I bought myself a fanless PSU for my birthday. I'd been eying one for a while now. Corey now has no fan on the CPU, a SSD and a fanless PSU; total, deafening silence. I had to move Corey into a different case because the PSU wants to be vented from the top. So now I've changed corey's CPU, motherboard, heatsink, hard drive, RAM, case and PSU. But it's still the same ax!
Of note: when you switch on a computer you've just assembled, one of the first bits of feedback you get is the fans going WUURRRwuuurrrrr. But not if your computer has no fans! It took me at least one panicky minute to figure this our.