Question is psu fan location important

[itox2003]

is the location of psu fan important?
i want to build a pc using my old case, the location of the psu is at the back top case, i am afraid that if my psu fan is facing upward, the fan will be covered by the case and disrupted air flow, is it true?

 

[Gam3r01]

You should face the fan whichever way produces best airflow, so typically fan down in a top mount.
Almost every PSU should be reversible.

 

[itox2003]

You should face the fan whichever way produces best airflow, so typically fan down in a top mount.
Almost every PSU should be reversible.

to be honest i never build a pc before, my old case come with a power supply in it, when i remove it and try to put it back the screw did not align properly until i reverse it
there are 4 screw, 3 of them are at the corner, while 1 of them is a little bit to the center

 

[Gam3r01]

Ah so you have one of those cases, if that happens 3/4 screws is still good enough considering you want airflow.