Floodlighting technology - installation tips for floodlights

The following points should be considered:

1. Angle of incidence

It is the shadow that embosses the façade. Therefore, the illumination should always provide surface imaging. The light that is directed at the elevation to the façade will not form a shadow and make the surface appear flat.

The size of the shadow depends on the surface relief and the angle of incidence of the light. The average illumination direction angle should be 45° (see Figure 1A). If the undulation is extremely small, the angle should be greater than 45° (see Figure 1B).

2, the direction of illumination

In order for the surface illumination to appear balanced, all shadows should be projected in the same direction, and all fixtures that illuminate the surface in one projection area should have the same projection direction. For example, if two lights are symmetrically aimed at the vertical direction of a surface, the shadows will be reduced and confusion may occur. Therefore, it may be impossible to see the surface fluctuations. However, large protrusions can produce large, dense shadows. To avoid damaging the integrity of the façade, it is recommended to provide weaker illumination at a 90° angle to the main light illumination to weaken the shadow (see Figure 2).

3, viewing angle and lighting direction

In order to see the shadows and surface undulations, the direction of illumination should be different from the direction of observation. The angle between the two directions should be at least 45°. However, for monuments that can be seen from several places, it is impossible to strictly abide by this rule. The main observation point should be selected, and the direction of observation should be given priority in lighting design.

4, floodlights

position

In urban settings, it is often impossible to install a floodlight in an ideal position. Initial studies based on lighting design should be made on site to take into account the physical limitations of the location and to achieve the most satisfactory solution, such as the appearance of the fluorescent lamp, glare, maintenance and adjustment of the entrance.

Beam range

The beam width produced by the floodlight may be larger or smaller depending on the positional adjustment of the optical system and the light source in the luminaire. Conventionally, the beam range of a floodlight is determined by a direction of illumination intensity equal to 50% of the peak illumination intensity on the beam axis (see Figure 3A). The beam range of a circular symmetrical floodlight remains constant on all sides. The beam range of a rectangular floodlight is usually oval, which is determined by two values ​​corresponding to two planes of symmetry.

In some applications, the luminaire beam used is asymmetrical at peak intensity. In this case, the beam range is equal to the two half angles determined by the light intensity of 50% (see Fig. 3B).

5, light intensity segment curve

Due to the narrow beam range of many floodlights, the curves in polar coordinates in Figure 3 are unlikely to be read or inaccurate. In general, if XY is used, where the vertical axis OY represents illuminance and the horizontal axis OX represents the angle of the beam (see Figure 4). In most floodlights, the source of the transfer optics will change the shape of the profile (beam range, intensity, and symmetry).

6, application examples

(1) Column tower

In order to be able to see the circle of the tower, the brightness on the width of the tower should be constantly changing. However, the fiber should remain unchanged on the vertical line. The floodlights are arranged in accordance with FIGS. 5A and 5B. The choice depends on the ratio of the distance of the luminaire from the object to the diameter of the tower.

When the ratio is high, that is, when the narrow tower is illuminated by a distant floodlight, it is appropriate to arrange 2 floodlights according to Figure 5A. When illuminated by a floodlight installed near a building, three sets of floodlights shall be arranged for the low tower according to Figure 5B, with an angle of approximately 120°.

When large diameter cylindrical towers can only be seen from one direction, two effects may occur. An illuminated central zone can be created between the two darker areas (Fig. 5B/Fig. 5D/Fig. 5E), or the opposite arrangement (Fig. 5A/Fig. 5C/Fig. 5F). The choice depends on the characteristics of the building's background. .

(2) Multi-faceted tower

For rectangular or hexagonal buildings that can be viewed from all directions, usually two illumination directions are sufficient (Fig. 6A, Fig. 6B).

For structures of 8 or more faces that can be viewed from all directions, the number of floodlight locations depends on the location available, and each actual situation should be studied to avoid any faces being in shadow (Figure 6C).

(3) Roof shape

The roof is usually made of a material that is darker than the inside, so its brightness is low, even during the day. In order to maintain balance, the illumination of the roof lighting cannot be higher than the rest of the building. If the color of the roof is conspicuous, this effect can be enhanced by using a light source with a suitable primary color.

When the floodlights that illuminate the facade are close together, it is often impossible to illuminate the roof from the same location. In towns, floodlights can usually be installed on adjacent buildings. In other cases, the floodlights can be mounted on masts or on the roof at the appropriate distance (see Figure 7A/Figure 7B).

If floodlights are installed on the roof, be aware that these floodlights should be installed in concealed locations to maintain the aesthetics of the building during the day. Skylights, windows, drainage systems, chimneys and other buildings can provide locations to install and conceal floodlights. Mounting the floodlight on the edge of the roof platform makes it easy to illuminate the façade above the platform (Figure 7C)

When architectural lighting is provided by a floodlight mounted at approximately twice the height of the façade, the beam of light is usually able to illuminate the roof (Figure 7D).

(4) Balcony and corridor

The projection of balconies and corridors creates shadows on walls or facades. The farther the light source is from the building, the larger the protruding part of the balcony, the deeper the corridor, and the greater the shadow. If the effect is unsightly, you need to change the floodlight arrangement or add another floodlight in the balcony or corridor. Lights to reduce contrast and thus reduce the effects of shadows (Figure 8)

There are significant differences in the use of warm and cold lighting components, and sometimes the contour illusion can be enhanced, and the application of this technology is very complicated.

(5) Colonnade

The colonnade enhances the visual effect through the positive and negative contours of the background. Under the illumination background (Fig. 9A), the outline of the column will be highlighted, and the column should be provided with low-intensity illumination to limit contrast or highlight the texture of the column, in direct illumination (Fig. 9B), using a searchlight to illuminate each column And make it appear from a dark or dark background.

(6) Trees, flower beds and low bushes

Trees are usually illuminated by floodlights mounted on the ground. The arrangement of the lighting device depends on the specific shape and shape of each object. It is not recommended to install it on trees when there is a possibility of damage to the floodlights. If it is fixed to the branch by the collar, it is necessary to regularly adjust the collar as the branch grows. If it is required to illuminate the upper part of the tree, for example, to illuminate the first layer of trees above the tree, it is necessary to fix the floodlights to the thin rod above the plane. (See Figure 10A-H)

For green grass or low bushes, PAR lights can be installed on or near the ground like floodlights, maintaining a safe distance and proper mechanical and electrical protection (Figure 10I). Among them, the flowerbed can be down-lit from a height of 50 cm to 1 M using a floodlight (mushroom lamp) (Fig. 10J and K).

Flowers have a variety of colors, which requires the use of a well-developed light source with a color rendering index higher than 75 and a color temperature close to 2500K.