I have a question and I don't know if you can answer it but would a vacuum system filled with a thinner gas but more easily heatable would be possible and a good cooling solution(of course with something to coold that gas like in a water cooler).
I was thinking with ionized air first that would reduced friction and would probably increase air flow but I'm not sure it would be compatible with all the metal and electrical current.
You don't want a thinner less dense gas!
While maximum heat transfer possible for a given heat sink design is determined by the above equation, there is a limit to the amount of heat the gas as a heat transfer fluid itself can absorb. That's governed by the following:
Q = m x Cp x ΔT
Where,
m is the mass flow rate of the fluid
Cp is the specific heat capacity of the fluid
and ΔT is the temperature change of the fluid.
Dropping the pressure of the heat transfer fluid decreases the density and so decreases the mass flow rate of the fluid, thus dropping the overall heat absorption rate in the above equation.
Ideally, you'd want to increase the air pressure, but this requires a considerable amount of mechanical work and thus electrical power to achieve. And so for devices like these, any compressor type fans only increase the pressure by a few hundred millibars at best, but doing so also raises the acoustic output as the higher pressure air exits the console and expands again into the open air.
The density dependence is why liquid cooling is better than air cooling because for the same volumetric flowrate you can take two to three orders of magnitude higher heat absorption, making the water cooling loop an effective heat sink.