Modification of a guarded hot-plate for the automated measurement of thermal storage properties of PhaseChange Materials (PCMs)

Phase-Change Materials are gaining attention for their application in HVAC systems and buildings. They are commonly used in combination with system and envelope components to improve their behavior reducing the energy demand. PCMs are commercially available in different formats, whose behavior cannot be accurately measured by means of the existing calorimetric methods, which are applied to the PCM substance alone instead of the overall component as a whole. In fact, the thermal properties of PCMs are normally evaluated using DSC (Differential Scanning Calorimetry) method carried out on a very small quantity of material, very far from the real installation. This scaling factor could lead to different results than expected under working conditions. Finally, many laboratories are already provided with tools for measuring thermal properties in regular materials, which could be adapted for measuring thermal storage properties in PCMs. In such a context, the need for appropriate standards and tools for measuring the thermal storage properties of commercially available PCM components arises, possibly by means of equipment already available in laboratories. For this purpose, standard ASTM C1784-20 was developed, with specific reference to heat flow meter apparatus (HFMA). This paper reports about the application of this standard in the laboratory of Environmental Applied Physics of Università Iuav di Venezia, where a guarded hot-plate was adapted to measure thermal storage properties of PCMs.