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Lighting Design + Application : LD + A, 40, Dec 12, p. 26, 28,30, 2010-12-01

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Research matters: lighting that benefits organizations and the

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Veitch, J. A.

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Re se a rc h m a t t e rs: light ing t ha t be ne fit s orga niza t ions a nd t he

e nvironm e nt

N R C C - 5 3 9 5 1

V e i t c h , J . A .

D e c e m b e r 2 0 1 0

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Lighting Design + Application : LD + A, 40, (12), Dec, pp. 26, 28,30, December

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Published in Lighting Design + Application, 40, (12), December. 2010, pp. 26- 28, 30.

RESEARCH MATTERS: LIGHTING THAT BENEFITS ORGANIZATIONS AND THE ENVIRONMENT

By Jennifer A. Veitch

In a previous column (March 2008), I wrote about laboratory experiments that showed the benefits of individual, personal control over lighting. These experiments showed that giving people the opportunity to choose their own local lighting levels enables them to create conditions closer to their personal preferences. Working in one’s preferred conditions leads to more positive mood and to better satisfaction with lighting. In experiments supported by the Light Right Consortium (www.lightright.org), having individual control over lighting seemed to improve motivation over the workday; people without control showed a drop in motivation from morning to afternoon. Today, I can update you on our progress in studying these effects in the field.

When writing the final report for the Light Right Albany experiments, the team concluded that laboratory investigations of the effects of light distribution and individual control had reached the end of their usefulness (Boyce, et al., 2006; Boyce, Veitch, Newsham, Myer, & Hunter, 2003). To demonstrate the overall organizational benefits of high-quality, energy-efficient lighting in offices would require a field study in a functioning work setting. Our team at NRC-IRC has now completed that study, with funding from the Light Right Consortium. The investigation was designed to achieve two objectives:

1. To replicate the results of the Light Right Albany experiments in a functioning work setting. 2. To extend the model

developed from the Albany data to organizational effectiveness outcomes.

Figure 1. Proposed conceptual model.

The black lines indicate relationships observed in the Albany experiments. The blue lines are relationships derived from

other research. The red line is a logical inference.

RESEARCH DESIGN

The project was designed around a linked mechanisms map (Figure 1). As in the Albany experiments, each concept in the linked mechanisms map had at least one associated measurement.

The experimental design was a naturally-occurring field experiment in an organization that has undertaken a major renovation of three office buildings, involving both furnishings and lighting. Individual floors in all buildings will be renovated in phases over several years. During the study period (May 2008-September 2009), both old (pre-renovation) and new (post-renovation) conditions existed in the buildings. The old lighting consisted of recessed parabolic-louvered

luminaires (similar to the Base Case condition in the Albany experiment 1), and the new lighting consisted of workstation-specific individually-controllable suspended direct/indirect luminaires (similar to the Dimming Control condition in the Albany experiment 1). Furnishings also

changed with the lighting (from (dark) teal to (light) off-white), except for four floors in one building that have had the new lighting for several years and that are keeping their medium grey panels. All of the buildings had large windows on all orientations. Figure 2 shows examples of the old and new lighting and furnishings. Health Lighting  Appraisal Mood   Motivation  Creativity  Operational  Efficiency  Lighting  Design Environmental  Satisfaction  Individual  Control  Room  Appearance  Luminous  Conditions  Intent to  Turnover  Job Satisfaction Organizational  Commitment

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Published in Lighting Design + Application, 40, (12), December. 2010, pp. 26- 28, 30.

Figure 2. Left: Old panels, old lighting. Middle: New panels, new lighting.

Right: Older panels, new lighting.

All occupants of the three buildings were asked to complete an online questionnaire on three occasions during the study, in May-June 2008, June 2009, and September 2009. Each time, the questionnaire included questions and tasks to assess the individual-level concepts in the linked

mechanisms map. Each measurement wave included a site visit by the research team, during which the physical conditions in selected locations were measured, with photometric measurements both by day and by night (electric lighting only). Some of the participants moved to newly-renovated offices between the first and second measurement waves; others had already moved to new or newly-renovated spaces before the first wave; and others did not experience any office design or lighting changes during the study period.

As is evident from the photos, the three luminaire and furnishing combinations created markedly different visual conditions. (There were also three variations in the operation of the workstation-specific direct-indirect luminaires, which resulted in different proportions of indirect illumination, but these were small in comparison to the difference between workstation-specific direct-indirect lighting and recessed parabolic louvered luminaires.) All the measured locations met or exceeded IES recommendations for work plane illuminance. The offices with workstation-specific luminaires had higher ceiling luminances than the parabolic-louvered luminaire spaces; those with with high-reflectance furnishings also had higher vertical luminances in the field of view.

QUESTIONNAIRE RESULTS1

Workstation-specific lighting with individual control is the higher-quality lighting solution. Workstation-specific

lighting with individual (personal) control was preferred over parabolic-louvered luminaires regardless of the surface

reflectances of the furnishings. The workstation-specific luminaires were rated as providing lighting that was better than in other similar

workplaces; the parabolic-louvered luminaires were seen as being the same as in other similar workplaces. In the most sensitive statistical tests, small effects were found for several outcomes. Pleasure, room attractiveness and illumination, lighting satisfaction, overall environmental satisfaction, job

Figure 3. Group means for the overall comparison between

responses from people in workstations lit with parabolic-louvered luminaires (PARAB), compared to those with workstation-specific direct-indirect luminaires with individual control (WS-60U-C), all

with low-reflectance, old furniture. All differences are statistically significant.

1 2 3 4 5 6 7 Satis. w/  Lighting

OES Job Satis Org'l  Commit. Intent to  Turnover PARAB WS‐60U‐C 1

Detailed results are available in the project report (Veitch, Newsham, Mancini, & Arsenault, 2010, in press) on the Light Right (www.lightright.org) and NRC (www.nrc-cnrc.gc.ca) web sites.

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Published in Lighting Design + Application, 40, (12), December. 2010, pp. 26- 28, 30.

satisfaction and organizational commitment were all higher for the people in offices with workstation-specific luminaires. The frequency and intensity of physical symptoms and the intent to turnover (voluntarily seek other employment) were all lower for the people in offices with workstation-specific luminaires. There were no effects that were contrary to the expected direction. Figure 3 shows some of the results in graphical format.

Room surface reflectances influence lighting quality. Workstation-specific luminaires with

individual control were more likely to be rated as being better than in other similar offices when the surface reflectances were high. The workstation was also judged to be more attractive and to be more highly illuminated, and to deliver a

better workplace image.

Luminous conditions matter to organizational

productivity. We tested the overall

linked mechanisms map using structural equation modelling. The best-fitting model was based on the Albany experiments’ linked

mechanisms map (Veitch,

Newsham, Boyce, & Jones, 2008). As shown in Figure 4, better luminous conditions (which in this case meant individually-controllable workstation-specific lighting and high-reflectance panels, as opposed to parabolic-louvered luminaires, no individual control, and dark panels),

generally produced better appraisals, and these in turn indirectly related to reduced health problems and to reduced intent to turnover.

Figure 4. Conceptual form of final structural equation model.

DISCUSSION

This field investigation achieved both objectives. The basic findings from the Albany experiments were replicated, in that we obtained clear evidence that energy-efficient lighting can deliver good lighting quality that benefits occupants, when it provides:

• Light distribution that lights all the room surfaces (i.e., a mix of direct and indirect lighting);

• Room surfaces that contribute to the light distribution; and, • Individual control to accommodate different needs and desires.

Moreover, we replicated the appraisal path from the Albany linked mechanisms map and extended it to include organizationally-relevant outcomes. The best-fitting model links these luminous conditions to higher ratings of room appearance; more favourable mood; fewer health problems; higher environmental satisfaction; higher job satisfaction; higher organizational commitment; and, lower intent to turnover. If good-quality lighting only resulted in more attractive spaces, the chain of relationships would stop at room appearance. It did not: We have shown that lighting conditions in employee offices affect organizational productivity through effects on employees.

Other NRC research in the same host organization has demonstrated that the workstation-specific direct-indirect luminaires with individual control, daylight harvesting, and occupancy sensors, can save 69% of the electricity used compared to a conventional grid of parabolic-louvered luminaires (Galasiu, Newsham, Suvagau, & Sander, 2007). The evidence that these luminaires also deliver a higher-quality work environment, and furthermore that this environment is associated with fewer health problems and better employee retention, makes this lighting solution an excellent choice for individuals, their employers, and the environment.

REFERENCES

Boyce, P. R., Veitch, J. A., Newsham, G. R., Jones, C. C., Heerwagen, J., Myer, M., et al. (2006). Lighting quality and office work: Two field simulation experiments. Lighting Research and Technology,

38(3), 191-223.

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Published in Lighting Design + Application, 40, (12), December. 2010, pp. 26- 28, 30.

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Boyce, P. R., Veitch, J. A., Newsham, G. R., Myer, M., & Hunter, C. (2003). Lighting quality and office

work: A field simulation study. (PNNL 14506). Richland, WA, USA: Pacific Northwest National Laboratory Retrieved from http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/b3214.1/B3214.1.pdf. Galasiu, A. D., Newsham, G. R., Suvagau, C., & Sander, D. M. (2007). Energy saving lighting control

systems for open-plan offices: a field study. Leukos, 4(1), 7-29.

Veitch, J. A., Newsham, G. R., Boyce, P. R., & Jones, C. C. (2008). Lighting appraisal, well-being, and performance in open-plan offices: A linked mechanisms approach. Lighting Research and

Technology, 40(2), 133-151.

Veitch, J. A., Newsham, G. R., Mancini, S., & Arsenault, C. D. (2010, in press). Lighting and office

renovation effects on employee and organizational well-being. (NRC-IRC B3230.1). Ottawa, ON:

NRC Institute for Research in Construction.

Jennifer A. Veitch, PhD, Fellow IESNA, is a senior research officer at the National Research Council Canada Institute for Research in Construction (NRC-IRC). She's best known for her research on lighting quality, and her contributions to Chapter 10, Quality of the Visual Environment, in the IESNA Lighting Handbook (9th

ed.), and more recently for research into environmental and job satisfaction in open-plan offices. She is

active in several professional associations including CIE, where she is secretary of Division 3 (Interior Environment and Lighting Design), and vice president of the Canadian National Committee. She serves on the IES Lighting Criteria Committee and the Operations Advisory Board for Leukos.

Figure

Figure 1. Proposed conceptual model.
Figure 2. Left: Old panels, old lighting. Middle: New panels, new lighting.
Figure 4. Conceptual form of final structural equation model.

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