The OrigenAE S16V case (http://www.origenae.com/en/htpc_s16v.htm) is only 15'' deep and does not offer enough space to install the fan of the Ninja Mini so that air flows in the direction of the rear exhaust fans.
I ended up installing the fan so that air flows in the direction of the PSU exhaust fan with the heatsink fan sitting over the G45 heatsink (I have an Asus P5Q-EM board).
Can this unusual position of the heatsink fan harm the PSU (Corsair HX520) or any other nearby component?
If yes, which other quiet heatsink would you suggest that fits the OrigenAE s16V?

Thanks!

Harm? Not likely. Though depending on the CPU, it may add considerably to the heat going through the PSU, causing it's fan controller to run higher, which will, of course, be noisier.

Thanks for the reply.
I have a Core 2 Duo E8400. I am using it only for recording/playing TV shows and playing DVD/Blu-ray. When doing this I did not see MB and CPU temps higher than 50C (using speedfan). Unfortunately I do not have a sensor for the PSU.