Smarter lighting makes for healthier people

If people are spending most of their time indoors, lighting should mimic the positive effects of natural daylight.

Indoors is not outdoors. A kindergarten is not a factory floor. A kitchen is not an operating theatre. And yet, when it comes to lighting, we often treat them as if they are equivalent.

Lighting fixtures go on the ceiling and bathe each room in a steady glow from above. If you need more (or less) light, light delivered in different ways or light that helps you cope with spending long hours indoors, that is your problem to solve as an individual.

It shouldn’t be this way. The role that light plays in ensuring that our homes, offices and factories keep us healthy, comfortable and effective is not trivial.

In fact, lighting matters so much that UNESCO, the United Nations Educational, Scientific and Cultural Organization, designated May 16 as the annual International Day of Light to recognize the role it plays in the lives of citizens of the world.

Good lighting

If uniform downlighters delivering cool-white light from LED fixtures are less than adequate for all situations, what should we look for instead? The Good Light Group, a non-profit alliance, argues that humans need plenty of daylight to synchronize their body clocks.

If people are spending almost all their time indoors, as many of us do, indoor lighting should mimic the positive effects of natural daylight. The Group therefore defines good light as lighting that is attractive, of high quality, comfortable for the eyes and dynamic. The Group adds that good light has spectral characteristics that vary according to time of day or specific tasks and adapts to users’ needs.

The Light and Health Research Center (LHRC) at the Icahn School of Medicine at Mount Sinai in New York is advancing one aspect of this charter with the second release of a circadian stimulus calculator. This free, open-access software lets lighting professionals compare how well different light sources, exposure times and lighting levels stimulate the circadian system.

The calculator uses recent biophysical research and retinal neurophysiology. Researchers at the Center have also been working on using light to reduce depression and agitation in people living with dementia, improve the sleep and mood of office workers and help U.S. Navy submariners cope with life under water.

At the launch of the updated software, Mark Rea, co-director of the LHRC, said: “The CS Calculator 2.0 takes us another step closer to routinely engineering bright days and dim nights that lead to better sleep at night and less sleepiness during the day.”

Lighting at work

There is, of course, a flip side to this benevolent ambition. A 2021 study reported in the journal Nature and Science of Sleep what happened when night-shift workers at a chemical plant were asked to work under much brighter conditions than usual, using lights that produced more short (i.e., blue) wavelengths than usual. The study showed that the workers remained more alert and worked with greater accuracy and for longer periods of time when subjected to the brighter, bluer lighting. It didn’t explore how the intense illumination affected their circadian rhythms during the rest of the day.

One way of fulfilling Good Light Group’s mission and ensuring we all live by “good light” is to implement a smart lighting strategy, which makes lighting a dynamic part of a building’s operation rather than just a static feature — installed once and endured forever.

Smart lighting can increase lighting efficiency by ensuring that the right lighting goes to the right places at the right time – and only to those places. It can make a positive contribution to user well-being by providing the right amount of light, at the right wavelength, to ensure that people can work without eye strain, can be alert when they need to be and can relax when appropriate. It can help increase the utilization of a building by providing flexible ways to style its spaces and to quickly reconfigure those spaces to suit changing usage patterns, the time of day or the desired mood.

Smart lighting can also have more utilitarian functions, such as increasing safety and security, through intelligent approaches to lighting common areas, and enabling “light harvesting” by automatically adjusting lighting levels to take advantage of ambient light coming in through windows. Of course, many of these features rely on more centralized control of light use, which can increase efficiency and save costs, while also integrating with other aspects of a building automation system.

Smart lighting is a large and rapidly growing market, according to a report from Mordor Intelligence, which says that the global smart lighting market was worth $12.72 billion in 2020 and will grow 20.26% per year, each year to reach a value of $37.41 billion by 2026. However, the report does caution that supply chain disruptions caused by COVID-19 could limit that growth. It also points out that smart lighting currently only accounts for a small fraction of global lighting revenue.

Lighting as a platform

One way to accelerate the uptake of smart lighting could be to present it as more than just a way to improve building lighting and instead as a platform for increased building intelligence.

The fact that lighting fixtures are wired throughout a building makes them an attractive way of distributing functions such as sensing and network connectivity.

Some vendors are even considering using power over Ethernet (PoE) strategies to light LED fixtures while distributing WiFi network connectivity.

Adding Bluetooth beaconing technology to the fixtures would enable asset tracking that could, for example, make it easier to find essential equipment in large hospitals. And smart lighting fixtures could also carry ambient light sensors to enable light harvesting, PIR or radar sensors to check for room occupancy, and CO2 and particulate sensors to monitor environmental air quality.

Good lighting matters, and now we have smart lighting strategies to make it easier to implement.

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