An experimental investigation on the indoor hygrothermal environment of a reinforced-EPS based temporary housing solution

Abstract

In a post-disaster scenario, temporary lightweight housing solutions are generally used for quickly providing disaster victims with a temporary living place. Developed for limited periods of occupation and typically built shortly with lightweight technologies, people can end up living in these buildings, especially in low-income countries, for years or even decades. Considering a possible long-occupation period, it is necessary to improve the ability of these building to grant adequate comfort even considering their temporary character. Nevertheless, few studies in the literature are focused on the indoor thermal comfort environment of these buildings. This paper shows some results of a study addressed to analyze and improve the indoor hygrothermal behavior of a novel, modular and lightweight temporary housing solution, named HOMEDONE, based on the assembly of 3D-reinforced EPS panels. After a preliminary characterization of the system in terms of in situ thermal transmittance and airtightness performance, useful to provide a reference for the numerical simulations, the indoor hygrothermal behavior of an experimental unit is monitored during the spring and the summer season. Then, hygrothermal simulations are carried out to verify the occurrence of the experimentally observed moisture-related issues in different climatic contexts and to evaluate the effectiveness of possible improvement solutions. The results showed a low in situ thermal transmittance and good airtightness performance of the HOMEDONE construction system. However, the experimental measurements revealed that, at closed opening condition, indoor air temperature and relative humidity can be very high and unacceptable during the cooling season, due to the low thermal storage capacity and the low moisture buffering/water absorption capacity of the building components. The simulations demonstrate that an internal finishing layer with adequate moisture buffering capacity can significantly reduce RH levels, preventing condensation issues and mold growth. Nevertheless, the use of the HOMEDONE unit for long periods of occupation is discouraged, especially in hot climates, unless appropriate measures to reduce the indoor overheating and to improve thermal comfort are adopted.