Dimensioning of soil depressurization system for radon remediation in existing buildings

The aim of this study is to help dimension the Sol Depressurization System against radon inexisting buildings.First, various remediation techniques implemented on existing buildings are comparedregarding the reduction of indoor radon concentration. The results show that techniques thatdeal with basements have generally the best efficiency and in particular the SoilDepressurization Systems.In situ test equipment has been developed in order to dimension these systems. It has beenused on different basements such as crawl spaces and cellar. For each case, the test has beenconducted before and after the sealing of the interface between the soil and the building. Insome cases, depressurization of the basement can be obtained for very low airflow rate in thebasement once it is airtight.An experiment on a high radon level building with a ground floor has also been undertaken.After the sealing of this basement, it is shown that the necessary airflow rate needed to makecreate an under-pressure field under the floor is very low. The continuous measurement ofindoor radon concentration during the experiment shows a significant decrease inside thebuilding when the Soil Depressurization System is activated.