The thermal performance of building envelopes is essential for building thermal comfort and the reduction of building energy requirements. Phase change materials (PCMs) implemented in building envelopes can improve thermal performance. An explicit finite element method (ex-FEM) has been developed based on a previous study to investigate the heat transfer performance through building walls with installed PCMs. For verification, we introduce an electrical circuit analogy (ECA) method. For model validation, at first, COMSOL is used. For comparison, data were collected from experiments using a small hotbox, part of the sides are covered by PCMs with different configurations. This work shows how the ex-FEM model can predict the wall’s temperature profile with and without incorporated PCM. With the implementation of PCMs, the work problematizes unpredictable influences for modeling. In addition, the study introduces results from simulations of sequencing of PCM layers in wall construction.

To understand the influence of PCM wall configurations on the thermal performance of building envelopes, an explicit finite element model of heat transfer from indoor to outdoor (or vice versa) is developed. The accuracy of this model is first validated against the electrical circuit analogy model, and then compared with the experimental data measured in a Hot-Box device. A good agreement between the simulation results and experimental results is obtained. The results of this study show that the PCM configuration layer sequence significantly will affect the thermal performance of building envelopes and that the FEM model developed is a promising tool, which after some more development may be used for optimising PCM wall configurations.