An Innovative Method for Dynamic Characterization of Fan Filter Unit Operation

Fan filter units (FFUs) are widely used to deliver re-circulated air while providing filtration control of particle concentration in controlled environments such as cleanrooms, minienvironments, and operating rooms in hospitals. The objective of this study is to document an innovative method for characterizing operation and control of an individual FFU within its operable conditions. Built on a draft laboratory method previously published,¹ this study presents an updated method including a testing procedure to characterize dynamic operation of FFUs, i.e., steady-state operation conditions determined by varied control schemes, airflow rates, and pressure differential across the units. The parameters for dynamic characterization include total electric power demand, total pressure efficiency, airflow rate, pressure differential across FFUs, and airflow uniformity.