In building thermal energy storage system, the building structure, furniture and papers are used as the heat storage materials. However, it is difficult to know the actual condition of the thermal energy storage system. The aim of this study is to establish a calculation model to predict the actual condition of the system. This paper presents the experimental results of measured internal temperature and surface heat flux of the book and papers which have large thermal capacity. In addition, the mathematical models to estimate the surface heat flux are also shown.
