Airflow patterns in a five-storey apartment building.

Tracer gas tests were conducted on a five-storey apartment building to determine the air and contaminant flow patterns within the building. The test method involves the injection of a small amount of tracer gas, SF6, into a selected location to create a single source and monitoring the tracer gas concentrations at locations throughout the building. Based on the rates at which the tracer gas concentrations change at various locations, the air and contaminant flow patterns within the building can be determined. Several such tests were conducted. In each test, the tracer gas was injected into one of three locations: a garbage room on the ground floor, a party room in the basement and the supply air duct of the building's heating and ventilating system. This paper presents the results of the tracer gas tests. It also includes measurements of the overall airtightness of the building envelope, the exterior wall airtightness values of three individual storeys, and the airtightness values of interior partitions, stairwells and floor/ceiling separations.