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Circadian Lighting

Designing smarter human-centric lighting systems for optimal living

The ultimate guide for design professionals

Aligning artificial lighting systems with the natural human circadian rhythms, promoting health, well-being, and productivity

Circadian lighting is a lighting system concept that follows the human circadian rhythm – so our 24 hour internal clock.

Circadian lighting design uses specific wavelengths of light at different times of the day to simulate the natural progression of daylight. This can help to regulate the body’s internal clock and improve sleep, mood, and cognitive function.

Residential, commercial, healthcare and other types of environments, are exploring the benefits of a lighting system that follows the natural sleep/wake cycles of the human body. Such lighting systems have the power to positively affect people’s health, wellbeing, productivity and alertness.

Lighting objectives

The circadian lighting concept details that by providing the appropriate intensity of blue spectrum light levels during daylight hours, and then a warmer spectrum of lighting when the body is gearing up or winding down, you create the optimum mental environment for people.

As our understanding of the profound impact of light on our biological clocks deepens, integrating lighting solutions that support these natural processes has become increasingly crucial.

This includes melatonin suppression and cortisol release to control body temperature.

Currently, there are three variable inputs when implementing a circadian lighting system for designers to consider – intensity tuning, colour tuning, and stimulus tuning.

Colour tuning

This is the most familiar solution to circadian lighting. Here, the lighting fixtures and controls maintain a fixed correlated colour temperature (CCT) while the brightness (or intensity) is adjusted through a controlled dimming system.

This is to match with the appropriate time of day.

High-intensity light (measured in lux) is beneficial during the day, mimicking natural sunlight to boost alertness and mood. Lower intensity is preferable in the evening to prepare the body for sleep.

Bright, cool light in the morning and afternoon supports wakefulness and productivity. Warm, dimmer light in the evening helps signal the body to wind down.

Intensity tuning

This involves changing the brightness (or intensity) of the light and also the correlated colour temperature (CCT) to mimic the daytime/nighttime cycle.

Warmer temperatures reflect more daylight hours when the sun is rising and/or setting, so when people are falling asleep or waking up.

Cooler temperatures are used during times when it’s appropriate to promote alertness and attention.

The typical range should span from 2700K-3000K (warm) to 5000K-6500K (cool).

Some advanced systems may offer an even broader range, potentially extending down to 2200K for very warm, candlelight-like tones in the late evening.

Stimulus tuning

This approach closely mimics the daylight spectrum out of all three circadian lighting systems.

Stimulus tuning involves the dynamic adjustment of light intensity and spectral composition to mimic the natural progression of daylight. In the morning, lighting systems can be tuned to emit higher levels of blue-enriched light, enhancing alertness and cognitive function. As the day progresses, the light can gradually shift to a warmer spectrum, reducing blue light exposure and promoting relaxation and readiness for sleep in the evening.

Stimulus tuning light fixtures can be programmed with relevant lighting controls to reduce blue light wavelengths during the evening or night time hours, to limit melatonin suppression without changing the CCT. The idea here is to reduce stimulus within the body at a time where we are winding down.


Circadian lighting in each building sector

Circadian lighting systems in residential buildings are designed to mimic natural light patterns, supporting the biological rhythms of the occupants.

These systems offer a range of benefits that contribute to overall well-being, improved sleep quality, and enhanced daily functioning.

Warmer, dimmer light in the evening promotes melatonin production for better sleep, while brighter, cooler light in the morning helps wake residents by suppressing melatonin and stimulating cortisol.

Appropriate light levels and colour temperatures during the day enhance concentration and cognitive function. Daytime exposure to bright, cool light can improve mood and reduce anxiety. And warmer light in the evening aids in relaxation and unwinding.

Circadian lighting systems transform residential spaces into environments that support health, well-being, and sustainable living, by mimicking natural light patterns and integrating advanced technologies.

Circadian lighting systems in commercial buildings are designed to enhance the well-being, productivity, and overall performance of occupants by aligning artificial lighting with natural circadian rhythms.

Exposure to bright, cool light during the day can improve mood, reduce symptoms of depression and anxiety, and enhance overall mental health. This is particularly beneficial in high-stress work environments.

Proper circadian lighting supports healthy sleep patterns, which are crucial for physical health. Employees who sleep better are less likely to suffer from chronic illnesses, fatigue, and burnout.

By providing appropriate light levels for different tasks, circadian lighting reduces eye strain and visual discomfort, contributing to a more comfortable work environment.

Layered lighting systems, including ambient, task, and accent lighting, offer flexibility to adapt lighting conditions to various work activities and personal preferences.

Circadian lighting systems in commercial buildings offer significant advantages by promoting health, well-being, and productivity, while also contributing to energy efficiency and sustainability. By aligning artificial lighting with natural circadian rhythms, these systems create more supportive and dynamic work environments, enhancing the overall performance and satisfaction of occupants.

The circadian system and its effects on human health have been studied in greater detail due to the demand for well-being-focused buildings and environments, particularly in patient rehabilitation where natural light can not be the dominant light source.

In healthcare settings, circadian lighting is often used in patient rooms, operating rooms, and recovery areas. The lighting in these areas can be programmed to match the natural light-dark cycle of the sun, with bright, cool light during the day and dimmer, warm light in the evening and at night. This can help to regulate the body’s internal clock and improve sleep, mood and cognitive function for patients, and also for staff who are working long hours shift.

Circadian systems can also be used in healthcare settings such as intensive care units, cancer treatment centres, and neonatal units to promote healing and recovery while reducing stress and anxiety in patients and their families.

The cost of installing circadian lighting in healthcare settings varies depending on the size of the facility, the type of lighting fixtures and bulbs used, and other factors, but the benefits for patients and staff, such as improved sleep, healing, and overall health, make it a worthwhile investment.

Our designers here at Detail Lighting work with you to design lighting schemes with the appropriate circadian rhythm approach, depending on the internal area and the purpose of the space.

Our primary focus is to design lighting schemes that promote wellbeing and aid patient recovery within healthcare environments.

Circadian Lighting Products

Here is a small collection of our circadian lighting products.

For more information or more bespoke options, contact our team.

Contact us for more information on how to design a circadian lighting system

Speak to our team using the details below, or fill out the contact form and we will get back to you as soon as we can.

Telephone: 01908 613 256


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