Case is MetallicGear NEO Qube. I have two fans at the bottom and 2 and the top (they used to be 3 in total, but I admit I added a forth recently, even if temps didn't change that much). Fans are NOCTUA and run at about 600-700 rpm. CPU is ryzen 4650, I undervolted it slightly. Integrated GPU. There is a direct airflow, with no restrictions of any sort, from bottom to top of the case passing through CPU heatsink which is a simple noctua NH-U9S where I just removed the fan. I often leave the system rendering for days as a support machine to my main system (which is in another room) and believe me if I say I just can't hear it even if it's in my bedroom during night. Temps can raise a little but never go above 75-80c. I know there's no dedicated GPU working, the point wasn't that I'm doing better than this admirable case, the point is that you will have an hard time hearing a bunch of quality low rpm fans in a closed case with good clearance and cable management, so putting so much effort in having 0 fans, while admirable, is a little wasted.