The emissions from hot driving conditions, in which the exhaust-after-treatment systems are working properly, continue to decrease, which is why the emissions of cold starts have gained in importance. Traffic emission models are used to estimate and predict vehicle fleet emissions and the air quality of countries, regions, cities, etc. In addition to the statistical input of fleet activities, these models are mostly based on the use of separate emission sub-models for hot driving and cold start driving.
View Article and Find Full Text PDFMobile air conditioning (MAC) systems are the second-largest energy consumers in cars after driving itself. While different measurement series are available to illustrate their behavior in hot ambient conditions, little data are available for lower temperatures. There are also no data available on diesel vehicles, despite these being quite common in Europe (up to 70% of the fleet in some countries).
View Article and Find Full Text PDFRegenerating exhaust after-treatment systems are increasingly employed in passenger cars in order to comply with regulatory emission standards. These systems include pollutant storage units that occasionally have to be regenerated. The regeneration strategy applied, the resultant emission levels and their share of the emission level during normal operation mode are key issues in determining realistic overall emission factors for these cars.
View Article and Find Full Text PDFThe influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U.
View Article and Find Full Text PDFEnviron Sci Technol
January 2006
Passenger cars are the primary means of transportation in Europe. Over the past decade, a great deal of attention has therefore been paid to reducing their emissions. This has resulted in notable technical progress, leading to unprecedentedly low exhaust emissions.
View Article and Find Full Text PDFEnviron Sci Technol
October 2004
Instantaneous emission models of vehicles describe the amount of emitted pollutants as a function of the driving state of the car. Emission measurements of chassis dynamometer tests with high time resolution are necessary for the development of such models. However, the dynamics of gas transport in both the exhaust system of the car and the measurement line last significantly longer than 1 s.
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