This is the final version. Available on open access from Elsevier via the DOI in this recordIn this paper, a composite structure double layer phase change walls with expanded graphite (EG) was investigated. By adding the EG, the time needed for the phase change process and the wall to work was both accelerated. The effect of composite phase change walls on the indoor thermal comfort and building energy consumption were investigated experimentally. The results show that the double layer phase change wall with the EG can suppress the temperature fluctuation. In addition, it simulated the cooling and heating loads with or without phase change walls based on the climatic conditions in Shanghai. The results show that the heating load in winter is reduced by more than 15%. The simulated values are consistent with the experimental values, and the temperature deviation at the same measuring point within the same period is small. The maximum temperature change between the experimental and simulated values is less than 1 °C. The double layer phase change wall with the EG can reduce the temperature fluctuation and improve the indoor thermal comfort.National Natural Science Foundation of ChinaYouth Eastern Scholar Program of Shanghai Municipal Education CommissionShanghai Municipal Science and Technology Committee of Shanghai outstanding academic leaders pla
