After looking at your pic again...

Was wondering if those are standard PC type fans... If so it looks like you have one sucking out and one blowing in. If so, not the best idea for the PC case. If thats the case then you should simply flip one around so they are both sucking out. You should have another mount for a fan near the bottom front of the case. This should not be sealed off so that fresh cool air can enter passively. You want to create a negative air pressure inside the case to draw cool air in.