The paper describes experiments to verify an indoor air quality (IAQ) model, EXPOSURE, that includes the interactions of sources, sinks, and air movement between rooms and between buildings and the outdoors. Sources may be located in rooms, in the heating, ventilation, and air-conditioning (HVAC) system, or outdoors. There may be sinks (i.e., materials that adsorb indoor pollutants) in the same locations. Sinks may also act as sources when pollutant concentrations drop below a given value. The model EXPOSURE, described in the paper, is based on the model INDOOR. Major differences between EXPOSURE and INDOOR are an improved user interface, a faster solution technique, and the ability to predict individual exposure. EXPOSURE also incorporates the results of recent research on sources and sinks. Combining chamber studies, test house studies, and modeling has been quite valuable. The chamber tests allow many factors to be investigated rapidly. The model allows coupling chamber data to the test house. And test house studies provide model verification, identification of weakness in the model, and the chamber data that require additional chamber testing, theoretical analysis, and test house experiments.