The doctoral dissertation in the field of Aerosol Physics will be examined at the Faculty of Science, Forestry and Technology, Kuopio campus and online.
Topic of the thesis is emissions from fuel operated auxiliary heaters of passenger cars, with specific focus on particle emissions. Auxiliary heaters are used to preheat both cabins and engines of vehicles during wintertime and in some vehicles during the driving to provide supplementary heat. Because current emission regulation of vehicles does not consider auxiliary heater emissions as part of regulated vehicle emissions and specific regulations of heaters are looser than those of engine emissions. Thus, heater emissions are not mitigated using modern emission aftertreatment methods such as catalytic converters and particle filters.
Because of this researching auxiliary heater emissions is important to get more accurate view of the total emissions of vehicle use. Emissions from fuel operated auxiliary heaters of passenger cars have not previously studied as extensively as vehicle emissions despite extensive research of major air quality and health effects of vehicle emissions.
What are the key findings or observations of your doctoral research?
Preheating the vehicle with fuel operated auxiliary heaters was not observed to reduce fuel use during the driving significantly and when the fuel use of the heater is accounted for the preheating the total fuel use of the vehicle increased. Preheating was also observed to produce notable amount of direct emissions. For example, a single 30-minute preheating with a gasoline heater was observed to produce as many particles over 23 nm in size as driving 97 kilometres, assuming that the vehicle’s particle emissions are at the Euro 6 regulatory limit.
Another notable observation was that preheating did not reduce particle number emissions during driving, while for some vehicles particle mass generated by driving decreased slightly.
In addition, particle emissions of the heaters were observed to increase significantly when secondary particles formed from gaseous compounds of the exhaust after combustion were accounted for.
How can the results of your doctoral research be utilised in practice?
Results of this PHD research can be used to improve emission regulations of vehicles by counting the currently neglected auxiliary heater emissions as part of vehicle emissions. This is justified as conducted research establishes that emissions from AHs are not insignificant in comparison to driving emissions for cars with AHs installed.
More work is needed to achieve similar emission reductions in preheaters as has been achieved with engine emissions of vehicles. Incentives for such development could be achieved by including AH emissions as part of regulated vehicle emissions.
Reduction of auxiliary heater emissions could be achieved by development of emission aftertreatment methods suitable for heaters as has been done for engine emissions or by development of alternative heating methods. National vehicle fleet emission inventories could also be improved by accounting additional emissions generated by heaters as part of fleet level emission estimates.
What are the key research methods and materials used in your doctoral research?
Dataset used in this research was collected during three year joint project AHMA between University of Eastern Finland and Tampere University, which was funded by Jane and Aatos Erkko Foundation.
Fuel operated auxiliary heater emissions were studied from heaters of vehicles in regular use in realistic operating conditions in Finnish winter conditions both to measure direct preheating emissions and effect of preheating to driving emissions was determined by chase measurements. The chase measurements were conducted by Tampere University’s mobile laboratory ATMo-Lab.
Additionally aging of the heater emissions were studied in ILMARI laboratory of University of Eastern Finland to get more comprehensive data of how exhaust from heater develops when it interacts with surrounding air in atmospherically relevant conditions.
In all measurements, data on particle number, particle mass, and black carbon mass were collected, along with gaseous emissions of carbon dioxide, nitrogen oxides, and unburned hydrocarbons.
The doctoral dissertation of Henri Oikarinen, MSc, entitled Emissions from fuel operated auxiliary heaters of passenger cars will be examined at the Faculty of Science, Forestry and Technology, Kuopio campus and online. The opponent will be Professor Alexander Bergmann, Graz University of Technology, and the custos will be Research Director Santtu Mikkonen, University of Eastern Finland. Language of the public defence is English, but the lectio praecursoria will be held in Finnish.
For more information, please contact:
Henri Oikarinen, [email protected], tel. 044 204 6296
- Public examination
- Dissertation (PDF)
- Photo (coming)
