Power supply with two fans a good idea?

I'm wondering if its worth the added price. My CPU seems to be right below where the fan would be, so its seems like it would help. I just want an opinion, or an experience someone had with it changing temperatures, or the likely hood of it helping enought to be worth the price.

One other thing. The fan on the bottom of the power supply, pulls air in, and the one on the back pulls that air out of the PC, or does the fan on the bottom blow air onto the PC?

The fan on the bottom pulls air into the PSU from the computer. The fan on the back of the PSU blows air out of the PSU

i have a single fan (blowing out) PSU, would it be worth adding an "in" fan to the PSU in my case the psu sits above the MB so it would draw the heat off the board would this be better then the way it is now?

Lately, I've been Dremeling the bottom of cheapo PSUs and adding an additional fan to suck air from the case and out the PSU. As I have extra fans around all the time, this seems like an easy way to get some extra cooling at little or no cost.

2 PSU fans are not necessary, it is really just a sales gimmick. One low speed fan is enough to keep pretty much all PSU's cool. PSU's are not that temperature sensitive. When PSU's are designed, they are worst case scenario tested. I.E, outback Australia with no air con type environment. If one fan can keep a PSU cool in that kind of environment....

I cant say for sure if the 2 fans work better or not. My Enermax PSU has them and came with my case(PC61).

My theory?
if it sucks heat from the CPU, it is a good thing.
Futura

Yeah, thats what I would want it for. Not for cooling the power supply itself, but to take the hot air from the CPU, which would be rising right into the second fan, and pull that out of the case.

Not so sure about that. I would argue that it is also highly dependent on how much you load the supply. If you can supply more cooling you might be able to squeeze an extra 10% on the total wattage output before it pops. Basically the more you load it the more cooling you will need. One fan can only cool so much. Obviously one is still restricted by the ratings of the components in the supply but if you have a 80 plus bronze supply you might get closer to 80 plus gold rating with two fans. I guess the real question is, is it worth all that effort for an extra 5 or 10%? Personally I am going to retrofit another case fan and one on my psu output because I am not happy with the temperatures out of the psu when its under 100% load on both cpu's.

Closing the thread, that's almost a fifteen year necro post.