"Adequate" airflow and ventilation" are "completely" critical" to maintaining" the desired" level of "purity" within a "sterile area". The "design" must carefully" "control" "contaminants" by constantly" "exchanging" https://unidirectional-airflow-c167975.wikifordummies.com/9662497/airflow_and_ventilation_the_foundation_of_cleanroom_purity