|Title||Data Center Economizer Contamination and Humidity Study|
|Year of Publication||2007|
|Authors||Arman Shehabi, William F Tschudi, Ashok J Gadgil|
Data centers require continuous air conditioning to address high internal heat loads (heat release from equipment) and maintain indoor temperatures within recommended operating levels for computers. Air economizer cycles, which bring in large amounts of outside air to cool internal loads when weather conditions are favorable, could save cooling energy. There is reluctance from many data center owners to use this common cooling technique, however, due to fear of introducing pollutants and potential loss of humidity control. Concerns about equipment failure from airborne pollutants lead to specifying as little outside air as permissible for human occupants.
To investigate contamination levels, particle monitoring was conducted at eight data centers in Northern California. Particle counters were placed at three to four different locations within and outside of each data center evaluated in this study. Humidity was also monitored at many of the sites to determine how economizers affect humidity control. The results from this study indicate that economizers do increase the outdoor concentration in data centers, but this concentration, when averaged annually, is still below current particle concentration limits. Study results are summarized below:
The average particle concentrations measured at each of the eight data center locations are shown in Table 1. The data centers ranged in size from approximately 5,000 ft2 to 20,000 ft2 . The indoor concentrations and humidity in Table 1 represents measurements taken at the server rack. Temperature measurements at the server rack consistently fell between 65-70°F. The Findings section contains a discussion of the individual findings from each center.
|LBNL Report Number|| |