NVIDIA Cools Its Chips with Water Hotter Than a Hot Tub — and Saves Millions

Next-generation NVIDIA Rubin servers are cooled with liquid at 45°C (113°F) — a few degrees hotter than a standard hot tub. This is not a design flaw; it's a deliberate choice: liquid at that temperature makes it possible to eliminate traditional mechanical chillers entirely.

The principle is straightforward: coolant enters the system at 45°C, absorbs the heat load from the processors, and exits at 55°C. That temperature differential is enough for outdoor dry coolers to dissipate heat naturally — no refrigerant-based cooling required. Historically, cooling systems have consumed up to 40% of a data center's electricity; every degree increase in chiller inlet temperature yields roughly 4% in energy savings.

At a 50 MW facility, that translates to roughly $4 million in annual savings from cooling alone. The closed loop also addresses the water problem: traditional evaporative cooling towers consume approximately 2.6 million gallons per megawatt per year, whereas the new system brings that figure to nearly zero.

Additional benefits include quieter operation, a smaller physical footprint (2U in a rack instead of 6U), and stable chip performance. As AI infrastructure power consumption continues to climb, these changes could significantly cut operating costs and the environmental footprint of the world's largest data centers.