Thermal Performance Measurement Procedure and Its Accuracy for Shape-Stabilized Phase-Change Material and Microcapsule Phase-Change Material Combined with Building Materials

The accuracy of differential scanning calorimetry (DSC) used in the dynamic method, which is the method most widely used to measure the thermal performance of existing phase-change materials (PCMs), is limited when measuring the phase-change range and peak temperature of PCMs combined with building materials. Therefore, we measured the thermal performance in a thermochamber; the samples were a sheet of shape-stabilized phase-change material (SSPCM) and a microencapsulated PCM-impregnated gypsum board fabricated by combining PCM building materials with paraffin. Then, we investigated ways to improve the measurement accuracy. We confirmed the setting time of the thermochamber temperature change based on the internal temperature of the PCM and the effect of the PCM capacity on its thermal performance using the dynamic method. The temperature was increased or decreased in uniform steps at regular time intervals. The error of the heat absorption and release was less than 2% when a stabilization time of at least 4 h elapsed before the start of the heating or cooling process. Overall trends in the specific heat and enthalpy, such as the phase-change section and peak temperature of the PCM, were similar regardless of the setting time. Thus, it was confirmed that the latent heat performance did not increase proportionally with the increase in the PCM capacity. The proposed approach can be used to measure the specific heat and enthalpy of various types of PCMs and building materials.