User behavior, influence factors, and impacts on real-world pollutant emissions from the household heating stoves in rural China.

Household heating stoves are commonly used for heating in rural China during winter and are responsible for a large portion of the particulate matter in the atmosphere. Pollutant emissions from household stoves are influenced by user behaviors in actual use, in addition to purely technological reasons (i.e., type and age of appliance) and installation conditions (i.e., the natural draft of chimney system). The variability in user behavior is one of the reasons for uncertainty in household emission inventories. In this study, household stove user behaviors, including ignition frequency, heating with or without cooking, smoldering duration, and fuel-adding times, were investigated through face-to-face surveys in Shanxi province, north China. The survey of user behaviors showed that the majority of the RHS users (81.3%) and approximately half of the WHS users (49.4%) used their stoves for both cooking and heating, whereas the remaining users used their stoves just for heating. Approximately 80% of surveyed households (97.4% for water heating stove and 68.7% for radiant heating stove) kept the stoves smoldering at night, whereas the remaining users ignited their stoves every day. The highest frequency of smoldering duration and highest frequency of fuel-adding operation were 8-9 h and 4-7 times, respectively. Principal component analysis showed that stove type, permanent population, and annual income are the potential influencing factors of user behavior. The smoldering duration was positively related to indoor air pollutant concentrations and fuel-adding times had a significant impact on outdoor PM emission factors. The results from this research will be beneficial for understanding the cause of fluctuation in emissions and designing heating appliances for real-life operations.