Barclays Climate Ventures and Two Seas Capital led the British precision-liquid-cooling company’s Series B, with existing backers ABC Impact, Northern Gritstone, Edinv, and British Patient Capital all returning
Iceotope, the British precision-liquid-cooling company, has closed a $26 million Series B round to expand its product line and patent portfolio as the AI hardware cycle pushes rack power densities past the point where air cooling can keep up.
Two Seas Capital and Barclays Climate Ventures led the round, with existing backers Edinv, ABC Impact, Northern Gritstone, and British Patient Capital all participating again, the company said on Wednesday.
The pitch is timing as much as technology. Next-generation Nvidia accelerator platforms are driving per-rack power densities toward and beyond 1 MW, a level at which both conventional air cooling and direct-to-chip liquid loops fail to remove heat fast enough to keep silicon at sustainable operating temperatures.
Iceotope’s approach, which the company calls chassis-based precision liquid cooling, replaces air with a dielectric fluid circulated directly around server components inside a sealed chassis, eliminating the fans, hot aisles, and water-intensive cooling towers that traditional data-centre architecture has relied on for decades.
The market reading underneath the round is more striking than the round itself. Iceotope cited SemiAnalysis figures projecting that the installed base of liquid-cooled AI accelerators will grow from roughly 3 GW today to 40 GW within two years, a more-than-tenfold expansion driven by hyperscaler and colocation operators forced to adopt liquid cooling for AI workloads that conventional architectures cannot sustain.
The thesis is becoming visible at the operator end of the stack as well: Nvidia-backed Firmus is building modular, fully liquid-cooled AI factories across Australia to host 36,000 GB300 Grace Blackwell chips, financed in part by a $10 billion Blackstone debt facility.
Iceotope’s commercial position rests on a 219-strong patent portfolio, granted and pending, and an early-mover claim on chassis-level liquid cooling that the company has been refining since 2005.
The current product line includes KUL BOX, aimed at edge and AI deployments where space and noise constraints rule out conventional cooling, and KUL AI, designed for high-density rack deployments at the heart of new AI data centres.
The technology can operate with near-silent operation and uses what the company describes as minimal water, which is the second part of the cooling story that has been drawing AI infrastructure money into the category: data-centre water draw has become a politically charged metric in jurisdictions including the US Southwest, Ireland, and the Netherlands.
“Securing such high-caliber investors validates both our technology and our market timing,” said Simon Jesenko, Iceotope’s chief executive and chief financial officer.
“We’ve spent years developing a robust, differentiated IP portfolio and products purpose-built for AI infrastructure, and we’re ready to scale at precisely the moment the industry demands more advanced, sustainable cooling technology. The opportunity ahead, both directly with customers and through our partner ecosystem, is significant.”
Barclays Climate Ventures framed its participation in climate-policy terms. “With AI adoption rapidly increasing globally, Iceotope’s liquid-cooling technology offers a timely and innovative solution to the mounting limitations of traditional cooling systems,” said Steven Poulter, head of Barclays Climate Ventures.
“Its approach not only meets the escalating demands of AI and high-performance computing but also materially advances datacenter sustainability.”
The competitive set is becoming crowded. LiquidStack, Submer, JetCool, GRC, and Asperitas are all targeting elements of the liquid-cooling stack, with the major hyperscalers, Amazon, Microsoft, Google, and Meta, each running internal cooling-architecture programmes alongside their external supplier roster.
Iceotope’s wedge is the chassis-level approach and the patent depth: the company has positioned itself as more deployable than open-bath immersion and more thermally capable than direct-to-chip cold-plate systems, with the second-largest IP portfolio in the precision-cooling category after Equinix.
Iceotope previously raised £30 million ($38 million) in 2022, led by ABC Impact, and the Series B brings cumulative disclosed funding to comfortably over $80 million.
The capital is earmarked for product and engineering, patent extension, and ecosystem partnerships rather than a step-change in headcount, which the company has been growing more steadily through 2025 and 2026.
