Super-insulated wooden envelopes in Mediterranean climate: Summer overheating, thermal comfort optimization, environmental impact on an Italian case study

Abstract

The aim of the study is to verify the actual performance of a super-insulated wooden envelope in a residential building located in a hot dry summer temperate climate and to optimize its thermal behavior favoring a dynamic interaction with the indoor environment.The method involved an integrated strategy between monitoring and calibrated simulations on experimental data and the simultaneous analysis of several aspects such as energy performance (EnergyPlus software), comfort (dynamic analysis with Fanger’s PMV comfort model) and environmental-economic sustainability (LCA analysis with SimaPro software). Parametric analyses were carried out to generalize the results to various usage patterns of plants and passive cooling techniques and to several climate zones.The study highlighted the presence of overheating phenomena and demonstrated that this problem can be solved or reduced through the adoption of appropriate passive strategies, such as massive inner linings combined with natural or hybrid ventilation.Appropriate values of internal areal heat capacity and decrement factor will configure comfortable and energy efficient solutions.In temperate climates the optimal solution, namely the adoption of a 12cm thick solid brick (or double dry clay panel) and natural ventilation, reduces the discomfort levels of 30–50%. In hottest periods of extreme climates the best solution, namely CMV+free-cooling combined with internal lightweight plaster, only slightly reduces the overheating with a 6% reduction of discomfort.