NVIDIA says its new liquid cooling system can reduce water and energy use for AI data centre

NVIDIA has announced a groundbreaking advancement in its Rubin AI servers, capable of operating with cooling liquids at temperatures as high as 45 degrees Celsius—hotter than a typical hot tub. This innovative approach marks a significant shift towards enhanced efficiency in data centers, as the Rubin system is the first of its kind to utilize 100% liquid cooling, eliminating fans entirely from the architecture. The company's new design, outlined in its DSX AI factory reference architecture, is touted to significantly decrease both power and water consumption in hyperscale data centers. Ali Heydari, director of data center cooling and infrastructure at NVIDIA, highlighted that the DSX reference model boasts zero water consumption, effectively cutting down substantial energy use along with nearly all water usage. He noted that while some regions might still require chillers for about 1% of the year, the overall water usage in AI data centers is a topic of heated discussion—one that may come with surprising statistics. According to the Manhattan Institute, data centers account for just 0.2% of daily water consumption in the U.S., a figure that has seen a significant decline in recent years due to efficiency improvements. Historically, cooling has represented up to 40% of a data center's electricity demand, and industry estimates suggest that every one-degree increase in chiller plant temperature can reduce cooling energy expenses by approximately 4%. For a 50-megawatt hyperscale facility, this could translate to annual savings exceeding $4 million in energy and water costs. In optimal conditions, the new 45-degree cooling system can diminish cooling water usage from around 2.6 million gallons per megawatt per year—common in traditional cooling-tower systems—to nearly zero. Unlike conventional setups that rely on cooled air and generate fan noise levels of 85 decibels or more, the Rubin systems utilize a coolant mix consisting of 75% water and 25% propylene glycol, which circulates through cold plates on processors. This coolant enters the system at 45 degrees Celsius and exits at approximately 55 degrees after absorbing heat, all while processors maintain peak performance. Richard Whitmore, president and CEO of Motivair, part of Schneider Electric’s advanced cooling division, emphasized the necessity of liquid cooling as processor power demands increase. NVIDIA also noted that the full liquid cooling system necessitated a redesign of previously air-cooled components. The new architecture employs a single inlet and outlet, sealed front panels, and increased rack density, enabling systems that once occupied six rack units to fit into just two. In favorable locations, operators may even opt for outdoor dry coolers without refrigeration systems. NVIDIA reported that cloud service providers and data center operators are already transitioning to build for the Rubin architecture. Additionally, this innovative approach could facilitate waste heat recovery for adjacent buildings, aligning with the burgeoning demands of AI workloads and data center development.