微软用闭环液冷解决了AI数据中心的高耗水痛点，做数据中心运维或关注绿色计算的团队值得了解这项技术，它直接降低了运营成本和环境压力。
微软CEO萨提亚·纳德拉宣布，其威斯康星州Fairwater AI数据中心通过采用闭环直接到芯片的液冷技术，实现了极低的年耗水量，仅相当于一家当地餐厅的用水量。该技术用密封管道中的冷却液循环替代了传统蒸发冷却，避免了水蒸发消耗。冷却液吸收芯片热量后，通过数据中心外的散热鳍片和风扇将热量排入空气，再循环回服务器。超过90%的设施使用闭环液冷，仅在极端高温日才辅助使用外部空气和水。这解决了高功率AI芯片（如GB200）的散热难题，同时大幅节约水资源。
Satya Nadella: Microsoft’s latest Wisconsin AI dat…
Satya Nadella: Microsoft’s latest Wisconsin AI data center keeps yearly water consumption no higher than that of 1 local restaurant.
"The cooling loop is filled once and the data centre can operate effectively with zero water consumption. Daily water usage across a year is roughly equivalent to what a single restaurant would use"
The mechanism is mainly about replacing evaporative cooling with closed-loop direct-to-chip liquid cooling, so water moves like coolant inside a sealed machine rather than being boiled off into the air.
Hot GB200-class AI racks produce too much heat for normal air cooling, so cold liquid is pushed through pipes into the servers and across metal cold plates touching the hottest chips.
The liquid enters the rack cool, absorbs heat from the chips through cold plates, then exits the rack at a higher temperature and carries that heat through pipes to a huge cooling system outside the compute floor.
Microsoft says Fairwater sends that hot water to cooling “fins” beside the datacenter, where 172 20-foot fans blow air across the fins and dump the heat into the outside air.
The important detail is that the air cools the water through metal surfaces, so the water does not need to evaporate the way many older datacenters use cooling towers.
The cooled liquid then returns to the servers, repeats the loop, and keeps absorbing heat from the chips.
In older data centers, heat is often removed partly through cooling towers. Hot water meets moving air, some water evaporates, and that phase change carries heat away. Effective, but it consumes fresh water continuously.
But Firwater is a closed loop because the same coolant keeps circulating through sealed pipes: it absorbs heat from the chips, releases that heat through radiator-like fins, then flows back to the chips again.
For Wisconsin Fairwater, Microsoft says more than 90% of the facility uses closed-loop liquid cooling, while the remaining portion uses outside air and switches to water only on the hottest days.
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From "Microsoft" YouTube channel, (link in comment)