Elastomeric Panels with Phase Change Material for Summer Thermal Management: Experimental Thermal Performance in a Real Wall Design

This study investigates the integration of elastomeric panels containing Phase Change Materials (PCMs) into real-scale building wall assemblies to improve their transient thermal performance. PCMs offer a promising passive strategy to enhance thermal inertia and reduce cooling loads by absorbing and releasing latent heat during phase transitions. Despite their potential, their performance in real-world wall configurations under dynamic boundary conditions remains insufficiently explored. To address this gap, three wall systems were experimentally tested: a reference wall (made up of fruit processing organic by-products), the same wall with a 5 mm PCM layer, and with a 10 mm double PCM layer. Tests were conducted using a double climatic chamber to simulate real daily temperature profiles based on standard sinusoidal conditions and representative summer climates of Trento and Palermo (Italy). Key dynamic thermal parameters, including periodic thermal transmittance, decrement factor, and time-shift, were evaluated along with the thermal capacitance. Results showed that 5 mm PCM integration substantially improved the wall thermal behaviour: the periodic thermal transmittance was decreased from 1.1 to 0.4 W m−2 K−1, the time shift was increased from 2.8 to 6.7 h, the decrement factor was reduced from 0.72 to 0.29 and the energy stored in a daily cycle was increased from 247 to 427 Wh m−2. The 10 mm PCM configuration reduced the peak of the internal heat flux by up to 64.6% and increased time-shift of the reference wall by over 130% under sinusoidal forcing. Additionally, stored thermal energy increased by over 70% compared to the reference wall. The evaluation of the energy and thermal power implication of the PCM integration revealed the possibility of size reduction of HVAC system due to the lower peak demand.