A Numerical Study of Indoor 222Rn_Air Quality in a Ventilated Room

This study aimed to numerically investigate the radon (222Rn) dispersion in a ventilated room. The Reynolds-averaged Navier-Stokes (RANS) equations supplemented with equation of energy and radon concentration are solved using the FLUENT code. We are targeting primarily the ventilation effectiveness ($\varepsilon_{\mathrm{c}}$) and the index of indoor air quality (IIAQ). Different displacement and mixing ventilation modes are investigated in isothermal conditions. Computations have been performed with Reynolds numbers between 5 102 and 4 104, and different Rayleigh numbers between 9.33 108 and 4.66 109, in order to suggest effective ventilation that can ensure a good indoor air quality. The simulation results indicate that the ventilation effectiveness to remove a contaminant of radon 222Rn and the index of indoor air quality are substantially influenced by the ventilation mode and the location of outlet air. From this study, it appears that the air flow and radon dispersion in a ventilated room can be typically predicted or evaluated by computer simulations.