Interzonal airflow from garages to occupied zones as one reason for building related illness: three case studies using tracer gas measurements.

Tracer distribution measurements were performed to assess pollutant transport from basement garages situated in a commercial building and in two residential buildings, in which the occupants had reported typical garage odors and complained about bad indoor air and typical SBS symptoms. A tracer gas technique (tracer gas SF6, infrared detection) was used in all three buildings to study the contaminant distribution in the buildings. In the commercial building, a leaky HVAC system distributed contaminated air from the garage to other zones of the building. A second reason was a large opening in the encasing wall of the exhaust shaft of the garage. In the residential buildings exhaust fans as well as tightly sealed windows and doors led to interzonal airflow from the garage. The results indicate that faulty construction and insufficient sealing between the garage and the occupied floors can most certainly be a reason for building-related illness. The tracer gas technique applied has proved a good tool for detecting leaks and faulty construction in buildings.