Experimental study on passive Soil Depressurisation System to prevent soil gaseous pollutants into building

The following paper focuses on the study of the ability and the efficiency of passive Soil Depressurisation System which helps to prevent buildings from gaseous pollutants coming from the ground. The Soil Depressurisation System (S.D.S.) is one of the most effective methods of lowering gaseous pollutants (radon) levels and for remedial measures. This system is mainly used with a fan which enables to extract mechanically the air from the sub-slab region in order to under pressurise it. Nevertheless, in this study the soil depressurisation is obtained naturally using thermal buoyancy and wind effect. When natural forces are insufficient, hybrid solutions have been tested using stato-mechanical extractor (operating mechanically or statically). One-year follow up of a passive S.D.S. has been carried out in an experimental house in order to analyse the performance of such a system over time. A specific sump has been installed in the sub-slab region and different parameters have been measured in order to analyse the behaviour of such a system. This paper shows experimental results and the analysis of the one-year follow up. It appears that such a passive system could run efficiently a significant part of the year if properly designed, mainly during cold conditions, when it is more important to have a good protection against soil gas and radon.