New DC design claims most efficient cooling system
2 August 2012 | 0
A new kind of data centre claiming to employ "the world’s most efficient cooling system" turns the traditionally unbearable "hot aisle" between server racks into a rather pleasant air-conditioned hallway, all the while using significantly less energy.
Integrated energy technology company Inertech and construction partner Skanska held a tour of their new data centre design last week at Inertech’s headquarters in Danbury, Connecticut, USA. During the tour, analysts and members of the media walked through a sample hot aisle, which runs between the rear walls of two rows of 60kW server racks filled with fully operating servers.
Though the temperature inside the server racks reached as high as 105 degrees Fahrenheit, which the tour guides proved by briefly opening the rear side of the rack, the aisle itself felt no different than the air-conditioned room where the companies had hosted lunch minutes earlier.
The impressive part, though, is how this feat was accomplished.
Cooling the air
Dubbed eOpti-Trax, the system reduces energy usage through air circulation in the server aisles. A traditional method of data centre cooling is based on the raised-floor design, through which an under-floor air distribution system pushes cold air up and into the server racks. Forcing cold air upward requires heavy use of fans, which consume high amounts of energy.
The eOpti-Trax cooling system works from the inside out. The rear side of the servers generates the most hot air, hence the name "hot aisle" for the area located behind it. In the eOpti-Trax system, the heat is absorbed in a 1.25-inch cooling coil lining the inside of the rear walls of the server racks. This coil operates without a compressor. The compressor system, which is common in traditional data centres, cools the air through an evaporation method, consuming massive amounts of water in the process.
The result is an air-conditioned hot aisle where data centre engineers have long endured unbearable temperatures to access wiring and other equipment. The companies claim that tests have shown air can be cooled from 160 degrees Fahrenheit inside the server rack to 75 degrees in the hot aisle.
From there, the cooling system allows the air to distribute itself naturally throughout the hot aisle, employing just two fans to help draw the cooled air into the front of the server racks, or the "cool aisle."
The companies claim the system requires just 0.5 watts of energy to cool a 300-watt server, compared to the 90 watts needed to cool the same size server with traditional chiller system. Additionally, eOpti-Trax uses an estimated 80% less water than more common cooling systems.
As more companies feel the need to expand data centres, the cost benefits of energy efficiency will become more appealing. The question that remains is whether green technology is enough to persuade potential customers.
Interest is high, barriers remain
The eOpti-Trax system is offered as a prefabricated modular (PFM) data centre, the intent being to provide customers the ability to add capacity as needed. While cost is the main reason energy efficiency "has become has become top of mind for the data centre industry," the market may still be reluctant to adopt the PFM data centre model, says Rhonda Ascierto, a senior analyst covering data centre technologies and eco-efficient IT for 451 Research who also saw the eOpti-Trax technology first-hand.
Ascierto says although "there have been very few commercial deployments" of PFM data centres to date, interest in the technology remains high. The firm forecasts revenues in the sector to grow from about $460 million last year to $2.46 billion by 2015. It may take some time for the industry to build that kind of momentum, though.
"The data centre industry is slow moving because it is very capital- and time-intensive," Ascierto says. "Prefabricated modular data centres are disruptive, and it won’t be until 2014 until we expect to see a meaningful uptick in revenues for the PFM data centre market."
Among those that have deployed PFM data centres, Ascierto says the top drivers are the ability to scale capacity as needed and to stagger capital costs across a long period. For Canadian telecom Telus, an early adopter of eOpti-Trax, reducing the initial capital investment had a major financial impact.
Inertech CEO Earl Keisling said that Telus was looking to spend $200 million upfront for a new data centre. In the PFM model, Keisling says the company can instead distribute that cost in $20 million blocks.
Barriers to adoption include concerns about security and reliability, on account of a current lack of standardisation of products for PFM data centres, Ascierto says. Without standards, potential customers can be concerned that they may not be able to integrate new PFM products into their data centre infrastructure.
Furthermore, energy efficiency can only go so far as a selling point for such a substantial data centre investment, she says.
"Power costs comprise a significant portion of data centre operating costs," Ascierto says. "But in the context of total data centre costs, including both capital and operating costs, when calculated over the typical lifetime of a facility, power is a relatively small portion."
Before investing in PFM data centres, some companies may even turn to alternatives, including public cloud computing services, third-party colocation data centres, or server virtualisation, to help cut their power distribution, Ascierto says.
Even with these obstacles, energy-efficient PFM data centres like eOpti-Trax remain appealing to large companies with extensive data centre needs, Ascierto says. At this point, though, it will be evaluated on a case-by-case basis, and decisions will be made only after others have seen its full impact.
"Most companies are taking a wait-and-see approach, as is often the case with new technologies. This is especially true of the data centre industry," Ascierto says. "Companies are concerned that PFM data centres will not offer them the flexibility in design and operations that they need, or will be too expensive. The degree to whether this is true or not can vary widely from company to company and it really depends on the data centre project in question."
IDG News Service