Rich Miller of Datacenter Knowledge covered this last week and it caught my interest. I’m super interested in modular data centers (Architecture for Modular Datacenters) and highly efficient infrastructure (Data Center Efficiency Best Practices) so the Yahoo! Computing Coop caught my interest.
As much as I like the cost, strength, and availability of ISO standard shipping containers, 8’ is an inconvenient width. It’s not quite wide enough for two rows of standard racks and there are cost and design advantages in having at least two rows in a container. With two rows, air can be pulled in each side with a single hot aisle in the middle with large central exhaust fans. Its an attractive design point and there is nothing magical about shipping containers. What we want is commodity, prefab, and a moderate increment of growth.
The Yahoo design is a nice one. They are using a shell borrowed from a Tyson foods design. Tyson is the grower of a large part of the North American chicken production. These prefab facilities are essentially giant air handlers with the shell making up a good part of the mechanical plant. They pull air in either side of the building, it passes through two rows of servers into the center of the building. The roof slopes to the center from both side with central exhaust fans. Each unit is 120’ x 60’ and houses 3.6 MW of critical load.
Because of the module width they have 4 rows of servers. It’s not clear if the air from outside has to pass through both rows to get the central hot aisle but it sounds like that is the approach. Generally serial cooling where the hot air from one set of servers is routed through another is worth avoiding. It certainly can work but requires more air flow than single pass cooling using the same approach temperature.
Yahoo! believes they will be able to bring a new building online in 6 months at a cost of $5M per megawatt. In the Buffalo New York location, they expect to only use process-based cooling 212 hours/year and have close to zero water consumption when the air conditioning is not in use. See the Data Center Knowledge article for more detail: Yahoo Computing Coop: Shape of Things to Come?
More pictures at: A Closer Look at Yahoo’s New Data Center. Nice design Yahoo.