%0 Journal Article
%A William J Riley
%A Ashok J Gadgil
%A Yves C Bonnefous
%A William W Nazaroff
%B Atmospheric Environment
%D 1996
%G eng
%P 1167-1176
%T The Effect of Steady Winds on Radon Entry into Houses
%V 30
%1 <p>2.4</p>
%X <p>Wind affects the radon entry rate from soil into buildings and the resulting indoor concentration. To investigate this phenomenon. we employ a previously tested three-dimensional numerical model of soil-gas flow around houses. a commercial computational fluid dynamics code. an established model for determining ventilation rates in the presence of wind. and new wind tunnel results for the ground-surface pressure field caused by wind. These tools and data, applied under steady-state conditions to a prototypical residential building, allow us to</p><ol><li>determine the complex soil-gas flow patterns that result from the presence of wind-generated ground-surface pressures,</li><li>evaluate the effect of these flows on the radon concentration in the soil. and</li><li>calculate the effect of wind on the radon entry rate and indoor concentration.</li></ol><p>For a broad range of soil permeabilities. two wind speeds, and two wind directions, we quantify the "flushing" effect of wind on the radon in the soil surrounding a house, and the consequent sharp decrease in radon entry rates. Experimental measurements of the time-dependent radon concentration in soil gas beneath houses confirm the existence of wind-induced flushing. Comparisons are made to modeling predictions obtained while ignoring the effect of the wind-generated ground-surface pressures. These investigations lead to the conclusion that wind-generated ground-surface pressures play a significant role in determining radon entry rates into residential buildings.</p>