Hygrothermal Performance of Thick PCM Mortar behind PV Panels in Energy-Activated ETICS Facades

Abstract

The concept of integrating PV panels into traditional ETICS facades has been developing for several years. Problems concerning the options for passively controlling the temperatures of PV panels with PCM and directing excess moisture out of the wall via diffusion channels have been previously studied theoretically. During this study, real wall-scale experiments were conducted to test the thermal and hygrothermal performance of the wall system in an extreme climatic environment, as well as in a real outdoor environment in Tallinn, Estonia. Finally, a simulation model was calibrated according to the measured data. It was found that in case of test walls with diffusion channels, it was possible to keep the moisture content of PCM mortar under 0.11 m3/m3. Excess water drained out via channels leading to the external environment. Without diffusion channels, the moisture content rose as high as 0.18 m3/m3. Both the experiments and hygrothermal modelling showed that the high moisture content of PCM mortar, caused by water leakage, dropped to 0.08 m3/m3 over 10 solar cycles as moisture escaped via the diffusion channels. PCM mortar with a moisture content of 0.08 m3/m3 endured extreme rain and freeze-thaw cycles without visual damage, and PV panels retained their electrical production capabilities.

Aesthetic and functional aspects of BIPV – an architectural outlook

“…Combining Pv with ETiCS façade insulation systems may prove another promising technology. Research is underway with the use of phase change materials (PCM) materials and methods to remove moisture from the inner surface of such hybrid systems (Talvik et al, 2023). Overcoming technological barriers will likely exert a revolutionary impact on the development of biPv once Pv is introduced in the area of insulation materials used each time thermomodernisation of buildings and their façades is conducted.…”