The development of a radon entry model for a house with a cellar

A widely used CFD package, FLUENT was used to develop a model of multiple radon entry in a house with a cellar. Methods applied in the model development are presented, including modifying a subroutine to specify radon source that originates in the soil cells only but decays throughout the computational domain, designing a simulation procedure that allowed the ground surface be simulated with appropriate boundary conditions, and verifying the model. The verification of the model includes a grid-independency test, convergency behaviour analysis and comparison with analytical solutions. This verification was carried out under a range of conditions which represent the most probable situations in reality. Inter-model validation technique was also used to validate the model’s robustness: the model was used to run a case that has been simulated by an existing model. Two predictions show good agreement. The study shows that this complex model is applicable and reliable for a large range of parametric conditions and can be used to carry out a parametric study aiming at obtaining a deeper understanding of the radon issue in a house with a cellar. It also shows that CFD models need a systematic verification before being applied.