Coupling the transient plane source method with a dynamically controlled environment to study PCM-doped building materials

Abstract

In recent years the combination of latent and sensible thermal energy storage processes within passive and active building components has gathered increasing attention among researchers all over the world. All this considered, an ever-increasing hunger for bridging the gap between chemistry-based characterization methods and engineering-scale monitoring solutions is spreading worldwide, with the aim of developing new experimental procedures allowing to test these advanced systems under realistic operative environmental conditions. In this view, the present paper aims at proposing an innovative characterization procedure for real-scale engineered applications with reference to dynamically variable composites, such as PCM-doped cement-based mixes for building envelope applications. Therefore, in this work, thermally enhanced concretes were produced using micro-encapsulated paraffin and their activation was investigated by means of an innovative experimental technique coupling transient plane source method and controlled environmental dynamic forcing. The dynamic-TPS analysis allowed to produce temperature dependent profiles for three basic material thermal properties, i.e. thermal conductivity, thermal diffusivity and volumetric specific heat. Results show that the proposed methodology is capable of detecting PCM activation within the engineered composites during the imposed hygrothermal cycle, where, for example, the effective thermal conductivity of the composites varied between 40 and 90% amid the melting/freezing process. Furthermore, the transient plane source method also showed to be suitable to investigate PCM dispersion within the composites.