Thanks for the tip, dukla. I've always been told that case ventilation is important, but I have never, ever had a case that allowed for that. I've tried putting fans in the lower-front of my case before, but even the loud ones never pushed enough air to make a difference. But your post got me thinking about the problem again....
So here's what I did: first, I removed my case's front panel to allow for some airflow. I moved my CD-ROM drives as low as possible, then put a 7-volted Papst 8412NGL in the upper
-front of my case (resting on top of the CD-ROM drive). Instead of having it blow in, though, which did nothing to help, I have it blow out
. Now the PS fan never spins up above 1000RPM (I think... that's what Motherboard Monitor says. It doesn't give me an accurate reading until the RPMs are > 800RPM; anything lower and it tells me the RPM is at 18750 or 21093). Of course, now my case is ugly as sin, but I'll figure out some way to fix that later.
Funny that blowing in cool air from the front of the case didn't work anywhere as well as evacuating heat from the front the case. Acutally, now that I think about it, it makes sense: if I blew in cool air, that air has to travel a long way to reach the PSU, and along the way, it's going to get warmed up by the air inside the case. PSU gets fed warm air, so its fan spins up. This relates perfectly with what MikeC postulates in his "Evacuate the heat" role for the PSU
thread -- the PSU should not have the job of evacuating heat from the case.
This setup will work perfectly for my plan of installing a fan in the back of the case blowing inward -- cool air will blow in from the back, and leave from the front. This post
from MikeC's thread also makes a lot of sense to me... why blow air out from the back? That only means that the PSU fan will be fighting with the rear case fan for air, which is noisy and inefficient.
Anyway, long story short... I've solved my noisy PSU fan problems, and I'm a happy camper.
However, I think I can make the PSU fan even quieter, so my question still stands... what's a quieter replacement 120mm fan that'll work well with the PSU's temperature sensor?