ARCHIVED – IRC illuminates lighting control/performance link v4n2-12

Volume 4, Number 2, Winter 1999

Archived Content

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Despite conventional wisdom, ongoing research at IRC is indicating that, under certain conditions, having control over office lighting may not affect employee performance. This important finding has implications for building designers and managers considering complex - and expensive - controls for lighting systems.

Researchers in IRC's Indoor Environment Program have shown that if people already have good lighting, there might not be significant benefit in adding individual lighting controls. Their research will also assist lighting designers, by showing what kinds of lighting conditions people prefer.

In this experiment, conducted in IRC's Indoor Environment Research Facility, people were paired off, and spent the day doing typical, computer-related office work. In each pair, one person had control of the lighting, while the other wasn't told that lighting was an issue. At the start of the day, the person with control set the lighting conditions under which the day's work would be done.

Most workers chose lighting levels that were typical of current practice. Because new office lighting tends to be fairly energy efficient, the findings indicate that good quality lighting can also be energy efficient. The two groups of people had similar high levels of satisfaction and performance. In fact, it is unlikely that providing additional lighting control could have improved them.

When given the chance to change lighting settings at the end of the day, many workers opted to reduce glare on computer screens. This suggests that people can identify problems with lighting and fix them, given the opportunity, which could have long-term effects on satisfaction. (Long-term worker satisfaction was not examined in this experiment.)


Overall, this research has demonstrated the need for caution when considering the installation of sophisticated lighting-control systems. There may be insufficient benefit to justify the expense of providing individual controls. In fact, studies in the United Kingdom have shown that if systems are too complex to be easily understood, they can actually be sources of dissatisfaction.

IRC researchers believe that it is important to understand what kinds of lighting people want, and what kinds of lighting they will use. Thus the research will now turn to analyzing the lighting preferences expressed by the participants in the experiment, in order to further investigate these lighting conditions.

Specific questions can be directed to Dr. Jennifer Veitch at (613) 993-9671, fax (613) 954-3733, or e-mail

This project is supported by:
Canadian Electrical Association (Agreement No. 9433 U 1059)
Natural Resources Canada
Panel on Energy Research and Development
National Research Council of Canada (NRC).

Lighting equipment was donated by the following companies: CANLYTE Inc.
General Electric Co.
Ledalite Architectural Products Inc.
Litecontrol Corp.
Luxo Lamp Ltd.
Osram-Sylvania Inc.
Peerless Lighting Ltd.

Together, these partners are assisting both building designers and users by identifying and describing lighting systems that more fully account for user preferences, thus removing a possible source of worker dissatisfaction. At the same time, this research may eliminate the need for expensive individual lighting control systems, while still pointing the way to lighting conditions that improve worker satisfaction and productivity.