our simulations were performed with two different CFD software packages, PHOENICS v.2.1 (PHOENICS, 1994) and FLUENT v.4 (FLUENT, 1994), which allowed us to examine the validity of several turbulence models by comparing their results with those of experiments described in the literature (Sase et al., 1984; Boulard et al., 1997). After the predictive accuracy of the models was investigated, the most successful of them was used to analyse the influence of design characteristics on the wind-driven ventilation efficiency of greenhouses.