Air-Cooled vs Liquid-Cooled Data Centers
Inside the building, cooling ranges from air handlers to direct liquid cooling; the choice affects on-site water but not the larger upstream power-plant water.
The on-site spectrum
- Air cooling: fans and CRAC/CRAH units move heat to the outdoors, sometimes via evaporative assist
- Evaporative / adiabatic: sprays water to cool intake air, trading water for efficiency
- Liquid cooling: coolant contacts hot components directly, enabling high density and dry heat rejection
- Immersion: servers sit in dielectric fluid, with heat rejected through a closed loop
High-density AI hardware increasingly favors liquid and immersion cooling, which can reject heat to dry coolers without evaporating water, cutting on-site consumption.
Why this alone is not enough
Even a data center with water-free liquid cooling still imports electricity, and if that electricity comes from steam plants, its true water footprint is large and upstream. Optimizing on-site cooling addresses the smaller share of the problem.
MetroVolt completes the picture
Pairing low-water on-site cooling (liquid or immersion) with MetroVolt generation, which has almost no generation-side water, addresses both loads at once. The building rejects its server heat to air, and the power that feeds it also carries essentially no evaporative water. Both halves of the data-center water problem are answered with dry heat rejection.