Three buildings were characterized in this project by examining radon concentrations and indoor air quality (IAQ) levels as affected by building ventilation dynamics. IAQ data collection stations (IAQDS) for monitoring and data logging, remote switches (pressure and sail switches), and a weather station were installed. Measurements of indoor radon carbon dioxide (CO2), particle concentrations, temperature, humidity, pressure differentials, ambient and sub-slab radon concentrations, and outdoor air (OA) intake flow rates were collected. The OA intake was adjusted when possible, and fan cycles were controlled while tracer gas measurements were taken in all zones and IAQDS data were collected. Ventilation, infiltration, mixing rates, radon entry, pressure/temperature convective driving forces, CO2 generation/decay rates, and IAQ levels were established for baseline and OA-adjusted conditions.