Interpretation of calorimetry experiments to characterise phase change materials

In the building field, the topic of thermal storage is generally studied with assistance from dedicated software programs. To generate transient thermal simulations, these software programs use enthalpy functions h (T) to describe the thermal behaviour of the different parts of a modelled structure. Unfortunately, the mathematical form of these functions is often extremely unrealistic due to an erroneous interpretation of the calorimetric experiments that were performed to determine these functions. The purpose of this study was to evaluate the energy-related errors that occur if a misinterpreted enthalpy function is used and to thereby assess the impact that these inaccurate functions generate with respect to thermal simulations of buildings.