Pilot-study on airborne PM2.5 filtration with particle accelerated collision technology in office environments

Particulate matter in an indoor air is the cause of various health concerns. Implementing appropriate air filtration strategies to mitigate its effects would improve occupants' wellbeing who spend many hours a day inside buildings. This study examined PM2.5 with a new filtration technology that incorporates particle-accelerated collision, utilizing semiconductor airborne contamination reduction. In-situ monitoring for 240 h was conducted for an office space. Outdoor PM2.5 concentrations were measured during high variability periods, and indoor-outdoor ratios (I/O) were classified by occupancy conditions. The results indicated that under the new technology, 95% of the hourly indoor PM2.5 concentration readings were below the acceptable threshold of 12 μg/m3, yielding a median of 5 μg/m3 and interquartile range of 3 μg/m3. The factor by which I/O increased from unoccupied to occupied hours ranged between 1.10-2.88, with indoor PM2.5 exceeding outdoor concentrations for 11.67% of the time. The respective range for a comparative filtration system with a standard efficiency rating was 4.35-10.43, with excess rate of 25.45%. Scatterplots of co-located indoor and outdoor PM2.5 generated regression line with a slope of 0.004 and deviation of 15.3% for the new technology, deeming indoor levels almost independent of outdoor conditions