The thermal break structure of aluminum curtain walls significantly optimizes the thermal conductivity of the curtain wall system by embedding low thermal conductivity insulation materials into the aluminum alloy profiles, creating a "cold-heat bridge" blocking mechanism. The core of this structure lies in dividing the originally continuous metal profile into inner and outer parts, connected by a thermal break strip with a much lower thermal conductivity than the metal, thus drastically reducing the efficiency of heat conduction through the profile. Traditional aluminum alloy profiles, due to the high thermal conductivity of the metal, are prone to forming thermal bridges when there is a large temperature difference between indoors and outdoors, leading to rapid heat loss or intrusion. The thermal break structure, through the intervention of materials science, achieves a qualitative improvement in thermal performance while maintaining the strength and aesthetics of the aluminum alloy.
The choice of material for the thermal break strip is crucial for optimizing the thermal conductivity. Currently, the mainstream thermal break strip uses polyamide 66 (PA66) reinforced glass fiber (GF25) composite material, whose thermal conductivity is only about one percent of that of aluminum alloy. This material not only possesses a coefficient of linear expansion similar to aluminum alloys, ensuring synchronized expansion and contraction with the profiles during temperature changes and preventing loosening or cracking due to thermal expansion and contraction, but also enhances tensile strength through the reinforcement of glass fibers, enabling it to withstand wind pressure, self-weight, and other loads on the curtain wall system. The internal structural design of the thermal break strip is equally important; the multi-chamber structure increases the complexity of the heat conduction path, further hindering heat transfer and forming multiple thermal barriers.
The optimization effect of the thermal break structure on the thermal conductivity of the aluminum curtain wall is reflected in a significant reduction in the overall heat transfer coefficient (K-value). The K-value is a core indicator for measuring the comprehensive thermal insulation performance of a curtain wall system; the lower the value, the better the insulation effect. Traditional non-thermal break aluminum curtain walls typically have high K-values, making it difficult to meet modern building energy efficiency standards; however, with the use of a thermal break structure, the K-value can be significantly reduced. This optimization effect is attributed to the heat conduction blocking effect of the thermal break strip, as well as the synergistic effect of supporting components such as insulated glass and sealing strips. Insulating glass, with its low-emissivity (Low-E) coating and inert gas filling, further reduces radiative and convective heat transfer. The sealing strips, with their high elasticity and aging resistance, ensure the airtightness and watertightness of the curtain wall, reducing heat loss due to air infiltration.
From an application perspective, thermally broken aluminum curtain walls significantly reduce heat loss through the curtain wall in winter, lowering heating energy consumption. In summer, they effectively block the transfer of high outdoor temperatures to the interior, reducing air conditioning load. This dual energy-saving characteristic makes them advantageous in both cold and hot regions. Furthermore, the thermally broken structure improves the surface temperature distribution of the curtain wall, preventing condensation caused by excessively low profile temperatures, thus enhancing indoor comfort and curtain wall durability.
The energy-saving contribution of thermally broken aluminum curtain walls is also reflected in the reduction of overall building energy consumption. Research indicates that heat loss through doors, windows, and curtain walls accounts for over 50% of building energy consumption, and the application of thermal break technology can significantly reduce this proportion. In the fields of green building and ultra-low energy building, thermal break aluminum curtain walls have become standard, helping buildings achieve higher energy efficiency standards by optimizing thermal conductivity and driving the industry towards low-carbon and sustainable development.
The thermal break structure also provides more possibilities for aluminum curtain wall design. By adjusting the width, shape, and material of the thermal break strips, curtain wall systems with different performance characteristics can be customized to meet diverse building needs. For example, in extreme climatic conditions, wider thermal break strips or high-performance composite insulation materials can be used to further improve insulation performance; in scenarios where aesthetic design is important, the thermal break strips can be coordinated with the profile color and surface treatment process to achieve a unity of function and aesthetics.
Through material innovation and structural optimization, the thermal break structure of aluminum curtain walls has achieved a significant improvement in the thermal conductivity coefficient. This not only enhances the thermal insulation performance and energy-saving effect of the curtain wall, but also expands its application potential in green buildings, becoming an important direction for the upgrading of modern building envelopes.
