Your fan is going to cause you two problems... one is the noise, and the second is dust. You do not want a fan pulling dust into your enclosure; otherwise, you will have a heat problem.
On the other hand, your fan is very cool <pun intended>. I like it. You now have a RPi project to work on... use one of your PWM pins and 'control' the speed of that fan; just slow it down a bit so that it runs quietly, then it will still look 'cool' --- by the way, I like your case too! very nice plexiglass...
Seriously, just turn the fan off; it isn't necessary at all.