Experiments on the cooling effect of modular vertical greening on double-glazed façade in summer

Abstract

Double-glazed façades (DGFs) increase the indoor temperature and energy consumption in summer. Vertical greening systems have significant cooling effects, but most are used on exterior walls. This study combines DGF and modular vertical greening to propose a double-glazed green façade (DGGF) and investigates its thermal performance. Based on the construction of a DGGF model, comparative experiments were conducted in two identical experimental rooms. The DGGF could reduce the indoor temperature by 4.9 °C or 2.9 °C compared to the DGF or the DGF with louver shading, which saved 12% of the cooling energy consumption. Ventilation inside the double glazing enhances the cooling effect of the DGGF, and the indoor temperature can be reduced by 2.3 °C compared to the DGGF with no ventilation. Plant activities play an important role in maintaining the thermal microclimate inside the DGGF, e.g., photosynthesis absorbs solar radiation, and evapotranspiration transfers sensible heat to latent heat. The cooling mechanism of the DGGF was analyzed, and its heat exchange process was explored. This paper verifies the feasibility of applying modular vertical greening in DGFs and proves that DGGFs have a better insulation effect than DGFs with or without louvers.