In-home performance of pellet stoves in Medford and Klamath Falls, Oregon

Pollutant emissions, thermal efficiencies, and heat outputs of pellet stoves operating in homes located in Klamath Falls and Medford, Oregon were documented. Six stoves representing two commercially available, certified models were studied during the 1989-1990 heating season. Three models exempt from certification (a total of six stoves) were studied during the 1990-1991 heating season. An automated emission sampler (AES) system was used to conduct long-term, in-home monitoring of the stoves. The results of the studies have permitted an evaluation of the environmental and energy performance characteristics of the stoves. For the certified stoves, the average overall particulate emissions were 1.05 grams per hour (g/hr), which is about 75% lower than the best-performing cordwood stoves. The in-home particulate emission values were close to their laboratory certification values. Preliminary results for the exempt stoves produced an average particulate emission value of 2.02 g/hr. Also, for the certified stoves, altitude appeared to have little or no effect on particulate emissions and there appeared to be no differences in particulate emission rates between the two models studied. Polycyclic aromatic hydrocarbon (PAH) and carbon monoxide emissions were low. The carbon monoxide emission rates averaged 14 g/hr, the average net thermal efficiency of the stoves was 68%, and the average heat output was 8,747 Btu per hour. Similar data are currently being evaluated for the exempt stoves. Emission and energy performance data obtained for the pellet stoves assessed in this study demonstrated that pellet stoves offer a viable residential biomass-fueled heating option