A couple years ago, the TEM-led SCOPE Alliance undertook the task of identifying the relevant environmental requirements for data centers and telecommunications from several different standards groups (Telcordia, ETSI, TIA, etc.) and came up with the Environmental Profile: Central Offices and Network Data Centers, eventually published last May. It was a lot of work, but I think we developed the most comprehensive overlay of those standards that has been published to date.
Last August, ASHRAE issued its 2008 ASHRAE Environmental Guidelines for Datacom Equipment, which changed the recommended setpoints in data centers from 20-25°C to 18-27°C. This may not seem like much, but it's a step in the right direction towards better allowances for dry-side (air) economizers.
Last November, Telcordia released GR-3160, NEBS(TM) Requirements for Telecommunications Data CenterEquipment and Spaces. [I had provided information for this to Telcordia through the two years this document was in process.] Though those outside the telecom world may not be familiar with Telcordia (or its predecessor, Bellcore), the Telcordia NEBS standards have become the de facto standards for how telecommunications facilties and equipment is designed in the U.S. and many places around the world. GR-3160 is effectively Telcordia's first major foray into data center standards, a clear recognition that telecommunications carriers like AT&T, Verizon, and Qwest have a large number of data centers and a growing need to ensure maximum availability in those facilities. Among the interesting elements of GR-3160 is Telcordia's expectation for allowable maximum ambient temperatures at the air inlet to the rack-mounted equipment:
- 30°C long-term max ambient
- 40°C short-term max ambient (up to 360 hours per year)
These two upper limits provide a reasonable target that equipment manufacturers can design to, while providing enough freedom that facility designers can make maximum use of economizers.