Occasionally I come across a noteworthy datacenter design that is worth covering. Late last year a very interesting Japanese facility was brought to my attention by Mikio Uzawa an IT consultant who authors the Agile Cat blog. I know Mikio because he occasionally translates Perspectives articles for publication in Japan.
Mikio pointed me to the Ishikari Datacenter in Ishikari City, Hokkaido Japan. Phase I of this facility was just completed in November 2011. This facility is interesting for a variety of reasons but the design features I found most interesting are: 1) High voltage direct current power distribution, 2) whole building ductless cooling, and 3) aggressive free air cooling.
High Voltage Direct Current Power Distribution
I first came across the use of direct current when Annabel Pratt took me through the joint work Intel was doing with Lawrence Berkeley National Lab on datacenter HVDC distribution (Evaluation of Direct Current Distribution in Data Centers to Improve Energy Efficiency). In this approach they distribute 400V direct current rather than the more conventional 208V to 240V alternating current used in most facilities today.
High voltage direct current work in datacenters has been around for around a decade and it is in extensive test at many facilities world-wide. Many companies are 100% focused on HVDC design consulting with Validus being one of the better known.
The savings potential of HVDC are often shown to be very exciting with numbers beyond 30% frequently quoted. But the marketing material I’ve gone through in detail compare excellent HVDC designs with very poor AC designs. Predictably the savings are around 30%. Unfortunately, the difference between good AC and bad AC designs are also around 30% :-).
When I look closely at HVDC distribution, I see slight improvements in efficiency at around 3 to 5%, somewhat higher costs of equipment since it is less broadly used, less equipment availability and longer delivery times, and somewhat more complex jurisdictional issues with permitting and other approvals taking longer in some regions. Nonetheless, the picture continues to improve, the industry as a whole continues to learn, and I think there is a good chance that high voltage DC distribution will end up becoming a more common choice in modern datacenters.
The Ishikari facility is a high voltage DC distribution design. I’m looking forward to learning more about this aspect of the facility and watching how the system performs.
Whole Building Ductless Cooling
Air handling ducts costs money and restrict flow so why not recognize that the entire purpose of a datacenter shell is to keep the equipment dry and secure and to transport heat. Instead of installing extensive duct work, just treat the entire building as a very large air duct.
Perhaps the nicest mechanical design I’ve come across based upon ductless cooling is the Facebook Prineville facility. In this design, they use the entire second floor of the building for air handling and the lower floor for the server rooms.
The Ishikari design shares many design aspects with the Intel Jones Farms facility where the IT equipment is on the second floor and the electrical equipment is on the first.
Aggressive Free-Air Cooling
Looking at the air flow diagram above, you can see that the Ishikari Datacenter is making good use of the datacenter friendly climate of Japan and aggressively using free-air cooling. Free-air cooling, often called air side economization, is one of the most effective ways of driving down datacenter costs and substantially increasing overall efficiency. It’s good to see this design point spreading rapidly.
More information is available at: http://ishikari.sakura.ad.jp/index_eng.html
Some datacenter designs I’ve covered in the past: