Years ago someone posted about plumbing it in with their swimming pool. If you could resolve the contamination and corrosion issues that would be pretty sweet.
I think this is a better approach to passively cooling the CPU. If you use an SSD and fanless power supply, you have a virtually silent system. There might be a slight 60Hz buzz in the power supply which you'll hear in a very quiet room, but that will be about it.
No, it's definitely not for a high-powered PC. That setup will only work if the CPU's TDP is maybe 70 watts, perhaps 100 watts at the most.That won't work very well if the PC is drawing high power for an extended period.