Phase change materials performance at radiant floor heating systems for building purposes study = Estudio del comportamiento de los materiales de cambio de fase en sistemas de calefacción por suelo radiante de aplicación en construcción

摘要

Recent research in the field of building materials has led to focus on phase change materials (PCMs). These materials allow the adjustment between energy demand and supply of the climate control systems by storing. Experiments were carried out to investigate the feasibility of using heat storage materials (with PCM addition), placed as one of the flooring layers over radiant floor heating system. In this study, paraffin wax ASTM D 87 (mp 53-57?C) has been added directly during the mixing stage as a PCM, used in mixtures with various contents of paraffin (0.75%, 1.5%, 2.5% with respect to the weight of cement. It was also produced a none paraffin content specimen) and 0.45 water/cement ratio cement mortar. The experiments have been carried out inside of a completely isolated thermal box in which a heating system has been arranged and a measurement equipment for the temperature record. Every experiment consist on four stages that complete the full process of charging the energy storage mortar specimens, by heating the system fluid, and its subsequent progressive discharge after the heating source is off. While testing each specimen different temperatures have been collected: environment temperature outside the thermal box, indoor air temperature, surface temperature of each specimen with the corresponding PCM content, inlet and outlet fluid temperature inside heating system pipe. After carrying out every specimen test it is notice that PCM addition to cement mortar floor layer over the heating system is effective, the more proportion of paraffin added the most appropriate, since it takes a longer period of time to release storage heat during the phase change. Paraffin is an organic material easy to add to the cement mortar porous composition not adversely affecting material resistance, and it has the power to store energy as latent heat by phase changing.