"Adequate" airflow and ventilation" are absolutely" "essential" to "preserving" the "required" level of "purity" within a cleanroom". The "design" must carefully" "control" "dust" by "continuously" "filtering" the air" https://airflow-and-ventilation-956926.mysticwiki.com/2400021/airflow_and_ventilation_the_foundation_of_cleanroom_purity