침수 냉각 벤더 Ferveret은 증가하는 AI 워크로드 밀도를 처리하기 위해 랙 통합형 액티브 냉각 솔루션을 개발 중입니다.

Reza Azizian founded Ferveret after his first visit to a data center in 2016. He recalls: “I first walked into a data center in 2016 and thought to myself, ‘ok, this is not how this facility has to work’... It was very clear that, from a heat transfer perspective at least, data centers were not very efficient and air cooling was not going to be effective for much longer.”

Since then, the rise of AI has accelerated liquid cooling adoption, forcing operators to move beyond traditional air-based systems. While efficiency has improved, significant work remains to optimize cooling for next-generation, power-hungry AI chips. Ferveret aims to address this through immersion cooling, specifically by solving form factor and reliability challenges with a “cold box” that encases hardware and its cooling system in a single package designed for traditional racks. Using what the company calls adaptive immersion cooling, Ferveret targets reduced operational costs for data centers.

Liquid cooling generally falls into two categories: direct-to-chip, which circulates fluid across hardware via cold plate heat exchangers within standard vertical racks, and immersion, which submerges servers in cooling fluid. Direct-to-chip currently holds wider adoption, while immersion faces operator hesitation regarding equipment exposure and form factor constraints, as traditional immersion setups rely on large, freezer-like tanks that struggle to integrate into conventional data center layouts. However, the landscape is shifting. Samantha Yates, principal engineer at Intel, noted on a recent DCD broadcast that immersion supports large-scale deployments for specific workloads. “It hasn’t hit an inflection point yet, like AI was for direct-to-chip, but it’s steadily growing, and it’s not a niche technology,” she said. Yates highlighted the Open Compute Project (OCP) as a key driver of standardization and adoption: “The immersion community in OCP is very large and very motivated, and an incredible amount of work is being done very rapidly to proliferate immersion as a capable cooling technology that has its specific benefits and has a place in data centers.”

Ferveret leverages this momentum. Azizian holds a PhD from MIT and began his career researching heat transfer in nuclear reactors before moving to consumer technology as lead thermal engineer for Microsoft’s HoloLens headset. “We couldn’t put a fan in it, so we had to use natural convection, but we couldn’t use copper as the material for this because it would have been too heavy. So we ended up building an ultra-thin, ultra-light, titanium vapor chamber that took the heat from the electronics close to your eyes and spread it across the band that goes around the head, using that large surface area,” he explains. He later worked at Nvidia and TSMC before co-founding Ferveret with MIT colleague Matteo Bucci. The pair previously collaborated on an EDF-funded project exploring efficient nuclear reactor cooling methods. “I could see the challenge of electronics getting smaller and smaller and generating more heat,” Azizian says. “I started looking at different ways to cool a data center, and two-phase immersion cooling was particularly interesting to me because it resembled some of the processes I was familiar with from nuclear reactors.”

Two-phase immersion cooling boils the coolant, dispersing heat as gas before condensing and recirculating it—a process more efficient than single-phase cooling, where the fluid remains liquid throughout. Azizian identified a critical gap in commercial applications: “What stood out to me was that people in the data center cooling space had no idea how to make this process work in an efficient way, and I felt there was a gap that could be filled with some of the knowledge we had from the nuclear industry.”

Despite progress, Azizian notes persistent challenges, primarily infrastructure compatibility and fluid management. “If you want to use the large tank form factor, you can’t just drop that into a typical data center,” he says. Additionally, two-phase systems suffer from fluid loss as gas bubbles escape and pressure builds, eventually compromising seals. Ferveret’s adaptive immersion approach bridges single- and two-phase cooling by boiling the liquid while trapping the resulting gas within the system, preventing pressure accumulation. Drawing on nuclear engineering techniques known as subcooled boiling, the system generates smaller bubbles that detach frequently and condense rapidly in the surrounding cooler liquid.

“Our heat exchanger has a unique design that sits in the fluid and keeps the top layer cool,” Azizian explains. “That means the bubbles get collapsed in the bulk of the liquid, so we get the benefits of two-phase without having to deal with the challenges of pressure and other issues you typically get with two-phase. The beauty here is that this fundamental difference in basic physics opens up a lot of doors for us.”

This physics-driven design enables a compact footprint. Without pressure constraints, Ferveret’s units fit into 4U enclosures that slot directly into standard 42U racks, with up to ten boxes per rack delivering an estimated 600kW of cooling capacity. “The box sits in a typical rack, with a single inlet and outlet manifold,” Azizian says. “The idea is that you can have a rack that is half direct-to-chip, half Ferveret’s solution, so it’s truly plug-and-play in that sense.” The company also claims minimal weight penalties compared to direct-to-chip alternatives, eliminating heavy copper cold plates and heat sinks while requiring significantly less fluid than large-tank systems.

Ferveret also addresses environmental concerns surrounding immersion fluids. Traditional two-phase systems often rely on polyfluoroalkyl substances (PFAS), which face increasing global regulation and bans. Instead, Ferveret utilizes standard PG25, a readily available glycol-based dielectric fluid with lower environmental impact. “The fluid we use has a low boiling point, somewhere between 45-50°C (113-122°F),” Azizian says. “If you put that in a large tank, you would start building up pressure and losing fluid very fast. Our tanks are smaller, and we don’t have that pressure build-up challenge.”

Maintenance remains straightforward, with servers easily removable for repairs. Unlike single-phase immersion, which requires extensive cleaning after extraction, Ferveret’s glycol-based fluid eliminates residue issues. “One beauty of our system is that, by using this kind of dielectric fluid, when you take the server out, it is completely dry,” Azizian says. “That’s very different to single-phase, where an oil-based fluid leaves residue behind.”