Research on Application of Solar Air Heating in Buildings of Villages in Northern China—Based on Experimental Study

In this paper, a test bench was built to study the thermal performance of three typical air collectors. Based on the test data, this paper conducted a comprehensive study on the physical and economic performance of the solar air heating systems including indoor temperature, solar energy guarantee rate, investment payback period and life cycle cost, and gave recommendations for their applications. The research showed that under the specified air flow rate range, the efficiency of the three typical collectors all reached above 45%. When the flow rate increased twice, the efficiencies of the V-groove collector, S-type spoiler collector, seams penetration collector were increased by 16%, 20%, 19%, respectively. This research recommended the ideal flow rate for solar air heating in China was 36 m³/(h.m²) ~ 54 m³/(h.m²). The simulation results in15 typical cities showed that the solar energy guarantee rate was generally above 20%, and in more than half of cities the solar energy guarantee rate reached 30% or above, with the highest in Lhasa, reached 62%. Economic analysis indicated more than 70% of the cities in northern China have a simple payback period of less than 6 years. The results indicated that solar air heating technology not only has a wide range of adaptability but also yield great financial benefits in northern China. This paper will have a significant impact on guiding the application of solar air heating in rural areas of China.