Diesel Fuel-Fired Heater Emissions from a Battery Electric Transit
Bus in Real-World Conditions 2024-01-5011
Battery electric transit buses sold in Canada generally include a fuel-fired
diesel auxiliary heater for cabin heating in cold weather. This report details a
test project, performed in collaboration with OC Transpo, to capture and
quantify the emissions from such a fuel-fired heater (FFH) installed on a New
Flyer XE40 battery electric transit bus from OC Transpo’s fleet in Ottawa,
Canada. The FFH was tested while the bus was both stationary and being driven
on-road in cold conditions. The results include the emissions rates of carbon
dioxide, carbon monoxide, nitrogen oxides, hydrocarbons and methane, and soot.
Additionally, total particulate matter results were obtained during stationary
testing. The results of stationary testing were compared to the California Air
Resources Board and European Union standards for FFH emissions, even though
these standards do not apply directly to buses operated outside of these
jurisdictions. During stationary testing, average emissions of carbon monoxide
and non-methane organic gases (hydrocarbons) were 0.069 g/mi and 0.035 g/mi,
respectively, which are both within their respective regulated limits for FFH
emissions in California. However, the California nitrogen oxide limit was
exceeded during stationary testing with an average value of 0.337 g/mi. In
addition, momentary exceedances of the concentration limits for carbon monoxide
and hydrocarbons set in European Union Regulation 122 were detected during
stationary testing, but these were very short-lived.
Citation: Humphries, K., Rashid, H., and Araji, F., "Diesel Fuel-Fired Heater Emissions from a Battery Electric Transit Bus in Real-World Conditions," SAE Technical Paper 2024-01-5011, 2024, https://doi.org/10.4271/2024-01-5011. Download Citation