Whether the external window (including transparent curtain wall and lighting ceiling) is energy-saving, and whether its energy-saving affects the whole building, and how big is the impact? has no meaning? What is the proportion of windows, doors and curtain walls in the total construction cost? It may not be necessary for an ordinary consumer to understand it, but it is necessary for a worker in a building's doors and windows and curtain wall decoration industry to be clear about it.
At present, the total area of ​​existing buildings in urban and rural areas in China is approximately 40 billion square meters. During the use of these buildings, the energy consumed in heating, air-conditioning, ventilation, and lighting accounts for about 30% of the total energy consumption in the country. Large-scale public construction units The energy consumption of the building area is about 10 times that of ordinary residential buildings, and it can be called a big energy consumer. Each year, 300 million square meters of public buildings are newly built in the country. If energy is saved at about 50% per square meter of building area, 1 square meter of public buildings will save 30 kilograms of standard coal annually, and the annual energy saving will reach 9 million tons. At present, the total area of ​​public buildings in the country is about 4.5 billion square meters, of which the large commercial buildings, office buildings, and hotels using central air-conditioning are between 500 million and 600 million square meters. If it is reformed according to the standard of energy saving of 50%, the total energy saving potential is about 135 million tons of standard coal.
The gap between us and the developed countries in building energy efficiency is mainly not in materials, equipment, and construction technology, but in design and standards. In recent years, Beijing has opened more than 100 million square meters of construction area. If such a large-scale construction scale continues to implement the design standards with lower energy-saving standards, it will leave a heavy burden of energy consumption and governance difficulties.
The Design Standard for Energy Efficiency of Public Buildings is applicable to the energy-saving design of public buildings built, expanded and rebuilt. By improving the insulation and thermal insulation performance of building envelope structures, improving the energy efficiency ratio of heating, ventilation, air-conditioning equipment and systems, and taking measures to increase the efficiency of lighting equipment, under the same conditions of indoor thermal thermal comfort, and the 1980s The total energy consumption for heating, ventilation, air conditioning and lighting can be reduced by 50% compared to the public buildings originally designed and constructed.
Lang Siwei, one of the main drafters of the Standards and the deputy chief engineer of the China Academy of Building Research, said that in order to achieve the grand goals of China in 2020, we must ensure that GDP is quadrupled on the basis of 2000, and energy consumption must be increased. Control is within doubling levels. According to forecast, if the progress of building energy-saving works is poor, by 2020, the building energy consumption will reach 1.1 billion tons of standard coal, which is 3.1 times the current; if the building energy-saving work is progressing well, that is, the energy-saving design of residential buildings can be fully implemented. Standards: In 2005, energy-saving design standards for public buildings were implemented. Each year, the existing buildings were rebuilt in batches. After 2010, energy-saving standards of 65% and 75% were gradually implemented in various places so that the building energy consumption could be maintained at 750 million tons of standard coal. For the current 2.15 times, to ensure that building energy consumption growth is controlled at about one time. This shows the importance of the establishment and implementation of energy efficiency standards.
In addition, the establishment of standards is only a means. The ultimate goal is to strengthen supervision and strictly implement energy conservation standards so that the basic technical requirements for building energy conservation as stipulated in the standards are implemented. To this end, the relevant laws and administrative regulations of the country all have clear requirements. For example, the Energy Law stipulates: The design and construction of fixed assets investment engineering projects shall abide by reasonable energy use standards and energy conservation design specifications. For projects that fail to meet the requirements for reasonable energy use and energy saving design specifications, the examination and approval authority must not approve the construction according to law; after the completion of the project, if it fails to meet the standards for reasonable energy use and energy conservation design specifications, it will not be accepted. The Ministry of Construction has issued regulations such as the Regulations on the Administration of Energy Saving for Civil Buildings and the Regulations on the Supervision of Mandatory Standards for the Implementation of Construction Projects, and printed and issued documents such as the Notice on Strengthening the Examination of Building Energy Conservation in Civil Building Projects. However, since 1996, less than 20% of newly-built residential buildings have strictly implemented or met the requirements for energy-saving standards. To further strengthen the implementation and supervision of building energy efficiency standards, the task is arduous and urgent.
Second, curtain wall energy-saving materials selection
Among the existing existing buildings in our country, 95% of the buildings are of high energy-consuming buildings, of which 40% of energy consumption is lost through the doors and windows and lighting curtain walls, then reducing energy consumption and changing the high energy consumption status of our industry. The heavy responsibility falls on the employees of our industry. This problem has also received the attention of the government's functional departments. It also requires the entire society to raise awareness of architecture, windows, and curtain wall energy conservation, especially the owners, developers and consumers. We work together to raise awareness of energy conservation and implement the national policy of energy conservation and environmental protection to achieve the strategic goal of sustainable development.
The thermal insulation performance of the outer window (including the transparent curtain wall and the lighting roof) mainly depends on the thermal insulation performance of the glass used, the number of gap layers of the insulating glass, the distance, the gas in the spacer layer, and spacer bars such as warm edge technology. The radiant rate of the LOW-E insulating glass film layer has an effect on the heat insulating performance of the glass. The glass can be determined according to the standard for the heat transfer coefficient limits of different types of external windows (including the transparent curtain wall and the light collecting top).
The window frames of different materials have a great influence on the heat transfer coefficient of the external window (including transparent curtain wall and lighting roof) and can not be ignored. The heat transfer coefficient of the plastic window frame, wood window frame, etc. due to the material itself is small, and the heat transfer coefficient of the external window The impact is not significant. Aluminum alloy window frames, steel window frames and other materials have a large thermal conductivity. The thermal bridge formed has a great influence on the heat transfer coefficient of the external windows and must be treated with a broken bridge.
There are many kinds of aluminum alloy bridge handling practices, materials are also different, such as polyamide (PA) insulation strips, polyurethane (PU), etc., for the insulation performance requirements of the external window (including transparent curtain wall, lighting ceiling) should be selected Broken bridge effect of aluminum.
The proportion of the window frame area to the outer window is about 20-40% depending on the material of the window frame and the window type. Different window frame areas have different effects on the heat transfer coefficient of the window. The construction practice of transparent curtain wall also has different effects on the heat transfer coefficient. The influence of the glass curtain wall and the semi-hidden frame glass curtain wall is greater than that of the point-supported curtain wall and hidden frame curtain wall.
The shading coefficient of the outer window (including the transparent curtain wall and the lighting roof) can be selected according to the different shading coefficient of the glass itself and the external shading to meet the limit value. The shaded glass, heat-reflecting glass, and LOW-E insulating glass film layers of different color series have different shading coefficients and optical properties.
At this stage, the main measures to improve the energy conservation and insulation performance of transparent curtain walls are to use coated glass, LOW-E glass, heat-reflective glass, insulating glass and heat-insulating aluminum to reduce the structural heat transfer coefficient, eliminate the structural system 'thermal bridge', and reduce Air permeability heat loss, reduce the opening window area, improve the sealing and so on. The thermal insulation principle of the insulated bridge aluminum profile is based on the creation of a continuous insulation zone, using heat insulation strips to separate the aluminum alloy profile into two parts. Thermal barrier 'Cold Bridge' selection material for polyamide nylon 66, the thermal conductivity of 0. 3W / (m · K), far less than the thermal conductivity of aluminum alloy, while the mechanical properties and aluminum alloy equivalent.
At the end of the 1970s, thermal insulation aluminum profiles were introduced abroad, mainly for aluminum alloy doors and windows in the alpine region, and began to be used as a framed glass curtain wall in the cold regions in the late 1980s. At present, China has begun to use it in bright-insulated glass curtain walls, hidden frame heat-insulating glass curtain walls, and point-supporting heat-insulating glass curtain walls in buildings that require high thermal insulation performance.
In addition, it is worth mentioning that in the energy-saving heat-insulating curtain wall or door and window, if 6+12A+6 hollow glass is used at the same time, the heat transfer coefficient K value is about 3. 0W/(m2·K), and the heat transfer coefficient is better than the single-layer glass curtain wall. 1/2 lower, can greatly reduce energy consumption, therefore, in the case of relatively high insulation performance requirements, such as the use of gold glass 6 +12 A +6 hollow glass, then the heat transfer coefficient K value of 1. 7W / (m 2 · K ) Left and right, the heat transfer coefficient is lower than the single-layer glass curtain wall 4/5 hollow glass, if the hollow glass is filled with inert gas, its K value can also be reduced to a lower, its heat transfer coefficient K reaches 1. 5W / (m2 · K), energy saving effect is remarkable.
Building materials knowledge villa design windows and doors glass aluminum alloy heating heating glass door
High temperatures caster series , as a professional chinese caster manufacturer ,with rich R&D experience , which enable us to customize according to client's request , Size of thread stem , wheel material , type of brake , just let me know what you want , Rich Industrial Caster series , various from rigid wheel caster , Swivel Caster and Brake Caster , full size series make us become one-stop caster services center for you .
High Temperature Casters,High Temperature Phenolic Caster,High Temperature Rigid Casters,High Temperature Trolley Caster
Zhejiang Lingda Caster Co., Ltd , http://www.ldcaster.com