PSU airflow direction

[MickeyCoquin]

Hello

 

i have a Seasonic Focus Platinum 850 which is an hybrid PSU if i'm not mistaken.

 

So ideal use of the PSU would be fanless in idle and fan running automatically when system is under load ?

 

I have 2 questions regarding the airflow of the fan:

 

Are PSU all the same regarding the direction of the airflow ? Intake, right ?

If i think it would be better to change the orientation of the airflow, could i theoretically open the PSU (loose the warranty i guess) and flip the fan ?

 

I'm really confused about the right position of the PSU, i need to hav the PSU on top of my case, but i think intake airflow isn't what would extract the hot air the more effectively.

 

Thanks for reading. Sorry for the bad english.

 

Here's what Seasonic recommend:

 

https://seasonic.com/how-to-position-your-power-supply (old version)

https://seasonic.com/pub/media/pdf/consumer/user-manual/Seasonic-installation-guide-digital.pdf  (new version)

[Cereal5]

To my knowledge, all PSU fans pull air into the PSU and push it out the back. It doesn't matter whether you mount it face up or face down, but if you mount it face down, you have to make sure there is room under the case for the fan to pull air. You can't set the case on like a shag carpet where it will block the intake. If it's on a thinner carpet or hard floor/desk then it's fine. If you have a flipped case (PSU on top), then I think you can only mount it with the fan on the interior of the case. But correct me if I'm wrong.

[MickeyCoquin]

I think you're wrong lol ^^

 

See the doc i linked...

 

Quote

If you wish to mount the power supply with its ventilation top cover facing UPWARD, please make sure that there is at least 5 cm between the power supply and the metal plate of the computer case.

 

Same recommendation on the newer version.

 

Not sure to understand why they recommend 5 cm... Why would it perform better than without space at all ?

 

And i was told that heat dissipating in the direction of the top not the bottom, so wouldn't it make more sense to extract the heat from the components than pushing cold air on it ?

 

 

[MickeyCoquin]

Btw why when top mounted is it recommended to push (hot) air on the components ? I'm asking because when top mounted the recommended position like you said (and you were right) is top cover facing downward. Again recommended not the only option available as stated on the doc.

[FastRDust]

8 minutes ago, MickeyCoquin said:

I think you're wrong lol ^^

 

See the doc i linked...

 

 

Same recommendation on the newer version.

 

Not sure to understand why they recommend 5 cm... Why would it perform better than without space at all ?

 

And i was told that heat dissipating in the direction of the top not the bottom, so wouldn't it make more sense to extract the heat from the components than pushing cold air on it ?

 

 

The 5 cm is breathing room for the PSU to take air from.

Heat naturally migrates upward in the case so that means if you put your PSU at the top it will need a bit more breathing room to compensate with airflow for the warmer air. ( try holding a piece of paper in front of your mouth and close the distance while you try to breathe )

It will also radiate heat itself which means if closed off it will get it's own warmth back from the sides.

 

PSU will always such air from inside the case and blow it out of the back ( where the cable is plugged )

when the PSU is mounted at the top it will automatically assist in Airflow by pulling it form the case out of the back.

It is not better for the PSU but saves you an extra fan sort of.

[razaldo]

36 minutes ago, MickeyCoquin said:

 

If i think it would be better to change the orientation of the airflow, could i theoretically open the PSU (loose the warranty i guess) and flip the fan ?

 

 

If you do plan on flipping the fan on the PSU then you might want a case that not only allows top mounting the PSU, but also has vents for the PSU fan - so that way the PSU sucks air from the back and exhausts it from the vents.

 

You would not want it the other way (with the PSU top mounted but the fan facing the inside of the case) - that would only take the warm air of the PSU and direct it most probably towards your CPU. 

[MickeyCoquin]

OK thanks @FastRDust it's more clear now. 5 cm is recommended when top case have no holes for airflow, but in my case the top will have the room for airflow even without the 5 cm because the case will be opened and it will be able to suck in te cold air or extract the hot.

 

Hope i get it correctly this time.

 

I guess flipping the fan in the PSU won't impact that much the performance, maybe it doesn't worth the trouble...

[MickeyCoquin]

28 minutes ago, razaldo said:

If you do plan on flipping the fan on the PSU then you might want a case that not only allows top mounting the PSU, but also has vents for the PSU fan - so that way the PSU sucks air from the back and exhausts it from the vents.

Yes it is exactly what i had in mind ^^

 

I even thought about adding an intake fan on the back of the case to suck air in with a 80 mm fan.