The answer: HCL lighting control
For people who spend a lot of time in buildings with little or no daylight, it would be ideal
to have a system that could light with daylight-like dynamics. Today, technology makes
this relatively easy, thanks to the convergence of the LED revolution, intelligent control
and advanced, higher performance luminaires. This makes it possible to create lighting
systems that better support circadian rhythms, aiding concentration, improving mood and
well-being and preventing sleep disorders. This is the revolutionary concept of HCL or
Human Centric Lighting: providing high-quality light in the required quantity at all times,
while always focusing on the individual needs and well-being of people.
The components of HCL control
Three components are required to implement lighting control that follows circadian
rhythms:
• light sources adjustable in intensity and with the possibility of varying
the shade of white light emitted;
• an intelligent control system to support the function;
• luminaires with light emission over a wide area, possibly with direct and
indirect components.
LED sources have made this much easier than in the past: they are able to emit different
shades of white light and the intensity of their output can be easily controlled by digital
systems. In addition, more and more luminaires have versions with independently
switchable direct and indirect light components. In this way, over the course of the day,
it is possible to gradually vary the colour temperature from cold white in the morning
to neutral tones closer to daylight in the evening. This allows the colour temperature to
gradually change from cool white in the morning to neutral tones closer to daylight in the
middle of the day - and then to warm white in the evening, while at the same time reducing
the emitted intensity and making greater use of the indirect component.
This management of artificial light has a positive biological effect, as it tends to
stabilise the day-night rhythm of human beings. The Ekinex control system uses open,
interoperable KNX technology with sensors, actuators and a supervisory system that work
in coordination not only with each other, but also with the other technical systems in the
building. In order to take account of the fact that light has different effects at different
times of day, the astronomical clock integrated into the Delégo control system makes it
possible to reproduce the course of daylight dynamically throughout the year, gradually
switching from one lighting scenario to the next.
Easy interfacing to the DALI standard also means that almost any requirement can be
met. Without the intelligence built into every Ekinex device, it would be very difficult
to translate the objectives of an HCL control into reality. A few examples? At home,
people often get up when the alarm clock goes off at a time that does not correspond
exactly to their individual rhythm. For a more natural and less traumatic awakening, a
gradual increase in artificial light can be envisaged. When moving to the kitchen to have
breakfast, increased brightness and a colour tone closer to natural light - with a high blue
light component - stimulates and has an activating effect on the body; at the same time
wall-mounted luminaires are also switched on for a more even distribution of brightness.
In the workplace, light supports people’s visual tasks to the best of its ability; correct
illuminance and glare-free light as prescribed by legislation are essential prerequisites,
but a white light colour with a tendency to cool helps to maintain cognitive performance
and concentration over a longer period of time.
Midnight
00:00
Midday
12:00
Morning
Evening
06:00
18:00
High
attention
Improved
coordination
Onset
of drowsiness
Deep sleep
and physical recovery
Early
awakening
Quicker
reaction
time
Source: Lighting Europe
Biological (non-visual) effects of Human Centric Lighting
Impact
Definition
Examples
Feeling
Mood
Emotional state describing the positive or negative disposition that is infl uenced by personality traits, sleep,
(social) context and behaviour.
Aff ective state, depression prevention,
anxiety prevention
Energy
Bringing the body and mind into a state of general wakefulness and activity readiness.
Increased level of activation, vitality
Relax
The emotional state of reduced tension and emotional pressure, while feeling at ease.
Reduced activation level, reduced stress
Operativity
Attention spam
The state of active attention due to high sensory awareness
Increased concentration, vigilance, accident and error prevention
Mental performance including working memory, language production and comprehension, learning,
reasoning, problem solving, complex response, decision making
Improvement of memory, learning,
creativity, motivation
Salute
Sleep/wake cycle A stable 24-hour rhythm of rest and activity, controlled by an individual’s biological clock, is essential for
optimised functioning during the day and for a good night’s rest to promote sound health.
Disease/disorder prevention, treatment and mitigation (dementia,
SAD, ADHD, schizophrenia, sleep disorders), social jetlag,
chronomedication, improved healing environments
1. ADHD: Attention Deficit Hyperactivity Disorder, SAD: Seasonal Affective Disorder, DSPD: Delayed Sleep-Phase Disorder - Fonte: WG Light for Life, A.T. Kearne
1,900K
Candle
2,200K
High pressure
sodium vapor lamp
2,700-3,000K
Warm White
Halogen
Incandescent
4,000-4,500K
Natural White
Metal Halide
4,800K
Direct light
5,000-6,000K
White
7,000-8,000K
Cold White
10,000K
Blue Sky
SMART LIGHTING
22
23
9 a.m.
3 a.m.
6.00
12.00
18.00
24.00
6.00
12.00
18.00
24.00
6.00
cortisol level melatonin level
© licht.de
More productivity at work by following the circadian rhythm
In 2016, the Amsterdam offi ces of CBRE, a global real estate consulting fi rm,
hosted a multidisciplinary study on how the work environment aff ects the
health and well-being of employees. A section of the offi ces was equipped with
a biodynamic lighting control system and a research team, coordinated by the
University of Twente, studied the reactions of 120 people over a seven-month
period. The lighting control was set up to reproduce the natural light coming
from the sun in order to support the circadian rhythm of the body: the focus was
therefore on cold light tones in the middle of the day, to stimulate attention and
concentration, and on warm light tones at the end of the afternoon, to promote
relaxation at the end of the working day. The results of the study exceeded all
expectations and confi rmed that light has a great impact on people’s well-being
and performance: after just one month, 71% of participants felt more energetic,
76% happier and 50% healthier; productivity increased by 12%.
(fonte: www.cbre.com)
