DAYLIGHT AS A NATURAL REGULATOR
SAVING ENERGY WITH INTELLIGENT DAYLIGHT-LIKE LIGHTING
Light management systems not only increase comfort levels. When used effectively, daylight control and similar solutions also help to save energy. A clever built-in sensor records parameters like lighting intensity, presence or motion, and passes on the recorded data to a control unit, which then adapts the lighting intensity to previously defined levels. You can read all the relevant information about how daylight control works in this article, as well as about the different types and expansion levels that exist and the requirements to be fulfilled for operation.
Why is natural daylight so important for us?
Daylight can do much more than enable vision: it is vital for human wellbeing. Not enough light can make us feel gloomy and tired and defeated. Stimuli that are important for the biological system are lacking. In the worst-case scenario, this can even lead to serious illnesses. Light stimulates the processing of signals in the brain and the production of neurotransmitters that help to regulate our internal body clock. Moreover, we need bright light to be active and productive in general. Bright light activates precisely those parts of our brain that control mental performance, for example speed of reaction or concentration.
How does daylight control work?
Modern light management systems integrate daylight to reduce the energy requirement of buildings and thus to lower operating costs. Depending on the available incident light, the contribution of artificial light can be limited to as much as is needed to achieve a certain lighting intensity. The lighting level remains constant as a result and allows energy savings of up to 15 percent. A sensor continuously records the current amount of light and passes on the parameters to the control unit, which in turn adjusts the lighting to the set level. Constant light quickly becomes tedious however. Modern systems can respond more intelligently to daylight and, for example, allow additional daylight to be only partly compensated for. A slight increase in the lighting level as it gets brighter outside is something that also appeals to users. Daylight control systems can be configured individually. This means that the artificial light can also be switched off fully, for example, on especially bright days.
The influence of daylight on the human body
Which expansion levels exist for daylight controls?
There are different expansion levels for regulating daylight-controlled systems. In smaller environments, for example in individual offices or the living room at home, it sometimes suffices to limit the control to individual luminaires. However, several groups of light sources or the entire building lighting are incorporated in the case of more complex systems. Modern office luminaires are capable, for example, of communicating with one another and then responding in unison. Isolated pockets of light or darkness within rooms can therefore be avoided. There is increasing evidence of the importance of daylight in conjunction with the biological effects of light. Daylight is an essential element of Human Centric Lighting. So while it is important to ensure sufficient incident daylight on work surfaces, the light that is available to the user is important too. The required lighting intensity on the eye should be at least 250 lx over the course of the day. If there is not sufficient daylight available, the light should be supplemented by daylight-like lighting. Cold white light colors are preferred for this purpose, because they simulate the effect of daylight most closely. When the natural daylight has faded in the evening, warm white lighting projects as much light onto the work surface as we still need to see properly.
What are the requirements for operating daylight control?
To use daylight to control lighting, you first of all need luminaires that can be activated individually and combined in groups. In addition, the lighting system must be able to continuously simulate different switching and dimming states, as this is the only way to ensure the room lighting can be adjusted dynamically. Apart from the technical requirements, the conditions locally also play a key role: All sensors and motion sensors should be positioned where they can actually measure the critical photometric parameters at all times, and not be disrupted, for example, by direct sunlight or shading by other objects.