Fluorescent lights that make faces look green or reflect in computer monitors may seem inconsequential, but poor illumination can affect people's moods, productivity, job satisfaction and overall well-being.
Understanding how lighting and other elements of the physical environment influence people requires the combined expertise of engineers, physicists and psychologists. These disparate disciplines have a rare opportunity to work together at the National Research Council (NRC) of Canada, the country's principal federal science and research organization in Ottawa. Jennifer Veitch, PhD, is one of three environmental psychologists among 120 other scientists in the NRC's Construction Research Centre, where she partners with researchers who seek to maximize energy efficiency in heating, lighting and ventilation while also valuing people's well-being.
Veitch's psychological knowledge is informing the development of lighting that enhances mood and saves energy by giving people more personalized control over their office environments and new options for lighting their homes. Her work in the lab and office buildings is not only influencing building and renovation practices in Canada and internationally, but also changing the way that other scientists think.
Changing minds
One of those scientists is Chantal Arsenault, a physicist in the lighting and ventilation quality group at the NRC. "I come from a very technical, raw physics background, and I always thought that if you make the technology clever enough, people won't notice small changes in the indoor environment," she says. "But after working with Jennifer, I realized how much people detect minor environmental changes and how much they value their well-being."
When Veitch started working at the NRC 27 years ago, she sometimes encountered resistance from engineering researchers who were skeptical about results from human participant studies that included what seemed like too much variability. Scientists also worried that the requirement for approval from an ethics board for these studies would add extra administrative burdens and delays, which made such work less attractive to them.
"Engineers and psychologists do not speak the same language, but Jennifer took the time to reinforce a common language that each side could understand," says Guy Newsham, PhD, a physicist who has worked with Veitch for more than two decades. "Referring to psychology as a 'soft' science was common, but over time, we all came to realize that in fact it is often more quantitatively rigorous than what people traditionally think of as 'hard' sciences."
Now Veitch's knowledge of experimental methods, statistical analysis and ethics are well respected and even inspiring colleagues like Newsham to return to school to gain these skills.
"Often the publications in the construction field lack formal statistical analysis, and Jennifer taught me about the process of collecting data in a way that supported rigorous analysis, suitable statistical techniques and reliable conclusions," says Newsham, who completed a yearlong master's-level statistics course in the psychology department at Carleton University in Ottawa. "With this added dimension, we are in a superior position as we present research."
Green buildings put to the test
Veitch's interest in the effects of the physical environment on behavior took root when one of her undergraduate professors covered environmental psychology in an introductory psychology course.
That experience, coupled with lessons she gleaned from her father, a professor of interior design, led her to enroll in a social ecology doctoral program at the University of California, Irvine, that offered an environmental psychology track. Her professors emphasized the importance of interdisciplinary work, and Veitch's classmates included sociologists, criminologists, urban planners and demographers, so she learned how to explain her work to people with different academic backgrounds. She then moved back to Canada and completed her PhD in environmental psychology at the University of Victoria, British Columbia.
Afterward, she applied for a postdoctoral fellowship in the NRC's lighting group, a role that would allow her to pursue her interest in interdisciplinary studies.
Three years later, the NRC gave her a full-time position. "The NRC hired me because the researchers saw that buildings only perform well when they support the health, well-being and activities of the occupants in addition to being structurally sound, energy-efficient and fire-safe," says Veitch.
In a series of experiments, for example, Veitch showed that people's lighting preferences vary significantly and that giving employees control over their local light levels contributes to better mood, higher environmental satisfaction, fewer physical and visual discomfort problems and higher job satisfaction. The studies also revealed that providing personalized control over local light levels can save about 10 percent in lighting energy compared with keeping light levels fixed (Lighting Research & Technology, Vol. 38, No. 4, 2006opens in new window and Vol. 40, No. 2, 2008opens in new window).
Human behavior and energy efficiency are also intersecting as scientists explore whether green buildings—which must meet standards for energy efficiency, air quality, noise levels and multiple other factors—are beneficial not only for the environment but also for the people who work in them. When Newsham and Veitch reviewed the literature on this topic, they discovered that there was scant research on the effects of green buildings on their occupants' behavior.
The duo teamed up with a large Canadian banking organization to study whether employees working in green buildings experienced more job satisfaction, earned higher performance reviews and showed increased commitment to the company compared with employees who worked in conventional buildings. After years of collaborating with Veitch, Newsham was well versed in carefully matching conditions. For example, he made sure to compare buildings of similar size, age and geographical location or climate, whose occupants had similar demographic profiles.
After analyzing the data, Veitch and Newsham discovered that organizational productivity indicators, including job satisfaction and employee performance evaluations, were better, on average, in green buildings (Building Research & Informationopens in new window, Vol. 46, No. 7, 2018). The green buildings could be boosting organizational productivity because the improved physical conditions—including better air quality, more comfortable temperatures and better ventilation—might lead to improved satisfaction and better conditions that support work, Veitch says. The study results provided evidence for the organizational benefits of adopting standards for greener buildings that leave a smaller carbon footprint than conventional buildings, says Newsham.
Debunking lighting myths
Although Veitch's colleagues value her contribution to the team, the scientists have also taught her how physics, engineering and design elements interact to create the conditions that people experience. "If we want to understand people-environment relations, we need to deepen our understanding of the 'environment' side as much as the 'people' side," she says. Another reward of collaborating with physicists and engineers at NRC is the potential for immediate applications of her work to policies and standards that affect millions of people, says Veitch. That's why she's excited by a current project that could bring new lighting choices to consumers.
She's partnering with physicist Lorne Whitehead, PhD, to study "color rendering," or the ability of a light source to accurately reveal the colors of objects. "Some spectral power distributions with fluorescents make things look wrong, and people can find this quite sickening," says Whitehead, a professor at the University of British Columbia. "Some people are very sensitive to whether the environment feels normal, and if it looks abnormal, this can create a sense of worry and discomfort," he says.
Veitch and Whitehead set out to disprove the misconception that consumers had to forgo quality color rendering in favor of more energy-efficient alternatives. In one ongoing study, Veitch is testing lights designed by Whitehead that differ in the amount of light and the mix of colors they emit. The team is assessing mood and satisfaction as well as participants' ability to see well enough to complete tasks. They predict that people won't notice a small decrease in the amount of light—which means less energy consumed—but will be bothered by poor color (Leukosopens in new window, Vol. 12, No. 1–2, 2016). "We aim to show that it is possible to have LEDs that provide high color quality while also saving energy," Veitch says.
The research could ultimately guide regulators who make decisions that affect which products are offered to consumers. Compact fluorescents—which were designed to save energy—never took off because they didn't provide the amount of light or color accuracy that people wanted and needed, explains Veitch. "So many people did not buy them in spite of financial incentives from utility companies," she says. "We hope this kind of research can change the likelihood that more sustainable technologies are adopted."
Fixing a power problem
While most of Veitch's work centers around participants who work in office buildings or laboratory settings, she recently applied her expertise to a collaborative project involving people at home. An electric utility company in New Brunswick, Canada, needed help solving a problem rooted in energy usage habits among their customers: In this province, the demand for electricity in the winter peaked around 7:30 a.m. when a large percentage of the local population woke up and turned on lights, cranked up their thermostats and used power in other ways. While hydroelectric, nuclear, solar and wind sources could provide enough power for most electrical needs, the utility company was forced to turn to expensive fossil-fuel-based generation plants to meet the peak demand.
The company had an idea to solve the problem: installing smart thermostats in some homes to automatically pump up the heat at 5:30 a.m. and then decrease the temperature by one degree at 7:30 a.m. Ajit Pardasani, MSc, a mechanical engineer at the NRC, and Veitch partnered to study how this method to reduce the peak power demand would affect people. Together, they designed an intervention study, and Veitch created online surveys for more than 600 customers to assess whether they were feeling warm or cold at certain times and whether they had noticed any changes in their thermal comfort.
The findings from the study revealed that people were comfortable with preheating their homes at 5:30 a.m. and then experiencing a slightly lower temperature set point for a couple of hours starting at 7:30 a.m. With the new system, the utility company could lower the peak demand for power because the heating was spread out over time.
When Pardasani and the electric utility company originally considered raising the temperature set point by more than 2 degrees Celsius—or 3.6 degrees Fahrenheit—at 5:30 a.m. to preheat the homes before the peak period, Veitch intervened. She explained that this would not pass muster in the ethics review because people might become uncomfortable.
"Jennifer's role was crucial because this was an experiment on human beings, and I relied on her to navigate details like informed consent from the customers and designing questionnaires that would give us a good sense of how they were feeling during the experiment," says Pardasani.
Now the company is aiming to develop a winter season peak reduction program, which could include financial incentives in exchange for giving the company more control of the morning temperature settings. The technology could also be applied to reducing peak demands in other regions where electricity is used for heating, says Pardasani.
Before working with Veitch in the construction group, Pardasani spent many years at the NRC in manufacturing and information technology, but he had never collaborated with a psychologist. After partnering with her, he's convinced that more psychologists should be included in engineering and physical science research. And building scientists like Newsham are starting to see other researchers drawn to this kind of collaboration.
"A lot of my colleagues see this interdisciplinary research with psychologists as the next frontier in energy efficiency," says Newsham. Environmental scientists have historically focused on developing more energy-efficient equipment, but now they are starting to appreciate the importance of decisions people make with equipment, like whether to buy it in the first place and how to control it, he says. "The opportunity to get energy savings by influencing the behavior of individuals and organizations is growing."
"Psychologists on the Team" is a regular feature in which the Monitor explores the work of psychologists on interprofessional teams.
