A Gaussian dispersion model is applied to the evaluation of the impact of district heating on winter sulfur pollution in Vienna. It is found that by reducing households emission of ~60% corresponding to ~13% of the total annual SO2 emission the maximum SO2 concentration averaged over the heating period, which approximately runs from November to March, can be reduced by ~30%. The analysis has been conducted by embedding the Gaussian model in an algorithm which computes the minimum cost heat conveyance network to achieve a prescribed reduction of SO2 concentration.