Datacenter Trends

Datacenter Liquid Cooling Systems Are Hot Commodity

• By John K. Waters
• 08/20/2018

The enterprise datacenter is changing in myriad ways thanks to a range of trends, from serverless computing to the sudden ubiquity of applications relying on AI and machine learning. But one thing remains the same: Datacenters are hot and cooling them is expensive.

Keeping the rows of fevered cabinets properly cooled can account for close to half of a datacenter's total energy usage. The most common technology employed for that purpose has been, of course, air conditioning. But liquid cooling, the go-to tech for academic mainframes and supercomputers, is gaining serious traction in the enterprise.

Analysts at Research and Markets expect the trend to continue for at least the next few years. In a new report ("Global Datacenter Liquid Cooling Market 2018-2022"), they project a compound annual growth rate (CAGR) of 14.2 percent through 2022.

Meanwhile, researchers at Technavio ("Global Data Center Liquid Cooling Market 2016-2020") expect the datacenter liquid cooling market to grow at a CAGR of closer to 16 percent over the same period.

This isn't exactly explosive growth, but it's a serious spike that's worth noting. Researchers cite several drivers in this market, including rising rack density and the growing use of accelerator processors, such as GPUs and FPGAs. Liquid cooling is proving to be a solution in two ways: new, advanced liquid cooling technologies and geographic opportunity.

One example of the new tech is liquid immersion technology.

"These cooling solutions operate on the principle of liquid submersion technology, in which the server and other IT equipment are placed inside tanks containing non-conductive coolants," the Technavio researchers explained. "The coolant dissolves the heat generated by the equipment and circulates it throughout the system. Also, these solutions offer uniform and effective cooling with high thermal efficiency, which will fuel this market's growth in the future."

Obviously, this solution won't work on non-sealed hard disk drives, but new solid-state drives can be cooled in full-immersion solutions.

Facebook's new StatePoint Liquid Cooling (SPLC) system, which the social media giant developed with Nortek Air Solutions and unveiled in June, is another example. The first of its kind to be applied to datacenters, the SPLC uses a liquid-to-air energy exchanger in which water is cooled as it evaporates through a membrane-separation layer. This cold water is then used to cool the air inside the datacenter.

In May, Alphabet's Google introduced liquid cooling in its datacenters for the first time. Alphabet CEO Sundar Pichai announced the next-gen Tensor Processing Units (TPUs) in his keynote at this year's annual Google I/O conference in Mountain View, Calif. The TPUs underpin the AI capabilities in a wide range of Google products, from Gmail to Google Photos, Pichai told conference attendees. "These chips are so powerful that, for the first time, we've had to introduce liquid cooling in our datacenters," he said.

Where geography fits into this emerging picture should be obvious: About 70 percent of the earth is covered with water, and about 50 percent of the global population lives near a coastal area.

In 2011, Google pioneered this approach with a cooling system in its Hamina, Finland, server farm, which uses fresh seawater from the nearby Gulf of Finland. In 2013, Interxion, a colocation company based in the Netherlands that rents datacenter space in 11 countries, uses water pumped from the Baltic Sea to cool the equipment in its Stockholm facility.

It's also worth noting that a group of hyperscale cloud operators that includes Google, Facebook, Microsoft, Intel, Baidu, LinkedIn, Tencent, Alibaba, the China Institute of Electronics and Lawrence Berkeley National Laboratory is working on an open specification for liquid-cooled server racks. The group published a progress update on the Web under the auspices of the Center of Expertise for Energy Efficiency in Datacenters that's worth a look.

But it's not just the established players that are betting on liquid cooling for datacenters. Over the past five years or so, some promising startups have entered this market, including Chilldyne, a Carlsbad, Calif.-based company with a direct-to-chip cooling system; Ebullient Cooling, a Madison, Wis.-based startup with a "waterless" direct-to-chip system; Asperitas, a Dutch startup offering a self-contained liquid-cooled plug-and-play modular datacenter; and Iceotope, which isn't technically a startup, but recently shifted its focus from supercomputers to enterprise datacenters.

Iceotope's Web site pitch goes to the heart of the new popularity of liquid cooling: "Liquid cooling can no longer be seen as a niche technology but rather the technology that will enable the continued growth in the size and complexity of data centers required to keep pace with our demands."