In the realm of heritage conservation and energy efficiency, a groundbreaking study has emerged that could reshape how we approach retrofitting historic buildings. Led by A. Rubio-Aguinaga from the MATCH Research Group at the University of Navarra, the research delves into the sustainability of Phase Change Material (PCM)-enhanced lime mortars, offering a promising solution to reduce energy demands and carbon footprints across diverse climates.
The study, published in *Case Studies in Construction Materials* (translated from Spanish as “Case Studies in Construction Materials”), addresses a critical gap in the current research landscape. While previous studies have focused on material behavior or single-climate scenarios, Rubio-Aguinaga’s work provides a comprehensive, climate-resolved assessment that integrates embodied carbon and operational energy impacts at the building scale. This is particularly relevant for heritage structures, which often face stringent conservation constraints.
The research team examined three types of PCMs: two paraffin-based (with melting points of 18°C and 24°C) and one bio-based, derived from agricultural by-products (melting point of 29°C). These PCMs were integrated into lime mortars and modeled across three retrofit strategies—internal grouting, internal rendering, and a combined approach—applied to the 13th-century Hermitage of Santa Brígida in Spain. The results were then extrapolated to all Spanish climate zones to evaluate performance under varying thermal conditions.
The findings are compelling. PCM-enhanced mortars demonstrated the potential to eliminate cooling demands and significantly reduce heating needs. “This technology not only preserves the historical integrity of heritage buildings but also offers substantial energy savings,” Rubio-Aguinaga noted. The study revealed that the bio-based PCM achieved the maximum total carbon footprint reduction (89.1%), followed by the 24°C paraffin PCM (87.2%) and the 18°C paraffin PCM (74.6%), depending on the climate zone.
The implications for the energy sector are profound. As the world increasingly focuses on sustainability and reducing carbon emissions, the integration of PCM-enhanced lime mortars into heritage retrofitting presents a viable and eco-friendly solution. “This research highlights the importance of climate-PCM compatibility and provides critical insights into the long-term environmental impact of these mortars,” Rubio-Aguinaga explained.
The study’s findings could pave the way for future developments in the field, encouraging further exploration of PCM technologies in construction. By offering a sustainable approach to energy efficiency, this research not only benefits heritage conservation but also contributes to the broader goal of reducing global carbon footprints.
As the construction industry continues to evolve, the integration of innovative materials like PCM-enhanced lime mortars could become a standard practice, driving the energy sector towards a more sustainable future. This research serves as a testament to the potential of combining traditional materials with cutting-edge technology to achieve both conservation and efficiency goals.