Simulated equilibrium factor studies in radon chamber

A series of experiments have been conducted to study the influences of environmental parameters on the equilibrium factor. Most of them were carried out in a walk-in type chamber. The deposition velocity was calculated using the Jacobi model. The ranges of the environmental parameters studied in the experiments are humidity 30–90% r.h. and radon concentration 2–40 kBqm−3. The aerosol sources included electric fumigator, mosquito coil, incense, and cigarette with the particle concentration 2000–6500 cm−3 and the attachment rate 10–350 h−1. The results of the experiment show that the equilibrium factor tends to decrease as the radon concentration increases. On the other hand, the equilibrium factor tends to increase as the humidity increases, and so is the increasing attachment rate. Of all the parameters mentioned above, the influence that aerosols have on the equilibrium factor is the predominant factor. The calculated deposition velocity for the unattached fraction of radon daughters tends to increase as the radon concentration increases. However, it tends to decrease as the humidity increases.