Recently - motivated by the recent heat where we live - an acquaintance argued that a water cooled computer will not heat up the room as much as an air cooled computer will. His reasoning was that the processors never reach temperatures as high as they would with air cooling, so the room will not absorb as much heat.
This seems flawed to me; the processors have an energy consumption that is regulated by how much processing they do, and that doesn't depend on whether they are air cooled or water cooled. I figured the amount of energy that gets converted to heat should be the same in both cases, the water cooling just doesn't reach temperatures as high as the air cooling because water has a higher capacity for absorbing energy than air does. In the end, the same amount of heat energy would end up in my room in both cases, so I would expect the room to heat up the same, independent of whether we cool our computers with water or air cooling systems.
Which one is right?