As data centre operators race to meet the growing computational demands of AI, they also face significant environmental challenges. How do they cool powerful hardware efficiently? Castrol may have found the answer.
The global lubricant brand is now leveraging its 125+ years of fluid expertise in the automotive sector to develop cooling solutions for the data centre industry.
“We see an enormous opportunity in improving the thermal management of data centres,” says Chris Lockett, Senior Vice President for Electrification and Castrol Products Innovation. “When we look at the way data centres are cooled today with air cooling, a significant amount of power is being utilised to keep the servers cool – up to 40% of the data centre’s power.”
The evolution away from air cooling
Immersion cooling involves submerging server components directly in dielectric fluids that conduct heat, but not electricity. For the data centre industry, moving away from traditional air cooling towards immersion cooling solutions represents a paradigm shift.
According to Stephen Zhao, Thermal Management Director for EMEA at Castrol, this cooling method dramatically decreases energy consumption. “You cut down on everything. The only thing you really operate is just the pumps on the tanks, and those pumps are not very strong,” he says.
“Data centres themselves consume a lot of power. And from the traditional format of using air cooling to get the most efficient cooling method, you also need to consume a lot of water.”
These resource demands inevitably create environmental challenges, as Stephen explains: “From the power and water perspective, you have a lot of impact, and then you also have land use as well.”
Immersion cooling emerges as a critical solution during a turbulent time for the industry, as AI workloads threaten to continue increasing compute demand. The heat generated by these high-performance computing (HPC) components has outpaced what traditional cooling methods can deliver within the data centre.
“AI is driving a lot of changes as it requires high-performance CPUs and GPUs, which generate a lot of heat,” says Sung Kim, Global Head of Data Centre Liquid Cooling Solutions at Castrol. “The data centre industry is mostly on air cooling design, which can cool up to only 50 kilowatts (kW), but that is not enough for high-performance CPUs and GPUs required by AI.”
As processing power increases, what was once sufficient is now becoming a bottleneck for technology advancement.
Nick Barrett, Senior Engineer – Data Centre Testing at Castrol, points to the ongoing evolution of processing hardware: “All of those changes going on in the industry lead to higher-powered chips. We can do more work, but that means more heat generation.”
Using automotive expertise to drive data centre innovation
Castrol’s entry into the data centre cooling market builds upon its extensive thermal management experience in the automotive sector, particularly with electric vehicles (EVs). Now, the company is on a pathway of change, exploring opportunities to provide solutions and services that will complement its core lubricants business and provide more value to customers.
When it comes to data centres, Castrol is using dielectric fluids, using its experience with EV cooling systems to inform its approach to data centre cooling solutions. This has enabled Castrol to leverage its existing expertise in a new market.
“We’ve been working with dielectric fluids for a long time,” Chris explains. “Our first EV fluid approval was back in 2013. Now we’ve got hundreds of EV fluid approvals around the world. Some of those EV fluids are immersion, dielectric fluids that we’re working on with EV OEMs in terms of immersion cooling their batteries.”
Chris emphasises that this transition still aligns with Castrol's traditional business approach: “It’s basically an extension of what we’ve always done, fluid interaction with an application. It’s now about understanding how our fluids can improve the performance of data centres.”
The company’s approach to data centre cooling reflects its broader business strategy, understanding data centre operators’ need for reliable, end-to-end mission-critical solutions.
Sung adds: “In terms of liquid cooling solutions from Castrol, what we offer is not just a fluid, but also the service, maintenance and refill as part of our complete solution.
“We have this opportunity of joint development and co-engineering with the customers, so not just developing our own fluid, but working closely with customers to understand their pain points.”
Powering the ecosystem with collaboration
When speaking with the Castrol team on site in Pangbourne in the UK, a recurring theme is the importance placed on the company’s partnerships. With immersion cooling changing how data centre hardware is deployed and managed, collaboration across multiple stakeholders is essential for success.
“Once you start moving into things like direct chip and immersion, you have fluid coming very close to the IT,” Stephen explains. “All the different components are going to be touched by the fluid – the tank, the pump, the CDU, the piping, the wires, the servers, the chips.
“This means all of the different industry components need to be comfortable with the idea of moving over. If one party is saying they’re not quite ready for that transition, that’s holding back the whole thing.”
Stephen elaborates on the ecosystem relationships that Castrol has cultivated: “From an immersion perspective, we have very good relationships with the technology environment. We work a lot with all the different chip companies, the cooling system manufacturers, server OEMs and many different component manufacturers.”
These partnerships extend across the entire cooling infrastructure, with Castrol working very closely with cooling system manufacturers, those who make the immersion tanks and the people who make the servers. This approach puts Castrol at a competitive advantage to drive the industry forward.
“What also makes us a leader is the fact that we're already quite active in data centre cooling,” Stephen adds.
To address these challenges, Castrol has established partnerships with key players in the ecosystem. One such partnership is with Unicom Engineering, a company that designs liquid-cooled servers specifically for AI and machine learning environments.
Austin Hypes, Chief Technologist and VP of Engineering at Unicom Engineering, describes the partnership: “We are designing a whole series of liquid cool servers, primarily for AI and machine learning environments. We require very high-performance dielectric fluids to cool our server designs.
“There is a lot of back and forth collaboration with Castrol. We have certain needs and characteristics of dielectric fluids to meet not just thermal performance, but signal integrity performance.”
Driving market confidence
To facilitate the industry's transition to immersion cooling, Castrol has invested in a state-of-the-art testing facility at its Pangbourne technology campus. This facility is designed to demonstrate the company’s commitment to the data centre market.
“Overall on the technology campus, we’re actually investing up to £50 million (US$60m) in building up new testing equipment,” Chris reveals. “We’ve built out this data centre wing with a number of different cells, where we’ve got different immersion cooling technology all working on our Castrol fluids.”
The facility serves as both a research and development centre and a demonstration site where customers can witness immersion cooling in action. This hands-on approach helps Castrol to address concerns about the new technology.
Sung explains: “Not a lot of companies have a facility like this. It really sets us apart from our competitors because we can do the co-engineering and joint development with all these strategic partners and customers.”
The facility is also designed to support the company’s co-engineering philosophy. Chris adds: “We’re not a company that makes a fluid, gives it to someone who’s going to use it, and says ‘let us know how it works.’ We very much like to co-engineer. That’s always been part of Castrol’s DNA. We’ve done that historically with car manufacturers and now with data centre companies and server manufacturers.”
Nick adds: “As new technologies come along, it’s really important to find partners that you can collaborate with, to get access to the latest and greatest equipment.”
“Co-engineering means we can quantify and qualify our fluids with the latest and greatest equipment, but also work together to find out really in depth about how it’s working, why it’s working, or maybe why it doesn’t work.”
This collaborative approach to product development enables Castrol to refine its fluids based on real-world testing and feedback. It means that the company can identify potential issues before they affect customer deployments.
Austin explains how partners like Unicom are a critical part of this validation process: “Validation is critical because we are designing and selling fully warranted, certified solutions. These have to work for years. You can’t just take individual building blocks, put them together and assume they’re going to work.”
Moving beyond energy efficiency
While energy efficiency is a primary driver for immersion cooling adoption, the technology is also able to offer additional benefits that align with broader environmental goals in the data centre industry.
âBy reducing heat rejection, it's almost whatâs termed as free cooling,â Stephen explains. âBecause you have the immersion environment, all the heat is being taken away by the dielectric fluids, and then you just need to cool down the dielectric fluids with a cooling loop.
âAdditionally, because of the high temperatures of operating, you donât need to do any kind of refrigeration activity, you donât need to use any water to accelerate the cooling process. This means you dramatically decrease the amount of energy you use, both from a cooling side, but also now your servers donât have fans in them anymore. So even on the IT side, youâre saving a lot of power.â
Traditional cooling methods often require substantial amounts of water for evaporative cooling. By reducing water consumption, Castrol hopes to address a growing concern for data centre operators, particularly in regions where water scarcity is an issue.
âLiquid cooling, specifically immersion cooling, has a benefit of energy saving up to 30% and water consumption reduction of about 80%,â Sung quantifies, based on the companyâs research. âSo, in the long run, it adds a reduction of the total cost of ownership for data centre owners.â
Beyond operational efficiency, Castrol is also considering the entire lifecycle of its cooling fluids. Chris explains: âAt Castrol, weâve got a circularity strategy where we can collect our fluids at the end of their lifecycle and reprocess them into fresh fluids, making that a more sustainable solution.â
The company will continue to utilise its global partnerships to support the evolution of immersion cooling across the data centre industry.
âNo part of the world that we have found has access to excess power and excess water,â Austin says. âYou need one or the other. Immersion solutions really take care of both and can lead to up to 30% power savings per server.
âThe solutions weâre designing with Castrol and the data centres weâre designing aren't applicable just to today's chips. We know the roadmap â we know everything is going to have higher TDPs and it's designed to support that as well.â