Aerosol Deposition in Turbulent Channel Flow: Implications for Energy-Efficient Indoor Air Quality Control

The occupants of buildings are exposed to a range of aerosol contaminants, of both indoor and outdoor origin; at present, filtered mechanical ventilation is the only effective means of airborne particulate control in polluted urban areas. Significant energy costs may be incurred, however, through the large pressure drops associated with membrane filtration. An alternative to filtration might be the enhancement of aerosol deposition on a protruding surface which is parallel to the incoming airflow direction, but which does not significantly retard the airflow. However, current understanding of aerosol interaction with non-planar surfaces is limited. An experimental technique is described whereby tracer-labelled aerosol particles are injected into a ducting rig which has a ribbed surface, and the spatial variation in particle deposition is studied by neutron activation analysis. Significant aerosol deposition enhancement, compared with a smooth surface was observed, for particles in the range in the range 0.7 - 7.1μm.