Sustainable Cooling Strategies for AI Data Centers

Every cloud provider faces the same AI infrastructure challenge: chips need to be positioned close together to exchange data quickly, but they generate intense heat, creating unprecedented cooling demands. We needed a strategic solution that allowed us to use our existing air-cooled data centers to do liquid cooling without waiting for new construction. And it needed to be rapidly deployed so we could bring customers these powerful AI capabilities while we transition towards facility-level liquid cooling. Think of a home where only one sunny room needs AC, while the rest stays naturally cool – that’s what we wanted to achieve, allowing us to efficiently land both liquid and air-cooled racks in the same facilities with complete flexibility. The available options weren't great. Either we could wait to build specialized liquid-cooled facilities or adopt off-the-shelf solutions that didn't scale or meet our unique needs. Neither worked for our customers, so we did what we often do at Amazon… we invented our own solution. Our teams designed and delivered our In-Row Heat Exchanger (IRHX), which uses a direct-to-chip approach with a "cold plate" on the chips. The liquid runs through this sealed plate in a closed loop, continuously removing heat without increasing water use. This enables us to support traditional workloads and demanding AI applications in the same facilities. By 2026, our liquid-cooled capacity will grow to over 20% of our ML capacity, which is at multi-gigawatt scale today. While liquid cooling technology itself isn't unique, our approach was. Creating something this effective that could be deployed across our 120 Availability Zones in 38 Regions was significant. Because this solution didn't exist in the market, we developed a system that enables greater liquid cooling capacity with a smaller physical footprint, while maintaining flexibility and efficiency. Our IRHX can support a wide range of racks requiring liquid cooling, uses 9% less water than fully-air cooled sites, and offers a 20% improvement in power efficiency compared to off-the-shelf solutions. And because we invented it in-house, we can deploy it within months in any of our data centers, creating a flexible foundation to serve our customers for decades to come. Reimagining and innovating at scale has been something Amazon has done for a long time and one of the reasons we’ve been the leader in technology infrastructure and data center invention, sustainability, and resilience. We're not done… there's still so much more to invent for customers.

How Full Liquid Cooling Is Powering the Next Generation of AI Data Centers.... . . As AI workloads grow, traditional cooling methods are no longer enough. Modern high-performance data centers are now built around full liquid cooling architectures designed to manage the extreme heat generated by advanced AI processors. At the facility level, water from the building cooling system flows into in-row Coolant Distribution Units (CDUs). Inside, a liquid-to-liquid heat exchanger transfers cooling capacity to a secondary fluid that circulates directly to each rack, creating an efficient bridge between facility cooling and IT equipment. Inside every server, a dedicated liquid loop is engineered to match the processor layout and power density of AI hardware. Instead of relying on air, this loop absorbs heat directly from CPUs, GPUs, and memory modules, removing thermal energy at the source. The heated liquid then returns to the CDU, where high-performance heat exchangers move the heat away from the IT space toward the facility cooling system. From there, rooftop chillers or dry coolers reject the heat into the ambient environment. Even in fully liquid-cooled data centers, air still plays a supporting role. Air handlers remove residual heat from components not connected to the liquid loop, creating a balanced ecosystem where liquid handles high-density loads and air maintains room stability. Full liquid cooling is becoming a foundation for AI-ready infrastructure, enabling higher rack densities, better efficiency, and stable performance under extreme compute demand. As a Data Center Operations & Maintenance Engineer, I closely follow how these cooling architectures are transforming operations and facility design. Always happy to connect with professionals working on next-generation, AI-ready data centers. Video copyright: BOYD © Abdullah Mahrous – CC BY 4.0

🚀 Pumped Two-Phase Direct-to-Chip Cooling: Powering the Future of AI Data Centers Summary: As AI workloads surge, we are entering a new era of compute intensity. Chips like the NVIDIA Blackwell (2000W TDP), AMD MI300X (750W), and Gaudi HL-2080 (600W) are pushing thermal design limits far beyond traditional cooling capabilities. With cooling systems already accounting for up to 40% of an AI data center’s total energy use, the industry must innovate—fast. 🔍 Pumped Two-Phase (P2P) Direct-to-Chip Cooling is emerging as a transformative solution. By leveraging the latent heat of vaporization, P2P cooling removes heat more efficiently than single-phase methods. Cold plates are placed directly on high-power components, and a refrigerant circulates in a closed loop—absorbing heat through flow boiling and returning to the CDU for condensation and recirculation. 💡 Recent research from Vertiv, Intel, NVIDIA, and Binghamton University—presented at ASME InterPACK 2024—has validated P2P D2C cooling as commercially viable (TRL 7, CRL 2). Notable performance metrics include: - Heat load handling up to 170kW per rack - Case temperatures below 56.4°C - Thermal resistance of cold plates as low as 0.012°C/W - Efficient operation across dynamic loads, including hot-swapping scenarios - Stable control via flow regulators (2–32 PSID) to manage vapor quality and avoid dry-out 🔧 Two main system architectures are being optimized: Refrigerant-to-Air (R2A): For integration into existing air-cooled environments. R2A CDUs with microchannel condensers and variable-speed fans deliver up to 40kW in 600mm racks, making them ideal for gradual liquid cooling adoption. Refrigerant-to-Liquid (R2L): Using brazed plate heat exchangers and chilled water loops, R2L systems are ideal for high-power density clusters, leveraging liquid’s superior heat transport. 🧪 In real-world tests, the Vertiv R2L system maintained a constant pump flow of 39 GPM while supporting transient and asymmetric IT loads. Even under high refrigerant saturation temperatures and pressure drops (up to 7.6 psi across cold plates), the system remained within design parameters. Importantly, system resilience was demonstrated under failure simulations (e.g., pump switch-over, loss of heat rejection) without triggering pressure relief valves—ensuring safe shutdown protocols and zero refrigerant release. 🌍 Why it matters: As we push toward 600kW+ rack densities and AI training workloads scale exponentially, efficient and safe heat removal will be the linchpin of sustainable digital infrastructure. P2P D2C cooling isn’t just a stopgap—it may be the definitive pathway for next-gen AI data centers. #AIDataCenters #LiquidCooling #DirectToChip #TwoPhaseCooling #Vertiv #NVIDIA #ThermalManagement #SustainableComputing #HighDensityCooling #DataCenterInnovation #CoolingEfficiency #BlackwellGPU #HPC #GreenDigitalInfrastructure #EnergyEfficiency #PUE #NetZeroTech #FutureOfCooling #R2L #R2A #FlowBoiling #ColdPlate

Liquid Cooling: The $8 Billion Architecture Powering AI & Hyperscale Density Air cooling is officially struggling to keep up. As AI acceleration and HPC (High-Performance Computing) drive server power density past 30kW per rack, operators are rapidly shifting to liquid cooling—the only viable solution that is both efficient and future-ready. According to the latest forecast, the Data Center Liquid Cooling Market is set to surge from $2.2 billion to nearly $8 billion by 2031 🚀. This massive trajectory is fueled by sustainability demands and the insatiable appetite for compute power. 💡 So, What Makes Liquid Cooling Unstoppable? Liquid cooling replaces roaring fans with a targeted, high-precision pipeline, leveraging the superior heat transfer capacity of fluid over air. The primary architectures include: 1. Direct-to-Chip (Cold Plate) Cooling: Heat is transferred directly from the hot chip surface (CPU/GPU) to a Cold Plate. This is highly efficient for high-power chips. 2. Rear-Door Heat Exchanger (RDHx): Liquid-cooled coils in the rear door remove heat from the exhaust air before it enters the data hall. 3. Immersion Cooling: Servers are fully submerged in a non-conductive dielectric fluid, offering the highest possible density. 🧠 The Core Component: Coolant Distribution Units (CDUs) All these systems rely on the Coolant Distribution Unit (CDU). The CDU acts as the intelligent bridge, managing the precise flow, pressure, and temperature of the coolant between the facility's heat rejection system and the IT gear. ✨ Quantifiable Benefits for Operators Liquid cooling is not an upgrade—it's an essential architectural shift delivering powerful ROI: Higher Density: Enables compute density previously impossible with air. Energy Efficiency: Drastically reduced cooling power (PUE), leading to lower operating costs. Sustainability: Supports greener data centers by facilitating heat reuse and lowering the carbon footprint. Reliability: Eliminates thermal strain and hot spots, improving system stability for critical AI + HPC workloads. If you are shaping data center cooling strategies for 2025–2030, understanding the dynamics of D2C, Immersion, and CDU integration is now non-negotiable. High-Impact Hashtags #LiquidCooling #DataCenterCooling #AIWorkloads #HPC #CDU #ImmersionCooling #DirectToChip #ThermalManagement #PUE #GreenDataCenters #Hyperscale #DataCenterDesign #Infrastructure #CoolingArchitecture #Engineering

Liquid cooling is redefining data center efficiency... Delivering a powerful combination of sustainability and cost savings. As computing demands increase, traditional air cooling is falling behind. Data centers are turning to liquid cooling to reduce energy use, cut costs, and support high-performance workloads. Operators are considering direct-to-chip cooling, which circulates liquid over heat-generating components, and immersion cooling, where servers are fully submerged in a dielectric fluid for maximum efficiency. Developed markets, like the U.S. and Europe, are adopting liquid cooling to support AI-driven workloads and reduce carbon footprints in large-scale facilities. Meanwhile, emerging markets in Southeast Asia and Latin America are leveraging liquid cooling to manage high-density computing in regions with hotter climates and less reliable power grids, ensuring operational stability and efficiency. Greater Energy Efficiency Liquid cooling reduces total data center power consumption by 10.2%, with facility-wide savings up to 18.1%. It also uses 90% less energy than air conditioning, improving heat transfer and maintaining stable operating temperatures. Sustainability Gains Lower PUE (Power Usage Effectiveness) means less wasted energy, while reduced electricity use cuts carbon emissions. Closed-loop systems also minimize water consumption, making liquid cooling a more sustainable option. Cost and Performance Advantages Efficient temperature management prevents thermal throttling, optimizing CPU and GPU performance. Higher-density computing lowers construction costs by 15-30%, while cooling energy savings of up to 50% reduce long-term operational expenses. The Future of Cooling As #AI and cloud workloads grow, liquid cooling is becoming a competitive advantage. Early adopters will benefit from lower costs, improved efficiency, and a more sustainable infrastructure. #datacenters

🚀 The Future of Data Centers is Zero-Water, Solar-Powered & Built for AI As AI workloads explode and GPU clusters demand unprecedented density, traditional data centers are hitting a wall — high cooling costs, water scarcity, and rising carbon intensity. The next leap forward is here: Zero-Water Immersion Cooling + Solar PV + BESS Hybrid Power Architecture A design that makes data centers sustainable, scalable, and future-proof for high-density compute. ⸻ 🌡 Why Zero-Water Cooling? Conventional cooling towers consume millions of liters per MW annually. Immersion Cooling eliminates all of it. ✔ No water ✔ No cooling tower ✔ No chilled water plant ✔ No CRAC/CRAH overhaul Heat is directly absorbed by dielectric fluid and rejected via air-cooled dry coolers, making the system independent of outside temperature and humidity. ⸻ ⚡ Solar + BESS: The New Power Backbone A modern data center cannot rely only on the grid. This model integrates: • Solar PV → reduces daytime grid draw • BESS → stabilizes power, manages peak tariffs, enables black-start • UPS (N+1) → ensures continuous IT and cooling load • DG (optional) → only as a last resort backup The result is a resilient, flexible, hybrid power ecosystem. ⸻ 🤖 Designed for AI, HPC & GPU Clusters AI servers (A100, H100, TPU v5) generate extreme heat. Immersion cooling enables 30–80 kW per tank, making this model ideal for: • AI/ML workloads • High Performance Computing • Blockchain & FinTech compute • Cloud & hyperscale deployments With a target PUE of 1.15–1.25, it also delivers massive energy savings. ⸻ 🏗 High-Level Architecture Power Block: Grid • Solar PV • PCS • BESS • UPS • LV Distribution IT Block: Immersion Tanks • CDUs • Networking • Structured Cabling Cooling Block: Dry Coolers • Zero-water heat rejection • Minimal comfort cooling Control & Monitoring: DCIM • BMS • EMS • Real-time PUE • Solar/BESS optimization ⸻ 🌱 Key Benefits 🔹 Zero water consumption 🔹 High-density compute capability 🔹 Low PUE and operational efficiency 🔹 Lower carbon footprint 🔹 24/7 reliability with hybrid power 🔹 Scalable from edge pods to 20+ MW campuses ⸻ 🏆 Why This Matters Now • Water scarcity is rising • AI compute demand is exploding • Power tariffs and grid instability are increasing • Sustainability is becoming a global compliance standard Zero-water, renewable-integrated data centers are no longer optional — they’re the new benchmark for the AI era. Bhavita Shukla

AWS Builds Custom Liquid Cooling System for Data Centers Amazon Web Services (AWS) is sharing details of a new liquid cooling system to support high-density AI infrastructure in its data centers, including custom designs for a coolant distribution unit and an engineered fluid. “We've crossed a threshold where it becomes more economical to use liquid cooling to extract the heat,” said Dave Klusas, AWS’s senior manager of data center cooling systems, in a blog post. The AWS team considered multiple vendor liquid cooling solutions, but found none met its needs and began designing a completely custom system, which was delivered in 11 months, the company said. The direct-to-chip solution uses a cold plate placed directly on top of the chip. The coolant, a fluid specifically engineered by AWS, runs in tubes through the sealed cold plate, absorbing the heat and carrying it out of the server rack to a heat rejection system, and then back to the cold plates. It’s a closed loop system, meaning the liquid continuously recirculates without increasing the data center’s water consumption. AWS also developed a custom coolant distribution unit, which it said is more powerful and more efficient than its off-the-shelf competitors. “We invented that specifically for our needs,” Klusas says. “By focusing specifically on our problem, we were able to optimize for lower cost, greater efficiency, and higher capacity.” Klusas said the liquid is typically at “hot tub” temperatures for improved efficiency. AWS has shared details of its process, including photos: https://lnkd.in/e-D4HvcK

In January, Jensen Huang flew to China to meet with a diamond manufacturing company. The visit was reported as a curiosity. It wasn't. It was a signal about where AI hardware is headed. At CES 2026, NVIDIA announced that its next-generation Vera Rubin GPUs will use diamond-copper composite cooling, paired with 45°C warm-water systems instead of traditional chilled water. That's a quiet bet that the rest of the industry hasn't fully priced in yet. Here's why it matters. The growth in AI compute is colliding with two physical constraints that don't bend: Power. US data center electricity demand is projected to roughly double between 2025 and 2028 — from 80 to 150 gigawatts. That's the equivalent of adding the energy needs of Spain to the grid in three years. Water. AI data centers consumed 17 billion gallons of water in 2023. That number is projected to hit 68 billion by 2028 — a 300% increase. A single 100-word ChatGPT prompt uses about half a liter of water just for cooling. Both problems trace back to the same source. Silicon overheats. As chip density rises, cooling demand grows non-linearly, and we're paying for it in coal-fired electricity and aquifer drawdown that small towns are starting to organize against. Diamond changes the underlying physics: • Thermal conductivity above 2,000 W/m·K — around 5x silicon • A wide 5.5 eV bandgap means it operates reliably at junction temperatures that would destroy conventional chips • Stanford recently demonstrated low-temperature growth of polycrystalline diamond — the manufacturing breakthrough that finally makes scale realistic • DARPA-backed "diamond blanket" prototypes have dropped transistor temperatures by ~70°C in lab testing Real-world tests show diamond-based cooling cutting chip temps 20–60°C and reducing cooling energy by up to 40%. If that holds at scale, warm-water cooling becomes viable — which means data centers stop needing the chilled-water volumes that are driving today's resource crisis. NVIDIA tends not to move first unless they've already done the math. This is the most important infrastructure story almost nobody outside hardware circles is following — not because of what it lets AI do, but because of what it lets AI avoid destroying on the way there. What's the next overlooked materials story you're tracking?

It would be an understatement to say that the APAC data center industry is undergoing a significant transformation driven by the rapid adoption of AI and increasing power density requirements. This has led to an evolution in cooling, which promises to reshape data center operations and design across the region. The APAC data center cooling market is experiencing remarkable growth, with projections indicating it will reach USD 5.73 billion by 2029, growing at a CAGR of 10.12% from 2023. This surge is fueled by factors including the rise in internet users, increased social media presence, widespread smartphone adoption, and the growing need for enterprises to transition to advanced data center environments. Globally, the market for data center liquid cooling is set to expand from USD 4.9 billion in 2024 to USD 21.3 billion by 2030, representing a CAGR of 27.6%. Liquid cooling technologies are gaining traction in the APAC region due to their superior heat dissipation capabilities compared to traditional air cooling methods. This shift is particularly crucial in the region's warm climate. The adoption of liquid cooling is driven by increasing power densities, with some APAC facilities now supporting up to 70 kW per rack, the growth of AI and high-performance computing applications, and significant improvements in energy efficiency. The transition to liquid cooling presents challenges, especially for existing data centers designed for air cooling. These facilities face hurdles in retrofitting their infrastructure to accommodate liquid cooling systems, including the installation of extensive piping networks and the integration of Coolant Distribution Units (CDUs). Technical considerations such as flow rate optimisation, pressure management, and material compatibility must be carefully addressed during implementation. While existing data centers grapple with retrofitting challenges, new facilities are being designed from the ground up with liquid cooling and AI requirements in mind. These SOTA data centers incorporate innovative features such as modular designs for easy scaling, hybrid cooling approaches combining air and liquid cooling, and dedicated high-density zones for AI workloads. Technical implementations include direct-to-chip cooling systems capable of handling heat loads up to 2,000 watts per processor, immersion cooling tanks allowing for density computing up to 300 kW per rack, and advanced CDUs with higher capacities and more precise control systems. Companies in the APAC region are making significant investments in liquid cooling technologies. For ex., AirTrunk has deployed over 20 MW of liquid cooling within first phase of its JHB1 campus in Malaysia, demonstrating growing confidence in these solutions and their ability to deliver energy savings and improved PUE in tropical climates. Despite the challenges, as the technology matures and becomes more widely adopted, further innovations and cost reductions are expected.