What is it Circadian Rhythm?
The concept of circadian rhythm follows that of the human circadian rhythm, a 24-hour indoor clock. The area of the brain called the hypothalamus controls each person’s biological time by receiving signals from the eyes that tell when it’s day and night. The hypothalamus controls the amount of melatonin released. This way is correlating sleepiness with darkness and alertness with brightness.
Today we know that the colour and amount of light we receive, the duration and time of day we are exposed, and even the direction within the field of view that light enters our eyes are important considerations.
The timing is everything
It is widely accepted that daylight or natural light from the sun is the primary and most natural light source. Day light provides a bright blue light first thing in the morning to send an alarm signal when you wake up. However, if you are exposed to the same light at night, you can stay awake at night or at least having problems with sleeping.
At sunset, the daylight offers a warm and soft light to encourage our body to rest.
Improvement of LED light technology, especially in the control systems, can successfully mimic the daylight. This can bring us feeling like we are living outside in the open sky. Using this technology will benefit endless possibilities like improving the biorhythm, health, we will have more energy during the day and better sleep.
There are currently three approaches for electric light to implement a circadian rhythm: intensity regulation and colour regulation.
Dimming is the best known and cheapest solution for circadian lighting. The luminaires maintain a fixed correlated colour temperature (CCT) while adjusting the intensity (brightness) of the luminaire via dimmers so that it correlates with the time of day. The lights are set to a lower intensity first in the morning, change to a higher intensity during the day, and are dimmed to a lower intensity at night.
To adjust the color, you need to change the intensity of the light and the CCT to mimic the day/night cycle.
When is around noon or when the sun is highest in the sky and people are usually most awake during the day the color temperature is between 4000 K and around 10,000 K. The warmest color temperatures (<2700K to 3500K) represent the hours of light when the sun rises and sets when people fall asleep or wake up. Circadian lighting systems are configured to adapt to the CCT that we normally observe at any time of the day. The LED fixtures often are with two LED chips of different color temperatures, warm white and cold white. With a precise control system, it can create any color temperature from warm to cold white. These fixtures have this possibility called tunable white LED.
A combination of these two regulations can bring you the most of the lighting and can most closely mimic the natural light. Aside from the health benefits that a lot of researches are on the way the implementation of the Circadian Rhythm Lighting is a very good investment in you are living space.