Google's Liquid Cooling

I see frequent mentions of AI wasting water. Is this one such setup, perhaps with the CDU using the facility's water supply for evaporative cooling?

The CDU is inside the datacenter and strictly liquid to liquid exchange. It transfers heat from the rack block's coolant to the facility coolant. The facility then provides outdoor heat exchange for the facility coolant, which is sometimes accomplished using open-loop evaporative cooling (spraying down the cooling towers). All datacenters have some form of facility cooling, whether there's a CDU and local water cooling or not, so it's not particularly relevant.

The whole AI-water conversation is sort of tiring, since water just moves to more or less efficient parts or locations in the water cycle - I think a "total runtime energy consumption" metric would be much more useful if it were possible to accurately price in water-related externalities (ie - is a massive amount of energy spent moving water because a datacenter evaporates it? or is it no big deal?). And the whole thing really just shows how inefficient and inaccurately priced the market for water is, especially in the US where water rights, price, and the actual utility of water in a given location are often shockingly uncorrelated.

Even without AI the whole water conservation topic is kinda silly.

The margin at which it makes sense to save water varies wildly by location, but the cultural dominance of the western USA infiltrates everything.

Here in Zürich, my office briefly installed water saving taps. This is a city of less than half a million where the government maintains 1,200 fountains that spew drinkable water 24/7. But someone at the California HQ said saving water is important and someone at the Swiss subsidiary said yes sir we'll look into it right away sir.

It's on the same level as people using incandescent light bulbs. Well we clear 160k Euros after taxes and have public medical care, and electricity is 10c/kWh here, so why does it matter what bulbs we use?

We live in an area surrounded by grass fed cows, so what does it matter if we throw away 3/4 of our steak?

Without regard to how plentiful resources are in our particular area, being needlessly wasteful is in bad taste more than anything. It's a lack of appreciation of the value of what we have.

For water specifically - it is generally speaking the most valuable resource available, we just don't appreciate it because we happen to have a lot of it.

> For water specifically - it is generally speaking the most valuable resource available, we just don't appreciate it because we happen to have a lot of it.

And for water specifically, the second order effects from "water saving" programs can be actually negative. Not enough water means that sewers don't work properly any more, leading from events of stink to helping fatbergs grow [1].

To make it worse, the "obvious" idea of scaling down sewer mains doesn't work either because the sewers are (at least in Europe) also used as storm drains, so if you'd scale down the sewers you'd get streets flooded.

[1] https://www.wiwo.de/technologie/blockierte-kanalisation-die-...