Experimental Study on a Capillary Radiant Heating Bed System Based on Solar and Air-Source Heat Pump Dual Heat Source

The traditional Chinese Kang heating system can effectively utilize the waste heat of cooking for heating and has been widely used in rural areas. However, this system may cause severe air pollution since it is heated by directly burning coal and biomass fuel. The promotion and utilization of clean heating technology are therefore attracting more and more attention. In this research, a capillary radiation heating terminals was proposed to reform the traditional Chinese Kang system. Both air-source heat pump and solar energy were used as heat source for the system. An experimental bench was set up, and a series of tests were conducted to validate the feasibility of the system. The experimental results have shown that when the temperature of the supplied water reaches to 40 °C, the indoor air temperature can satisfy the thermal environment need of residents. The solar energy can be used for about 3.5–4.5 h per day when the daily average solar radiation is greater than 2000 Wh m–2 d–1. These results may lead to the development of designing and distributing the solar energy for building heating during winter.