In today's world, where computational power underpins an array of processes and systems we rely on daily, maintaining efficient data centre operations is crucial. Data centres serve as the core of our digital infrastructure. They are the unsung champions of a rapidly advancing world powered by AI, cloud computing, and high-performance computing (HPC). Like any other vital system, data centres require an environment that maximises their efficiency, which means keeping them cool.
Traditionally, data centres have used air-cooled servers to manage heat, but the rise of AI and the subsequent increase in Thermal Design Power (TDP) is driving a shift towards liquid cooling solutions. Liquid cooling, employing water or other coolants, can dissipate heat far more effectively than conventional air cooling—by a factor of 23, to be precise.
Consider the difference between touching a 40W lightbulb and a 500W bulb after being lit for some time; this illustrates the heat produced by high-performance CPUs. Placing such a hot bulb inside a metal container and relying on airflow for cooling would only partially address the heat issue and take considerable time to do so. Attempting to disperse heat in a data centre with high-performance servers would be like recreating a wind tunnel, yet cooling would still fall short.
Liquid cooling leverages the superior thermal properties of water, offering 23 times more heat transfer efficiency compared to air. Water's thermal conductivity is 0.3632 Btu/h ft °F compared to air’s 0.01580 Btu/h ft °F, thus allowing heat to be removed closer to where it's generated.
Liquid cooling supports companies' sustainability initiatives by reducing power consumption, aligning with ESG objectives and shrinking carbon footprints. As a closed-loop system, it minimizes water usage, providing a sustainable solution without water wastage.
This brings us to costs. When constructing new data centres, the initial investment in liquid cooling is on par with traditional systems. However, retrofitting existing centres for liquid cooling can be costly due to potential infrastructure overhauls.
Importantly, organisations don't need to completely revamp their data centres to implement liquid cooling. They can adopt this technology selectively for high-performance settings. This modular approach allows businesses to tailor cooling solutions to specific high-demand applications.
Adopting liquid cooling comes with new skill requirements. Technicians will need training in handling liquid immersion, which involves complex tasks like using cranes to remove servers from cooling oil baths for maintenance.
Despite these challenges, the long-term advantages of liquid cooling are compelling. It can lead to substantial operational cost reductions, extend the lifespan of equipment by removing failure-prone parts like fans, and bolster overall reliability.
Additionally, it results in lower energy consumption. Cooling 20 kilowatts of equipment with liquid is far more effective than using air. This efficiency allows for smaller data centre footprints, enhancing compute density and freeing up valuable space for expansion or other uses.
Ben Selier is the Vice President for Secure Power, Anglophone Africa at Schneider Electric, where he oversees operations in 26 countries. He brings extensive industry experience, having previously held senior roles at go2Invest GmbH and Wesco Anixter, where he managed high-performance data centres. His expertise includes design, ownership, and product placement within data centre operations.
