A mathematical model for a house integrated with an elevated Chinese Kang heating system

Chinese kang, a potentially energy-efficient domestic heating system in China, uses high thermal mass to store surplus heat from the stove during cooking and releases it later for space heating. In this paper a preliminary mathematical model is developed for a House Integrated with an Elevated Kang system (HIEK). This model considers the transient thermal behaviors of building envelope, kang system and indoor air. The macroscopic approach is used to model the thermal and airflow process for the elevated kang system. The numerical method for solving the resultant non-linear equations of HIEK is proposed and implemented. The HIEK model is preliminarily evaluated using the measured data from a field survey, and agreement is reasonably good. This model can be used to predict the indoor air temperature for multi-zone HIEK by inputting the basic parameters like geometry, physical properties of building and kang. The model can be easily extended for investigating the thermal performance of a kang system and its influence on indoor thermal environment and building energy consumption. Finally, suggestions for incorporating the kang model into existing building simulation tools are also described.