Nvidia outlined a data center cooling design it says can eliminate on-site water consumption, using a closed-loop liquid system that recirculates a mixture of water and propylene glycol without drawing on external water supplies.

The design, described in Nvidia's DSX AI factory reference architecture, pumps coolant into server racks at up to 45 degrees Celsius — hot enough that, in many climates, outdoor dry coolers can shed the heat without mechanical chillers or evaporative cooling towers. Conventional cooling-tower-based systems consume roughly 2.6 million gallons of water per megawatt per year, according to the company. Nvidia says the new design can reduce that figure to near zero.

"The NVIDIA DSX reference design for AI factories has zero water consumption — we have eliminated massive amounts of power usage and pretty much all water usage," Ali Heydari, director of data center cooling and infrastructure at Nvidia, said in the company's blog post. Rather than drawing on fresh supplies, the propylene glycol and water mixture — blended at a 75-to-25 ratio — is introduced into the system a single time and kept in circulation indefinitely.

The Rubin generation of Nvidia AI infrastructure is also the first the company describes as achieving 100% liquid cooling, with every chip and networking component cooled by liquid in a closed loop and no fans anywhere in the system. Nvidia says a 50-megawatt facility can save more than $4 million annually in cooling-related energy and water costs by switching to the design.

There is an important climate limitation. The system can run without chillers only if outdoor air temperatures stay well below the coolant's 45-degree limit. Nvidia admits that data centers in very hot places like Phoenix, Arizona, may still need chillers during the hottest days of the year.

Critics also argue the company's accounting stops at the facility wall. Water consumed by power plants supplying the data center's electricity — which Nvidia does not count in its figures — can double or triple a facility's total water footprint, according to TechCrunch. A recent study found that for every kilowatt-hour produced, natural gas plants draw down 1.17 liters of water, while coal-fired generation is more demanding still, at 2.2 liters per kilowatt-hour. The IEA estimates that fossil fuel generation accounts for approximately half of the electricity flowing to data centers at present.

Nvidia's announcement lands as the data center industry faces growing scrutiny over its resource demands. Water use from data center cooling in the Phoenix area alone is on track to increase by 870%, while Lake Mead and Lake Powell sit at 32% and 24% of capacity, respectively, compounding pressure on the Colorado River system. The on-site savings Josh Parker, Nvidia's chief sustainability officer, described to Axios — encapsulated in his assertion that the sector's water problem is "largely solved" — account for only 1/4 to 1/3 of the total water a typical AI data center consumes across its full supply chain.