Optimization of thermal performance in a Chinese traditional heating system - Burning cave

Nowadays, inhabitants living in rural areas of northern China still rely on traditional heating methods, such as kangs (bed-stoves), radiators heated by mini stoves, and burning caves in cold winter period. Burning caves are increasingly used due to free fuels from crop wastes, simple structures, and better heating effect than kangs and mini stoves. In this study, field measurements of indoor environment in several rural houses with burning caves designed by local craftsmen and located in northern China were carried out in 2010-2011. The results show that indoor temperatures maintained at above 18 °C and it was felt more comfortable than houses heated by kangs and mini stoves. To solve some existing problems in houses with burning caves built by local craftsmen, a new house integrated with an improved burning cave was built in December 6, 2011. The results from theoretical analysis and field measurements showed that temperature difference between adjacent rooms could be reduced by 4-6 °C, which is 2-5 °C lower than the houses with the burning caves designed by craftsmen, and the thermal efficiency reached 56.7%. In addition, the concentration of CO was reduced to 1/5 of the value in the houses with burning caves by local craftsmen.