Originally posted by: godmare
Originally posted by: aRCeNiTe
Shouldn't there be one or two on the panel, and maybe on on the top?
Bill
Well, no, there doesn't
have to be. If you really want a blowhole, they're not hard to add. What you can do is cut the metal around the two intake fans (the grate) so it's just a circular hole (you can do the same ot that back, too, if you like, and ass 80mm wire grills for less restriction), this will greatly improve your airflow and reduce your air turbulence and noise. I recommend this to everyone, not just if you want 'extra' airflow. You could use a dremel or even wire or tin snips with perfect success

You could run 2 quiet intake fans and 2 quiet exhaust fans and get perfectly adequate airflow with minimal noise.
Does this help you, or did you have something specific as pertains to airflow in mind?
I've seen your HP with the added fans- how many fans total do you have in that system and at what temperature (case and cpu)?