جستجوی مقالات مرتبط با کلیدواژه « natural ventilation » در نشریات گروه « فیزیک »

This study aims to investigate changes in radon concentrations in residuals areas, using a sample closed room with the surface area of 12 m2. In the room, radon gas emitted from the floor and walls surfaces with different emission rates, and gaps under the door and around the window were the natural ventilation routes. Radon concentrations were measured in different points of the room in different circumstances and times using an accurate radon detector and then compared with the simulation results from Computational Fluid Dynamics (CFD) technique under corresponding conditions and times. The analytical data were used to validate the results of these two techniques. The results indicate that the radon concentration decreases from a relatively uniform distribution of about 81 Bq/m3 to a relative non-uniform distribution in the range from 12 Bq/m3 to 44 Bq/m3 after a very slow natural ventilation. The simulation results demonstrate an appropriate agreement with the experimental data that indicate the accuracy of performed modeling.

Due to the increasing of closed ventilation systems used in buildings, the risk of indoor radon is increased day by day. In this study, we selected two sample rooms to calculate the radon emission coefficient from different levels, radon concentration measured when the natural ventilation was completely closed and compared with the analytical results. The results clearly show the difference in the amount of radon concentration at different levels; then, by overcoming the common gaps in the entrance of the rooms, the natural ventilation caused by the temperature difference between the room and the outside is obtained. By substituting them in the analytical equations, the radon concentration is calculated with ventilation. The calculated results are in good agreement with the experimental results and show the important role of natural ventilation to reduce indoor radon even to over 90%.