Bottom Mounted PSU, fan facing Up or Down?

[litwicki23]

Hi everyone,

- PSU: FX XXX Edition Pro Modularny 80Plus Bronze - 750W (P1-750X-XXB9)

http://www.morele.net/zasilacz-xfx-xxx-edition-pro-modularny-80plus-bronze-750w-p1-750x-xxb9-554274/

- case: Centurion 590

http://www.coolermaster.com/case/mid-tower/centurion-590/


Question: Should this PSU be mounted with the fan facing UP, or Down, or it doesn't matter?

The PSU mounts on the bottom.

 

[litwicki23]

Finally. I want ask you dear forum. So piece of wood will be the best yes? Like this? 2 screens: That will be ok?: