In situ measurement of air cleaner ventilation effectiveness.

A test room was used to evaluate the impact of airflow parameters on the effectiveness of an air cleaning system. The room’s dimensions were nominally 11.2 m x 5.7 m x 2.7 m. The room has a drop-ceiling with space above for installation of above-ceiling air cleaning equipment and routing of ventilation ductwork. The HV AC system supplying the room could be turned on for constant flow (-349 ls·1) or left off to independently evaluate the effectiveness of the air filtration system. Smoke was generated in the room by five smoking machines (8 cigarette ports) or eight human smokers situated throughout the room. A new type of air cleaning system (consisting of three-stage particulate filtration and a novel activated carbon filter panel) was tested and compared to commercial, off-the-shelf air cleaners. Different diffuser types and airflow patterns were evaluated to determine the most effective way to distribute air throughout the room. Testing revealed that when careful attention is paid to ventilation airflow design, greater effective ventilation could be achieved than when mixing alone is used to distribute clean air and contaminants throughout a space.