A significant portion of the energy in data centers is currently dedicated to provide cooling for the server equipment. Data centers must provide continuous air conditioning to address high internal heat loads (heat release from computer servers) and maintain indoor temperatures within recommended operating levels for computers. Air-side economizers, which bring in large amounts of outside air to cool internal loads when weather conditions are favorable, could save cooling energy. However, this technology is not widely adopted because the climate dependant energy savings from air-side economizers are expressed only qualitatively. Further, the lifecycle costing of this system is not well understood. A major barrier to economizer implementation is the fear of increasing pollutants levels in the data center during economizer cycle, and the fear that these pollutants could affect computer server reliability High efficiency HVAC filters are suggested as an option to effectively reduce particulate contamination inside the data center. Further, the energy implication of using improved filters in an air-side economizer system is also discussed. Strategies to reduce this economizer implementation barrier are explored in this study. Pollutants of concern are measured in a data center enabled with economizer operation while using air filtration of varying levels of efficiency.