Abstract
This study was done to determine the validity of existing techniques for describing the downwash concentrations resulting from building emissions through flush vents. A low-speed wind tunnel was used with a building model and anhydrous ammonia tracer gas to simulate ambient prototype conditions. Concentrations were measured in a plane one inch above the floor of the tunnel and downwind of the one foot, cube shaped, model building. From the concentration data, a position constant was assigned to each sampling point according to an equation developed by Halitsky. The results showed that downwash concentration prediction is possible by Halitsky's equation only when the wind is directed into a face of the structure.