Circadian lighting opens the door to a whole host of exciting possibilities.
Various sectors have begun to explore the potential benefits of lighting systems that follow circadian rhythms – in other words, lighting that mimics the natural sleep/wake cycles of the human body. This is known as circadian lighting.
Research has indicated that electric light can impact circadian rhythm and reducing exposure to certain wavelengths of blue lights has been shown to improve melatonin production and positively affect people’s health, alertness, productivity and more.
1. Promoting a healthy sleep cycle
Melatonin is a hormone that is naturally made by the body to make us feel sleepy. Its production is closely tied to natural levels of light. Our brains initiate the production of melatonin in response to darkness – as it gets darker, we start to feel sleepier – but light exposure slows or halts that production.
Scientists have discovered that long-term exposure to certain wavelengths of blue light at a specific intensity can have a negative impact on melatonin production. Therefore, implementing a circadian lighting system that mimics the natural daylight cycle can help promote a healthier sleep cycle.
2. Further health benefits of circadian lighting
Through allowing people to get a better night’s sleep, circadian lighting systems can lead to several other long term health benefits, including higher productivity (natural light in office spaces has been linked to higher worker productivity and increased employee satisfaction), improved memory and cognitive function, healthier immune systems, and a better metabolic function.
3. Improved mood
Disrupting our circadian rhythm with artificial lighting has also been proven to have a negative effect on our overall mood.
According to the National Library of Medicine (NIH), natural light affects our mood in several ways: by directly modulating the availability of serotonin, which is involved in mood regulation, and by stabilising circadian rhythms. In the last few decades, light therapy has been increasingly used for treating mood and other psychiatric disorders.
How can you implement a circadian lighting system?
At present, there are three approaches to implementing a circadian lighting system:
Fixtures maintain a fixed correlated colour temperature (CCT), while the intensity of the fixture is adjusted through a controlled dimming system, to correlate with time of day. Light fixtures are then set to a lower intensity in the early morning, transition to a higher intensity as the day progresses, and reduce to a lower intensity in the evening.
This involves changing the light intensity and CCT to mimic the day/night-time cycle. We experience cooler colour temperatures when the sun is highest in the sky and people are typically most alert during the day. Therefore, cooler CCTs are used in spaces and during times when it’s appropriate to promote alertness and attention. In contrast, warmer colour temperatures represent daylight hours, when the sun is rising and setting when people are falling asleep or waking up. Circadian lighting systems are set to adjust based on the CCT we typically observe at any given time of the day.
Stimulus tuning works through replacing the “bad blue” with “good blue” light wavelengths. Mimicking the daylight spectrum, stimulus tuning light fixtures can be programmed to reduce blue light wavelengths during the evening hours to limit melatonin suppression without changing the CCT. Similar to colour tuning, this lighting approach is most effective when paired with intensity tuning.
Circadian lighting in action
Check out the fully-tunable LED light fixture demonstration video from our lighting partner, Crestron, and see the circadian cycle in action here.