Steel Frame Glass Curtain Wall for Building Energy Saving

With the continuous promotion of the national strategy for energy conservation and emission reduction, building energy conservation, which accounts for 30% of the total energy consumption of the entire society, has received increasing attention from the society.

Building energy efficiency as a comprehensive system engineering, it involves the implementation of laws and regulations, the design of buildings, the selection of materials, the construction of nodes, processing and installation, and even the user's behavior. Only in every aspect ensure the correct plan and strict implementation, building energy efficiency is not just some bright concepts and selling points, but the real energy-saving buildings that can stand the test of practice.

The steel frame glass curtain wall is a special field in the glass curtain wall system. It is suitable for large-span, large-space building facades and lighting roofs. Since steel has lower thermal conductivity than aluminum alloy, a beautiful, energy-saving and environmentally friendly building façade can be achieved through the selection of profiles and the construction of nodes. In addition, the excellent fire resistance of the steel frame makes the energy-saving curtain wall safe and fire-proof at the same time, thus achieving the perfect unity of function and form.

In recent years, the use of glass curtain walls in buildings has become more and more widespread. As a component that displays the architectural image while at the same time taking on the external construction of the building, the energy conservation of glass curtain walls has often become the focus of attention. Technically speaking, the energy conservation of glass curtain walls is also a systematic project. In addition to the correct selection of the glass with the largest area in the curtain wall, proper support frame systems, fasteners, sealing strips, adhesives, and embedded parts are required. These related components form a complete system.

At present, the production and application of Chinese curtain walls have already taken the lead in the world. In practical projects, although there have been many excellent works, no curtain wall system that can be universally adopted domestically or internationally has yet been created. It is a common practice in China to design certain curtain wall nodes in a “tailor-made” approach for specific projects. They may be very distinctive, but due to various reasons such as duration and cost, these nodes are difficult to achieve. Compared with the long-term R&D and test system products in terms of performance and comprehensive indicators. They must not be simply copied, or difficult to popularize and promote, which has become a bottleneck on the road to energy conservation and development.

In general, a building that can be called energy-saving or low-carbon needs to have the following characteristics: consume less resources during design, production, and production; have good performance, such as strength, insulation, waterproof, and tightness; No pollution and damage; long service life; can be recycled and recycled.

Most of the glass curtain walls we have seen are aluminum curtain walls with supporting structures. The use of steel frames seems to be rare. In fact, in the curtain wall project, the use of steel frames has a long history in the world, and it is also the same in China, for example, in large-scale exhibitions, stations, airports and other public buildings. However, most of these buildings use I-beams, T-beams or U-beams, which together with the steel structure form a mechanical support system. This type of steel is basically a thermoformed steel, or "crude steel," and its forming mechanism determines that its appearance is more than adequate and fine enough, and the degree of fineness is far from that of common aluminum alloy profiles.

Today, the steel profiles commonly used in Europe are thin-walled steel coils, which are cold-formed and cold drawn and formed by high-frequency butt welding to form seamless steel tubes of high strength and accuracy. , And aluminum alloy profiles as exquisite and beautiful. Its profile structure can be welded (this is totally different from the domestic common color plate opening profile or bent steel plate), and it has a series of hardware and sealing accessories, including glass pressure plate and decorative cover plate. Form a complete curtain wall system. They have passed the most rigorous tests in Europe, and the thermal insulation and energy saving performance has reached a very high level. Steel profiles are beautiful and excellent in performance, not only thermal insulation and energy saving, but also very high safety performance. They are often used in the eye-catching parts of the outer walls of the podium building, entrance hall entrances, or cross-floor atrium space.

As a special category of glass curtain walls, steel frames have the following advantages over our common aluminum alloys:

The first is that the strength (ie, the modulus of elasticity) of steel is 3 times that of aluminum alloy. It is possible to accept larger glass weights with finer profiles, more glass on a larger scale, and more transparent building facades, especially in the transverse dimension of glass. The beam size is smaller. Within a certain span of space, some structural parts of the curtain wall can also be omitted. Second, the coefficient of thermal expansion of steel is only 58% of that of aluminum alloys. The deformation requirements of the joints between steel profiles and walls are lower, and the sealing performance is more easily ensured. Third, the thermal conductivity of steel is only 32% of aluminum. From the point of view of the material itself, the steel frame has a lower U-value (ie, Kjff), ie, better insulation performance.

There are many factors affecting the energy efficiency of curtain walls. In addition to the correct choice of insulating glass, such as lowE insulating glass, inert gas, and warm edge spacers, the frame system supporting the glass and the entire curtain wall is often the most difficult and most complex. Modeling is also the most abundant component.

Energy efficiency in buildings and building safety are often needed at the same time, especially in public buildings. For example, in areas with fire prevention, it is necessary to set up fireproof curtain walls or doors and windows, and according to the requirements of fire protection, put forward fire detection test reports and products with corresponding levels. Generally, it is difficult for the energy-saving curtain wall to meet the fire protection requirements at the same time (aluminum-framed curtain walls do not have a fire protection function), and it is difficult for a general fireproof curtain wall to meet the energy-saving construction requirements at the same time.

The steel frame curtain wall system, in keeping with its basic structure, that is, the thermal insulation performance is not changed, the common hardware components such as the sealant strips, the insulating nails, the glass pressure plate and the support blocks are skillfully made of fire-resistant components. The hollow fireproof glass achieves the perfect unity of energy saving and fire prevention without changing any appearance of the curtain wall.

By the same token, only partial adjustment of the hardware fittings, together with the corresponding glass, can make the curtain walls have the functions of anti-theft and **, and maintain the transparency and appearance of the facade. In the building façade, different positions often have different functions. The use of steel frame curtain walls can combine different functional materials and maintain a uniform appearance and complete performance, so that the energy-saving curtain wall can also satisfy many requirements. Functional requirements for use.

The development of the construction industry today is not only required to meet the most basic quantitative requirements, but also to meet the requirements of high performance and high quality. The use of a system solution is an effective way for energy saving and sustainable development of curtain wall doors and windows. Both aluminum alloy and steel frame systems are responsible for different functions and divisions of work in the field of curtain walls, complementing and interdependent. Reasonable choice of materials can achieve resource conservation and optimization, thus fulfilling a responsibility for achieving a low-carbon society.