Thermal and Energy Performance of Double Skin Facades in Different Climate Types

This paper explores thermal and energy performance of double skin facades (DSFs) in different climate types, specifically focusing on three typologies: box window, corridor type and multistory DSFs. These systems were investigated and analyzed to answer the question of how the different DSFs perform in comparison to each other, as well as a typical curtain wall (single skin facade used as a baseline), in a multitude of climate applications. The utilized research methods included two-dimensional heat transfer analysis (finite element analysis), Computational Fluid Dynamics (CFD) analysis and energy modeling. Heat transfer analysis was used to determine heat transfer coefficients (U-values) of all analyzed facade types, as well as temperature gradients through the facades for four exterior environmental conditions (exterior temperatures of 32°C, 16°C, -1°C and -18°C). Results indicate that there is little variation in thermal performance of the different DSF types, but that all DSF facades would have significantly improved thermal performance compared to the baseline single skin facade. Then, CFD analysis investigated three dimensional heat flow, airflow and air velocity within air cavity of DSFs. Results indicate that the differences between the three types of DSFs influence airflow in the air cavity. Lastly, energy modeling was conducted for south-oriented office space, which would be enclosed by the analyzed facade types. Individual energy models were developed for each facade type and for 15 different climates, representing various climate zones and subzones. The results were analyzed to compare energy performance of DSFs and baseline single skin facade, as well performance of DSFs in various climate types. The results indicate significant differences between the DSFs and single skin facade, but less variations between the different typologies of investigated DSFs. Moreover, the results show what would be the effect of DSFs in different climate types on energy performance, heating and cooling loads.