Intelligent Data Centres Issue 69 | Page 76

T H E E D G E
Some liquid cooling considerations :
Keith Dunnavant , VP Offer Strategy & Portfolio Management , Munters
that more cooling work will be done by liquid , which is more efficient .
Adaptability and customisation : Critical for optimal cooling
Customisable cooling solutions are crucial for air and liquid cooling because each data centre design can have unique constraints that cannot often be met with standard cooling products . Liquid cooling at a large scale is relatively new , so data
• The capacity of individual liquid cooling loops impacts pipe sizing , potential damage resulting from a leak , optimal sizing of supporting CDUs and has overall cost implications
• Liquid cooling systems must ensure compatibility between the working fluid and all materials that contact the fluid . The current piping material of choice is 316 stainless steel . Maximum velocity of the fluid within the piping , to minimise potential erosion , is recommended at 2.7 m / s . It is suggested that the circulating single-phase fluids be filtered to 25 microns to prevent fouling of microchannels in the cold plates
• A common design metric for single-phase technology working fluids is 1.5 litres / minute per kW of heat rejection , which for PG25 results in a 10 ° C ( 18 ° F ) temperature difference between the supply and return fluid
• Pumps within CDUs should derive their power from a UPS ( Uninterruptible Power Supply ) source and be sized to allow for the hydronic losses from discharge , through the entire hydronic circuit , and back . CDUs with single pumps ( VFD controlled ) provide better efficiency and control relative to CDUs with multiple pumps and VFDs
• Redundant CDUs are needed to provide the best resiliency and simplicity , as opposed to CDUs that provide redundant internal components . Components like expansion tanks are ideally installed in the common hydronic loop piping , and not internal to CDUs
• New considerations can be found in ASHRAE ’ s Liquid Cooling : Resiliency Guidance for Cold Plate Deployments . centre owners , consulting engineers , contractors and equipment suppliers must work in close collaboration to achieve an optimal outcome .
What lies ahead : The future of cooling
We are in a period of rapid innovation as hybrid air and liquid-cooled data centres are deployed at an unprecedented scale . It will take several years for the industry to define best practices and adopt standards .
Fuelled by the increase in computational demand created by Generative AI , almost 50GW of data centre capacity is projected to be added to the US grid by 2028 .
With increasing demand for data centres and their ability to support heavier workloads , advanced cooling solutions will continue to evolve . Embracing the emerging best practices and technologies will become more important than ever before , and as we look toward the future , one thing is clear : this is an exciting time to engage in the conversation surrounding data centre cooling . �
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