energies Article Modeling PCM Phase Change Temperature and Hysteresis in Ventilation Cooling and Heating Applications Yue Hu *, Rui Guo , Per Kvols Heiselberg and Hicham Johra Division of Architectural Engineering, Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, DK-9220 Aalborg Øst, Denmark;
[email protected] (R.G.);
[email protected] (P.K.H.);
[email protected] (H.J.) * Correspondence:
[email protected] Received: 22 October 2020; Accepted: 1 December 2020; Published: 6 December 2020 Abstract: Applying phase change material (PCM) for latent heat storage in sustainable building systems has gained increasing attention. However, the nonlinear thermal properties of the material and the hysteresis between the two-phase change processes make the modelling of PCM challenging. Moreover, the influences of the PCM phase transition and hysteresis on the building thermal and energy performance have not been fully understood. This paper reviews the most commonly used modelling methods for PCM from the literature and discusses their advantages and disadvantages. A case study is carried out to examine the accuracy of those models in building simulation tools, including four methods to model the melting and freezing process of a PCM heat exchanger. These results are compared to experimental data of the heat transfer process in a PCM heat exchanger. That showed that the four modelling methods are all accurate for representing the thermal behavior of the PCM heat exchanger. The model with the DSC Cp method with hysteresis performs the best at predicting the heat transfer process in PCM in this case. The impacts of PCM phase change temperature and hysteresis on the building energy-saving potential and thermal comfort are analyzed in another case study, based on one modelling method from the first case study.