- A new evolution in data center cooling technology could soon sweep the data center market
- Accelsius' CEO said its two-phase direct-to-chip tech is catching on with hyperscalers
- A lack of supply chain diversity remains a key hurdle
Single-phase direct-to-chip systems currently dominate the liquid cooling landscape, with companies like Vertiv, CoolIT and Schneider Electric all cashing in. But another version of direct liquid cooling is waiting in the wings, and its moment in the spotlight is just around the corner.
We’re talking about two-phase direct-to-chip technology, which is offered by the likes of Accelsius and Zutacore. Unlike single-phase, which circulates a dielectric fluid that remains in the liquid state, two-phase includes a phase change from liquid to gas that increases the amount of heat removal that’s possible.
Single-phase still has some runway, but as chip power levels continue to rise so are concerns that the technology will soon hit its heat management ceiling (JetCool’s optimism notwithstanding).
Speaking on the sidelines of Nvidia GTC, Accelsius CEO Josh Claman told Fierce that while single-phase direct-to-chip is the current industry darling, “we think the tipping point is happening” for two-phase technology. This is especially the case when it comes to bleeding edge companies like cloud hyperscalers.
“Our pipeline is growing dramatically every quarter,” Claman said. “We had a goal of having a proof of concept in one hyperscaler this year – we’re in two already. And I think we’ll have our third by the end of this year.”
Growing pains
The thermal management market grew 29% year on year in Q2 2025, according to Dell’Oro Group. Within this category, direct liquid cooling exhibited standout growth of 156%. The firm did not break out growth rates for single phase and two phase.
Claman said there remains one major hurdle for its two-phase technology: supply chain.
Claman said hyperscalers and other data center operators are looking for supply chain diversity – that is, they want to ensure that there are multiple manufacturers of the technology they use so that if there’s an issue with one supplier, they have another to fall back on. That’s what Accelsius is working on now, Claman said.
“We’re trying to create an ecosystem of multiple sources of availability for two-phase,” Claman said. “So, we think we can manufacture that tipping point by having good strategic partnerships.”
More than just chips
Claman noted another interesting trend that’s cropped up over the past four or so months: an increase in the number of conversations Accelsius is having with data center power conditioning companies. Why?
“Busways are becoming hot. PDUs are becoming hot. PSUs are becoming hot,” Claman said, referring to the different kinds of power infrastructure that sits within data centers. “We need to cool everything.”