I know there are a bunch or threads about cooling but I have a question about my setup. I have a denon avr891 and my htpc in this cabinet. I usually leave the doors open while using my htpc but would like to be able to keep them shut. The back is cut open but there is not really any airflow unless the front door is open. Would some 120mm fans in the back top help pull the hot air out when the door is closed?