Not sure what you hoped to accomplish with this post, but I have actually seen a computer that had inbound airflow from the rear and outbound airflow coming from the top front.
You could also consider not putting a side fan on. Unless you have a particularly hot GPU, you may actually be disrupting the front-back and/or up-down airflow in the case.
Experimentation is the name of the game here. Get HWMonitor and run your PC to see what your internal temps are like. Then install the side fan. See how the temps are affected. Flip the side fan to the opposite sense and go again...takes time, but you'll work it out from that.
i definitely have a hot gpu, ever since my previous side fan stopped working it's been getting up to 190 deg F (88 deg C) -- with my face i have a 300mm outbound fan on the top, a 120mm outbound fan on the back (near the cpu), an inbound fan on the front at the bottom (probably not doing much since that's just where the extra psu cables are, it's below the hdd and gpu) and this side fan will be right next to the GPU, so i'm thinking out ...
i guess the last post is probably the best overall idea though, try both and see what gets me better temps!
If you're GPU is running hot then it should be blowing in, onto the GPU. As mentioned above however this can disrupt your cases airflow, i dont see it being an issue here though.
One thing i cant stress enough though is make sure you have a dust filter if it is blowing inwards.
@Raiddinn it was my mistake a read wrong. The side fan is made to cool the graphic card. Must be intake.
with the fan on outflow it reduced my gpu's temp by about 20 deg F ... let's try it on inflow and see what i get
It was my mistake the side fan must be intake , to cool the video card.
i'm actually getting about the same results either way, but in either case it's a pretty good drop from having no fan