I'm posting this here as it isn't specific to PSUs, or fans, but rather, a combination of both.
My latest build is built around an Antec Solo II
, which includes a air intake cutout on top of the case (towards the back). You can clearly see this if you have a look at any pictures. This air intake is in the general vicinity of the case where the PSU is mounted.
If you mount the PSU in the traditional (right side up) orientation, the PSU fan as well as the case's exhaust fan (which is on the back panel) are very close to one another, both drawing air in from the same general area of the case (top back). During my build, I thought, why not install the PSU upside down, thereby having the PSU fan make use of the extra air intake on top of the case. This would allow me to establish two independent airflow paths through the system:
1) One for the PSU only, intake through top of the case exhaust out the back of the PSU.
2) Traditional flow of intake through the front of the case, exhaust out the back.
Can you folks think of any downsides of doing this?