In the lighting field, one often hears the gospel of lighting quality. We are told lighting quality should not be sacrificed for energy savings. Lighting quality, after all, ensures people are satisfied with the visual environment. It is lighting quality that provides true economic value to the owner by supporting productivity, sales, etc.
It makes intuitive sense, but it gets tricky when one tries to define lighting quality. Lighting quality goes far beyond simple light levels, covering factors such as brightness, light distribution, color, daylight and aesthetics. Individual metrics support implementation of lighting quality elements, but there is no single lighting quality metric, the development of which at one time was one of the industry’s Holy Grails.
One solution is not to try to objectively evaluate the art of lighting but to subjectively evaluate how satisfied users are with the outcome. This approach is based on a simple definition of lighting quality as a lighting design that achieves its application goals. In office lighting, for example, industry research indicates greater satisfaction with lighting can result in greater job and environmental satisfaction, a universally desirable goal.
To address this opportunity, the Pacific Northwest National Laboratory (PNNL)—funded by the Department of Energy, the General Services Administration, the National Electrical Manufacturers Association and the Lighting Controls Association—developed the Light Right Survey, a free tool for building owners, facility managers and industry practitioners to inventory and evaluate lighting systems in office spaces. (Full disclosure: I consulted on a phase of the tool’s development.)
“Lighting provides a great opportunity for increasing worker satisfaction, reducing a building’s operating costs, and saving energy,” said Tracy Beeson, L.C., Energy and Environment Directorate, PNNL. “There is no better way to understand the acceptability of a lighting system than to ask the people who live and work in the space.”
The Light Right Survey Tool, available free at www.lightingsolutions.energy.gov/cls-survey, includes 50 questions profiling the respondents, what type of lighting equipment they use, and how satisfied they are with numerous aspects of their lighting. The questions were written by lighting experts but in language easily understood by people with little to no lighting knowledge. The results can be used to objectively determine which aspects of the lighting design are working and which aren’t. This knowledge can support prioritizing solutions that can improve user satisfaction.
The results, packaged as an extensive report that provides a graphical narrative about lighting satisfaction among respondents, can specifically be used in the following ways:
• As a diagnostic tool to determine if any changes could be made to a lighting system to increase user satisfaction
• As a way to measure the effectiveness of various lighting improvements
• To identify equipment and design choices that produce higher levels of lighting satisfaction
• To increase communication between lighting decision-makers and those who actually use the lighting
• As a way to justify appropriate lighting investments to the owner of the lighting system
“The Light Right Survey Tool has been designed to provide a deep understanding of satisfaction associated with a lighting system, and any problems that lead to dissatisfaction, well enough to provide actionable guidance,” Beeson said. “Imagine if a building owner had a place to turn to understand why cubicle forts were popping up across an open office or why office workers were wearing hats, visors and sunglasses indoors. This survey can help identify and resolve problems from glare to flicker to dissatisfaction with controls to dropping light levels.
“The survey can be used as a diagnostic tool. It could be used to compare different lighting systems or validate a new system is acceptable to a building’s occupants. Building owners and tenants could use it to validate satisfaction of occupants in the space and allow the outcome to instruct any upgrades being considered. Designers and electrical engineers can circle back to validate the quality of their design approach. Manufacturers can use the input to increase the quality of their equipment.”
The party originating the survey, called the survey manager, distributes the survey and generates data reports using a special interface. All responses are anonymous. Survey managers can create and conduct multiple surveys at the same time. Data is available in many formats, including raw numbers, an HTML summary for decision-makers seeking a higher level of understanding, and advanced reports for facility managers interested in ideas on how to remedy areas requiring corrective action. Philips is supporting an effort to allow photos of actual lighting equipment to be uploaded into the survey. In the future, PNNL may collect data into a national database, an extraordinary step that would allow benchmarking and support identification of best practices for lighting.