Efficiency is also good
Liquid cooling systems, like air cooling systems, also make noise. It is formed primarily due to the operation of the pump. The German company Wieland has developed a prototype of liquid CO without a pump, and there is already a review of it on the Internet.
The famous overclocker Der8auer tested this device, comparing it with the classic liquid CO from Corsair, and using the same fans for a more correct comparison.
It turned out that the pumpless system is quite viable. Yes, under maximum load, in this case in the form of the Cinebench R23 benchmark, the Corsair cooler did better, gaining 8 degrees (70 degrees versus 78 degrees). However, firstly, both results are quite good, taking into account the test 16-core Ryzen 9 7950X, and secondly, in games there was no difference between the COs at all, that is, there will be no difference in average loads.
But in terms of noise level, of course, the Wieland prototype is significantly ahead. That is, if you use some very quiet fans, the system as a whole will be relatively silent. In addition, the author of the review says that the system can be improved, for example, by closing the gaps on the sides of the radiator and using a copper cooling plate instead of the current aluminum one.
As for the operating principle, we are talking about the thermosiphon principle.