Subslab ventilation system: Installation and follow-up in a high-radon house in Brittany, France

A subslab ventilation system was designed and installed in a high radon house in Brittany, France. Radon concentration in the basement of this house was reduced from an average 10 000 Bq/m 3 to less than 200 Bq/m 3 , thanks to a subslab depressurization system with a double barrier and a 32 W fan. Sealing the concrete slab cracks greatly improved the system performance. Finally, the feasibility of using a passive double barrier ventilation system is shown.