2 exhaust fans, one top one back, should I change?

[Fireball_1]

I am using the nzxt s340 with stock fans but I hear I should have an intake, but I'm also hearing that top and back is intake, so I don't really understand what I should do, help?
Edit: my games also crash (tf2) in 5 seconds after I launch, all my fans are at max too and my cpu is 36 Celsius, am I doing something wrong or

 

[synphul]

You can try monitoring gpu temps with msi afterburner, make sure they're within reason. Your cpu temps seems to be fine. Unless you have configured your airflow differently for the case, most cases use a front to rear or front to rear/top airlow. Front as intake, rear/top as exhaust. Do you have any fans in front as intake? There should be room for up to 2 120mm or 140mm fans. If you have 2 fans as exhaust it would be more balanced to have 2 fans as intake though 1 would likely still work.

The front fan mounts are filtered for intake use. I'm not positive but I don't think the top has a dust filter on that case. The rear doesn't have a dust filter, they're usually used as exhaust.

If you have set the top and rear fans as intake try turning them around to use as exhaust. It's possible the abnormal airflow is causing your gpu to overheat. If gpu temps are fine the the games crashing may be a software issue. It's best not to use unfiltered fans as intakes, the filters help keep dust out.