clean room

Aerosol detection in HVAC duct components is a critical component of contaminant detection and analysis. Incorrect placement of a sensor inlet within the ductwork can have a significant, deleterious effect on capture efficiency and sample accuracy. Computational fluid dynamics studies were conducted of straight rectangular cross-section ductwork and a 90° bend to determine flow patterns and simulations of particulate injections were made at various locations across the inlet. The resultant particle distributions were analyzed to determine the optimal placement for a sensor inlet.

In general, there are 3 locations used for the fresh air supply in a standard cleanroom : under the ceiling of supply air plenum, at the return air shaft, and under the raised floor. In this study, the influences of the three different fresh air supply locations on field velocity and temperature distributions of fan filter unit are investigated then compared. The airflow distribution is simulated by the standard k-e turbulence model. Results are presented and discussed..