A simplified method for evaluating fine particulate matter removal performance of portable air cleaners

A simplified method for evaluating the fine particulate matter (PM_2.5) removal efficiency of portable air cleaners is presented to support community-engaged research and citizen science. Clean air delivery rate (CADR) values measured in a residence with low-cost sensors were ≈ 26% lower than laboratory measurements obtained using research-grade instruments, providing conservative estimates of air cleaner performance. Ten portable air cleaners (PACs), including seven homemade ("DIY") prototypes and three commercial models, were evaluated for physical and economic performance. A four-filter Corsi-Rosenthal box achieved the highest PM_2.5 removal performance among the DIY prototypes and adding a fan shroud increased CADR by ≈ 11%. A single 102-mm MERV 13 filter attached to a box fan also produced high CADR values with a compact form factor and low initial cost. Additional tests indicated minimal concerns related to motor temperature and power consumption during residential operation. Analysis of 135 DIY and commercial PAC models showed substantially lower initial cost per CADR unit for DIY models compared to commercial units. This method includes three main elements:•Introducing a short-lived particle source, such as a medical nebulizer, in a well-sealed room.•Measuring PM_2.5 concentrations with and without the air cleaner running.•Calculating CADR values using particle decay rates.