Air filtration serves to reduce concentrations of particles in indoor environments. Most standalone, also referred to as portable or in-room, air filtration systems use HEPA filters, and cost generally scales with the clean air delivery rate. A 'do-it-yourself' lower-cost alternative, known as the Corsi-Rosenthal Box, that uses MERV-13 filters coupled with a box fan has been recently proposed, but lacks systematic performance characterization. We have characterized the performance of a five-panel Corsi-Rosenthal air filter. Measurements of size-resolved and overall decay rates of aerosol particles larger than 0.5 microns emitted into rooms of varying size with and without the air filter allowed for determination of the apparent clean air delivery rate, both as a function of size and integrated across particle sizes. The measurements made in the different rooms produced similar results, demonstrating the robustness of the method used. The size-integrated apparent clean air delivery rate increases with fan speed, from about 600 to 850 ft3 min-1 (1019 to 1444 m3 h-1). Overall, our results demonstrate that the Corsi-Rosenthal filter efficiently reduces suspended particle concentrations in indoor environments.
Characterizing the performance of a DIY air filter
