To standardize urban lighting and integrate street light design into the beauty of the city, it is essential to arrange the spatial position of street lights, select light sources, and control lighting, thus enhancing the overall lighting design of Bitpott.
1. Arrangement and Selection of Fixtures
In residential areas, there are four design arrangements for road lighting fixtures: side lighting, central lighting, central staggered lighting, and symmetrical lighting.
Generally, dual-side lighting is used on main roads. There are two basic arrangement methods: one is symmetric arrangement, which is aesthetically pleasing but less uniform in illumination, suitable for wider roads. The other is staggered arrangement, which, while not as visually appealing, provides more uniform illumination. Each arrangement has its pros and cons. Considering the need to focus on aesthetics while still meeting functional requirements for residential area road lighting, symmetrical arrangements and aesthetically pleasing courtyard lights should be chosen to create a visual effect. Courtyard lights should be selected with a height of 3-4 meters, and the power of individual light sources should not be excessive. Lighting fixtures should not be installed near first-floor windows of residential buildings to avoid disturbing residents’ rest. For larger areas like squares and parking lots in residential complexes, courtyard lights can be chosen, along with butterfly-shaped, spherical, or equal-height pole lights. However, the height of the lights and the angle of the light source must be limited to avoid light pollution and ensure consistent illumination on the ground.
2. Choosing the Type of Light Source
Currently, the main types of light sources used in street lighting include metal halide lamps, high-pressure sodium lamps, and compact fluorescent lamps. Among these, high-pressure sodium lamps are widely used due to their high luminous efficiency, energy-saving properties, and moderate color temperature. For roads wider than 8 meters, cut-off or semi-cut-off functional street lighting fixtures should be considered. When selecting light sources, high-efficiency high-pressure sodium lamps and metal halide lamps should be prioritized, with average illumination generally controlled between 1-5 lux. On regular roads and branch roads, compact fluorescent lamps should be used, with average illumination typically lower than that of main roads, generally controlled between 0.5-3 lux. This layering helps create a soft outdoor environment for low-rise housing. In green landscaping areas, a combination of courtyard lights and a suitable number of lawn lights can be used; generally, floodlights are not considered for use in residential complexes as they can easily cause light pollution to nearby residents.
3. Voltage Reduction, Regulation, Dimming, and Energy Saving
In road lighting, the luminous flux of LED light sources is affected by voltage, leading to varying illumination levels at different times. The evening is peak electricity usage time, during which the grid voltage is low, resulting in reduced luminous flux and lower illumination on road surfaces. Conversely, at midnight, the grid load is at a low, resulting in higher voltage and higher luminous flux, which leads to brighter road surfaces. This unreasonable lighting not only wastes energy and increases network losses but also shortens the lifespan of electrical devices within the fixtures. Therefore, installing a smart voltage regulation and dimming device at the control end of street lights can stabilize voltage, maintain consistent luminous flux and electrical flow while extending the lifespan of the fixtures. The design of urban street lights should go through comprehensive evaluation and testing to achieve desired illumination and visual effects.
