Optimal case cooling for this layout?

[BlueWeasel]

Layout Image (you probably need to zoom in to see it all)

Currently, in a room with an ambient temperature in the mid 70's (24C), here's the temps I'm getting:

System: 31C
CPU: 35C idle (Sempron @ 2.45Ghz with 1.5v)
HD1: 32C
HD2: 33C

The temps are all fine, and the OC'ed Sempron doesn't hit 50C even with more voltage at 2.5Ghz. I recently added the CM 120mm fan in the front after seeing what others have done with their C5 cases, and it helped lower the case temperature 2-3C.

But with the hot summer temps approaching, I'm wondering if the case temperature could be slightly improved.

Would adding a 80mm fan on the Centurion side panel help, and if so, would it be better for it to be intake or exhaust?

 

[RallyMaster]

try adding a 120 mm in the 5.25" drive bays. it will take up 3 slots but it's well worth the extra intake.

 

[996GT2]

Do what RallyMaster said (get a Scythe Kama Bay if you want a non-DIY look) and also add a side 120mm exhaust for some serious airflow.

 

[BlueWeasel]

I was actually thinking of moving the 120mm fan I have now up to the 5.25" bays. I've already got the 80mm front intake to keep the HDs cool, and I don't really benefit much more from having 2 fans at such a low position.

I'm kinda hesitant of adding even more fans to my current PSU. It's a reliable Antec, but at only 350W, I don't know how many more it can support.

 

[996GT2]

Fans draw very, very little power (with the exception of a 200+ CFM Delta, maybe. ) Most fans draw between 0.1 and 0.25A at 12V, meaning that they draw less than 5 watts in most cases. Adding a couple more low-mid speed 120mm fans will not overtax your PSU much at all.