Mid-build question: which way round to mount cooler

[Mr Jack]

I'm mounting a Noctua NH-U12F into a Akasa Zen case. Am I best to mount the heatsink horizontally so that it points the fan towards the PSU, and across the exhaust fan or vertically so that it faces the exhaust fan (but will block a lot of the intake to the PSU to which it is very close)?

I'm currently going with vertically.

Quick response appreciated. The PSU is a corsair 520W modular if that makes a difference.

 

[MikeTimbers]

PSU shouldn't need a vast amount of air so I would direct the air off the cpu towards the exhaust. I wouldn't ever direct hot air into a PSU.

 

[Mr Jack]

Ta