Yeah... I'm talking something that would be shorter in width and length... so less volume. Anyway rack-mount equipment is so loud because it all uses tiny fans

Yeah... I'm talking something that would be shorter in width and length... so less volume. Anyway rack-mount equipment is so loud because it all uses tiny fans that are driven at very high RPMs. Using fewer larger fans that spun slower would be much quieter. I would guess that using water cooling might be still quieter but I suspect that would be a lot of effort. Having a single very large fan at the top of the rack, that ran on mains AC, might work fine, assuming the right heat sinks and ducting.