Comment by frollogaston

Closed-loop water cooling chips is nothing new. There are two separate water systems that often get conflated*. The loop warms up the water, which is recycled but first needs to be cooled externally somehow. Normally they use evaporative cooling towers that do use water, or chillers that don't use water but use more energy. But they're claiming they can get that water loop so much hotter than the outdoor environment that active cooling isn't needed. They attribute this to improving the chip-to-water interaction.

Even air-cooled datacenters work somewhat the same way, but instead of water to chips, it's air. The air goes into hot aisles then exchanges heat with water, after which, see above.

* Other datacenter marketing materials talk about how they have a "closed loop system that uses no water" and they do still use water in the evap towers. I was half expecting this article to be that again, glad it wasn't.