Explore the scientific principles behind HEPA filters, explaining how they effectively capture 99.97% of airborne particles as small as 0.3 microns. Discover the mechanisms of impaction, interception, and diffusion that make HEPA technology indispensable for superior air purification.

High-Efficiency Particulate Air (HEPA) filters are a cornerstone of advanced air purification systems, renowned for their ability to capture 99.97% of airborne particles 0.3 microns in diameter. This efficiency extends to even smaller particles, as the 0.3 micron size represents the Most Penetrating Particle Size (MPPS). HEPA filters work through a combination of three mechanisms: impaction, interception, and diffusion. Impaction captures larger particles, interception traps medium-sized particles, and diffusion is effective for the smallest particles. Understanding these mechanisms highlights why HEPA filtration is critical for environments requiring stringent air quality, such as hospitals, cleanrooms, and homes with allergy sufferers.