PREDICTING EMISSION AND MEAN AIR QUALITY IN UNDERGROUND GARAGES

Air quality measurements in garages indicate that high pollutant concentrations caused by car-induced emissions may occur. In order to predict the emissions and air quality in a particular garage, a numerical model is required. With the garage volume, parking capacity, air exchange rate and temporal distribution of incoming and outgoing cars as input, the model should be useable to calculate the variation of the emissions and the mean concentrations of CO, NO, NO2, HC, benzene and soot in the garage. Such a model will be presented. To evaluate the method, measurements in 2 different garages were carried out. The predicted emission factors for CO, HC and benzene agree to a large extent, while the factor for NOx agree approximately with the results derived from the measurements. The evaporation of benzene by fuel tank ventilation was underestimated by the theoretical assessment. For soot, the emission factor derived from the measurements exceeded the theoretical values by a factor of 3. In respect to soot, this corresponds to the results of other authors. The study demonstrates that by combining the emission and mixture models, it is possible to predict air quality in garages. (A) For the covering abstract see IRRD E101903.