Exhaust Fan

[legend8887]

So basically an exhaust fan is in the rear of your case and it just blows hot air out of the case? 

 

Edit: I plan on putting an H100i or H105 at the top.

[zxcvbnmmssdh]

Normally at the top and back, sometimes the bottom but yes.

[Superarragon]

Yes, that is correct. It can also be in the top of the case.

[Kayn]

Essentially, You need a way for the hot air to exit your case other wise your components are just reusing hot air.

[Guest]

Cool air needs to be going in and hot air going out, you use intakes  to help that cool air in and likewise exhausts to suck that hot air out, it doesen't need to be on the back, just in most setups it makes sense for it to be there.

[MegaDave91]

Rear and top because heat rises.

[LogicalDrm]

Basic physics: hot air raises. That said, you can go without exhaust fan and have top fans as intake also. Sometimes chipset/northbridge can get hot when there isn't enough airflow.