- Nvidia says it can use hot water to cool its next-gen Vera Rubin systems
- The ability to use 45-degrees Celsius water means no chillers are needed
- That has implications for energy efficiency and the broader cooling market
When you think of liquid cooling for data centers, you probably don't think of hot water. But that’s exactly what Nvidia CEO Jensen Huang said it can use to cool its new Vera Rubin supercomputers.
Contrary to what you might think (again), this could be good news for liquid cooling companies, despite the stock market's reaction to the news today. But first, here is the break-down of the news and what it means.
“The power of Vera Rubin is twice as high as Grace Blackwell. And yet – and this is the miracle – the air that goes into it, the air flow is about the same. And very importantly, the water that goes into it is the same temperature, 45 degrees C,” Huang said on the CES keynote stage on Monday. “With 45 degrees C, no water chillers are necessary for data centers. We are basically cooling this supercomputer with hot water.”
In case it’s not immediately apparent, this is a big change: 45-degrees Celsius is around 113-degrees Fahrenheit.
There are two big takeaways from this shift: one, it could be very good news for liquid cooling, and two, it could be good news for energy efficiency.
Good news for energy efficiency
Taking the latter point first, the ability to use high-temperature water eliminates the need for chillers and their power-hungry compressors. This, in turn, enables a shift to dry cooler systems.
Without nerding out too much, dry cooler systems can use ambient air – which in many places is under 45-degrees Celsius for many parts of the year – to cool the liquid running through the cooling system rather than a chiller.
Huang said in his CES address that the shift “enables us to save about 6% of the world's data center power.” That’s a huge deal in a market where access to power is a key constraint and consumption is a point of public criticism.
Good news for liquid cooling, too
But circling back to the first takeaway, the shift could also be good news for liquid cooling systems in general.
Dell’Oro Group noted in December that direct liquid cooling – the leading option for cooling high-performance computing – grew 85% in Q3 2025 and was on track to surpass $2 billion in yearly revenue.
“Liquid cooling has always had the opportunity to work at higher temperatures, like at 45-degrees Celsius, to cool these AI workloads,” Lucas Beran, Director of Product Marketing at Accelsius, told Fierce. “This cements the value that liquid cooling is bringing to the data center. You could not use 45-Celsius air to cool these processors.”
Beran added the change could especially be a boon for two-phase direct liquid cooling, which he said functions more efficiently at higher temperatures.
The dominant liquid cooling systems today are single phase, meaning the cooling liquid stays a liquid. Two-phase systems include a change from liquid to gas and back again. In October, Accelsius CEO Josh Claman told Fierce he believed two-phase cooling had reached a “tipping point” but noted some supply chain issues were slowing uptake of the technology.
“This starts to open the door for two-phase cooling’s better performance at higher facility water temperatures to resonate,” Beran said.
The looming question, of course, is what this means for the rest of the multi-billion-dollar data center cooling market. It doesn’t seem to bode well for vendors of traditional chiller and HVAC systems.
“If being able to support Vera Rubin chips with 45-degree Celsius water means you don’t need a chiller, then instead of buying a chiller you’re going to buy a dry cooler, which probably isn’t going to come from your traditional [heat] rejection supplier,” Beran said.
And the stock market reaction
Despite Beran's positive angle on the news, investors took it as a bad sign. Stocks for traditional cooling players Vertiv, Schneider Electric, Johnson Controls and Eaton all took a sharp dive when the markets opened after Huang’s address. All but Johnson Controls had recovered a few hours later. Vertiv, Schneider and Johnson all make chillers for data center applications.
But Dell'Oro Group Research Director Alex Cordovil told Fierce that Huang's big reveal isn't exactly new. Indeed, Nvidia’s Wade Vinson said in a keynote at DCAC Live 2024 “Our chips run at 85 and 90C. That means that I need 45C water into it. That means it’s a dry cooler everywhere in the world.”
Cordovil noted that several existing cooling systems can already operate at higher temperatures and potentially forego some chiller capacity. Importantly, this doesn't mean eliminating chillers altogether though.
"In most of the U.S. it would be possible to reject a lot of the heat by free cooling alone with mechanical chillers kicking in only in the hottest of the days—and in some colder climates potentially not kicking in at all. Most vendors already sell flexible chillers that can operate in 'economizer mode' moving to free cooling when mechanical cooling is not required," he explained. "The reality is that operators, however, have preferred to run their GPUs at slightly lower temperatures to maximize clock speed."
Cordovil noted Dell'Oro had already expected the chiller market to be negatively impacted by higher temperature liquid cooling systems and said Huang's comments "is not material to make us revise down our forecast." Chillers, he said, will continue to be an important piece of the data center resiliency puzzle. "Even if not needed every day, nobody wants a data center to go down when a heat wave strikes," he stated.
In a statement provided to Fierce, Vertiv said "Using higher-temperature water does not eliminate the need for heat rejection. While approaches to heat rejection may change in a 45°C water-cooled design, cooling infrastructure is still required, with architectures shifting toward liquid-to-liquid heat transfer or dry-cooler-based approaches rather than removing cooling systems entirely." It added demand for liquid cooling solutions will increase as data center designs evolve and the company remains "well-positioned across heat rejection methods."
Fierce also reached out to Schneider and will update this story when we hear back.
Update 1/7/2026: This story has been updated to include comments from Dell'Oro Group and Vertiv.