Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That in Conventional Data Centers

There is a concern that environmental-contamination caused corrosion may negatively affect Information Technology (IT) equipment reliability. Nineteen data centers in the United States and two in India were evaluated using Corrosion Classification Coupons (CCC) to assess environmental air quality as it may relate IT equipment reliability. The data centers were of two basic types: "closed" and outside-air cooled. A closed data center provides cool air to the IT equipment using air conditioning in which only a small percentage of the recirculation air is "make-up" air continuously supplied from outside to meet human health requirements. An outside-air cooled data center uses outside air directly as the primary source for IT equipment cooling. Corrosion measuring coupons containing copper and silver metal strips were placed in both "closed" and outside-air cooled data centers. The coupons were placed at each data center (closed and outside-air cooled types) with the location categorized into three groups:

1. "Outside" - coupons sheltered, located near or at the supply air inlet, but located before any filtering,
2. "Supply" - starting just after initial air filtering continuing inside the plenums and ducts feeding the data center rooms, and
3. "Inside" located inside the data center rooms near the IT equipment.

Each coupon was exposed for thirty days and then sent to a laboratory for a corrosion rate measurement analysis.