There's always the pump...
I dont think the noise is going to be significantly any lower with or without a fan. To the human ear anyway. You can get a really low profile silent fan to attach rather than the stock. The pump on the H50 can make as much noise as the fans. When your case is shut its pretty quiet but open it up and you can hear the motor pump.
McT
tbh a noctua fan at 800rpm is totally inaudible..... passive cooling is most fail IMO
Yeah, but they have tons of external rads. And for some reason all the pictures i see are outside... when it's windy