Abstract
Literature suggests an influence of the luminance from non-horizontal surfaces in our visual field on our visual and psychological assessments of an office space. These assessments are believed to directly relate to our expressed preferred task illuminances.This paper describes an evaluation in a mock-up office, wherein wall conditions with a non-uniform and a more uniform light distribution of 3 different average luminance levels have been evaluated regarding their effect on users' preferred task illuminance. Each condition is evaluated starting from three different initial desk illuminances.For all test conditions, a wall with a non-uniformly distributed average luminance of 200 cd/m2 lead to significantly lower selected desk illuminances than a uniformly lit wall with the same average luminance level. In all cases, preferred task illuminances set were significantly lower when offering the lowest starting level for dimming of 300 lx. The range of preferred illuminance levels between subjects was also found to be smaller for dimming with the starting level of 300 lx at desk level.The study suggests that when providing users with personal control they will control the total perceived brightness in their visual field, even though they are only directly affecting their task illuminance level. Triggering the selection of lower preferred illuminance levels due to a personal control starting level of 300 lx, will positively influence the energy used for lighting. The smaller range of preferred illuminance levels between subjects at the starting of 300 lx could reduce the risk of lighting preference related conflict between people. However, more research is needed to confirm that these smaller differences are also perceivable by users.
Highlights
With the changing character of office work, the majority of our tasks today include non-horizontal surfaces in the visual field
This paper describes an evaluation in a mock-up office, wherein wall conditions with a non-uniform and a more uniform light distribution of 3 different average luminance levels have been evaluated regarding their effect on users' preferred task illuminance
The study suggests that when providing users with personal control they will control the total perceived brightness in their visual field, even though they are only directly affecting their task illuminance level
Summary
With the changing character of office work, the majority of our tasks today include non-horizontal surfaces in the visual field. Besides the benefits of lighting within the preference of users [5], Sadeghi et al recently reported a relation between occupant perception of control and the acceptability of a wider range of visual conditions [14]. This increases in relevance when dealing with multiple users in one open office space. In the interviews the participants shared their self-assessed lighting preference, which could be generalized in a bright, medium, or dark preference category [15] This selfclassification could be based on the users' preference for task illuminance levels for the visual task, but could be their preference regarding the office appearance. If perception of brightness could be maintained at a lower desk illuminance level, energy consumption could be reduced
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
