Data centre cooling in the AI era

During a busy Data Centre World London 2026, Joe from DCNN caught up with Alistair Barnes (pictured above), Global Head of Mechanical Engineering at Colt DCS, to ask how the mechanical engineering discipline is evolving in response to the rapid rise of AI workloads. The two discussed a variety of topics, from the shift towards liquid cooling solutions to the challenge of keeping pace with ever-increasing rack-level power densities. Here, you can read the full Q&A, in which Alistair shares his perspective on where liquid cooling stands today, how Colt DCS's Global Reference Design philosophy shapes its approach to data centre infrastructure, and what he believes remains the industry's toughest unsolved engineering challenge: Liquid cooling, rack densities, and the future of mechanical engineering Joe: Hi, Alistair! So, how is mechanical engineering keeping pace with the shift to higher-density AI workloads? Alistair: Mechanical engineers are keeping pace with higher‑density AI workloads by moving beyond traditional air‑only cooling and rethinking the entire thermal design stack. Instead of simply supplying cold air, they now operate more like system integrators, collaborating closely with IT and facilities teams to cool heat‑intensive components such as GPUs. This includes integrating direct‑to‑chip cold plates, liquid distribution loops, and hybrid cooling systems capable of managing the extreme heat generated by modern AI hardware. Joe: In your opinion, is liquid cooling now a mainstream solution or still a specialist one? Alistair: Liquid cooling is becoming increasingly mainstream, but the industry isn’t yet at a point where it can rely on liquid alone, as air still plays an important role in most deployments. Operators adopting Global Reference Designs (GRDs) now include liquid‑cooling options to support high‑density AI workloads that air alone can’t efficiently manage. As a result, many still use hybrid setups that combine air cooling with liquid where needed. Closed‑loop systems, such as liquid‑to‑chip, circulate coolant in a sealed loop, ensuring near‑zero wastewater and making them practical and sustainable. Joe: Where does mechanical engineering sit in Colt DCS's broader data centre design philosophy? Alistair: Mechanical engineering sits at the core of our design philosophy, supporting our commitment to delivering scalable, efficient, and sustainable data centre solutions. We adopt a GRD, a standardised and repeatable blueprint that accelerates deployment, optimises cost, and maintains consistent quality while remaining flexible enough to meet local requirements. Mechanical engineers play a key role in shaping the GRD, ensuring mission-critical cooling infrastructure and integrating new technologies across sites to support future growth and reliable operations. Joe: What's the hardest engineering problem the industry hasn't solved yet? Alistair: The hardest engineering problem the industry hasn’t solved is keeping pace with the accelerating rise in rack‑level power densities. Liquid cooling is advancing quickly and can manage far more heat than ever before, but single‑rack densities approaching 2MW and beyond are increasing faster than these solutions can be deployed at scale. The real challenge is delivering this capacity sustainably - balancing cooling performance, energy efficiency, and power availability - all while accelerating build timelines to keep up with customer demand. For more from Colt DCS, click here.

ING, UniCredit finance Retelit data centres

ING, a Dutch multinational banking and financial services corporation, and UniCredit, an Italian multinational banking group operating across Europe, have structured a €375 million (£324.7 million) project financing agreement for Retelit Datacentre, the data centre arm of the Italian telecommunications and ICT operator, supporting the expansion of its data centre footprint in Italy. The funding will be used to develop three new data centres in Milan and Rome, increasing Retelit’s total capacity from 18 MW to 45 MW. The expansion is intended to strengthen Italy’s position as a connectivity hub in Southern Europe. Retelit Datacentre operates an interconnection platform across 38 sites, including the Avalon Campus in Milan, serving telecoms providers, enterprises, public sector organisations, and global technology companies. ING and UniCredit acted as structuring banks, debt advisors, global coordinators, and bookrunners for the transaction, with ING Italia also serving as facility agent. Expansion targets growing interconnection demand The additional capacity reflects increasing demand for data centre interconnection across distributed infrastructure, particularly as organisations expand digital services and cloud deployments. Andrea Diamanti, CEO and Head of Wholesale Banking at ING Italy, says, "This deal reflects the strength of [ING's] Wholesale Banking division in Italy and the value of our global network, with ING's Italian and Dutch teams collaborating closely to bring it to completion." Sicco Boomsma, Global Head Digital Infrastructure Advisory at ING Bank, adds, “This is a very relevant transaction for the Italian DC market, allowing enterprises, carriers, and cloud service providers to optimise their DC communications function across a network of distributed DC infrastructure in Italy. "It was an absolute honour to support the company in this transaction during a phase of transition in the group, where they carved out the DC platform from the carrier-based business.” Retelit states that its data centres are powered entirely by renewable energy and operate with power usage effectiveness (PUE) levels below typical market benchmarks. ING reports it has now completed more than 200 data centre financing transactions globally, including projects involving Equinix, Atlas Edge, and Ark Data Centres.

SATLINE completes Tier III infrastructure modernisation

SATLINE, a Lithuanian provider of virtual satellite-to-IP streaming services and colocation for satellite communications, has upgraded its core infrastructure to align with Tier III standards under the Uptime Institute Tier Classification System, strengthening resilience across its power and cooling environments. The upgrade introduces full redundancy across critical systems, enabling concurrent maintainability and removing single points of failure, all without interrupting live operations. The project included a comprehensive overhaul of SATLINE’s infrastructure, namely: • Power redundancy — upgraded from a single generator to two fully redundant generators• Expanded UPS capacity — systems doubled to improve runtime and load handling• Modernised cooling — HVAC systems redesigned for full redundancy and improved efficiency• Tier III-aligned architecture — enabling maintenance without service disruption All improvements were reportedly completed with no customer-impacting downtime. Improved resilience and operational continuity The transition from Tier II to a Tier III-aligned design delivers a fully resilient environment. This allows any component within the infrastructure to be serviced without affecting operations, while also improving fault tolerance and scalability. For customers, the upgrade should provide greater continuity, even during maintenance or future system expansions. Simas Mockevicius, Senior Network Engineer at SATLINE, comments, “Our Tier III–aligned upgrade has already delivered measurable gains in operational resilience. “Building on a 10-year track record of 100% uptime across both network and power, we have further strengthened our infrastructure through fully redundant power generation, increased UPS capacity, and modernised cooling. "The result is a system that not only sustains uninterrupted service, but is engineered to exceed the reliability benchmarks our customers depend on.” The upgrade, according to the SATLINE, forms part of its broader strategy to support the uptime demands of satellite communications and critical connectivity services. The company has also outlined plans to expand into Asia, targeting regions with growing demand for satellite connectivity.

ABB extends VoltaGrid data centre power deal

ABB, a multinational corporation specialising in industrial automation and electrification products, has secured additional orders from VoltaGrid, a Texas-based microgrid power generation company, to support data centre power infrastructure projects, linked to growing demand from AI workloads. The agreement was signed on 25 March 2026 at CERAWeek in Houston, USA, extending the companies’ existing collaboration. The orders are expected to be recorded in the second quarter of 2026. Financial terms were not disclosed. Under the agreement, ABB will supply 35 synchronous condensers with flywheel technology, alongside prefabricated eHouse units. These systems are used to support voltage stability in power networks, particularly for high-density data centre environments. The equipment will form part of VoltaGrid’s behind-the-meter power infrastructure, designed to provide stable and rapidly deployable energy for large-scale data centre operations. Supporting power stability for AI workloads Synchronous condensers help stabilise electricity networks by providing inertia, supporting short-circuit events, and managing reactive power. ABB’s scope also includes medium- and low-voltage distribution systems, as well as excitation systems intended to maintain reliability and uptime. Nathan Ough, CEO of VoltaGrid, says, “VoltaGrid’s power platform is purpose built to deliver large-scale power with exceptional dynamic performance and reliability for next-generation digital infrastructure. “By integrating ABB’s advanced grid stabilisation technologies with our AI-optimised power systems, we are able to meet increasingly stringent transient performance requirements while accelerating deployment at gigawatt scale.” Per Erik Holsten, President of ABB’s Energy Industries division, adds, “Extending our collaboration with VoltaGrid demonstrates the strength of ABB’s businesses working together combining automation, electrification, and motion expertise and technologies with innovative distributed power systems to create greater value for customers. “Together, we are enabling reliable, resilient, and scalable power infrastructure for data centres serving the rapidly growing AI economy.” Data centres accounted for around 1.5% of global electricity consumption in 2024, with the United States representing approximately 45% of that total. For more from ABB, click here.

atNorth data centre heat reuse powers Finnish store

atNorth, a Nordic high-density data centre provider, has begun supplying recycled heat from its FIN02 data centre in Espoo, Finland, to a nearby retail store operated by Kesko Corporation. The heat reuse system became operational in November 2025 and captures surplus heat generated by the data centre, using it to provide most of the heating required by the adjacent store. The approach reduces reliance on district heating and lowers emissions for both organisations. For Kesko, the initiative supports its target to reduce Scope 1 and Scope 2 emissions by 58.8%. The recovered heat is expected to cut emissions linked to district heating by around 200 tonnes of CO₂ equivalent per year, representing approximately 0.9% of its district heating emissions. Antti Kokkonen, Director of Energy at Kesko, comments, “Reducing emissions from the heating of our properties is a key priority within our sustainability strategy. “Through this collaboration with atNorth, we are able to significantly cut emissions at one of our stores while demonstrating how innovative partnerships can accelerate the transition to lower-carbon operations.” Supporting local energy systems through heat reuse The project reflects a wider trend of integrating data centres into local energy systems by repurposing excess heat. By capturing waste heat, the FIN02 facility improves overall energy efficiency while contributing to Finland’s circular economy objectives. Erling Gudmundsson, COO of atNorth, notes, “As demand for AI-ready digital infrastructure continues to grow, it is essential that data centres scale responsibly. “This project demonstrates how data centres can become active contributors to local energy systems. By recycling excess heat, we can reduce our client’s environmental footprint while supporting our partners’ sustainability goals and delivering tangible benefits to the surrounding community.” The FIN02 site forms part of atNorth’s wider Nordic expansion strategy. The company is also involved in similar heat reuse projects, including a greenhouse development in Iceland and partnerships with Vestforbrænding in Denmark and Stockholm Exergi in Sweden to supply district heating networks. For more from atNorth, click here.

Echelon launches Ireland’s first Green Energy Park

Echelon Data Centres, a developer and operator of large-scale data centre infrastructure, has announced that its DUB20 campus in Arklow, Co Wicklow, will become Ireland’s first Green Energy Park, aligned with the Irish Government’s Large Energy Users Action Plan (LEAP). Green Energy Parks are defined by the Department of Enterprise Trade and Employment as developments that co-locate energy-intensive facilities, such as data centres, with renewable energy generation. They are designed to operate primarily on renewable power, supported by energy storage or backup generation, while reducing reliance on the national grid. Darragh O'Brien, Minister for Climate, Energy, and the Environment, comments, “The Large Energy Users Action Plan sets out a clear pathway for how energy-intensive industries can develop in a way that strengthens Ireland’s grid, accelerates renewable deployment, and supports our climate ambitions. “The Green Energy Park being developed at DUB20 is an important example of that model in action: co-locating data infrastructure with offshore wind, onsite solar, battery storage, and grid-supporting capacity. This is exactly the kind of forward-planned, sustainable development we want to see delivered under LEAP.” Integrating renewables with data centre infrastructure The DUB20 campus is being developed in line with the LEAP framework and will integrate several energy systems. Plans include a 220kV substation developed with SSE Renewables, enabling access to offshore wind energy from the Arklow Bank Wind Park Phase 2 project. Onsite solar PV is also planned, with expected generation exceeding 6,000MWh per year. The site will incorporate battery energy storage systems (BESS) and energy centres, including infrastructure capable of exporting power back to the grid during periods of low renewable output. Hydrotreated vegetable oil will be used to reduce emissions from onsite generation. The DUB20 campus forms part of Echelon’s wider investment in data centre developments in Wicklow and is located on a former industrial site at the Avoca River Business Park. Construction is underway, with completion expected by 2028. An economic impact assessment by KPMG indicates that the DUB20 and DUB30 developments could generate up to €7.5 billion (£6.4 billion) in economic output during construction, and €801 million (£693 million) annually once operational. Graeme McWilliams, Co-Founder of Echelon Data Centres, says, “The establishment of Ireland’s first Green Energy Park at DUB20 demonstrates how large-scale digital infrastructure can be developed responsibly and in lockstep with national climate and energy policy. “By co-locating data centre capacity with offshore wind, onsite solar, and grid-supporting infrastructure, we are delivering the exact model envisioned under the Government’s LEAP framework - cutting emissions, reinforcing energy security, and supporting regional economic growth.” For more from Echelon, click here.

CyrusOne breaks ground on first data centre in Italy

CyrusOne, a global data centre developer and operator, has broken ground on its first data centre in Italy, marking its entry into the Milan market. The facility, known as MIL1, is the first of two planned developments in the area. It will provide 27MW of IT capacity across 7,000m² of technical space within a three-storey building that includes three data halls. Andreas Paduch, Managing Director, Europe at CyrusOne, says, “Milan is an increasingly important digital infrastructure market for Southern Europe, and this development marks a key milestone in our European growth strategy. “With MIL1, we are establishing a strong platform in Milan to support our customers’ long-term capacity and connectivity needs.” Community investment and site regeneration The development is being delivered in collaboration with the Municipality of Segrate, with more than €6 million (£5.19 million) allocated to local infrastructure improvements. Plans include the redevelopment of Via delle Regioni into an urban boulevard, with improved connections to nearby schools, a library, and other public buildings. Additional work will include a new east–west road, cycle routes, and pedestrian pathways aimed at improving access and safety. CyrusOne has also transferred ownership of the Golfo Agricolo parkland to the local authority for community use, alongside landscaping works around the site. In addition, construction is expected to create up to 300 on-site roles at peak, with around 25 permanent positions once the facility becomes operational. Paolo Micheli, Mayor of Segrate, comments, “The start of construction on the CyrusOne data centre marks a significant step in the development of Segrate and strengthens our city's role as a leading hub for innovation and digital infrastructure. “An investment of this magnitude enhances the area, as it finally allows for the regeneration of a vast, problematic industrial area that has been abandoned for decades.” Focus on sustainability The facility is designed to operate using 100% renewable energy and is targeting a BREEAM ‘Very Good’ rating. It will also include systems to recover and reuse waste heat, initially within the site but with the potential to support a district heating network in future. Additionally, more than 15,000 plants and 170 trees are being planned as part of the development to support biodiversity. As the project involves the regeneration of a former industrial site, demolition materials will be reused or recycled to reduce waste, with around 60% of materials being reused on site and most excavated soil also retained for construction purposes. For more from CyrusOne, click here.

STULZ, Merford conduct unique acoustic test for data centres

STULZ, a manufacturer of mission-critical air conditioning technology, and Merford, a Dutch specialist in noise control systems and acoustic doors, have completed an acoustic test confirming that a newly developed chiller system can meet strict data centre noise regulations under operational conditions. The test was carried out on a chiller for a project in Valeggio sul Mincio, Italy. It used a validated measurement methodology designed to reflect real-world performance, as operators increasingly consider noise alongside cooling capacity and energy efficiency. As data centre power densities increase, larger cooling systems can create greater environmental impact, particularly in urban locations. The project required compliance with a maximum night-time noise level of 80.2dB(A), prompting acoustic considerations to be integrated early in the design process. Davide Mazzi, Head of the Application Team at STULZ, explains, “The challenge was not only to guarantee efficient cooling, but to comply with extremely strict noise limits. “The installation is located on a rooftop in a densely built urban environment. Our task was to deliver the required performance without disturbing the surroundings and without compromising the operational reliability of the data centre.” Acoustic testing under real operating conditions The companies developed a noise attenuation system tailored to the chiller configuration. Acoustic measurements were conducted in line with EN ISO 9614-2:1997, which determines sound power levels using sound intensity measurements. Before testing, the team carried out an environmental analysis using SoundPLAN software to model sound propagation. The test setup ensured that background noise levels were at least 10dB below the chiller’s output, with surrounding equipment positioned to avoid interference. Two attenuation configurations were assessed: Both used steel frame structures with integrated acoustic components to reduce airborne and structure-borne noise, while the second configuration also included additional optimisation measures, resulting in greater overall noise reduction (although it increased system weight and complexity). Engineers measured sound power levels with and without the attenuation system to quantify performance and confirm compliance with the required limits. Davide continues, “We were delighted to find that the chiller equipped with the developed attenuation system successfully met the stringent noise requirements. “This project demonstrates that data centre cooling and acoustic compliance can be achieved simultaneously when engineering, acoustic design, and validation are approached as an integrated process. "As data centres continue to expand into urban environments, such integrated approaches are likely to become essential for balancing performance, sustainability, and community impact.” For more from STULZ, click here.

Industry recognises International Data Centre Day

In celebration of International Data Centre Day (25 March), DCNN has brought together a series of expert perspectives from across the industry to reflect on the opportunities and challenges facing data centre infrastructure today. From soaring energy demands driven by AI workloads to the shifting geography of deployment and the importance of community stewardship, these industry figures offer a broad view of the forces reshaping the sector and what must be done to meet them responsibly: The future of deployment Ivo Ivanov, CEO of internet exchange operator DE-CIX, comments, "The AI boom used to be about building bigger, better data centres. That works for model training, where raw compute power is prioritised over connectivity and latency, but it doesn't work for inference, which is where the real value of AI is realised at edge deployments. "AI inference demands near real-time responsiveness and, as such, it can't tolerate the latency associated with long round-trip delays to remote data centre hubs. From driverless vehicles to real-time fraud detection, the deployment of AI in edge locations demands a far more distributed infrastructure environment than what we're currently used to. "AI depends on data moving constantly between locations, and if that movement slows down, performance drops off quickly, no matter how much compute you add into the equation. It's no longer about building bigger or better data centres, but about where they're deployed and how they're connected. In other words, geography is becoming just as important as power and compute. "In the coming years, that's going to stretch the definition of data centres: from hyperconnected edge deployments and emerging AI-focused data centre hubs to more experimental concepts that sit above the clouds in the Earth's orbit. The data centre map is being redrawn in real time." Sustainability continuing as a vital factor Professor Aoife Foley, IEEE Senior Member and Chair in Net Zero Infrastructure at the University of Manchester, notes, "The International Energy Agency expects data centre electricity demand to more than double by 2030, reaching around 945 terawatt-hours, slightly above Japan's annual use. This not only indicates a greater demand for energy, but also highlights the importance of balancing digital growth with sustainable energy practices. "Infrastructure and operations leaders have a responsibility here and need to consider the unnecessary waste associated with data storage and commit to generating power from more renewable sources. By eliminating unstructured data and improving operational efficiency, organisations can actually lower their maintenance costs and improve regulatory compliance. "AI workloads consume significantly more energy than traditional cloud computing tasks, and although hyperscale operators are investing in renewable energy to soften the impact, this alone is not enough. Cooling innovations such as liquid immersion and direct-to-chip systems add further efficiencies, yet they still address symptoms rather than the deeper inefficiencies in model design and compute intensity. These impacts can be reduced through smarter model optimisation and a closer alignment between data centre strategy and regional renewable generation." Infrastructure integrated into communities Dave Philp, Chief Value Officer at infrastructure engineering software and digital twin platform provider Bentley Systems, concludes, "International Data Centre Day is a moment to recognise the often-unseen critical infrastructure that underpins modern life. Like healthcare, transport, and energy systems, data centres have become essential civic infrastructure in an increasingly connected world. "Today, data centres are no longer isolated technical buildings; they are part of the fabric of local communities. Being a 'good neighbour' is no longer optional; it is fundamental to earning trust, securing consent, and operating sustainably over the long term. That requires a clear understanding of how data centres interact with local water resources, energy networks, transport infrastructure, and surrounding land use. "We need to put digital modelling, analysis, and visualisation at the heart of how we plan, design, deliver, and operate these facilities. This enables better decisions, earlier engagement, and more resilient outcomes, anticipating construction challenges, responding to environmental constraints, and embedding operational resilience from day one. "As global demand for digital services continues to accelerate, the challenge is not simply to build more data centres, but to build them better. Thoughtful design, digital insight, and a commitment to community and environmental stewardship are what turn a data centre from a functional box into a trusted, long‑term asset that genuinely serves society."

Ramon.Space, Foxconn to deliver space DC infrastructure

Ramon.Space, a developer of computing systems for satellites and space missions, has expanded its partnership with cloud infrastructure provider Ingrasys, a subsidiary of Foxconn Technology Group, to develop data centre infrastructure for use in orbit. The collaboration focuses on scaling computing platforms designed for space, which comes as demand reportedly grows for processing data generated by satellites. Traditional Earth-based infrastructure, the companies state, faces constraints including latency, bandwidth, and power availability, particularly when handling large volumes of space-generated data. Space-based data centres, they say, aim to address these challenges by enabling processing and storage directly in orbit, reducing reliance on data transmission back to Earth and supporting real-time applications. Ramon.Space develops computing, storage, and communications systems designed to operate in space environments. These systems are engineered to manage challenges such as radiation exposure, power efficiency, thermal conditions, and autonomous operation. Ingrasys has previously supported the manufacturing of Ramon.Space’s computing platforms. Under the expanded agreement, the companies will work towards a production-ready product line, using Ingrasys’ manufacturing capabilities to support scale and consistency. Scaling infrastructure for space-based data Avi Shabtai, CEO of Ramon.Space, comments, “Expanding our work with Ingrasys to build data centre capabilities in space marks a major milestone in turning space computing from innovation into infrastructure. “We are laying the foundation for in-orbit data centers that enable real-time processing, reduce reliance on downlink, and support the next generation of software-defined satellites and distributed systems.” Benjamin Ting, CEO of Ingrasys, adds, “Ingrasys is proud to extend our collaboration with Ramon.Space into the in-orbit data centre domain. “By combining world-class manufacturing with Ramon.Space’s innovative computing platform, we are helping unlock a new era of space infrastructure.” The initiative is intended to complement terrestrial data centres and cloud infrastructure, while supporting applications where processing in orbit is more efficient. These include Earth observation, communications, and government-led space programmes. The programme will begin with prototype development and testing, with plans to expand towards operational deployments as space-based data infrastructure develops.