A lighting project focusing on illuminating parks and public gardens should consider three main aspects:
- It must be based on an efficient energy consumption
- It must present a minimal environmental impact
- It must achieve a good quality / price investment.
Therefore, designing a good lighting for a park or garden must combine efficiency and saving with and security and comfort. Always consider an adequate lighting for all parks and gardens, as they are dynamic and living spaces, a lighting which must adapt properly to different seasons, luminosities and circumstances.
When the night falls, the chromaticism and clarity of the park are the main factors that influence the influx of people. The distribution of light, its intensity and its impact on the surrounding elements play an important role in whether people will use the park or not.
The design of the gardens is determined based on the perception of green areas with the day light but it is important that the nature’s creations can be viewed properly with an artificial light as well. The aesthetic potential of artificial lighting, as a tool in the design of parks and gardens, is noticeably high: creating and accentuating silhouettes, establishing the levels of illumination and darkness, emphasizing a few elements of interest, and accentuating the perspective and the three-dimensional effect.
It is also important to set certain objectives, since it is clear that the lighting solution will vary according to the main purpose of the lighting and the location.
The landscape lighting means that any direct lighting up of plants and objects should be avoided. For this purpose, the use of indirect lighting is advised: it can be achieved when the luminaire is hidden, and when only the light effects are seen.
The basic techniques commonly used for artificial lighting in parks and gardens include different degrees of brightness, depending on the location of the park or garden. Therefore, it is important to determine which areas have low light levels, which areas require an intense luminosity, and which areas require luminous objects installed.
To improve the visibility of some plant species in parks and gardens, we can use backlighting. In addition, these plants can be illuminated from the front, so that their volume is emphasized while their shape remains natural.
An artificial lighting and a brightness level equal to the sunlight cannot be achieved simultaneously, and we must take into account that the human eye perceives colors differently. Sometimes people try to reproduce the daylight by installing a high-intensity lighting, however, it is recommended to dose the level of light that should illuminate certain points, so that the light possesses an effect that helps revitalize different colors and shades.
However, it is recommended that light should be adjusted accordingly, making it so that the light possesses an effect that helps to revitalize the different colors and shades.
The installation must be designed to avoid light pollution. For that purpose, the distribution of light upward should be avoided.
To allow face recognition, there should be a minimum vertical illuminance (Ev. Min) and a minimum semi-cylindrical illuminance (Es. Min).
According to the CIE 115-2010, these are the values of the lighting criteria to be observed for different P classes :
Class P1: Emed= 15 lux Emin= 3 lux Ev.min= 5 lux Esc.min= 3 lux
Class P2: Emed= 10 lux Emin= 2 lux Ev.min= 3 lux Esc.min= 2 lux
Class P3: Emed= 7,5 lux Emin= 1,5 lux Ev.min= 2,5 lux Esc.min= 1,5 lux
Class P4: Emed= 5 lux Emin= 1 lux Ev.min= 1,5 lux Esc.min= 1 lux
Class P5: Emed= 3 lux Emin= 0,6 lux Ev.min= 1 lux Esc.min= 0,6 lux
Class P6: Emed= 2 lux Emin= 0,4 lux Ev.min= 0,6 lux Esc.min= 0,4 lux
As for the lighting of parks and gardens, areas to consider are the entrances to the park or garden, as well as stairs, sitting areas, etc. In these areas, we must take into account the criteria and minimum lighting levels established for lighting these public spaces.
Light sources providing white light to obtain good color rendering (CRI = 60), are suitable for areas where the peripheral vision of the user is important. Therefore white LED lamps generally required.
The luminaires are part of the street furniture of a municipality. The luminaires chosen to illuminate the parks should provide a high degree of protection, with an IP66 level of protection. If the lights are located at a low level, vandalism must be considered, and resistant light fixtures should be used, with materials including an IK10 rate. And finally we should always take into account the light pollution.
Today, a good lighting must be both efficient and economical. Greater energy consumption does not always mean a better service but the degree of optimum efficiency is achieved when there is a proper ratio between consumption and comfort. Energy efficiency in lighting refers to the reduction of energy consumption , protecting the environment. Therefore, when designing the lighting of parks and gardens of a municipality, we must establish minimum lighting levels required for the development of activities that take place in these areas, not forgetting safety and comfort of users but also preventing light pollution.