www . refrigerationandaircon . co . za RACA Journal I February 2025 17
Business
AIR , HYBRID AND LIQUID : THE COOLING MIX FOR 2025
Compiled by Eamonn Ryan from the transcript of a Vertiv website panel discussion
The following is a panel discussion hosted by Data Centre Dynamics on the Vertiv platform on the topic of hybrid cooling systems and the anticipated shifts in the cooling mix for the upcoming year .
Panellists included Gemma Reeves of Alfa Laval , Jacqueline
Davis of Uptime Institute Intelligence , Stephanie Schmidt of Intel Corp and Julia Diaz from Page , hosted by Kat Sullivan of Data CenterDynamics .
Davis notes that Uptime ’ s focus on cooling embraces direct liquid cooling ( DLC ), both immersion systems and cold plate systems . “ Our recent survey data indicates that approximately 11 % of respondents are currently utilising some form of DLC . This figure aligns closely with our findings on cooling high-density racks , indicating a growing adoption of DLC . The need to cool high-density setups is a significant catalyst for the current shift towards DLC .
Reeves says that it ' s evident that liquid cooling has gained popularity in the past 12 – 18 months . “ Liquids have become a focal point in recent discussions , with increased client engagement and visibility at events . While the interest is palpable , the adoption might not be as widespread as the ongoing dialogue suggests . However , the increase in rack densities signals a clear trajectory towards liquid cooling . This year , we anticipate more organisations testing and implementing these systems in real-world scenarios . Perhaps we might witness the emergence of fully liquid-cooled data centres , either through immersion or other innovative methods . The technology is evolving , and there is a growing need for it to adapt to the changing demands of data centres .
“ From our standpoint , focusing on the heat transfer aspect , we have observed considerable movement in the field of liquid cooling technologies . The question remains : is the pace of technological advancement sufficient for large-scale deployments in 2024 , specifically in DLC or immersion technologies rather than mixed liquid cooling solutions ? Ideally , the answer would be yes . While it might not happen in the first half of the year , there are possibilities for substantial roll-outs later in the year . The increasing interest and ongoing developments in the technology create a favourable environment for larger-scale implementations ,” says Reeves .
A BALANCED APPROACH Building on this , Diaz emphasises the importance of a balanced approach between air and liquid cooling systems . While a fully liquid-cooled data centre might not be a widespread reality in 2024 , the industry is witnessing a shift away from solely air-cooled systems . She notes the challenges of managing buildings with a 30-year lifespan that must adapt to technologies which may evolve within the next five years . Retrofits are becoming more common as organisations strive to remain relevant in the face of changing cooling requirements .
Sullivan directs the panel ’ s attention to the complexity of retrofitting existing infrastructure to accommodate hybrid cooling solutions and offers insights on the best approach to progress while utilising current resources . “ Retrofitting existing buildings to support a hybrid load presents a unique engineering challenge . Solutions vary based on the specific system , site , client and owner requirements . While quick fixes are scarce , I ’ m optimistic of the industry ' s commitment to finding innovative ways to repurpose existing infrastructure , rather than resorting to demolition and reconstruction .”
Schmidt notes that cold plate systems comprise approximately 80 % of deployments , with immersion systems accounting for the remaining 20 %, each offering unique advantages and catering to different deployment scenarios . She also highlights the role of artificial intelligence ( AI ) in driving liquid cooling deployments , particularly in supporting high thermal design power parts for AI applications .
The demand for higher temperatures , energy efficiency , and sustainability in data centre cooling derives from the pressure on the industry to become more environmentally friendly , user-friendly and circular . There is increasing focus on sustainability managers and district heating integration managers within companies , reflecting a shift toward more eco-conscious practices .
“ The industry ' s commitment to sustainability has evolved from a mere aspiration to a critical necessity . Companies are under pressure to offset power usage and adhere to new EU regulations . The integration of sustainability goals has led to a more circular and environmentally friendly approach within the data centre industry ,” Schmidt says .
The discussion shifts towards the potential reuse of heat generated by data centres . Diaz emphasises the opportunities presented by higher facility water temperatures , providing a chance to give back to local communities . The heat generated can be redirected for purposes such as district heating , greenhouse
www . refrigerationandaircon . co . za RACA Journal I February 2025 17