Page 71 - Lighting Magazine May 2018

High-Performance Buildings, U.S. General Services Administration (GSA), which helps federal agen- cies build and acquire o ce space, products, and other workspace services. Heerwagen and her colleague Bryan Steverson, Project Manager for GSA Workplace Research, collaborated with the Lighting Research Center (LRC) at the Rensselaer Polytechnic Institute (RPI) on the study.
According to Heerwagen, at the forefront of the research were the questions, “What can we do in the build environment to improve health?” and “Can we intentionally design indoor lighting to enhance circadian functioning for health and well-being?”
A core belief was that many people are not get- ting enough of the right kind of light at the right
time. As a result, their circadian rhythms are be- ing disrupted, leading to, among other conditions, daytime sleepiness and that dreaded 3 p.m. crash in energy that most o ce workers experience. To remedy the situation, however, will take much more than merely ge ing the o en-cited eight hours of sleep per night.
Who cares? The GSA for one. Why? It oper- ates 8,700 buildings spanning 374 rentable square feet and employing thousands of people. Consider the statistic that most people spend 90 percent of their lives indoors, and you can imagine why there is concern we might not be receiving as much of Mother Nature’s bene ts as our ances- tors did.
The study was conducted in GSA buildings na- tionwide and included both winter and summer months to provide seasonal balance.
The research team performed photometric analysis of each individual’s light exposure and tracked how much they moved during the day (using a small actigraph sensor unit similar to a Fitbit®), plus employed a Daysimeter on a stick (at the windows) to track light exposure in the work- space throughout the day. Nightly sleep quality was also part of the equation. There were three key ndings:
1. “We found study participants got more light at work than anywhere else — even in summer,” Heerwagen revealed, adding, “This surprised us!”
2. “Those with the most circadian stimulus – especially in the morning – had signi - cantly be er sleep at night and were less depressed,” she noted.
3. “But many did not receive su cient light during the day and were essentially in biological darkness,” Heerwagen said.
What was causing the reduction in light expo- sure had to do with the employees’ necessity to work on computer screens. To avoid glare, window shades were used to reduce the amount of day- light coming in.
“This is just the beginning of our research,” Heerwagen stated. The results of Phase 1 of the study pointed out that achieving su cient
2
worKspAcE lighting
“Daylight is
a critical psychological and aesthetic resource and can improve circadian health.”
May 2018 | enLIGHTenment Magazine 67