“Facility water loops generally have good water high quality, generally unhealthy,” says My Troung, CTO at ZutaCore, a liquid cooling firm. “Generally you’ve gotten organics you don’t wish to have contained in the technical loop.”
So there’s one set of pipes that goes across the knowledge middle, accumulating the warmth from the server racks, and one other set of smaller pipes that lives inside particular person racks or servers. “That inside loop is a few type of technical fluid, and the 2 loops trade warmth throughout a warmth exchanger,” says Troung.
The most typical method in the present day, he says, is to make use of a single-phase liquid — one which stays in liquid type and by no means evaporates right into a fuel — resembling water or propylene glycol. However it’s not essentially the most environment friendly choice.
Evaporation is a good way to dissipate warmth. That’s what our our bodies do after we sweat. When water goes from a liquid to a fuel it’s referred to as a part change, and it makes use of up power and makes the whole lot round it barely cooler.
After all, few servers run scorching sufficient to boil water — however they will boil different liquids. “Two part is essentially the most environment friendly cooling expertise,” says Xianming (Simon) Dai, a professor at College of Texas at Dallas.
And it is likely to be right here earlier than you assume. In a keynote deal with in March at Nvidia GTC, Nvidia CEO Jensen Huang unveiled the Rubin Extremely NVL576, due within the second half of 2027 — with 600 kilowatts per rack.
“With the 600 kilowatt racks that Nvidia is asserting, the trade must shift very quickly from single-phase approaches to two-phase,” says ZutaCore’s Troung.
One other highly-efficient cooling method is immersion cooling.
In response to a Castrol survey launched in March, 90% of 600 knowledge middle trade leaders say that they’re contemplating switching to immersion cooling by 2030.
However immersion cooling does have its downsides. In response to the survey, 38% of respondents are involved concerning the potential for leaks, 31% say that it’s too time-consuming to implement, and 31% fear about upkeep challenges.
Colocation supplier Equinix, which has greater than 260 knowledge facilities in 72 markets, has liquid cooling already accessible at 100 of them — and continues to construct new liquid-cooled amenities and retrofit older ones.
However it hasn’t seen a lot demand for immersion cooling but, says Phil Learn, the corporate’s senior director of knowledge middle companies. “It’s undoubtedly an space we’re monitoring,” he says. “It could possibly be attention-grabbing sooner or later.”
At the moment, nevertheless, the expertise nonetheless has some points. For one factor, there’s the load, he says. “You’re principally placing the load of a small automotive on a knowledge middle flooring.”
After which there’s the difficulty of the sorts of liquids which might be used for immersion cooling. “Equinix has a powerful sustainability posture and PFAS chemical substances are very problematic for us,” he says. “However we see these utilized in immersion cooling — and in two-phase cooling as properly.”
It’s not clear but precisely how the trade will handle the facility and cooling necessities of next-generation AI servers. Perhaps AI will provide you with some recommendations.