I have 15 fans in my server, one in the PSU, two for each proc, one to suck the hot air off the proc fans and out the back, two for each hard drive, and one huge one in the front to pull cool air in. It's really not too bad as long as I keep the case screws and all the fan mount screws tight to keep it all from rattling. That loudest part is when the thing boots and it mounts all the drives up.
Tell you what though Steve, if I were going to build another I would put almost all of the fans on a thermostat. Half of them don't need to be running full time.
I can't hear it at all from my house though.
