PSU, apparently for the PSU's fan.

Do I mount the PSU "upside down" in order to have the fan pull from (push to?) the bottom of the case?

 

[Seba]

Fan down.

 

[Hail The Brain Slug]

I would mount it fan down. Newer PSU's have a label on both sides that are mounted opposing directions so no matter if you mount it fan up or fan down, the side facing out is right side up to read.

 

[lehtv]

If you have the option to run the unit without turning off the fan at low loads, then do that and mount it facing down. That way it'll cool itself with filtered air from below the case.

If you can't turn off the semi passive fan, then it'd be better to mount it facing up. That will allow warm air to rise up through the grille when the fan isn't spinning.

 

[cruzinforit]

If you have the option to run the unit without turning off the fan at low loads, then do that and mount it facing down. That way it'll cool itself with filtered air from below the case.

If you can't turn off the semi passive fan, then it'd be better to mount it facing up. That will allow warm air to rise up through the grille when the fan isn't spinning.

No. Fans DO NOT blow air OUT of the power supply. They blow it out THROUGH THE BACK. Where the power plug goes. It sucks it in through the fan grille, and blows it out the back. You always want your power supply facing down, in a bottom-mounted case. Your case will either have a grille with a filter that lets it pull cool air in from outside, or it will have some little stands that hold the power supply a bit off the bottom of the case (See Antec 300 for an example of this). In this case, you still want to do that, because the air at the bottom of the case is the coolest, and that is what you want being pulled into your power supply.

The only exception to this when talking about bottom-mounted PSUs are fanless models, since they rely on the convection of air flowing in the back, and out through the vent.

 

[cruzinforit]

I would mount it fan down. Newer PSU's have a label on both sides that are mounted opposing directions so no matter if you mount it fan up or fan down, the side facing out is right side up to read.

Fan-cooled power supplies mounted in bottom-mount cases should always be mounted fan facing down. That is how these cases are designed. In most cases tehy ahve vents in the bottom that allows the fan to pull in cool air and then blow it out the back. I don't really get why people find it so difficult to determine which way air flows through a PC fan. If you look at the fan it tends to be pretty obvious which way it's supposed to turn and thus, blow the air, if you have the slightest clue how fans work.

 

[Seba]

No. Fans DO NOT blow air OUT of the power supply. They blow it out THROUGH THE BACK. Where the power plug goes. It sucks it in through the fan grille, and blows it out the back.

Re-read his post.

You misunderstood him.

I will rephrase what he said:
- If the power supply fan never stops (even at low power loads), install the power supply with the fan facing down.
- If the power supply fan completely stops (under low loads), then he says to install the power supply with the fan facing up so that when the fan is stopped, the heated air from the power supply can rise through the hole where the power supply fan is.

Even in the second case, I won't do that (install the power supply with the fan facing up), because when the power supply gets warm enough, the fan will start. And under higher power loads, if installed with fan facing up, will draw warmer air from inside of the case, instead of cooler air through the bottom of the case.

 

[Charlie98]

I'll be the odd man out... I mounted my Seasonic in my desktop fan up to draw 2x filtered air from inside the case (case filters + a magnetic filter over the PSU fan intake.) My house is abysmally dusty. The desktop doesn't see much of a CPU load except for the occasional video encode so heat isn't a problem.

 

[crashtech]

It's all dependent on usage. Quite a few of my clients have set their PC on thick shag carpet, which renders a bottom-breathing PSU fan rather ineffective. I'd like to see some rather tall feet on a "bottom-breather," unless a suitable mounting pedestal is to be supplied.

 

[Hugo Drax]

My seasonic gold ss-560-x has had the fan down inside a node 304 cases since I built it in 2012 and they run on 24/7 No issues whatsoever.