I'm assembling my first build, which in part is:
case: Antec P150
PSU: Corsair HX520W
mobo: Gigabyte GAMA78GM S2H
CPU: AMD 64 x2 5600+
cooler: Xigmatek HDT-S1283

The Corsair is mounted in the usual top-rear position with its fan lying flat, visible through the grid in the bottom of the PSU housing. The PSU is mounted rightside-up, according to its lettering.

I need to be absolutely sure that the PSU fan will be pulling air UP into the PSU and exhausting it out the back. I am just beginning to put things together, and I suppose I could simply plug in the power cord to the PSU--there is no mobo installed yet; just the PSU in the case--but I'm not sure it's OK to do that. So I'm being safe, and asking you.

The reason the question about airflow is so important to me is because the Xigmatek cooler, when mounted on an AMD mobo, seems to want to face only up or down. Some writers on the web say it can only face up, and the Corsair's fan is only an inch or two above it.

Well, if the cooler is collecting heat (which wants to rise anyway), and is dissipating it right into the PSU fan, I think that will work just fine--as long as the PSU fan really is pulling air UP and into and through the PSU and out the rear of the computer.

Anybody have any problems with that? And, is there someone running a Corsair HX520W who can tell me for absolutely sure its fan is pulling air up and exhausting it out of the case?

Thanks, fellows.

I have that PSU. The large fan is intake, and it exhausts out the rear.

Excellent! Thanks, Pyroflea. Everything looks good, then.

No problem Enjoy the computer.

I also have the same PSU. Its awesome. Super quiet, and the cables are of the best i have ever seen. They dont have any frills like fancy wrapping, they are all business with sturdy black plastic. Even comes with a little carrying bag for your extra cables.

In my RC-690, its bottom mounted, pulling air from under the case and blowing it right out the back. One less heat source to worry about!

Same here