Comparison of the water transport in single star (S) and binary star (B) systems. We restricted this study to binaries with two G-type stars. The various panels correspond to different semi-major axes of the secondary: a_b = 50–75–100 au. The colour code refers to different subrings of the HZ (see text). We note that the two results for each panel account for different initial asteroid belt distributions (depending on e_b), taken as the same for (S) and (B).