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
| Dec 17, 2014
ULI report looks at growing appeal of micro unit apartments
New research from the Urban Land Institute suggests that micro units have staying power as a housing type that appeals to urban dwellers in high-cost markets who are willing to trade space for improved affordability and proximity to downtown neighborhoods.
| Dec 17, 2014
11 predictions for high-rise construction in 2015
In its annual forecast, the Council on Tall Buildings and Urban Habitat predicts that 2015 will be the "Year of the Woodscraper," and that New York’s troubled B2 modular high-rise project will get back on track.
| Dec 17, 2014
Demand softens, but outlook for Architecture Billings Index remains positive
The AIA's Architecture Billings Index for November was 50.9, down from a mark of 53.7 in October. Despite the drop, the ABI continued its seven-month run of positive scores (above 50).
Sponsored | | Dec 16, 2014
Quadcopters save project team $15K in warranty work
On a recent trip to see what technology Todd Wynne and the rest of the team at Rogers-O’Brien Construction have been tinkering with, I had a chance to experience firsthand which new hardware innovations will one day be applied in the AEC space.
| Dec 16, 2014
Architect Eli Attia sues Google over tall building technology
Attia and tech company Max Sound Corp. have brought a lawsuit against Google because of Flux, a Google X-developed startup launched in 2014. Flux creates software to design environmentally-friendly buildings in a cost-effective way.
| Dec 15, 2014
SHoP Architects plans to turn NY's Seaport District into pedestrianized, mixed-use area
The scheme includes a proposed 500-foot luxury residential tower that would jut out into the harbor, extending the Manhattan grid out into the waterfront.
| Dec 15, 2014
Frank Lloyd Wright School of Architecture launches fundraising campaign for independent incorporation
The Frank Lloyd Wright Foundation announced today that it approved a possible path toward independent incorporation of the Frank Lloyd Wright School of Architecture by raising $2 million before the end of 2015.
| Dec 15, 2014
Studio Gang tapped for American Museum of Natural History expansion
Chicago-based Studio Gang Architects has been commissioned to design the $325 million Gilder Center for Science, Education and Innovation at the American Museum of Natural History in New York.
| Dec 12, 2014
Dunkin’ Donuts launches certification for green restaurant buildings
The company aims to build 100 new DD Green-certified restaurants by the end of 2016.
| Dec 12, 2014
COBE's striking 'concrete finned' scheme wins competition for Adidas' flagship building in Germany
Danish firm COBE has been announced the winner in a contest to design a new Adidas flagship building in Herzogenaurach, Germany. It beat out 29 other teams, including REX and Zaha Hadid.