Designing in “light” of circadian support: 6 strategies for commercial spaces
July 31, 2018
July 31, 2018
Employees spend most of their daylight hours indoors; the right workplace lighting systems can help create a healthier work environment
The dynamic of light and human health has been studied for years—and never so much as in the last decade. Discussions of how lighting affects our health are not limited to scientists or lighting design professionals; it’s become mainstream knowledge that light triggers our circadian system for good or bad.
We know daylight is good for us and that it sets our circadian system for the 24-hour clock, especially in the morning hours when blue light waves are prevalent. Blue light at night—including light from electronic devices such as televisions, tablets, and phones—is known to interrupt the circadian system by preventing the activation of melatonin that helps move our systems toward sleep.
Programs such as the WELL Building Standards focus on creating a sense of well-being for people working primarily in commercial and industrial sectors. Lighting has become a key part of the discussion because most of an employee’s daylight hours are spent indoors. For some, electric sources may provide the only light they experience in 24 hours.
We live and work in a 24/7 world with corporations allowing flexible work hours well beyond the 9-5 day. It’s not just the shift-worker that may be going to and from work in darkness. For some, it may be a preferred or family-necessary schedule. For many, the winter months include a commute to work in darkness and then home again in darkness. We need to consider how we light interior commercial spaces at night as much as for day use. Not everyone has access to daylight in their workspace, and many don’t sit next to a window where daylight can help support circadian health.
We should—and need to—make the office a healthier environment for people regardless of their work schedule.
At the recent Illuminating Engineering Society (IES) Light and Human Health Symposium in Atlanta, Dr. Mariana Figuerio, director of the Lighting Reach Center and Light and Health program director, reported that only those people sitting directly next to windows receive benefits of circadian stimulus from daylight and only when faced looking directly out of the window.
Most people now know that light and the color of light—more specifically, the spectral power distribution or wave length—affect our circadian internal clock. Media presentations have focused on reducing or eliminating blue light at night. Color-changing “tunable white light” sources are being promoted for schools, office buildings, and healthcare institutions. While most designs/implementations focus on the tunable white element, many do not also take into consideration the other elements required to support circadian rhythm: spectral power distribution (wave length), timing (24-hour clock), light history (prior exposure to light), spatial distribution (direction of light source), and intensity (brightness). All must be present to support our circadian well-being.
We are constantly gathering new information about lighting to support human health, but are we doing all we can today with our current knowledge? While it’s still a moving target, we know enough that we should—and need to—make the office a healthier environment for people regardless of their work schedule. The IES—including my colleague Rachel Fitzgerald—is currently working on recommendations for office lighting to support circadian rhythm to be released in 2019.
Our lighting design team at Stantec is already incorporating a number of creative ideas:
For new construction, bring more usable daylight into buildings. Daylight is the first and best option to initiate circadian stimulus. Research tells us that just half an hour of morning daylight sets our circadian rhythm. A tremendous amount of electric light is needed to provide the same stimulus, more than any energy budget would allow. Prioritize daylighted areas within buildings to be accessible to all staff: break rooms, conference rooms, or casual meeting/lounging spaces.
For older buildings or tenant improvement projects, consider using “artificial” skylights. There are varying levels of products available from simple, static luminaires that produce high levels of light that emulate the sky including dynamic portrayal of passing clouds, color-changing from cool to warm white light, variable luminous intensity (sunrise to sunset), and even overcast cloudy days.
A simple and budget-friendly design concept of illuminating vertical surfaces such as walls reflects light back into the space and provides “free” increased light levels. Finishes of surfaces will determine how much light is effectively redirected back into the room. The lighter the finish, the more light will be reflected into the space. Lighting vertical surfaces also adds visible brightness, which studies indicate increase alertness and productivity.
Dynamic white lighting systems can work well when fully programmed as a turn-key installation. A single manufacturer will provide plug and play lighting and control systems that leave nothing for the contractor to program. Color-tuning systems are currently being implemented not just for human biological support but also for psychological support. Employees like the dynamic nature of light changing over time—sharing that it just feels good. For biological support, color tuning and lighting systems must be able to provide higher intensities of light in the morning and early afternoon hours with reduced light levels in the late afternoon and further dimmed levels at night to allow for melatonin activation. Recent research indicates that intensity of light—high and low—may be more important than color to set circadian rhythm.
Direction of light—spatial distribution—is important and one of the five elements needed to support circadian rhythm. Consider how the sun moves over the course of a day. Daylight enters the eye primarily from above so electric light that works in a similar way is most effective. Think indirect lighting instead of direct lighting or a combination of both. Layer lighting systems with thoughtful control options to allow for diverse settings for all times of day or night. Overhead lighting can be reduced or dimmed while vertical lighting (walls) can provide good ambient lighting that still “feels” bright.
Implement lighting controls to support higher light levels during the day and reduced light levels at night. We don’t know “dose” specific information at this time (how much electric light for how long) so providing controls with as much range as possible will make for longer lasting or more adaptable systems. Studies indicate that over time we may need to provide lighting specific to a person’s visual acuity, age, and physical condition. Controls do not need to be overly complex or expensive to achieve goals.
Research is constantly evolving and lighting designers at Stantec are committed to staying at the forefront of lighting for well-being. We are always looking for opportunities to create lighting systems that support the office environment and the people who work there.
Daylight is dynamic, with clouds passing in front of the sun and rainbows magically appearing when sun interrupts the rain. Electric lighting can also provide some of that vibrancy when it is planned with thought and care. Our knowledge of how lighting supports circadian response continues to develop, so stay tuned and join the revolution.