Application Research of LED in Building Landscape Lighting
At present, LED has been popularized in the field of urban night lighting in China. LEDs are widely used in night lighting in almost all major cities in the country. In particular, China takes the 2008 Beijing Olympic Games and the 2010 Shanghai World Expo as an opportunity to promote the application of semiconductors in urban landscape lighting. This will definitely further promote the wider use of LED in the urban lighting field in China. However, we should see that quite a few cities do not understand the characteristics of LEDs in night lighting, and there are many misunderstandings in the design, construction and maintenance management of night lighting, resulting in poor LED lighting effect in urban night lighting, and the evaluation is not high. In particular, there have been some abuses of LEDs, which have caused the city's night scenes to feel damaged and negatively affected. This has led some people to doubt the use of LEDs in urban night lighting, which has affected the reputation of LEDs in urban night lighting. If not resolved in time, Will definitely affect the healthy development of China's LED industry chain.
1 Building landscape lighting requirements
Buildings are the most important elements of the city, such as residential, commercial, school, hospital, office, sports, theaters, exhibition buildings and some industrial buildings. These buildings mainly have traditional Chinese and Western styles, modern styles and national characteristics. Style buildings, etc., landscape lighting should understand the architectural characteristics of the object to be photographed.
For building lighting, the requirements of the â€œUrban Landscape Lighting Design Specificationâ€ just issued by the state are: (1) The light projection direction, the position of the cloth, the viewing direction, the material to be photographed, etc. should be fully considered to achieve aesthetic, safety and comfort. effect. (2) The color should be used scientifically and reasonably according to the color of the surface of the building. When using colored light, attention should be paid to the coordination of the surname Zhu, the surface color and the surrounding environment. The principles to be followed when selecting the lighting method are as follows: (1) Lighting needs to be highlighted, and various forms of local accent lighting should be used. Partial accent lighting should pay attention to the harmony of light and shadow characteristics, brightness and light color with the overall building facade. . (2) For curtain wall and buildings with large light transmissive area on the facade, it is advisable to use internal light-transmitting illumination. When using internal light-transmitting illumination, attention should be paid to the coordination of the brightness and light color of the internal light and ambient light to prevent light pollution caused by internal light transmission. . (3) When there are conditions, architectural night lighting can be used. When using this lighting method, it should be noted that architects and lighting design need to work closely together when designing the architectural plan. (4) If necessary, you can use more than two types of lighting methods: floodlighting, contour lighting, internal light-transmitting lighting, partial key lighting, architectural lighting, and special lighting in single or group buildings. Distinguish the primary and secondary lighting, pay attention to the overall effect of multiple lighting modes and the resulting night scene. According to these requirements, the landscape lighting of the building puts forward two requirements for us, how to illuminate the building, and how the architect loves to consider the architectural design.
1.1 How to landscape lighting the building
When performing night scene lighting, you should understand the characteristics, functions, styles, finish materials, surrounding environment and social historical and cultural connotations of the subject, as well as the architect's creative and design expression intentions, owner requirements and so on. According to the characteristics of the object being illuminated and the surrounding environment, the night lighting should combine various lighting methods to highlight the key points and take into account the overall image. At the same time, the night lighting facilities should not destroy the visual image of the city when it is white. Colored light has a strong emotional color, and color light should be used with caution in night lighting. The principle of use of colored light is that the color light is coordinated with the function of the building (structure), the color light is coordinated with the color of the building (structure) finishing material; the color light is coordinated with the hue and characteristics of the surrounding environment. The illumination direction should avoid people's sight and prevent glare; night illumination should control the light that is directed to the sky and cast into the residential window to reduce the degree of light pollution. The brightness and color should be reasonably determined according to the function of the object to be photographed, the architectural style, the structural features, the texture of the surface material, and the effects in the illumination of the night scene. The function, architectural style, structural characteristics, architectural features, cultural connotations and surface material color and reflection of the building (structure) should be analyzed to determine the appropriate lighting method.
1.2 How should architects consider architectural design
In order to make the building rich in nighttime, it is recommended to consider the following factors in the design of the building, especially the high-rise building facade:
(1) The faÃ§ade should be treated with some bumps and lines as much as possible. Try to avoid the whole flat gable. The gable handles some shapes that can be concealed and installed. Especially in the middle and upper part of the gable, there are some components that can be installed. The illumination distance reaches the upper middle.
(2) If the outer edge of the parapet is the place where the facade lighting is often handled, some lateral embossed decorative lines should also be considered to make the lamp installable (preferably to hide the luminaire).
(3) The faÃ§ade (the facade of the non-gable) is the focus of lighting treatment, with large windows. If it is a house, it is generally forbidden to use high-power spotlights to avoid light pollution to the house, but if there is no light, the image of the building at night will be affected. Therefore, the design of the building should consider both the position of the lamp to illuminate the building without the light entering the window. It is recommended to handle some vertical groove seams in the facade construction design. For example, if you are in a house, you can leave a little more of the concave surface of the kitchen and the bathroom to decorate the wall or the decorative line.
(4) Residential faÃ§ade balconies or side faÃ§ade balconies, window awnings and their outer edges should also be considered where low power or contour lights may be located.
(5) The top treatment of the building is the focus of architectural landscape lighting, and it is also the main light carrier of the city. It generally does not constitute a negative impact on the light of households or people. Light treatment on the light is more emphasis, the brightness is generally higher, the architectural design should be rich in style, while trying to consider hidden lamps do not expose it.
(6) The glass curtain wall is another difficulty of landscape lighting. It disables the floodlights and should be treated with internal light transmission. In developed countries, the entire building is not turned off at night, and naturally it is light inside. However, Chinaâ€™s economic development level and energy supply cannot fully meet the requirements of internal light transmission. According to Chinaâ€™s actual economic conditions, it is also necessary to make the building beautiful at night. Generally, the light is installed inside the glass curtain wall or the window, or the point outside the window is used for some point and line light source decoration. Therefore, the actual situation should be taken into consideration when designing the facade structure of the building. Considering the place where the point-like linear light source is installed.
(7) Pay attention to remind the electrical professional to consider the electric load for landscape lighting on the building, and reserve the problem of laying electricity or wiring in the glass curtain wall or the multi-window building of the public building.
2 LED problems in building landscape lighting
2.1 The wave of blind worship - the period of distrust - the period of neutral understanding
When LED was originally used for landscape lighting, it was widely promoted for its high efficiency, energy saving and long life. It was enthusiastically accepted by the society and used in landscape lighting, due to the production of LEDs from chip materials to component lamps. And a number of technical processes brought by some very complicated processes, such as landscape lighting engineering installation applications, affect the quality of LEDs. These important technical aspects are ignored by media and commercial sales promotion. When the society thinks that LED can solve all the problems of landscape lighting, the quality that appears in the real project reduces the amount of landscape lighting used. As the quality of LEDs continues to improve, LEDs have many advantages that other light sources do not have, such as energy saving, environmental protection, long life, rich colors, fast start-up, flexible combination of changes, etc., as long as they are properly used, they can fully express the beauty in landscape lighting. . At present, people's confidence in LED is gradually strengthening. We call it the neutral trust period, that is, trust and doubt coexist. This has raised warnings for the LED industry. The need to draft artwork and consolidate the quality of LED lighting products will continue to expand the impact of LEDs on landscape lighting applications and maintain social trust in LED landscape lighting.