HEPA Filtration in Ventilation Systems

HEPA Filtration in Ventilation Systems Indoor air quality changes fast when you add high-efficiency filtration. This article explains practical, step-by-step guidance for integrating HEPA filter ventilation into DIY and passive-house projects: what HEPA removes (and doesn't), how to size filters and fans, retrofit options, energy and noise trade-offs, and routine maintenance. Readers will learn how to choose between whole-house, inline, and portable HEPA approaches and how to estimate fan upgrades and replacement costs before committing to a project. TL;DR: - Use HEPA filter ventilation when you need particle removal at 0.3 µm and smaller: True HEPA removes 99.97% of 0.3 µm particles; add activated carbon for gas-phase contaminants. - For whole-house filtration: size to achieve target ACH (convert ACH to CFM), expect higher fan power for HEPA pressure drop, and consider an inline fan or booster; for 1,200 sq ft at 8 ft and 3 ACH you need ~480 CFM. - For retrofits or tight budgets: depl...