Jim Rosenthal
Thank you for this great explanation of how filters become more efficient as they get dirty. Unfortunately, they become more resistant which slows down airflow resulting in lower particle removal in the space. Remember - it is Filter + Fit + Flow.
Smart Air
@SusanDavidsonM2 @sameo416 @Ikat0 @TulaGbefi @JimRosenthal4 Here's some data on filters getting "full" over time. Filtration efficiency goes up. However, with filters that have an electrostatic charge (many HEPA and MERV filters these days), the data is a little more mixed.