The new trend is obvious: lighting should be focused on the workplace. This calls for a wider implementation of individual lighting control and leads to the active use of so-called "two-component" systems, which provide individual control of workplace lighting in combination with general, ambient light.
To improve visual comfort, it is desirable to illuminate the walls and ceiling separately, which will also minimize the discomfort from excess light.
More recently, a new digital control system based on the DALI (Digital Addressable Lighting Interface) standard has been introduced to the market. Using the DALI standard, luminaires with electronic ballasts can be individually controlled. This opens up new possibilities for controlling lighting from the workplace using a remote control or a personal computer. In addition, DALI can be integrated into any building automation system.
When intelligent control systems are used with daylight and in combination with other modern sensors, it is possible to accurately set the level of illumination that is needed, which will improve visual comfort and reduce energy consumption.
The application appeared in the mid-90s. new efficient luminaires with T5 light sources (fluorescent lamps with a diameter of 16 mm) also make it possible to solve such problems.
For example, calculations have shown that savings of up to 40% are possible in comparison with installations created before 1995 (and in the case of lamps with electromagnetic ballasts - up to 70%).
If we formulate the basic requirements for modern lighting, then these are as follows:
- action functionality and improved light comfort;
- providing the best conditions for visual work;
- individual control of workplace lighting;
- the ability to select the required lighting of the surrounding space, taking into account the lighting of the workplace and the presence of daylight;
- energy efficiency;
- valuation of energy saving for the entire period of operation;
- minimization of damage to the environment.
In previous years, as, indeed, even today, according to the standards in force, when planning to light, it was enough to comply with lighting standards. In the future, it will be necessary to consider compliance with the conditions for visual work.
Here are the main parameters that determine the light atmosphere according to the recently adopted European standard EN 12464 and which must be taken into account when planning lighting:
- light distribution;
- direction of light;
- color rendition and color temperature;
The standard specifically states: Lighting systems must be designed to avoid flicker and stroboscopic effects. The flicker is imperceptible to the naked eye, but it can cause headaches and stress the nervous system. In addition, a decision was made to ban the production and sale in European countries of electromagnetic ballasts, which are the cause of flicker, in a few years.
The new European Workplace Lighting Standard (EN 12464) defines the development of lighting systems.
Here are some examples of specific requirements foreseen by the new standard Lighting systems will be divided into zones following the layout of the office. In this case, the workplace or zone is defined as the part of the workplace where visual tasks are performed, and the intermediate zone is a strip of fewer than 0.5 m around the working area.
Workplace lighting requires a higher level of illumination and a lower level ≈ for the intermediate zone. The table shows this relationship for a number of illuminations normalized for specific visual tasks. All values are given as operational illuminances.
Operational illumination is defined as the value below which the average illumination of the working surface should not fall.
So, for example, with a normalized illumination of the workplace of 500 lx, the illumination of the intermediate zone should be 300 lx, while the uniformity coefficient (as the ratio of the minimum illumination to the average) should be 0.7 for the workplace and 0.5 for the intermediate zone. In practice, this means that the illumination should not be less than 350 lx at any point in the workplace and not less than 150 lx in the intermediate zone.
In areas with workplaces equipped with displays, the average brightness of luminaires that can be reflected in the screens is limited. In areas with displays of average or good quality, the average brightness of the luminaire should not exceed 1000 cd/m2 for a protective angle of 65 or more.
It should be noted that the specific power of lighting systems created in accordance with the requirements of the new standard is only 6 - 15 W/m2, while the existing systems have -15 - 25 W/m2.
Illumination of the workplace:
- >750 lx
- 500 lx
- 300 lx
- < 200 lx
- Uniformity > 0,7
- 500 lx
- 300 lx
- 200 lx
- Uniformity > 0,5