Pellet stoves that are considered exempt'' operate at an air-to-fuel ratio in excess of 35:1. They therefore qualify for exemption from the emissions certification process. A primary goal of this project was to determine how a sample of such stoves, operated in homes, would perform compared to their certified cousins,'' which were evaluated the previous year. In-home performance data documenting emissions from exempt stoves and net delivered efficiencies was particularly desired. This project evaluated six pellet stoves representing three major brands in Medford, Oregon. There were three Breckwell model P24FS, one Horizon Eclipse, one Horizon Destiny, and one Earth Stove TP40. The stoves were monitored for four week-long intervals in January and February 1991, for a total of 24 tests. Evaluations were conducted for particulate, CO (carbon monoxide) and PAH (polycyclic aromatic hydrocarbon) emissions and net efficiency. Monitoring was conducted using the AWES (automated woodstove emissions sampler) sampling system. A new data logger, developed for this project, was used to control the AWES and record real time data. 22 refs., 17 figs., 6 tabs.
