The thermal effect of the tandem kang model for rural houses in Northern China: a case study in Tangshan

The kang-stove system (KSS) is a combination cooking and heating system and is the core element of the living space of many rural houses in northern China. The traditional KSS is usually single kang model (SKM) that one stove combines with one kang, which causes inconveniences including an insufficient room heating supply, a small heating range, and subsequent privacy issues for family numbers. Therefore, this paper proposes a tandem kang model (TKM). By combining two kang together and re-organizing the house layout, this model both improves the heat supply effect of the KSS and transforms the kang from a multifunctional space to a relatively mono-functional space to provide more personal space for family members, especially in the winter. To verify the thermal effect of the TKM, CFD simulations were conducted to compare the indoor thermal indexes of a chosen prototype and its modified version with a tandem kang. The results reveal that, compared with the SKM, the TKM exhibits a better thermal performance. It can improve the temperature of the main rooms by 12.7-55.6%. Whereas the form of the TKM should be properly controlled or combined with other assistant facilities to optimize the condition of the uneven surface temperature distribution.