Effects of burnrate, wood species, altitude, and stove type on woodstove emissions.

During the winter of 1986-87, the U.S. Environmental Protection Agency (EPA) conducted an emission measurement program in Boise, ID, as part of the Integrated Air Cancer Project (IACP). This program was designed to identify the potential mutagenic impact of residential wood burning on ambient and indoor air. One facet of this field sampling effort involved obtaining emission samples from chimneys serving wood burning appliances in Boise. As a companion to the field source sampling, a parallel project was undertaken in an instrumented woodstove test laboratory to quantify woodstove emissions during operations typical of Boise usage. Two woodstoves were operated in a test laboratory over a range of burnrates, burning either eastern oak or white pine from the Boise, ID, area. A conventional stove, manufactured in the Boise area, was tested at altitudes of 90 and 825 m. A catalytic stove was tested only at the high altitude facility. All emission tests were started with kindling a fire in a cold stove using black and white newsprint. Emissions were collected using the wood stove dilution sampling system (WSDSS) for a continuous period of about 8 hours, encompassing start-up and several wood additions. The results showed wide variability probably due primarily to the difficulty in duplicating conditions during start-up. Total WSDSS emissions showed the expected inverse correlations with burnrate for the conventional stove and nearly flat for the catalytic stove. While there appeared to be little or no correlation of total WSDSS emissions with altitude, the sum of the 16 polynuclear aromatic hydrocarbons (PAHs) quantified showed an inverse correlation with altitude: higher PAH emissions at the lower altitude.