The art of liquid cooling has been demonstrated by Aquasar
and put to work inside the German supercomputer SuperMUC
which - *perversely* - harnesses warm water to cool its
circuits.
How is it perverse to cool hot circuits with warm water?
The efficiency of cooling is proportional to delta t, so it's much better (for the computer) to cool a computer with cold water. But how did you produce that cold water? Probably with some energy-intensive refrigeration process. Thus AFAIK it's more efficient overall to use a higher inlet temperature (presumably with a higher flow rate).
