also if you are worried about dust and your case doesn't have filters there is a couple options!
1st one is the cheapo foam type filters that can be washed but build up fast and impeed airflow. The other is quite cheap and easy to do.
Purchase
these kind or
these kind it doesn't matter. Then purchase some screen door screen (its very cheap and some places bulk sell it)
cut and attach this stuff to either of the fan grills above. It will seriously catch a lot of the dust/hair and keep your case much cleaner.