Overview of Cooling Systems

We are not talking about it enough but data center cooling isn’t just a technical constraint anymore, it’s a wall we’re about to crash into. Air cooling is already maxed out under modern AI workloads. Liquid cooling isn’t futuristic anymore, it’s baseline. But even that won’t get us where we need to go. The next leap in computing isn’t just about silicon. It’s about materials, the ones that move heat faster, more efficiently, with less space and energy overhead. Right now, the situation is crucial: → Direct-to-chip liquid cooling is here and scaling. It’s a good step, but it doesn’t solve component-level hotspots. → Immersion cooling is being rolled out by Microsoft, Meta, and others. Great for racks, but not a silver bullet. → Liquid metals, high-end phase change materials, and engineered coolants are improving edge-level thermal interfaces, but they hit their limits fast. One material getting serious attention is synthetic diamond. Its thermal conductivity is unmatched. Some startups, like Akash Systems, are already using diamond for heat spreaders and RF devices, claiming measurable performance gains. There’s even early work on growing diamond films directly on silicon — a concept that, if scalable, could shift how we build thermal pathways in packaging. But diamond isn’t a magic solution. It’s expensive. Manufacturing is complex. Integration with standard processes is still a challenge. Still, the interest isn’t hype. The physics is real. And as compute density increases, it’s clear we’ll need new materials in the stack to handle the thermal load. If you're building AI-scale infrastructure and not exploring this layer of the problem — the materials layer — you’re not preparing for what’s coming. Because it won’t be the airflow that holds you back. It’ll be heat. #DataCenterCooling #AdvancedMaterials #LiquidCooling #FutureOfComputing

Belgium Converts City Sewers Into Underground Cooling Loops for Data Centers and Supermarkets Beneath the city of Antwerp, engineers in Belgium have begun piping cold water through old municipal sewer tunnels — not to treat waste, but to cool buildings above. It’s part of a radical new geo-loop cooling system that turns underused infrastructure into a city-wide thermal network. Developed by KU Leuven and Hydroscan, the system uses narrow, insulated water lines threaded through decommissioned sewer pipes running beneath central Antwerp. These lines carry naturally cool groundwater and redirect it to surface-level heat exchangers in data centers, supermarkets, and hospitals — where they absorb waste heat without compressors or refrigerants. The cooled facilities then return warm water back into the loop, where it’s gradually dissipated through soil contact or re-cooled underground. Unlike traditional air conditioning systems, there’s no need for chillers or rooftop condensers — just quiet, passive, low-pressure flow driven by small pumps. Initial installations have reduced building cooling costs by 55% and carbon output by 80%. Because the sewer network already exists, the project avoids street excavation and permits fast retrofits. The entire system runs silently beneath people’s feet, cutting heat without any visible equipment. It’s not just smart cooling — it’s recycling the city’s underworld into a climate control system.

Water-cooled data centers are more energy-efficient than air-cooled data centers. Water can achieve higher thermal performance and lower energy consumption, resulting in increased energy savings and reduced operational costs. At Cerebras Systems all our data centers are all water cooled, which is part of the reason our systems consume so much less power per token than the competition....The benefits of water cooled data centers are... 👍 Higher Thermal Capacity. Water has a significantly higher heat capacity than air, meaning it can absorb more heat and transport it more heat more efficiently. 👍 Improved Heat Transfer Water can transfer heat away from components more effectively than air, allowing for a smaller, more efficient cooling system. 👍 Reduced Fan Power Water cooling eliminates the need for high-powered fans that are typically used in air-cooled systems, resulting in significant energy savings. 👍 High Density and Flexibility Water cooling allows for higher equipment density in data centers and greater flexibility in thermal management. 👍 Power Usage Effectiveness Water-cooled data centers achieve lower PUE values, which are a measure of the energy efficiency of a data center. 👍 Sustainability Reduced energy consumption and the possibility of using heat recovery systems make water cooling a more sustainable choice.

Open-Loop Equipment: With open-loop equipment, process fluid enters the top of the cooling tower and flows over the fill (or heat transfer media). At this point, the process water is open to outdoor air and any contaminants present in the atmosphere. Falling from the fill, water collects in a basin before returning to the facility’s cooling loop. Due to airborne pollutants, incoming contaminants from the makeup water supply, and the presence of absorbed oxygen, proper maintenance of all equipment in the loop is critical. This also heightens the importance of water/fluid filtration and treatment. If the process water in the basin of the open tower is not properly treated, filtrated, and maintained. Closed-Loop Technology: Some cooling applications require a closed-loop system for peak-efficiency long term operation. These types of systems generally include the use of small heat exchangers in terminal units or other connected equipment, making maintenance complicated, if at all possible. For example, buildings with water-source heat pump loops – widely used for office, hotel, and health care facilities – are among one of the largest markets for fluid coolers. Using an open-cooling loop could pose the significant risk of fouling hundreds of heat exchangers in a condominium or similar facility. Closed circuit systems are also prevalent among data centers, battery plants, grow room facilities, high-efficiency chiller applications, and multiple different types of industrial process loops. Water loss through evaporation is either reduced or eliminated, depending on the type of closed-loop cooling equipment selected. The same is true for water treatment chemicals and/or systems; closed-loop technology can help to dramatically reduce or even eliminate the need for chemical treatment of system fluids. Closed circuit coolers can also provide completely dry sensible heat rejection when outside ambient conditions are favorable. This dry capacity is an added benefit that can greatly reduce the overall water consumption on a project. Fluid coolers can be sized for full design or partial load based on a dry bulb switchover temperature. This means that the recirculating spray pump can be de-energized when the heat load can be fully satisfied by just the fluid cooler fans. While this operational mode greatly reduces water consumption, energy is also saved since the recirculating pump is off.

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

🌡️ Revolutionizing Data Center Cooling: The Power of Fluorinated Liquids!** 🌊✨ Discover how cutting-edge immersion cooling technology is transforming the way we manage heat in high-performance computing. With fluorinated liquids leading the charge, we’re not just enhancing efficiency—we’re paving the way for a sustainable future in tech! 🔧💚 Immersion cooling is an advanced cooling technique used primarily in data centers and high-performance computing environments. This method involves submerging electronic components, such as servers and other hardware, directly into a dielectric (non-conductive) liquid coolant. How Immersion Cooling Works The process of immersion cooling can be broken down into three main steps: 1. Submersion: Hardware components are fully submerged in a dielectric coolant, which is designed to avoid electrical interference. Fans and power supplies must be removed before submersion. 2. Heat Absorption: The liquid coolant, which has a higher thermal conductivity than air, absorbs the heat generated by the electronic components. 3. Heat Dissipation: The heated liquid is circulated to a heat exchanger where the heat is transferred away from the coolant, allowing it to be recirculated back to the hardware. Types of Immersion Cooling There are two main approaches to immersion cooling: 1. Single-Phase Immersion Cooling:    - The coolant remains in liquid form throughout the process.   - The liquid is pumped to a heat exchanger where heat is transferred to a cool water circuit.   - Cooling baths are typically open-topped due to low evaporation risk. 2. Two-Phase Immersion Cooling:   - Uses a dielectric fluid with a low boiling point (around 56°C).   - The heat causes the liquid to boil and change to gas.   - The gas rises, meets a condenser, and 'rains' back into the pool, cooling the working fluid again.   - Requires sealed baths to prevent gas escape. Benefits of Immersion Cooling Immersion cooling offers several advantages over traditional air cooling methods: - Energy Efficiency: Can reduce Power Usage Effectiveness (PUE) to below 1.1, compared to the global average of 1.55. - Space Saving: Allows for higher computing density in a smaller space. - Noise Reduction: Eliminates the need for fans, resulting in quieter operation. - Hardware Longevity: Maintains consistent temperatures, reducing thermal stress on components. - Sustainability: Can reduce carbon emissions by up to 39% and water consumption by up to 91%. Coolants Used The dielectric fluids used in immersion cooling fall into two categories: 1. Oils (synthetic, mineral, bio) 2. Engineered fluids (e.g., 3M's Novec or Fluorinert lines) Immersion cooling represents a significant advancement in data center cooling technology, offering improved efficiency, sustainability, and performance compared to traditional air cooling methods. What do you think? #DataCenter #CoolingTechnology #Sustainability #Innovation #3M #Novec #ai Video courtesy of MechMarvelTV