Re: Liquid cooling is expensive
You need to get 1000W of heat out of a couple of square cm of CPU/GPU in the middle of a box other parts, while keeping the hot end below 80C.
Air doesn't have much heat capacity, a little bit of energy heats the air above the temperature of the chip, at which point no more heat flows. So you need to start with the air really-really cold and blow lots-and-lots of air passed the chip.
Getting lots-and-lots of really-really cold air and delivering it to the chip and removing it afterwards is bloody expensive.
In theory it's much easier to have a pipe with outside temperature water going in, and 80C water coming out, through a radiator and being cooled to the outside temperature again