Effect of various factors on the rate of radon entry into two different types of houses

Various factors that affect the rate of radon entry were investigated in two detached hill-side houses. In the slab-on-grade house (A), this rate reached its maximum value during a particular weather condition when the wind-induced internal transport of radon, whereas the rate of radon entry into the basement house (B) on the upper slope of a esker was highest when the wind was blowing towards the esker. In neither house did changes in barometric pressure measured at 3 h intervals influence the radon entry rate. Nor did rain influence the rate of radon entry into house A. In house A, the radon entry rate was observed to have a 2–3 h delay; and after it was adjusted by the analysis of covariance, the radon entry rate was higher in the morning and lower in the evening. In house B, however, diurnal variations in the radon entry rate were negligible.