https://puritytech.me/news Practical HVAC filtration guides and indoor air quality insights with sources, test context and installation considerations from PURITY TECH. en https://puritytech.me/news/merv-11-hvac-filter-guide https://puritytech.me/news/merv-11-hvac-filter-guide Understand MERV 11, the PURITY TECH ASHRAE test report, airflow considerations and the difference between particle filtration and antiviral textile testing. Mon, 26 Oct 2026 17:00:00 +0400