Mechanical Sieving vs. Electrostatic Attraction
All residential air filters capture airborne particles through one of two primary mechanisms: mechanical capture (impaction, interception, and diffusion) or electrostatic electret charging. Understanding this distinction explains why some MERV 13 filters maintain low airflow resistance when new, but may lose capture efficiency over time as their electrostatic charge dissipates.
The Electret Advantage & Caveat
Electrostatically charged filters (like 3M Filtrete) capture tiny sub-micron particles with open, breathable fibers, creating 30% to 50% lower initial static pressure than mechanical glass filters. However, exposure to oil mists, high humidity, and dust loading gradually neutralizes this electrical charge.
About ClariSelect Editorial & Research Standards:
Sizing measurements, static pressure curves, and filtration ratings referenced across our educational guides are compiled from published ANSI/ASHRAE Standard 52.2 engineering data, AHAM AC-1 verified ratings, and manufacturer technical documentation. ClariSelect provides objective editorial research and analysis with zero sponsored placements.