This paper describes an experimental, domestic-sized, oil-fired furnace to be used for evaluation of fuel additives and equipment design modifications in reducing air pollutant emissions. Operating data and emissions of particulate matter, smoke, carbon monoxide, gaseous hydrocarbons, oxides of nitrogen, and oxides of sulfur are reported over the range of operable air-fuel ratio. Emission levels are interpreted in terms of key operating parameters and potential areas for reduction of emissions.