Noctua is a brand of CPU air cooling equipment that is quite famous for their CPU cooling blocks that efficiently transfer heat from the CPU components to the air without the need for a liquid cooling system like many other CPU cooler brands do.
At the Computex Taipei event this year, in addition to the power supply developed together with Seasonic, Noctua also showed a CPU cooling prototype that uses liquid. The most notable difference between this prototype and other AIO CPU cooler offerings is that it does not use a pump on the CPU side.
Noctua works with Calyos, a company that specializes in introducing phased cooling systems for the automotive, aviation and sustainable energy industries.
Both of these companies use a heat transfer technique called a thermosiphon that resembles a heat pipe and a vapor chamber where the cooling liquid in the radiator will flow to the CPU cooling block using gravity and become water vapor. This water vapor will then be flowed back to the radiator to be cooled through the radiator cooling fins and also the fan used.
This process will be repeated every time the CPU process causes the component to heat up, and in terms of the concept for now, it will reduce the use of electrical power that would normally be used to power the pump to drain the liquid from the CPU component back to the radiator.
The prototype shown at Noctua's booth at Computex came with a 240mm radiator, but said that they are also testing this prototype with a 360mm radiator. This thermosyphon cooler is still in the testing phase, and Noctua does not know when it will be ready to be introduced to the market.