Development of a methodology to characterize radon entry in dwellings

Radon measurement in buildings is generally performed by means of passive integrated radon measurements over a few months period. This long time period is necessary to assess the average indoor radon activity concentration due to its high variability along time. However, it could become problematic to deal efficiently with radon management, especially if radon measurement has to be carried out before each real estate transaction. The objective of this study was to test the ability of a rapid protocol to characterize radon entry in dwellings. An individual dwelling was rented during one year. Indoor, outdoor and soil radon activity concentrations were measured continuously with other parameters such as indoor temperature and meteorological conditions. Different tests using a blower door were performed and ventilation rate, indoor depressurization and indoor radon activity concentration evolution were measured. Experimental results show that it is possible to obtain an experimentally derived power law function of radon entry from the ground with acceptable repeatability. Also this power law function, when integrated in a building ventilation model, enables approximation of the measured annual average indoor radon activity concentration of the tested dwelling. In addition, the annual average indoor radon activity concentration was successfully assessed by using analytical simplified infiltration model based on the knowledge of some building characteristics and of this experimental radon entry function.