In the rush to slash energy consumption in power-hungry data centers, design teams, equipment manufacturers, and tech companies have been developing clever, low-energy cooling solutions—from Facebook’s open-rack server setup with exposed motherboards, to Skanska’s eOPTI-TRAX liquid refrigerant coil system, to Google’s evaporative cooling schemes.
Solutions like these have helped data center facility operators achieve unprecedented energy performance levels, with power utilization effectiveness (PUE) ratios dipping below 1.10 in some instances. This means that less than 10% of the total energy consumption in a facility is attributed to noncomputing functions, such as air-conditioning and lighting.
Now, a new technology promises to push the limits of data center energy efficiency even further. Called immersive cooling, it uses a liquid instead of air to cool the servers. LiquidCool Solutions, Green Revolution, and 3M are among the pioneers of this technology. Each system works a bit differently, but the basic idea is to submerge the motherboards in tanks filled with nonconductive fluid, which absorbs the heat generated by the processors.
LiquidCool Solutions, for example, uses an enclosed server module and pumps dielectric fluid through the server enclosure. Green Revolution uses a tub full of dielectric oil and circulates the liquid through the tubs. 3M also uses the tub approach, but the fluid boils and then is condensed to reject the heat.
By using liquid-based cooling at the server level, the need for air-conditioning is greatly reduced, or even eliminated in some climates. The same goes for traditional HVAC equipment and systems—chillers, fan units, raised floors, and so on.
The Allied Control 500 kW immersion-cooled data center in Hong Kong is capable of delivering a PUE of just 1.02. The standard, 19-inch server racks use 3M Novec Engineered Fluids to enable tight component packaging for greater computing power in less space, according to Allied. Its open-bath design permits easy access to hardware and eliminates the need for pressure vessel enclosures and charging/recovery systems. PHOTO: COURTESY ALLIED CONTROL
“In most parts of the world, compressorized cooling would not be required with immersive cooling, since the liquid temperatures can be at a level where direct heat rejection using outdoor condensers or cooling towers would be sufficient,” says Thomas Squillo, PE, LEED AP, Vice President with Environmental Systems Design, who is currently researching the technology for the firm’s data center clients. “The fan energy is also eliminated, both in the HVAC system and in the server itself. Fluid pumping energy is very low.”
Other advantages of the cooling technology, according to Squillo:
• Increased performance and service life of the computer chips by eliminating heat buildup and problems related to contaminated air and dust.
• Ability to deploy data centers in extremely harsh environments without greatly impacting energy performance.
• Potential construction cost savings by downsizing or eliminating traditional HVAC systems.
Other than a few pilot projects, including a Bitcoin mining data center in Hong Kong and a Lawrence Berkeley National Laboratory-led installation in Chippewa Falls, Wis., immersive cooling technology is largely untested. A year into the Bitcoin pilot, the data center operator reported a 95% reduction in cooling costs.
AEC professionals are starting to realize the potential for immersive cooling, especially for high-performance computing centers and consolidated, high-density data centers.
“Large data centers that have many homogenous machines at high density—like those operated by Internet and cloud providers—are a good application,” says Squillo. “Small footprint and minimal energy use are very important due to the volume of servers. These can be deployed in remote areas where space and energy are cheap, but where air quality may be a concern, without having to worry about the data center air.”
TRICKY DESIGN CONSIDERATIONS
Before the technology can be implemented, says Squillo, several nettlesome design factors specific to immersive cooling have to be addressed:
• Piping distribution to the racks and cooling units requires redundancy and valving to accommodate equipment maintenance without disrupting server performance.
• Additional equipment and space are needed to drain fluid from the tanks for server maintenance.
• Local code requirements may limit the amount of fluid that can be stored in a single room.
• For the foreseeable future, it’s unlikely that a large data center would be 100% liquid-immersion cooled. This means provisions will have to be made for both air- and liquid-cooling systems, which will require additional space in the data hall and mechanical room.
“I think that some form of this technology will definitely be the direction the data center market will take in the future,” says Squillo. “The market just needs to mature enough for owners to trust the technology and demand servers that are designed for a particular type of liquid cooling. In the short term, I see large companies and server manufacturers doing small-scale installations to test the concept, before wanting to implement it at a large scale.”
Related Stories
Coronavirus | May 20, 2022
Center for Green Schools says U.S. schools need more support to fight COVID-19
The Center for Green Schools at the U.S. Green Building Council released a new report detailing how school districts around the country have managed air quality within their buildings during the second year of the COVID-19 pandemic.
Regulations | May 20, 2022
Biden’s Clean Air in Buildings Challenge aims to reduce COVID-19 spread
The Biden Administration recently launched the Clean Air in Buildings Challenge that calls on all building owners and operators, schools, colleges and universities, and organizations to adopt strategies to improve indoor air quality in their buildings and reduce the spread of COVID-19.
Building Team | May 20, 2022
Caltech breaks ground on a new center to study climate and sustainability
The California Institute of Technology (Caltech) recently broke ground on its Resnick Sustainability Resource Center.
Laboratories | May 20, 2022
Brutalist former Berkeley Art Museum transformed into modern life science lab
After extensive renovation and an addition, the former Berkeley Art Museum and Pacific Film Archive at the University of California, Berkeley campus reopened in May 2022 as a modern life science lab building.
Sports and Recreational Facilities | May 19, 2022
Northern Arizona University opens a new training center for its student athletes
In Flagstaff, Ariz. Northern Arizona University (NAU) has opened its new Student-Athlete High Performance Center.
Energy-Efficient Design | May 19, 2022
Shipping containers used to build Research Triangle Park’s first community gathering space
Shipping containers were the prominent building material used to construct Boxyard RTP, the first public community and gathering place in North Carolina’s Research Triangle Park (RTP).
Mixed-Use | May 19, 2022
Seattle-area project will turn mall into residential neighborhood
A recently unveiled plan will transform a 463,000 sf mall into a mixed-use destination site in the Seattle suburb of Bellevue, Wash.
Architects | May 19, 2022
The art and trade of architectural photography, with Brad Feinknopf
Longtime architectural photographer Brad Feinknopf discusses his craft and helping AEC firms realize their visions photographically. Feinknopf also touches on the evolution of photo shoots and the role of technology in architectural photography.
Codes and Standards | May 19, 2022
JLL launches non-profit aiming to mitigate climate change
Real estate and investment management firm JLL recently launched JLL Foundation, a non-profit dedicated to making a long-term impact on environmental sustainability.
Office Buildings | May 19, 2022
JLL releases its 2022 Office Fit Out Guide
JLL’s 2022 Office Fit Out Guide report provides benchmark costs to build out a range of office types across major markets in the United States and Canada.