November 2, 2012


Unregulated Tailpipe Emissions from A Light-Duty Hybrid-Electric Vehicle Operating Under Real-World Grade


1:30 p.m. – 3:00 p.m


1065 Kemper Hall


The TOTEMS on-board emissions instrumentation package developed at the UVM
Transportation Air Quality Laboratory quantifies tailpipe gas and particle pollutant concentrations,
exhaust flow rates, exhaust and sample temperatures, vehicle position, engine operating behavior,
ambient and instrument conditions while a test vehicle is driven on the real-world road network.
Unlike previous “portable emissions measurement systems” (PEMS) that collect chiefly regulated
gases, TOTEMS collects: (i) the full number distributions of particle emissions using an EEPS (TSI,
Inc.) particle spectrometer; and (ii) quantifies mobile source air toxic (MSAT) gaseous emissions
in addition to criteria pollutant (CO, NOx, HC) and greenhouse gases (CO₂, N₂, CH₄) using a
high-speed FTIR instrument specifically designed for on-board vehicle exhaust testing. Here,
ultrafine particle and greenhouse gas emissions from two MY 2010 Toyota Camry vehicles, one
hybrid-electric and one conventional, are compared based on repeated real-world operation on a 32
mile route in Chittenden County, Vermont by a single driver. Road grade and road type effects on
hybrid-electric vehicle emissions and performance will be discussed.

Biographical Sketch

Dr. Holmén is an Associate Professor in the School of Engineering at the
University of Vermont (UVM). She is visiting UC Davis this academic year on her sabbatical.
Her research focuses on real-world measurements of pollutants from transportation and agriculture
sources, with an emphasis on airborne particles and organic contaminants. Dr. Holmén has studied
light-duty tailpipe emissions using on-board techniques; heavy-duty hybrid transit bus emissions;
laboratory and roadside pollutant measurement techniques; biodiesel emissions and health effects;
and agricultural particle pollutants. Her work has been funded by the NSF, USDA, NIH, CARB
and several Agencies of Transportation. Dr. Holmén led the UVM effort to design and build the
Transportation Air Quality Lab, a research laboratory of the UVM Transportation Research Center
(TRC). Between 1994 and 2001 Dr. Holmén was a post doc and research professor at UC Davis.

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