Treatment of natural stones with Phase Change Materials: Experiments and computational approaches

The treatment of natural stones with Phase Change Materials (PCMs) is experimentally and computationally investigated with respect to developing innovative products with thermal energy storage properties. The objective is to improve the thermal properties of natural stone by exploiting associated latent heat storage phenomena. As a consequence, natural stone treated with PCMs could be used as a construction material with the ability to store thermal energy leading to reduction of the overall buildings' energy consumption. In order to demonstrate the effectiveness of this concept, a series of experiments has been performed. At first, measurements were focused on the PCM influence at the natural stone thermal properties at sample scale. At product scale, a number of “model” concrete pilot houses have been constructed. The pilot houses were covered with trans-ventilated façade design using the Spanish “Bateig azul” natural stone. Two cases have been examined, with and without PCM integrated in the natural stone façade. Variations of indoor temperatures have been monitored for several day–night cycles showing that a smoother indoor temperature profile is obtained when PCMs are implemented. An improvement in human comfort and a reduction of energy consumption can thus be anticipated. Furthermore, a composite computational model based on the linking of TRNSYS platform to a MATLAB subroutine is introduced. The performance of the tool is evaluated with respect to the aforementioned measurements. It is shown that a good agreement between computational results and experimental data can be achieved. Parametric studies focused on the PCM influence, highlighting the advantages of the combined experimental and computational approaches.

► The treatment of natural stones with Phase Change Materials is investigated.
► Thermal properties of natural stone are modified when treated with PCMs.
► Experimental pilot houses are monitored with and without PCM in the façade.
► Reduced indoor air temperature variations due to PCM integration.
► Computational parametric studies highlight the potential of the concept.