What Is a Curtain Wall?

The curtain wall is the outer wall of the building. It does not bear weight and hangs like curtains. Therefore, it is also called "curtain wall". It is a lightweight wall with decorative effects commonly used in modern large and high-rise buildings. A building envelope structure or decorative structure composed of a panel and a supporting structure system that has a certain displacement capacity relative to the main structure or has a certain ability to deform itself and does not bear the role of the main structure (the outer wall frame-type support system is also a curtain wall system Kind of).

With the rapid development of China's national economy and the continuous improvement of people's living standards, as well as the improvement of the architect's design concept of "humanity in architecture", buildings are becoming more and more high-rise, high-end, and multifunctional. Therefore, building curtain wall products will inevitably develop in the direction of high-tech and multi-function, in order to meet people's increasing awareness of environmental protection and energy saving, and to meet market demand for building curtain wall functions.

Double-layer curtain walls or ventilated curtain walls, which are relatively popular building envelopes, originated in North America and have been widely used in Europe. In terms of ventilation methods, it can be divided into two major systems: internal ventilation and external ventilation. The outer layer of the internal ventilation double-layer curtain wall is a closed structure. Ventilation is performed in the two-layer space of the curtain wall. Usually, the cooperation of a centralized forced ventilation system is required to exchange with the natural world to achieve the final effect. Internal ventilation double-layer curtain wall system is widely used in Italy; external ventilation relies on the outside air of the building to rationally organize airflow through the air inlets and outlets of the double-layer curtain wall, and directly exchange with nature to achieve the final effect. Externally ventilated double-layer curtain walls are widely used in Germany and Britain. ^[1]

The ventilation height of the curtain wall may be the height of a single floor, multiple floors or even the entire building, or some combination of the above. The most common is the single-story height structure. The single-story double-deck curtain wall has the advantages of separate fire, smoke, odor and noise between floors, and it is easy to achieve standardized design and production of curtain wall units.

In temperate climates such as continental Europe and the United Kingdom, the construction industry has a wide range of applications for double curtain walls. Architectural experts believe that double curtain walls can reduce the cooling load, facilitate good natural ventilation, facilitate lighting, control noise, and reduce thermal energy consumption.

Generally speaking, the cost of a double-layer curtain wall is much higher than that of an ordinary curtain wall. Therefore, a new curtain wall structure needs to be explored so that it has both the advantages of the double-layer curtain wall and the economy of the ordinary curtain wall.

This article introduces a kind of building curtain wall structure that has been applied abroad for the reference of curtain wall designers.

2. Structure of economic double-layer ventilation curtain wall

The economic double-layer ventilation curtain wall adopts the structural form of an integral unit system, and the space between the inner and outer curtain wall panels is 155mm. The entire system structure is light, simple, and economical. The curtain wall frame is made of aluminum alloy keel, which is processed, manufactured and assembled in the factory; the surface material is made of insulating glass, single-layer glass and lined insulation decorative board; the waterproof and sealing tape (pad) is made of EPDM or silicone, and aluminum The hardware accessories of the alloy contact parts are made of stainless steel. Then it is transported to the site and hung directly on the main structure of the building.

Glass curtain wall refers to a building envelope or decorative structure composed of a supporting structure system and glass, which has a certain displacement capacity relative to the main structure and does not share the role of the main structure. There are single and double glazed walls. Reflective insulating glass is 6mm thick and the wall weight is about 40kg / . It has the advantages of light weight, beautiful appearance, not easy pollution, energy saving, etc. The inner side of the outer glass of the curtain wall is coated with a colored metal coating. From the appearance, the entire outer wall is like a mirror, reflecting the scenery of the sky and the surrounding environment. When the light changes, the image is colorful and infinitely variable. Under the reflection of light, the room is not illuminated by strong light, and the vision is soft. China first adopted it in Beijing Great Wall Hotel Project in 1983.

Everyone who has been to New York City in the United States will be impressed by its bustling urban style. The soaring skyscrapers are spectacular, and the whole glass curtain wall reflects the clear blue sky and dancing white clouds, which adds even more. Brilliant colors. So, how is a glass curtain wall made? Glass curtain wall refers to the mirror glass used as the exterior wall decoration of the building. It is made by adding a small amount of Fe, Ni, Co, Se, etc. to the float glass composition, and is tempered to make a color transparent plate glass. The solar radiation entering the room reduces the room temperature. It can both reflect light like a mirror and transmit light like glass.

The glass curtain wall of modern high-rise buildings also uses hollow glass composed of mirror glass and ordinary glass, and the compartment is filled with dry air. Insulating glass is divided into two layers and three layers. The two-layer insulating glass consists of two layers of glass and a sealing frame to form a sandwich space. The three-layer glass is composed of three layers of glass. Insulating glass has the advantages of sound insulation, heat insulation, frost resistance, moisture resistance, and high wind pressure resistance. According to measurements, when the outdoor temperature is -10 ° C, the temperature in front of a single-layer glass window is -2 ° C, while the indoor temperature using three-layer insulating glass is 13 ° C. In summer, double-layer insulating glass can block 90% of solar radiation heat. Sunlight can still pass through the glass curtain wall, but it won't feel hot when you lay it on. A room using a hollow glass curtain wall can be warm in winter and cool in summer, which greatly improves the living environment. Intermediate PC sunlight glass-PC board, high temperature resistance up to 135 degrees, low temperature -45 degrees.