Fresh air could save millions in data center cooling costs, Intel has claimed, after a successful experiment in the New Mexico desert.
Replacing air conditioning by piping in outside air saved power costs, with no appreciable increase in server failure rates, Intel concluded in a research paper (PDF). Despite a lot of dust and major temperature changes--both long considered undesirable in data centers--the equipment was not affected, Intel said.
"Servers...were subjected to considerable variation in temperature and humidity, as well as poor air quality; however, there was no significant increase in server failures," the paper said. "If subsequent investigation confirms these promising results, we anticipate using this approach in future, high-density data centers."
Intel estimated an annual cost reduction of approximately US$143,000 for a small, 500-kilowatt data center, based on electricity costs of 8 cents per kilowatt-hour. In a larger 10-megawatt data center, the estimated annual cost reduction was US$2.87 million.
The chipmaker used a normal air filter that took larger particles out of the air, but not fine dust. While the 32 servers and racks became coated in dust, and humidity was monitored but not controlled, the failure rate was 4.46 percent, compared with a 3.83 percent failure rate in Intel's main data center over the same period.
The experiment was run for 10 months, between October 2007 and August 2008. Server units with more than 900 blades, used for production design, were split into two compartments. One of the compartments was air-cooled, with temperatures ranging from 64.4 degrees to 89.6 degrees Fahrenheit. The other compartment was cooled using air conditioning, and used as a control.
Intel set up the experiment to challenge assumptions about optimal operating conditions in data centers. Conventional wisdom has it that temperature, humidity, and air quality must be strictly maintained.
However, Intel set out with the premise that, as servers are designed for optimal performance in temperatures of up to 98.6 degrees Fahrenheit, using air cooling in desert regions could be feasible.
The experiment was run as part of the "Intel IT's Eight-Year Data Center Efficiency Strategy" program, which aims to reduce data center costs.