www. refrigerationandaircon. co. za RACA Journal I September 2025 29
Feature
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Georges Dubien, MEA sales director- data centres: Boreas and Exagate.
Michael Byrne, head of data centre design & engineering EMEA at Eaton.
Willem Weber, data centre environmental engineer at Master Power Technologies( MPT).
Lee Perrin, data centre lead, MEA.
THE DENSITY DILEMMA: AI, SHRINKING SERVERS AND COOLING EVOLUTION Dubien highlighted that while servers are shrinking in physical size, the heat they emit is enormous. He stressed that simple air cooling will not suffice for the new era of computing, with cabinets now reaching up to 100 kW and even potentially 600 kW in the future, compared to typical 5-10 kW racks. Dubien detailed the evolving cooling solutions:
• Air cooling: Still the most common, but increasingly insufficient for high densities
• Liquid cooling: The next step, often involving direct-to-chip solutions
• Immersive cooling: Where servers are submerged in non-conductive fluids, allowing for extreme heat dissipation. He noted a recent design he saw pushing 100 kW per cabinet using immersive cooling, requiring a completely new cabinet design for such high heat loads
• Fan wall units: These are becoming massive, with units capable of cooling 500 kW( and R & D targeting 1 MW per unit), essentially forming a complete wall of fans to dissipate heat from hot aisle containments
This shift means new data centres need to be inherently resilient, scalable and AI-ready from the ground up, with construction times potentially extending to two years or more for two-megawatt facilities, a significant increase from the traditional six months.
Weber supported the notion that while chip cooling handles the primary heat source, significant‘ residual’ heat still emanates from components like power supplies. This necessitates a dual cooling approach, managing both the direct-to-chip cooling and the remaining ambient heat. He underscored the need for a comprehensive design methodology to make systems scalable, potentially involving chillers, cooling towers and plate heat exchangers for precise temperature and flow regulation.
Perrin acknowledged the " brain-breaking " challenge of retrofitting legacy sites with these high-density requirements.“ While new builds offer the flexibility to design for such demands, existing infrastructure poses significant hurdles. The industry is effectively chasing the exponential demands from chip manufacturers and hyperscalers, leading to a constant state of design uncertainty. We ' re not being told... there ' s a little bit of guessing- a situation that places data centre designers and providers in a precarious position, with designs risking obsolescence almost as soon as they are completed."
The impact on real estate is also profound. Perrin questioned how the fixed footprint of existing data centres and their surrounding infrastructure( for generators and cooling units) will cope with vastly increased IT load per square metre in the white space. This could lead to " big, empty white spaces with a few heavy blocks " as facilities hit external real estate constraints. Dubien countered that this would necessitate a complete reimagining of the cabinet itself, moving towards fully immersive designs that manage 100 kW or more within a smaller physical footprint.
SKILLS, COLLABORATION AND THE FUTURE WORKFORCE The rapid evolution of cooling technologies and power demands inevitably impacts the required in-house skills. Byrne stated that Eaton ' s global innovation team is in continuous‘ workshop’ mode, collaborating daily with partners on the cooling side. " While power optimisation has reached a high level, the frontier of innovation now lies primarily in cooling, exploring solutions like two-phase immersion cooling. Companies are increasingly joining forces to find these complex solutions, recognising that without addressing cooling, they cannot meet client demands for power management either."
Weber emphasised the critical need for open-minded individuals in the workforce, as human nature often resists change. He noted a particular challenge within traditional electrical and mechanical engineering disciplines, urging them to embrace these new concepts. A skills shortage exists for those who can think‘ out of the box’ and provide innovative designs. Weber also lamented South Africa ' s reliance on importing components like chillers and air conditioning units, advocating for a return of manufacturing capabilities to the country to foster local expertise. A long-term view, spanning five years or more, is crucial for developing the specialised individuals needed to adapt to this continuously evolving environment.
www. refrigerationandaircon. co. za RACA Journal I September 2025 29