What Is Data Center Cooling And Why It'S Critical? August 4, 2026 Data center cooling refers to the systems and strategies used to remove heat generated by IT equipment — servers, networking gear, storage, and power infrastructure — to maintain safe operating temperatures, maximize uptime, and enable sustained compute performance. As data center density continues to climb, cooling has moved from a support function to a core design constraint. Why Cooling Defines Modern Data Center Performance The scale of heat generation in modern data centers is difficult to overstate. A standard server rack from a decade ago generated 3-5 kW of heat. Today's high-density AI and GPU clusters generate 30-80+ kW per rack — and some configurations exceed 100 kW. The cooling infrastructure required to handle that density is fundamentally different from traditional approaches. Data Center Generation Typical Heat Density Legacy (pre-2015) 3-8 kW per rack Modern enterprise (2015-2022) 10-20 kW per rack AI / HPC (2022-present) 30-80+ kW per rack Next-generation AI clusters 100+ kW per rack (emerging) "What's changed is density. Cooling is no longer about managing the room — it's about enabling compute at scale. The chiller system is no longer background infrastructure; it determines what the facility can run."— Paul Johnson, G&D Chillers The Consequences of Inadequate Cooling Temperature control failures in data centers have direct, measurable consequences: CPU and GPU throttling: processors automatically reduce performance when operating above thermal limits, degrading the compute output the facility exists to deliver Accelerated hardware degradation: sustained elevated temperatures shorten component lifespan and increase failure rates Unplanned downtime: thermal events trigger automatic shutdowns that interrupt workloads and violate SLAs Efficiency loss: a poorly cooled facility uses more energy to deliver the same compute output Common Cooling Methods Data center cooling architectures have evolved significantly as density has increased: Air cooling (CRAC/CRAH + containment): circulates cooled air through the facility. Effective up to approximately 20-30 kW per rack with proper airflow management. Cost-effective and widely deployed. Liquid cooling (direct-to-chip, immersion): brings cooling liquid into contact with or close proximity to heat-generating components. Handles 30-80+ kW per rack efficiently. Required for high-density AI and HPC deployments. Chilled water systems: central plant (chillers) produce chilled water that serves air handlers or CDUs throughout the facility. The backbone of large-scale data center cooling infrastructure. What Advanced Chiller Systems Contribute In chilled water-based data center cooling, chiller selection and design directly impact facility performance. Key engineering advantages in modern chiller systems include: Oil-free magnetic bearing compressors (Danfoss TurboCor): eliminate oil-related efficiency degradation over time, reduce maintenance requirements, and deliver stable performance under continuous high-load operation Flooded evaporator design: provides higher heat transfer efficiency, better performance under sustained load, and more stable suction pressure — important characteristics for the continuous, predictable loads data centers generate Higher cooling density: more cooling capacity per unit footprint, critical for facilities where mechanical space is constrained Frequently Asked Questions What is PUE and why does it matter? Power Usage Effectiveness (PUE) is the ratio of total facility energy to IT equipment energy. A PUE of 1.0 is theoretical perfection (all energy goes to compute); typical modern data centers target 1.2-1.4. Cooling efficiency is the primary variable in PUE improvement. At what rack density does liquid cooling become necessary? The practical threshold is approximately 20-30 kW per rack for air cooling. Above that, air-side cooling becomes increasingly difficult to make work reliably, and liquid cooling is the more practical approach for sustained operation. Talk with G&D's data center cooling engineers about your load and system design -> Contact us