Evaluation of the environmental impact of two different heating scenarios in urban area

In this work the impact of two different house-heating systems on pollution scenarios in the Turin town centre is evaluated by means of the three-dimensional modelling system RMS. The first scenario (present situation) refers to the NO_x ground level concentration due to an existing Combined Heat and Power Plant (CHP-plant) and to domestic heating, whereas the second one (future situation) considers the possible advantages of substituting the domestic heating of a central town district with a second Combined Heat and Power Plant to be installed in the district itself. A five consecutive days simulation has been carried out in a particularly severe dispersion situation, characterised by thermodynamic stability and low wind conditions. This period was selected on the basis of in situ observations and its choice was then confirmed as appropriate by means of a statistical analysis of the meteorological model outputs. The main result of the study is that hourly NO_x maxima g.l.c. in the centrally heated district is lower in the future scenario than in the present one; while maxima keep approximately the same in the rest of the town. Then, top-ten ground level concentrations of daily maxima over all the domain decrease in the new scenario.