Performance evaluation of different low-cost DIY air cleaner configurations

Do-it-yourself (DIY) air cleaners have been proposed as an affordable alternative to expensive portable HEPA air cleaners; however, their performance data is still limited. This study evaluated the performance of single- and multi-filter DIY air cleaner configurations with different filter thickness (1, 2, and 4 inches) and MERV ratings (8, 11, and 13). The filters were selected based on their availability to the public, with the resulting cost of less than 50 and 100 USD for single- and multi-filter configurations, respectively. DIY air cleaners were challenged with polydisperse NaCl particles, and their clean air delivery rate (CADR) was determined for ultrafine (< 100nm) and 300nm particle number concentration and PM2.5 mass concentration. Twelve single-filter configurations with filters from three companies, a 2-filter configuration, and a Corsi-Rosenthal (C-R) box with four 2-inch filters were tested. The CADR ranged from 84 to 635 cfm, depending on the particle metric and filter configuration. Among the single-filter configurations, the 4-inch filter performed the best. The multi-filter models, especially the C-R box, demonstrated the highest CADR: comparable to and exceeding the CADR of portable HEPA air cleaners. In addition, the C-R box also provided the highest CADR per power input while resulting in the lowest noise level and fan motor temperature. In addition to performance, the cost of operating and maintaining DIY air cleaners is also discussed. Overall, this study shows that DIY air cleaners are an affordable and effective means to reduce particulate air pollutants, thus improving indoor air quality. [GRAPHICS] .