Indoor Air Quality Evaluation in Rural Houses Using Different Heating Methods in Northern Shanxi, China

It has been shown that heating methods have a large impact on rural indoor air quality. Previous studies on indoor air quality in rural houses involved a limited number of heating methods and lacked comprehensive comparative research on the three heating methods: coal-fired boiler radiator heating, air-source heat pump radiator heating, and Chinese stove-kang heating. In this paper, subjective surveys and objective tests were conducted on indoor air quality in rural houses using these three heating methods in northern Shanxi, China. The gray relational analysis method and the comprehensive index method were used to evaluate the indoor air pollution levels of the three heating methods. The results were as follows: The subjective evaluations of most rural residents were overly optimistic about the indoor air quality of coal-fired boiler radiator heating and Chinese stove-kang heating. The indoor TVOC concentrations from these two heating methods far exceeded the standard limit of 0.6 mg/m3 at night. The indoor PM2.5 and PM10 concentrations from Chinese stove-kang heating varied greatly over a day and showed intermittent peak fluctuations that far exceeded the standard limits in the initial period of fuel combustion. The pollution levels from coal-fired boiler radiator heating, air-source heat pump radiator heating, and Chinese stove-kang heating were evaluated as light pollution, non-pollution, and medium or heavy pollution, respectively.