Smart buildings: Why more research is needed on human-centric lighting
Credit: Osram

Smart buildings: Why more research is needed on human-centric lighting

The science behind human-centric lighting in smart buildings is strong, but more empirical evidence of positive worker outcomes is needed to boost the market, reports Jessica Twentyman. 

At the recent Light + Building 2018 exhibition in Frankfurt, an annual get-together for the global lighting industry, Professor Russell Foster of Oxford University voiced an opinion that may not have been welcomed by some exhibitors:

“We can’t deliver human-centric lighting until we know what impact light has upon human biology across the day and night cycle,” he said.

That might be considered controversial, because the show was stuffed with examples of human-centric lighting (HCL) systems that manufacturers are already selling. These work on the principle that exposure to varying light levels, delivered via tuneable, light-emitting diodes (LEDs), can influence the motivation, wellbeing, and productivity of humans in schools, hospitals, offices, and factories.

The message from those companies is clear: the technology is here and ready to be used. But according to Foster, a professor of circadian neuroscience and director of the Nuffield Laboratory of Opthalmology at Oxford, much more research is needed before this complex science can be neatly commoditised.

Foster’s credentials are not in doubt. He led the team at Oxford University that first discovered the human eye’s third photosensitive cells in 1991, beyond the previously understood rods and cones. These are the retinal ganglion cells, which control our circadian rhythms – the physical, mental, and behavioural changes that follow our daily cycles.

Potential impacts

That’s not to say that Professor Foster was dismissing the potential utility of human-centric lighting outright, merely that the industry doesn’t yet fully understand its potential impacts. “We simply don’t know,” he told his audience.

His view ties in closely with a recent report by market analysis company Navigant Research, which analysed the potential role that HCL could play in smart buildings.

Growing interest in healthy buildings that focus on occupants’ wellbeing, health, and productivity is paving the way for new opportunities in the commercial lighting industry, it found. Connected LEDs and smart control systems are among the technologies helping to provide actionable data that can influence the relationships between occupants and buildings, in addition to providing cost savings and energy efficiencies.

But the report also found that technology to measure and help quantify HCL is under-utilised, and no clear standards of measurement have been agreed.

“Human-centric lighting has been a growing buzzword within the lighting industry and is gaining attention by manufacturers, building owners, operators and occupants, and researchers,” said Navigant Research analyst Krystal Maxwell. “But while interest and available products are increasing, there is still a lack of research available on human-centric lighting, how to quantify the benefits of it, and the best way to measure it.”

While standards organisations provide a starting point for understanding HCL and healthy buildings, lack of agreement on measurement is expected to delay the industry’s progress, she explained.

Internet of Business says

With so much profit potential here, it’s clear that the lighting industry has much to gain from helping with the research effort – but only if the results can be considered sufficiently independent to win the trust of buyers. Key players here include Arcluce, Fagerhult, NormaGrup Technology, Osram, Philips, and Zumtobel Lighting.

In other words, the science is strong in itself, but a lot more evidence is needed to quantify the benefits.

It stands to reason that a dark, poorly lit workspace is undesirable and that flickering fluorescent lamps aren’t good for concentration. The focus now must be to show, in empirical terms via before-and-after data collected from real-life workplaces, how HCL can contribute to improved worker outcomes.