Improving Energy Performance of Historic Buildings through Hygrothermal Assessment of the Envelope

Abstract

The intervention on historic buildings through building energy retrofitting has become one of the current challenges of improving energy efficiency. Nonetheless, this building typology presents certain complexities. Among them, one of the most relevant is the protection on their façades due to the historical and/or artistic values of a given façade and, therefore, the addition of external thermal insulation is restricted. However, at the same time, in several of those buildings indoor surfaces do not present that architectural value, and then internal thermal insulation becomes a promising strategy for improving their thermal performance. Nevertheless, its application must be carefully evaluated to avoid possible pathologies caused by moisture problems. This paper aims to identify constructive solutions for interior insulation of walls free from moisture problems. For this purpose, a comprehensive analysis of a series of constructive solutions based on internal insulation has been carried out through hygrothermal simulations. The results show how the application of water-repellent impregnation becomes essential to guaranteeing the integrity of the envelope. In addition, the combination of insulations with or without inner membranes, such as smart vapor retarders or vapor diffusion barriers, has been evaluated detecting the solutions that best fit the objective. Finally, taking advantage of the great potential of 2D simulation tools, the post-processing of the data has been performed to apply the wood decay model, and thus assess the behavior of a very conflictive point in this type of intervention, i.e., the wooden beam-ends. The results in this critical point have shown how the application of the proposed constructive solutions becomes essential to guarantee the integrity of the element and how the application of traditional solutions could lead to a hazard that must be avoided.

Energy Efficiency of Historic Buildings

“…These models are also used for defining a compatible retrofit. On hygrothermal evaluation, Martín-Garín et al [16] use hygrothermal simulations for assessing different interior insulation systems for walls, without generating damage and moisture problems. They discover that the application of water-repellent impregnation becomes essential to guarantee the integrity of the building envelope.…”

A Comparative Analysis of Traditional and New Construction Methods for External Wall Insulation in Jiangning, Nanjing, China

“…The construction industry is facing challenges, and "fine design" and "differentiated transformation" are critical for building enterprises to compete in the future. Studies have been conducted the design of exterior walls in buildings to address issues related to building insulation, heat, waterproofing, and moisture design [1]. However, there is a lack of research on the impact of macro-regulation of building market prices on the construction industry and the importance of "fine design" and "differentiated transformation" in addressing the challenges faced by the industry.…”

Evaluation Method on Energy-Efficient Retrofitting of Wooden Walls of Chinese Traditional Dwelling—A Case Study of Rendetang in Jinhua

“…In some studies, the dampproof problem of walls has been noticed, and the energy-efficient retrofitting idea of traditional wooden dwellings has been extended. Martín-Garín et al [24] comprehensively analyzed a series of internal insulation-based measures through hygrothermal simulations, and then concluded that waterproof materials were requirements for guaranteeing the air tightness of building envelopes. To facilitate traditional dwellings to adapt to the local humid environment, Liu [19] used raised floors to avoid the direct floor-ground contact, and the results showed that this construction measure could reduce the indoor humidity and reach a certain moisture-proof effect.…”