The paper describes the results of several field studies undertaken in North America since 1985 to establish the emission rates of typical, uncontrolled, conventional technology woodstoves and the degree of emission control achieved by newer woodstoves designed to reduce the emission of unburned organics. The new stoves, employing either catalytic or noncatalytic secondary combustion features, while reducing emissions, do not achieve the expected emission reduction. Studies during the northern winter of 1988-89 showed that emission control was gradually improving, but they also showed that some woodstove models were experiencing degraded emission control performance after only a few months use. Use of wood as a residential heating fuel increased markedly in the U.S. during the 1970s in response to an increase of fossil fuel costs. Most of the increase represented wood burned in airtight parlor stoves which are generally operated in an air-starved condition leading to low combustion efficiency and the release of substantial quantities of unburned organics into the atmosphere. Use of wood as a residential house heating fuel in the U.S. has been estimated to contribute up to 90% of the polynuclear organic material attributable to stationary sources and 50% from all sources.

"Presented at 10th International Conference of the Clean Air Society of Australia and New Zealand, Aukland, New Zealand 3/25-30/90." Microfiche.