Experimental Analysis of the Thermal Performance of a Green Remodeling Window System Using Suspended-film Multi-Cavity Glazing

Multilayer glazing is widely applied to improve the thermal performance of windows.However, its application to existing buildings is hampered by practical issues such as increased weight.To address these problems, this study established a green remodeling (GR) window system leveraging film-inserted triple glazing and experimentally evaluated its applicability.First, to examine whether the insulation performance of existing double glazing could be improved to the current standard, the thermal transmittance of the GR window system was analyzed using WINDOW 7.8.The simulation results indicated that the U-value decreased from 2.36 W/m 2 •K for the double-glazing system to 1.60 W/m 2 •K for the GR window system.The ECO2-OD program was used to determine the decrease in the energy demand of an existing building after applying the GR window system.The annual heating energy demand was reduced by 13% compared with that of a building featuring conventional double-glazed windows.For the fullscale experiment, two laboratories were constructed under identical conditions, one equipped with conventional double-glazed windows and the other featuring the GR window system.Heating was performed for 8 h under identical conditions using heaters, and measurements were recorded over three days using surface temperature sensors and energy-consumption loggers.The interior glass surface temperature of the GR window system was, on average, 2.32 K higher than that of the double-glazing system, while the exterior surface temperature was 1.6 K lower.Compared with the conventional double-glazing system, the laboratory with the GR window system exhibited an average reduction of approximately 11.05% in the heating energy consumption.