Since it's open on one side out of four, because it's square, it can direct the air in one of four directions.
It all depends on how you decide to mount it.
4690K @ 4.6Ghz
2X4 Gigs G Skill F3-14900CL8-4GBXM
EVGA GTX 760 SLI
Fractal Design Define R5
Dual loop WC
Some other stuff,
Even more stuff,
If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get a million miles per gallon, and explode once a year, killing everyone inside. --Robert X. Cringely, InfoWorld magazine