The nightscape lighting can express the details and essence of the building, express the functional characteristics of the building, highlight the cultural characteristics of the building, and add architectural charm.
However, the lighting design of buildings with different functions is different. If the front of a building is illuminated from a certain distance, the whole building will appear to have no sense of hierarchy when viewed from the main light direction.
Commonly used nightscape lighting techniques generally include flood lighting, contour lighting, key lighting, internal transmittance lighting, local lighting, hybrid lighting, etc. Among them, flood lighting is one of the more commonly used nightscape lighting techniques, and the number, location and projection angle of its lamps are key issues. When determining the position of the floodlight and the required luminous amount and photometric characteristics, the following factors need to be taken into account: surface quality and color, components, position of the viewpoint, luminous distance of the object, illumination of the surrounding area and the desired effect.
Therefore, this article will take you to understand: flood lighting.
What is floodlighting
Floodlighting usually refers to a lighting mode that uses floodlights or floodlights to illuminate a scene or target, and its illumination is significantly higher than the ambient illumination.
The purposes of flood lighting are various. One is to work safely or at night, such as parking lot, freight yard, etc; The second is to highlight the cultural characteristics of architecture and add architectural charm, such as buildings and statues.
The light of floodlighting
Generally speaking, the light colors used in building night scene lighting can be divided into white light and color light, in which white light includes about 6000k cold white light (such as light from sunlight fluorescent lamp high-pressure mercury lamp), about 4000k warm white light (such as light from metal halide lamp), and 2000~3000k warm yellow light (such as light from incandescent lamp high-pressure sodium lamp), The luster of color includes the color lamps of various colors obtained by using color light sources or color filters.
Because the light colors of various light sources are different, color filters are generally used when color light is needed, and the brightness for perspective will be greatly reduced. The color transmittance ratio is: amber color filter 0.4~0.6, red filter 0.15~0.2, green filter 0.05~0.1, blue color 0.03~0.05. Considering the absorption of the filter, in order to achieve the same illuminance as achromatic light or the same decorative effect, the illuminance of the light source should be increased accordingly.
Installation position and quantity of floodlights
According to the characteristics of the building, the floodlight shall be set at a certain distance from the building as far as possible. In order to obtain a more uniform brightness, the ratio of its distance to the height of the building should not be less than 1/10. If conditions are limited, floodlights can be directly installed on the building body. In the facade structure design of some foreign buildings, the need for lighting of the appearance has been taken into account. There is a special installation platform reserved for the floodlight installation, so that the floodlight can not be seen after the floodlight equipment is installed, thus maintaining the integrity of the facade appearance of the building.
Floodlighting principle
If you want to use floodlighting well, you must choose the light color reasonably. The color of light has emotional color, and the uncoordinated light color combination will make people feel uncomfortable. In addition, it is necessary to master the characteristics, architectural style and artistic conception of the building, find out the most striking features when projecting light from different angles, and select the facade illuminating surface with the highest viewing rate.
Generally, the principle requirements for floodlighting are:
The material color and texture of the details of the building facade can be clearly seen at a nearby place, and the building volume and the light color of the facade can be clearly seen at a distance;
It is necessary to master the characteristics of the building facade and illuminate it from several different angles, so as to produce a significant three-dimensional sense, especially the hierarchical effect of light and color;
The facade of the building should be highlighted to make it form a contrast with the surrounding environment and give full play to the role of the surrounding environment as a foil；
Understand the reflection ratio of building facade materials to light, and determine the required illuminance on this basis.
Prevent glare
In the design of nightscape lighting, we often encounter a problem, which is also the most difficult to avoid- glare.
The general causes of glare can be roughly divided into the following:
The brightness of the light source (the higher the brightness, the more obvious the glare);
The position of the light source (the closer to the line of sight, the more obvious the glare);
Appearance size and number of light sources (the larger the apparent area, the more the number of light sources, and the more significant the glare);
The surrounding environment (the darker the ambient brightness, the lower the adaptive brightness of the eyes, and the more obvious the glare).
So how to prevent glare in floodlighting design?
In the flood lighting design, the surrounding lighting environment shall be fully considered. In order to ensure a good uniformity, the spacing of lamps installed on the building shall be 2.5~3 times of the bracket length. If the spacing is too wide, a fan-shaped bright area will be generated.
In the floodlighting of buildings, the lamps can be illuminated from bottom to top, which is not easy to cause glare.
If side lighting is adopted, the shielding of lamps shall be considered to reduce the unnecessary light as much as possible. In the floodlighting of buildings, the lamps are basically illuminated from the bottom to the top to avoid glare as much as possible.
Floodlighting combined with the surrounding environment
If the same lighting mode is used for tall buildings on both sides of the urban trunk road, it will give people a dull, even dull feeling.
Considering the combination of building materials and light sources of lamps, the building floodlight illuminance is generally between 15~450lx, depending on the surrounding lighting conditions and the reflective capacity of building materials;
The combination of building shape and light source color shall be considered. Color lighting can be selected according to the shape of the building to create a clear color contrast between the front and side of the building, adding a festive atmosphere.
