I'm about to build an nas out of these parts but it could easily become a silent pc if you added a graphics card and used ssd's instead of mechanical disks. I would still recommend using fans though. Just get some resistors and make them run at 600-900 rpm and you won't hardly hear the big 120mm's at all. The 80mm fan in the psu only kicks on when it hits a certain temp from what i understand. The entire mobo including cpu only draws around 40 watts so the fan on that thing would probably never run unless you plan on hooking up 10 4tb WD reds to it like I am going to. That minisys case that tiptop2004 posted looks pretty awesome though.