Chinese kang as a domestic heating system in rural northern China—A review

The Chinese kang is an ancient integrated home system for cooking, sleeping, domestic heating and ventilation. It is still widely used today in nearly 85% of rural homes in northern China. In 2004, there were 67 million kangs used by 175 million people. Existing kang designs are mostly based on the intuition and accumulation of craftsman experience. There is a trend that Chinese kang is gradually replaced by bed and coal-burning radiators, domestic heating stoves, etc. using commercial energy. As rural building heating constitutes 25% of total building energy consumption in China, we consider that the transition and new technologies for rural home heating in northern China is crucial for managing future building energy consumption in China. This paper reviews the basic heat transfer and airflow principles of Chinese kang, as well as describing the traditional grounded kang and the relatively new elevated kang. The thermal performance of the kang is shown by data from literature and field surveys. The future of Chinese kang and research needs is also briefly discussed. There is also a need for scientific study in addition to experience accumulation, to form basis for engineering design.