Impact of the enthalpy function on the simulation of a building with phase change material wall

• Impact of the thermodynamical modeling on PCM in building walls is studied.
• Apparent enthalpy deduced from DSC is evaluated for 3 heating rates.
• Actual enthalpy is estimated using an inverse method.
• Apparent enthalpy cannot predict correctly thermal comfort in buildings.

Recent studies concerning phase change material (PCM) characterization show that important errors occur if differential scanning calorimetry (DSC) experiments are misinterpreted. Therefore, it is important to know the influence of such misinterpretation on system modeling. The present work deals with phase change materials integrated in building structure to reduce overheating. The objective is to evaluate the discrepancies consequences (temperatures, heat fluxes), due to the use of the misinterpreted DSC experiments at different heating rates to determine the enthalpy, in comparison with those determined with the actual value of the enthalpy of the PCM determined by a proven inverse method. A numerical model of a single-family house with a phase change material mortar is developed to evaluate the thermal comfort in the building. The results show that for free-running temperature, none of the enthalpy curve deduced directly from DSC can predict correctly the thermal behavior of the house and the thermal comfort. Moreover, the more the DSC heating rate and the more the discrepancy with the results from the reference inverse method.

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