Data Centers Look To Liquid Cooling As AI Future Heats Up

Authored by Bruce Parker via The Epoch Times (emphasis ours),

The boom in artificial intelligence (AI) technology and hyperscale facilities has created a growth opportunity for businesses that keep cloud- and AI-related computer servers from overheating.

Cooling is essential for electronics. Without it, today’s high-performance computer chips would literally melt down.

Navid Kazem is an electronics cooling expert and general chair of Semi-Therm, a leading global conference on thermal solutions for electronic components. He told The Epoch Times that data centers cannot function without proper cooling.

“You can burn down the chip pretty easily if you don’t have an effective cooling solution,” he said.

“What happens is the temperature of the chip rises to such high levels that you can effectively burn the chip.”

According to Kazem, silicon processors operate reliably at junction temperatures of 194–212 degrees Fahrenheit (90–100 degrees Celsius). If they rise much higher than 248 degrees Fahrenheit (120 degrees Celsius), they burn.

“The question comes down to, how can we cool them and keep them in that temperature range while spending as little energy as possible as we can,” he said. “So, there is a big push toward being able to use warm liquid for liquid cooling to cool this down.”

Switching From Air to Liquid

Data centers currently support rack power requirements of about 20 kilowatts. Since the latest central processing units and graphics processing units have higher thermal density than previous generations, that requirement is projected to exceed 50 kilowatts in the future.

But as high-performance AI computing becomes increasingly heat-intensive and energy-intensive, conventional air cooling—the traditional approach to heat management—cannot keep up.

“When you go from air cooling to liquid cooling, you can save between 20 [percent] and 30 percent of the energy for the whole data center,” Kazem said.

“The most important thing is the amount of energy they are required to use. So if you can reduce the energy required for cooling, that means that you can have a more sustainable data center.”

Not only are air-cooling systems less effective at dissipating heat, but they also require more energy—sometimes more electricity than the servers themselves.

And since water is up to 3,000 times more effective at heat transfer than air and uses less electricity, data center operators are exploring ways to switch to liquid.

Liquid Cooling Options

Operators have three liquid-cooling options for managing heat: rear-door heat exchangers, direct-to-chip liquid cooling, and immersion cooling.

The first involves replacing the rear door of the IT equipment rack with a liquid heat exchanger. This option is used in tandem with air cooling.

With direct-to-chip liquid cooling, cold plates are placed on the board’s heat-generating components to draw heat away with single-phase cold plates or two-phase evaporation units. This technology removes up to 75 percent of the heat produced within the racks, while the remaining heat is whisked away by air.

In immersion cooling, servers and other components in the rack are submerged in a thermally conductive dielectric fluid. This system eliminates the need for air cooling and is the most energy-efficient of the three.

Which Is More Common: Air or Liquid?

According to recent market data, most existing data centers are currently air cooled, but liquid cooling is on the rise.

A survey conducted by S&P Global Market Intelligence of data center operators found that 45 percent use a fully air-cooled system, while 42 percent use a hybrid air-and-liquid-cooled system. Just 12 percent use liquid cooling only.

However, when asked about their plans for the next five years, 59 percent of respondents said their organization expects to adopt liquid cooling.

Of the three liquid-cooling options, 45 percent of respondents preferred liquid-to-air direct-to-chip, while 41 percent preferred liquid-to-liquid direct-to-chip.

An additional 41 percent said they would opt for the rear-door heat exchanger and 37 percent said they prefer a fully submerged cooling system.

Market Trends

Overall, the liquid cooling market is projected to grow from $6.6 billion in 2026 to $38.4 billion in 2033, according to a report put out last month by market research firm Market Minds Advisory.

Top players in the space, the report states, include Schneider Electric, Vertiv, Johnson Controls, Hewlett Packard Enterprise, Green Revolution Cooling, Submer, LiquidStack, and Asetek Inc.

The trend was evident at last week’s 42nd annual Semi-Therm conference, a four-day symposium held in San Jose, California. The conference featured thermal engineers, researchers, and scientists for all-day sessions and short courses, and it attracted about 400 attendees, including engineers and planners from the hyperscale data center industry.

“Data centers and liquid cooling is one of the hot topics right now,” Laura Dobbs, marketing and exhibits manager for Semi-Therm, told The Epoch Times.

“For example, we have a track on liquid cooling, and we have a track on high-performance computer thermal interface management. ... As data centers have continued to grow, liquid cooling has become a very important piece of that, versus air cooling.”

According to Kazem, design teams from the hyperscalers and data center companies attend Semi-Therm “to learn about the latest technologies.”

“It’s mostly about the energy consumption, and how much of cooling we can do for these data centers that are having very high, high-powered densities,” he said.

“So, that has become a major issue, and the conference this year is reflecting that challenge and opportunities ahead.”