RADEX model results for the observed CH₃OH lines towards SMM1C (left) and IRS7A (right), using T_kin = 30 K. Red, orange and green contours represent lower limits for the integrated line intensities of optically thick lines whereas blue and grey contours represent the marginally optically thin lines and include the errors from Table B.1. The vertical line is the CH3OH column density calculated assuming LTE conditions and optically thin emission reported in Table 3.