Glass curtain wall building lighting and energy-saving shade

Glass curtain wall building lighting and energy-saving shade Glass curtain wall building lighting and energy-saving shade 1. Foreword The 20th century, the world of science and technology building by leaps and bounds, developed the structure of building envelope thermal insulation performance and the enormous increase in air tightness, heating, air conditioning and sun protection equipment and technology advances more and more people can be more gracious and comfortable the indoor environment to live and work. From the classic architectural treasures to the rough vernacular architecture, architectural shading invariably be given adequate attention, and reflected in different ways. 1 Construction of the main energy of the most important aspect of an effective monomer building design include insulation (windows, walls, roofs), shade, ventilation. Rational design of buildings can shade air-conditioning systems to reduce energy consumption of about 16% ~ 29%. 2. Glass curtain wall of energy-saving shade 2.1 The need for glass curtain wall shade 70 years after the energy crisis, development of different systems to enhance the thermal properties of glass curtain wall. Curtain walls of public buildings, the dominant external retaining structure is a building heat exchange, heat conduction of the most active and most sensitive parts, loss of traditional wall heat loss of the 5 ~ 6 times, its energy consumption, the whole building energy consumption 2 accounts for about 40 % or so, so energy-efficient glass curtain wall has an extremely important position. In China, as the market economic development, building energy efficiency in China’s economic and social sustainable development of the urgent need, the construction units and design units, increasing awareness of energy saving, energy-efficient glass curtain wall requirements continue to increase. Although the glass curtain wall building is shading measures can achieve the desired energy-saving insulation effect, but at home, at this stage that it received inadequate attention. A poorly designed all-glass curtain wall of buildings, year-round air-conditioning power consumption may be a general concrete wall building four times. The glass curtain wall over the service life of fifty years, its energy-saving effect is far more than short-lived air-conditioners, refrigerators, boilers and so on. Therefore, energy-efficient glass curtain wall building energy-efficient than other building products is more important to the development of glass curtain wall technology in the construction of the sun the most potential 3 energy saving tools. 2.2 The shade of the glass curtain wall Building the external energy-saving design of retaining structures, from windows, orientation, shading, and insulation materials, factors such as interlocking, these factors affect the energy consumption of buildings. Siraya Research in Taiwan Taiwan’s office buildings had external retaining structure study on the construction of retaining structures outside of the energy consumption of the various elements of the analysis, the results are as follows: From the above table it can be concluded: ? the external walls of the external walls of windows rate is the most important factor in energy conservation, reducing window area ratio is the most important means of 4 energy-saving, but the windows reduced rate and take into account the need to ensure adequate natural lighting, and the removal of a sense of psychological closure. However, the pursuit of transparent glass curtain wall in terms of effectiveness can only be used to reduce open window area and strengthen the non-translucent thermal insulation designed to meet local energy requirements. ? outer shade and glass wall shelter is the second most important factor in energy-saving, glass materials and outside the sun all affect the rate of the size of the shelter, but the installation of sun visor, sun shade than the 100 loaded with the effect of large changes in glass. Choose highly reflective glass reflective glass and heat-absorbing glass (reflectance of the reflective glass would cause too much glare pollution, pollution), so to choose the appropriate reflective glass. ? building orientation factor is the outer wall of the third 5 element of energy-saving design (13.8% weighting). Large areas of glass curtain wall should be avoided according to Xishai East, building a long north-south to the place to be North Korea. Measure is not only a sun-glass curtain wall building energy-saving design of the necessary means, but also a high standard of architectural glass curtain wall design in building the necessary means. 2.3 The role and effect of sun As the glass curtain wall of glass and metal composition, while the glass surface heat transfer is strong, the high rate of heat transmission, so the indoor thermal conditions have a great impact. In the summer, the sun through the glass injection room, the main cause of indoor overheating. 6 Particularly hot area in the south, if the body no longer be out of direct sunlight, it will feel hot and uncomfortable. Sun set in the glass curtain wall system that can minimize the sun’s rays, so as to avoid overheating indoors, is the construction by the hot heat of the main measures. After the setting sun, there will be the role and effects of the following: 2.3.1 The role of shading on solar radiation Retaining the structure of the external thermal insulation performance is affected by many factors, including the most influential indicator is the shading coefficient. In general, the shading coefficient characteristics and the environment by the material itself control. Shading coefficient is a measure of the envelope through a sun shade structures and there is no envelope measures the ratio of solar radiation heat. Shading coefficient of smaller, through the external heat retaining structures smaller solar radiation, thermal effects as possible. Thus, shade on the block the effect of solar radiation heat is quite large, glass curtain wall building measures to set the sun 7 is even more evident result. 2.3.2 shading effect on the indoor temperature Shade to prevent the rise in indoor temperature plays a significant role, in the summer and hot area test observations showed that in the case of closed windows, with or without shade, at room temperature a larger difference. And there is sun, the room temperature amplitude value is smaller, the maximum time delay occurs at room temperature, indoor temperature field uniformity. Therefore, the shade of the air-conditioned room can reduce the cooling load, so air-conditioned buildings, the sun is one of the main measures to save energy. 2.3.3 The role of shade on the light 8 From the point of view of natural light, shading measures would block direct sunlight to prevent glare, so that more uniform distribution of indoor illumination will help visual work. On the surrounding environment, the sun can be scattered glass curtain wall of glass (especially coated glass) of reflected light, avoiding the large glass reflector caused by light pollution. However, due to the role of shading measures are blocking light and thus reduce the indoor illumination, in the overcast and rainy days more disadvantageous position. Therefore, when the shading system design should be fully taken into account to satisfy the requirements of indoor natural light. Side lighting may lead to the brightness of the room is too high, and sometimes cause glare. Choose what form of glass need to take into account two aspects of lighting and energy saving requirements. Awning can be used both energy efficiency and natural lighting. Reposted elsewhere in the paper for free download 2.3.4 The role of shading on the building exterior 9 Is generally believed that flat-based glass-curtain wall design only, not design things such as sun shading facilities, but in many cases from abroad can be found in metallic glass curtain wall with lightweight sheet metal can be designed to form and become a beautiful shade of an interesting architectural form copies. Shading system in the appearance of the glass curtain wall formed on the glass wall light and shadow effects, reflect the modern architectural aesthetic effect. Thus, in the European construction industry, has the external shading system as an active facade elements be used, and even called the double-facade form. Layer is the elevation of the building itself, another level is a state of dynamic shading facade form. This has a “dynamic” of the building because the building facade is not the image of the fashion needs, but the construction of modern technology to solve mankind’s energy needs and to enjoy the natural arising of a new modern architectural form. 10 2.3.5 the impact of shading on the room ventilation Sun room ventilation facilities on the role of a certain block, in the case of open windows for ventilation, indoor wind speed will be reduced 22% -47%, depending on the construction of shade facilities, the case may be; pairs of glass rising hot air are blocking effect conducive to heat, in the shade of the structural design should be noted. 2.4 The form and structural design of shading Shade of preventing solar radiation, to avoid glare, improve the indoor environment, climate, and building exterior lighting aesthetic effects on the function, but also for indoor lighting, ventilation and bring different levels of impact. Shading system itself, according to the location is divided into external shading and internal shading, which can be divided into movable and fixed-style sun shade. The form of points on the 11 sun, generally divided into four categories: the level of shading, vertical shade, integrated style shade, and baffle type. The area’s climatic characteristics and the use of the room requirements, can shade as a permanent or temporary. In the glass curtain wall is a permanent set inside and outside the various forms of sun visor and window shades, temporary is the light in glass is set inside and outside the curtain, bamboo, soft 100, canvas-pont, etc.. In permanent shade facilities, their components can engage in activities, can be divided into two kinds of fixed or movable. Movable shading visual transformation of the year in the season, one day the situation changes and the sky Yinqing arbitrarily adjust the angle of sun visor; in the cold season, to avoid blocking the sun, fight for sunlight. In addition to the effect of sun shade on the form, but also with the structural design of a great relationship, the design 12 should pay special attention to the following points: 2.4.1 a combination of sun and tectonic plate surface A straight line to meet the block under the premise of the sun, you can have different forms of combination of plate surface should be chosen to ventilation, lighting, vision, structure and facade treatment require more favorable form. In order to dissipation in the hot air and reduce ventilation and lighting effects, often made of the plate surface, or part of the 100 made 100, or middle layer made of 100. Sun visor can be aluminum, light metal or Concrete system to do. 2.4.2 sun visor of the installation location Figure 3, the flexibility of shade facilities in large, the use of reasonable, so outside the building in recent years the 13 application of wider. The location of the sun visor to install heat and ventilation, have a great impact. For example, the board layout is close to the wall, the heating surface heating and the rising hot air will be subject to import the role of outdoor air-room. This situation is multi-purpose shade more serious, in order to overcome this shortcoming, board should leave a certain distance from the glass wall installed to make the most of the hot air along the wall to drain away, and should enable the sun visor to minimize the block the wind, the best and also played lead role in wind burglary. 2.4.3 Materials and Color In order to reduce weight and shade structures to adopt the quality of light is appropriate. Structures are constantly 14 exposed to outdoor sun by sun and rain, easy to damage, and therefore strong durable material. If the sun room movable, and also requested the light and flexible in order to adjust or remove. Materials, the appearance of the face of solar radiation absorption coefficient of heat should be small, designed in accordance with the above requirements and the actual situation and to select the appropriate shade material. Shade of the color components also have an impact on the insulation effect. To install inside the venetian blinds in the glass curtain wall, for example, dark, intermediate color and white shading coefficient are as follows: 86%, 74% and 62%. White than dark to reduce 24%. In order to enhance the surface reflection, reduce the absorption, sunshade side towards the sun, should be light-colored bright colors, and in the back side of the sun, should be darker dull color, so as to avoid glare. 15 2.4.4 external shading and internal shading In general, outdoor south elevation of the level of 45 ? sun visor that can easily obscure the 68% of the solar radiation heat. Mounted inside the window curtains, soft shade 100 and other facilities, they absorb solar radiant heat, most of the distribution to the indoor air. Mounted on the outside of the sun visor and absorption of radiant heat, most distributed to outdoor air, thereby reducing the impact of indoor temperature. Therefore, use of external shading (sun visor) is the best way of building energy efficiency. 3. Sunshade Systems Intelligent Design Intelligent shading system, the many advantages of being ignored, or simply as the building’s decoration only. We believe that the intelligent shading system is an integral part of building intelligent systems. Shading system to improve the 16 indoor environment all year round, and now a new type of smart glass curtain wall technology has in Germany, Britain and other western European countries to develop. Widely defined to include intelligent glass curtain wall glass curtain walls, ventilation systems, air-conditioning system environment detection systems, building automation systems. Its technical core is different from the traditional walls of a special curtain wall - hot-aisle wall, and its most prominent feature is formed between the inside and outside the two walls of a ventilation layer, because of this layer of air flow ventilation or circulation of the role, so that the inner wall temperature close to room temperature, thus reducing the temperature of the wall than the traditional energy-saving heating, when 42% -52%, cooling time 38% -60% energy saving. in the air cavity to increase light-control devices ( such as the thermometer, light reflector, heat reflector panels, etc.), can simultaneously satisfy the construction of natural ventilation, natural lighting requirements. In addition, as the use of double walls, the entire curtain wall of noise effect has 17 been greatly improved. 4. Conclusion Shading system, a reasonable construction of the glass curtain wall art and technology, the role and effectiveness, particularly in building energy-saving and intelligent context, all we need to continually to develop and research. Architectural shading technology, domestic and foreign research; right shade structure fitness programs; right shading coefficient of performance of constructed; right shading system for energy-saving software development; right shade structure will be our artistic evaluation of future focus. Architectural shading should not be just one set of physical basis, as long as the rational integration of technology and art, they can become with the expressive elements of the building 18 facade into the building skin can breathe better play its role to achieve the construction energy-saving. Reposted elsewhere in the paper for free download 19