It is noteworthy on several fronts: It was designed to be cooled using only outside air nearly 100 percent of the year (the holy grail of green data centers, so-called 'Free Cooling'). This by far exceeds The Green Grid's Air-Side economizer map and projections for the New York City area. Other sites have made this claim before, such as Yahoo's 'Chicken Coop' in Lockport, New York, which is located near the Canadian border. More significantly, unlike the Yahoo site, which is an Internet search site, this is an enterprise data center with production servers for Deutsche Bank, a major financial firm.
Moreover, besides using outside air for cooling, the high-density data center is able to support up to 5 blade servers (at 20-27KW) per cabinet, which are grouped together in a 16-cabinet pod designed for up to 250KW total power. The pilot site consists of five pods for a total capacity of 1.25 mW of critical load. The site is thoroughly instrumented using a significant number of multiple sensors feeding power and environmental information into a data center infrastructure management (DCIM) system and will provide a lot of performance data, which will serve as a reference model for other Deutsche Bank data centers.
Moreover, the design uses an adaptation of the age-old 'swamp cooler' method of evaporative cooling, but with a twist: The moisture is added to the air going directly into the data center, which raises the humidity while lowering the intake air temperature (when ambient air conditions permit). As a result, according to Stokes, the site has a projected PUE of 1.17 (including the UPS losses) and is expected to operate without any mechanical cooling at least 99 percent of the time. See the Psychometric chart showing the 'Zone 1-5' call-outs of projected hours of operation.
There is a DX cooling system incorporated in the system; however, it is not expected to be needed under most conditions as the primary cooling system. In fact, by the very nature of the design, it is inherently redundant since there are two sources capable of providing cool air. It should be noted that this design looks somewhat similar in principle to the NetApp site, which is the first data center to be awarded the EPA Energy Star rating and to achieve an annualized PUE of 1.35.
With an upper temperature limit of 85�F and a humidity range of 20-80 percent RH, in the cold aisle, it not just pushes the envelope, it exceeds the current ASHRAE 9.9 recommended guidelines issued in 2008 (and about to be expanded shortly in an upcoming third release). However, as Andrew Stokes pointed out, it does fall within the major server manufacturers' published operating range of 50-95�F and 20-80 percent RH. Of course, I would be remiss if I neglected to mention (given the name of this blog) that the hot aisles will be much hotter and could reach 120�F or more.
If a major conservative institution like Deutsche Bank can build and successfully operate a production site in the New York City area that avoids the traditional, but energy-intensive, approach to data center cooling (CRACs, CRACs and more CRACs), and succeeds in providing reliability and sustainability, it may set the tone for others to re-examine what a 'state-of-the-art' enterprise data center means in the face of rising energy costs and global warming. Nonetheless, it is still spring and the real test of the system will come in the dog days of summer.
If this leading-edge design example proves viable, it could bring new meaning to the classic adage: 'It's not just the heat, it's the humidity."