Warm, cold, dynamic or variable spectrum light: keys to use in lighting projects
Answering questions about what light is and how it behaves has been the subject of study for some of the most restless minds in the history of physics. Understanding the impact it has on physical, emotional and biological perception, as well as the difference between light colour temperature and spectral power distribution is key to proper lighting application.
Light colour temperature
When choosing a suitable colour temperature, it is necessary to understand the type of task to be carried out in a given space, as there is usually a close relationship between lighting levels and colour temperature, but it is also necessary to take into account the atmosphere to be created, as well as other cultural and biological aspects related to the people who will use the space.
To standardise the perception of light colour temperature, the scale based on the Kelvin (K) unit is used, a unit that determines at what temperature a black body should be heated to achieve a particular colour. Thus, reddish shades in light correspond to a lower colour temperature, as opposed to bluish shades.
Therefore, light can be classified into:
Warm: from 1000 to 3500 K
Neutral: from 3500 to 5000 K
Cold: over 5000 K
To have a clear idea of equivalences in this scale, it should be taken into account that sunlight at noon is around 6500 K, so it is a cold light, while at dawn and dusk these values decrease, becoming a warmer and redder light.
However, spaces are increasingly not being used in a fixed manner, on the contrary, they are becoming flexible, allowing for a multitude of activities with changing technical and environmental requirements to be developed.
For this reason, lighting solutions in tunable white are currently being implemented. It is lighting that uses different colour temperatures, ranging from 2700 K to 6500 K, so that users can select the most appropriate colour temperature depending on the time or the activity being performed in the space, thus obtaining emotional benefits, as it enables to achieve lighting according to the required atmosphere.
Dynamic lighting: synchronisation with natural light
As commented above, throughout the day, sunlight varies in colour temperature and intensity, generating a direct impact on humans at three levels:
Synchronising artificial lighting with natural lighting is key when talking about integrative lighting focused on user wellness.
This synchrony should not be limited only to changes in colour temperature, but its 'spectrum curve' should also be dynamic, allowing for the generation of dynamic lighting strategies with the purpose of adapting it to users' circadian rhythms, thus generating a positive impact on them at the biological level.
It is now known that emissions at 480 nm have the most positive effects when talking about activating biological clocks and keeping an adequate state of mind to develop activities that demand a high degree of concentration and alertness. On the other hand, as the day progresses, the most suitable light is that which allows for the reduction of emissions, leading to a state of relaxation and thus providing better rest by assisting natural melanin generation, minimising emissions at this wavelength.
This is what Well-being lighting technology enables, which is especially recommended for spaces where users spend a large part of their time in indoor areas and with prolonged exposure to artificial lighting, such as schools, offices, senior residences, hospitals, etc.
There are spaces where it is necessary to have full control of the light spectrum for various reasons:
- Adaptation of circadian cycles in environments with high demand on hygrothermal comfort parameters: such as intensive care units, spaces with total absence of natural lighting, work spaces in extensive night shifts;
- Spaces where, due the nature of the tasks developed, it is necessary to reproduce a specific light source: such as art restoration, or high performance activities in labs, etc.
Multispectral technology, on the other hand, based on the digitisation of light, and thanks to the incorporation of seven different colour channels, allows for a total control of all the parameters that make up the light spectrum, enabling to design up to 1025 possible customised light spectra by modifying the intensity of the emissions at the different wavelengths.
Choosing the right light
Soft ambient lighting is a very important issue within the most current lighting designs. This concept addresses the emotional and biological aspects of light, beyond the purely functional, and is defined as the concern for human response to lighting systems. Once the technical requirements of lighting systems aimed at visual capacity have been met, it is time to go further and incorporate strategies related to colour, spectral power distribution and user perception. All this will contribute to generating an emotional attachment with the spaces through light, and will intensify the comfort sensation.
As a consequence of these new realities, a detailed space function analysis is necessary. The most effective lighting designs are those that adapt to users' needs: spaces to relax, concentrate, perform a task, activate themselves... An intimate corner designed to enjoy a book will not have the same characteristics as a lab or a work station. It is also common for a space to be designed to accommodate different activities and, in these cases, dynamic lighting must respond to any needs that may arise.
To meet these changing needs, smart lighting systems make it possible for different light scene designs to be applied in a practical and simple way.
Lamp's experience implementing integrative lighting solutions
At Lamp, we are experts in the application and consultancy of the most appropriate technology at the service of lighting and space design. Let's see two specific examples.
In this case, the design of the space sought to connect with nature in order to express the company's commitment to natural ingredients and traditional manufacturing. To this end, Hance 2000 directional projectors were chosen for the counter area. These luminaires have a light colour temperature of 2700 K, located within the spectrum of the warm shades. This is a very good choice to get bread colour reproduction, highlighting their more appetising side.
For the cafeteria area, a dynamic control system was chosen, using Bluetooth Low Energy which allows for a variation of light colour temperature between 2700 and 6500 K, with the purpose of creating dynamic lighting that varies according to the time of day.
Yoga One by DIR
Bluetooth Low Energy Technology is a cross-cutting element to light different spaces in the centre. In a space with these characteristics, which is oriented to relaxation, it is essential to be able to play with light and enhance the effects of the activities hosted in the centre.
Thus, several dynamic scenes were designed with different light colour temperatures focused on the intensities the activities require.
- Warming-up is planned with a colour temperature of 3000 to 4000 K.
- Energetic Yoga practice was established at a colder temperature of about 4500 K.
- Meditation and restorative Yoga is established at 3000 K.
- Relaxation (Savasana): dynamic scene in which the CCT varies for 5 minutes from 3000 to 2700 K, staying at this last figure for the next 10 minutes.
Our experience and capacity to adapt to all types of projects make us a benchmark in the lighting industry. Our differentiating factor is our commitment to projects from the design phase. This allows us to plan and manufacture adaptations of our products to achieve optimum results. Contact us without any commitment and discover what we can do for your project.