Does it matter which way the fan on psu is pointing in purebase 500 case?

[SkeeterUK]

Hi.

Im building a new pc, almost done, but ive noticed utube vids have the psu fan face down in my case, and mine is pointing up, does it really matter, the case has a dust filter under the case which i thought is so if the fan is facing down then the intake air goes through dust filter to prevent dust getting in the psu or does it not really matter if the psu has the fan on top when slotted in the psu area on the case.

 

[Semple]

I imagine it'll depend how warm the internals of your case is. As that'll be what's feeding the PSU.