Comparison of Insulation Performance between Single Panel and Sandwich Panel Exterior Walls in Precast Concrete Apartment Buildings with Load-bearing Wall Structures and Frame Structures

The purpose of this study was to compare and evaluate the insulation performance of the precast concrete sandwich panels and single panels at the exterior wall-floor joints of PC apartment buildings. The energy performance and the risk of condensation were asssessed by applying single panels and sandwich panels to load-bearing wall structures and frame wall structures, respectively. For this purpose, a three-dimensional steady-state heat transfer simulation was conducted. The results showed that for the load-bearing wall structure, the effective U-factor of the exterior wall decreased by 33.2 % when the sandwich panel was applied, demonstrating a significant improvement in energy performance. Conversely, for the frame structure, the effective U-factor of the exterior wall increased by 47.7 % when the sandwich panel was applied, indicating that it was not effective in enhancing energy performance. Furthermore, in all cases, The effective U-factor was higher than the design U-factor, suggesting significant heat loss due to thermal bridges at the exterior wall-floor joint.