Facilities managers who work with an energy service company to increase the efficiency of their buildings might not be thinking about occupant productivity, but if the ESCO is familiar with circadian lighting, it’s possible they can work toward improvements on both efficiency and workplace management, according to Rahul Shira, senior product manager for controls and software at Genlyte Solutions.
Circadian lighting refers to the natural changes in intensity and color of sunlight over the course of the day. Genlyte tries to mimic this cycle in the ceiling lights that it offers facilities with the idea that workers are more productive if they feel connected to the rhythms of the day, Shira said in an interview. Genlyte is part of commercial lighting company Signify.
Genlyte’s circadian lighting, which gets brighter and cooler at midday and dimmer and warmer as afternoon progresses, is also tied to sensors that, for efficiency purposes, monitor occupancy patterns so building operators can optimize energy use based on where people are.
Combining circadian lighting with occupancy sensors gives facilities managers two levers they can pull to create value-added services for their organization: workplace productivity and building energy efficiency.
“Lighting is the only technology in the building that can give you a bird’s eye view of what’s happening in the space,” Shira said, “because lighting is in every corner of the building, from your lobby to your corridors to your cafeteria to your offices and meeting rooms.”
Increased productivity is one of several occupant wellness benefits of circadian lighting, according to research. These benefits can potentially translate into ROI for organizations that deploy the technology, some research suggests.
“Installation of a lighting system with a timer on a circadian-friendly schedule that adjusted the brightness and color of lighting throughout the day led people to say their work performance was 18 percent better,” an Urban Land Institute report says.
A study by the National Institutes of Health says the correlation between light exposure and how engaged people are at work is a tight one.
“Controlling the key characteristics of light exposure, including the timing, intensity, duration and spectrum facilitates synchronization of the endogenous circadian pacemaker [translates] to improved safety and productivity,” says a 2024 study by the NIH-affiliated National Center for Biotechnology Information.
On the energy efficiency side of lighting, occupancy sensors are one of the first things ESCOs will look at as they work with facilities managers to plan building retrofits, Shira said.
“We know from historical performance, case studies and industry reference points that we can get up to 75% energy sayings from the sensors because we know they can reduce the lighting load when the room is vacant and reduce the intensity if there’s too much daylight,” he said.
In Genlyte’s case, he said, the sensors communicate with one another within each room so even in an open office environment, lights over different cubicles can differ based on a granular level of monitoring.
“Because the sensors are talking to each other, they can figure out truly which workstations are occupied, and they alternate between the light levels based on the occupancy pattern,” he said.
The contact that Genlyte typically has with facilities is either on the retrofit side, where it typically works through the ESCOs, or the new constriction side, where it works with lighting designers and architects while the project is being planned.
“The industry is moving in the direction of occupant wellness through standards,” said Shira, pointing to the International WELL building certification, introduced in 2014 and updated regularly since then. “They look at how space is conducive [to occupant well being] through light quality, temperature, noise levels and humidity.”
