Thermal Insulation Performance of Metal-exterior Curtain Wall Panel Systems with Thermal Bridges in Winter

To reduce energy consumption in buildings, it is essential to enhance the thermal insulation performance of building envelopes. For metal-exterior curtain wall panel systems, thermal insulation performance cannot be ensured because of the additional heat loss through thermal bridges, such as joints between panels, metal screws, and brackets. This study examined thermally improved metal-exterior curtain wall panel systems with bracket fixings. The thermal insulation performance of a conventional panel and three alternatives were evaluated by conducting three-dimensional transient heat transfer simulations during winter. The results showed that the total heat loss from the Base, alternative 1 (Alt1), alternative 2 (Alt2), and alternative 3 (Alt3) systems were 120.4, 62.0, 34.2, and 20.3 MJ per unit wall area, respectively. Alt3 reduced the heat loss by 83.2% compared with the Base. Alt3 had a thermally insulated bracket with Azon and a modified aluminum mold with joints between the panels for reducing thermal bridges.