That is fundamentally not how PC cooling works. Each part is a closed system, with the PC an open system so long as you have fans. The heat sink temp over ambient could be what you are looking for, but that still would not work that way if you are looking at hot spot temps. If you tried to run a thread ripper at 500W in a closed space the air temp would end up hotter than than a 350W Graphics card. But the CPU if not throttling would have a temp over ambient of about 30c and the gpu core would be about 45c over ambient. The effect on your room will be that the 500W cpu raises the ambient temp more than the 350W gpu over the same period of time. The air in your room is what is cooling the components. Air at a given humidity has a specific heat capacity and will be your limiting factor. With your bath example you would need to have a much larger capacity of 60c water to melt the ice since the specific heat of water doesn't change when a liquid.

You have a fundamental misunderstanding of the 1st law of thermodynamics and what a "system" is as relating to the 2nd.

For your HDD you want them to run 45-60c. running them colder will impact their life span. The drive will try to heat up if under 30c to prevent damage.