Tianheng Building is an all-vacuum glass curtain wall building. It was put into use in 2005 and has been 17 years so far. Recently, the leaders of Xinliji Company led a team to conduct a return visit to the building's property management and users to understand the actual application of vacuum glass curtain walls and exterior windows.
Tianheng Building is located in the Dongzhimen business district of Beijing, covering an area of 3,693 square meters. The total construction area is 42,925 square meters. There are 4 underground floors and 22 above-ground floors. The main functions on the ground are business offices and supporting commercial facilities. The facade of the project uses all vacuum glass, including glass curtain walls and ordinary exterior windows. The total area is about 8,000 square meters, of which the curtain wall area is about 5,500 square meters.

Tianheng Building

The vacuum glass structure used in Tianheng Building is a vacuum composite double-insulated structure, namely 6T+12A+5L+V+5N+12A+6T. The heat transfer coefficient K value of the composite vacuum glass is 1.0W/(m²·K). Compared with the insulating glass commonly used at that time (6T+12A+6T structure, K value 3.0 W/(m²·K)), the thermal insulation performance is increased by more than three times.

As the developer of Tianheng Building, Beijing Wanheng Real Estate Development Co., Ltd. highly recognizes the application of vacuum glass in its project. As early as at the awarding ceremony for the first batch of vacuum glass production enterprises in 2018, Wang Yun, the general manager of Wanheng Real Estate, shared with the guests present the application of vacuum glass in energy-saving buildings. Taking the office building project of Beijing Tianheng Building as an example, she introduced the application of vacuum glass curtain walls in this project for more than ten years. Especially in terms of thermal insulation, sound insulation, and anti-frosting, the curtain walls and exterior windows of Tianheng Building show extremely excellent performance. According to the calculation results based on the property management data of this building, the use of vacuum glass can save about 50% of air conditioning energy. (For more details, scan the QR code below. See the birth of the first batch of vacuum glass production enterprises in China in Beijing_Sohu Auto_Sohu.com).

During this return visit, Mr. Zhang, the chief of the property engineering department of Tianheng Building, introduced the usage of the building to Xinliji Company. According to him, since 2012, the electricity consumption for heating and cooling in the building every year has been very stable. No users have reported that the temperature is low in winter and heating needs to be strengthened, or that the temperature is high in summer and cooling needs to be strengthened. This shows that the vacuum glass has good thermal insulation performance and its performance has been stable and consistent for more than ten years. Secondly, the glass has outstanding sound insulation performance. Although it is located in the bustling Dongzhimen Bridge area, no customers have reported noise problems.

The vacuum glass on Tianheng Building.

According to the feedback from users of Tianheng Building, the indoor environment of this building is warm in winter and cool in summer, and the office environment is quiet and comfortable. The owner of a hot pot restaurant in the commercial area reported that even when the outdoor temperature is more than ten degrees below zero in winter, the indoor is steaming hot, and there is no condensation or frosting on the curtain wall and exterior window glass. One can clearly overlook the scenery outside the window.

The application of glass curtain walls in buildings began in 1910. The modern architecture master Gropius designed the Fagus Factory and introduced glass curtain walls into buildings for the first time, thus unveiling the prelude to the application of architectural glass curtain walls. After World War II, glass curtain walls were introduced into high-rise buildings, greatly enriching the building's appearance and image, producing a concise and modern visual effect, and then rapidly developed worldwide. However, since the energy crisis and environmental problems in the 1970s, people have paid special attention to the energy consumption problem of glass curtain walls. With the development of coated glass, the use of Low-E glass, insulating glass, and vacuum glass has greatly promoted the improvement of the energy-saving effect of curtain walls.

The theoretical service life of vacuum glass is 50 years, and the guaranteed service life is about 25-30 years. Considering the contribution value of glass curtain walls in enhancing the building's appearance effect and the high investment and construction cost, applying vacuum glass with a longer service life and better energy-saving effect to building curtain walls is the best choice to reduce the investment cost of buildings throughout their life cycle.

Compared with exterior windows, glass curtain walls have higher requirements for various performances of vacuum glass. Tianheng Building was completed in 2005. Due to technical limitations at that time, the heat transfer coefficient K value of vacuum glass was still relatively high. After more than ten years of continuous exploration by Xinliji Company, continuously breaking through the limits of raw materials, equipment, and processes. At present, for the composite vacuum glass of the same structure 6T+12A+5TL+V+5T+12A+6T, the theoretically calculated K value can be as low as 0.36W/(m²·K). The thermal insulation performance has been further improved compared to before, and the sound insulation performance and service life have also been further enhanced.

On the basis of continuously improving the performance of vacuum glass, Xinliji Company will continuously conduct return visits on the application of vacuum glass in buildings, and help buildings achieve higher energy-saving standards with more abundant product application practices, brightening up a sustainable and beautiful life!