Research on the Factors Influencing Broken-Bridge Aluminum Exterior Windows with the Goal of Thermal Performance Improvement

The enhancement of the thermal performance of transparent envelopes has been demonstrated to be an effective measure for reducing building energy consumption. To achieve enhanced performance in the domain of building windows, considerable economic investments are frequently necessary. The present study focuses on the 70 series of broken-bridge aluminum windows, which are widely used in China. The investigation explores the potential factors affecting the thermal performance of these windows, mainly considering their glass and profiles. The study also explores the influencing characteristics of various factors and their optimal combinations for their combined effect by comprehensively applying the single-variable method, orthogonal test method, and a numerical simulation. The findings of the study indicate a substantial reduction in the heat transfer coefficient of the 70 series of broken-bridge aluminum windows, achieving a decrease of 25.98%. Additionally, the heat transfer coefficient of the frame and edge is reduced by 29–35%, and the heat transfer coefficient of the entire window is reduced by 28.34%. These findings suggest that the energy-saving requirements for green and low-carbon buildings in most regions of China can be met. Furthermore, the product offers a significant economic advantage over similar market offerings with an equivalent performance. Concurrently, the performance enhancement measures derived from the study are applicable to other types of aluminum windows.