I had an idea recently. But I don't have the physics knowledge to know if it makes sense or not. I've become a bit of a PC enthusiast lately and one thing that is big in the PC world lately is water cooling.
Here is my theory. If I take a regular PC water cooling loop, and lower the air pressure (custom loops typically have a bit of air at the top of the reservoir). I could lower the boiling point of the water to just above room temp (lets say about 30°C). Then when the system is running, the liquid water will hit the CPU block and vaporize, since CPU's can easily be 75°C. The water vapor will then travel to the radiator and re-condense to liquid. And continue back to the reservoir, etc.
Lets just assume the PC cooling parts can handle the lower pressure for now. Also I assume the system pressure would increase once some water is turned to vapor, but I should be able to continue lowering the pressure while the system is running until it reaches a steady state, right? Since heat pipes evidently don't have this problem.
Would this system remove heat from the CPU any faster then a regular water loop? From what I understand, the phase change will remove heat much faster then normal. It's the basic principal that heat pipes use, which are already widely used in PC's. But heat pipes don't have a pump to force the circulation of a large amount of water.
Are there factors I'm not aware of. Will the pressure in the system just skyrocket once water begins to vaporize? Would it require some kind of active pressure regulator mechanism? I'm guessing not since this isn't a problem for heat pipes.
I was thinking of testing the idea out in the next fews months, though maybe using a small heater element as a stand-in for a CPU, just in case things go sideways.
Also, if you are thinking that all this might be needlessly complicated for no real gain. Well, that's the PC enthusiast world right now! regular PC water cooling already isn't necessary right now. many air coolers are cheaper, quieter, more reliable and keep things cooler as it is. it's just fun to play with.