Results of comparison between the average line ratios presented in Table 5 with radex models for a range of n_H2 and N_H2O for six different temperatures ranging from 100 to 1500 K. The solid lines indicate the region within 1σ while the dashed lines show where the plane-of-the-sky emitting area, obtained from the ratio of the observed and model intensity in the 2₀₂ −1₁₁ line, corresponds to a circle with radius 100 AU.