I moved my system to an Antec P183 case. Because that case has an isolated bottom compartment for the disk drives and PSU, I need one that will exhaust air out the back, not out the top. Because the case places the hard drives in that same compartment, it would be nice if I had a low-noise fan rather than no fan at all.
My power needs are low; I think I currently have a 450 watt unit in there. I'd be willing to buy a higher-capacity supply to have it running at a lower percentage of its capacity.
I looked on endpcnoise.com, but their PSUs seem to all be top-exhaust. Or should I go with a fanless one and mount a low-rev fan behind the hard drives, hoping that it will push some air out through the PSU?
In this case, the intake is forward, not top or bottom. The PSU is an a separate compartment at the bottom. So I figured that sucking air through the very low clearance between the top of the PSU and the head of the compartment would be noisy.
I have the P182 - which has the same mounting for the PSU as the P183
My Seasonic SS-500HT is very happy in there, fans run so slow (PSU exhaust temps feel "just" above ambient) there is no noise
- this while folding@home with Q6600 @ 3.4GHz and my 5850 also ( - CPU and GPU @ 100% load)
even running at full speed the air flow space allowed should cause very little restriction
Power supplies are at their most efficient when putting out between 45 - 75% of their rated capacity
with a 450w PSU already in there will find you are not getting close to that amount of power usage.
- my system (with 4 x HDD and Creative discrete sound card) folding@home pulls only 280watts
With your more modern/efficient system you would be doing well to be able to hit as much 225w I think while doing something like folding@home
..and in regular usage will be only pulling well under 100watts at the plug socket (where I measure my system box)
unless your PSU is a no name brand I would be inclined to stick with it