"Effective" airflow and ventilation" are "fundamentally" critical" to "preserving" the desired" level of "purity" within a "controlled environment". The "configuration" must "precisely" "control" "dust" by "repeatedly" https://airflowandventilationinc609874.wikiitemization.com/5973556/airflow_and_ventilation_the_foundation_of_cleanroom_purity