DECREASING LUMINANCE CONTRAST ON WINDOW WALLS AS WELL AS USERS INTERVENTIONS: USING LED LIGHTING SYSTEM

Transcription

1 DECREASING LUMINANCE CONTRAST ON WINDOW WALLS AS WELL AS USERS INTERVENTIONS: USING LED LIGHTING SYSTEM Mehdi Amirkhani 1, Veronica Garcia-Hansen 2, Gillian Isoardi 3 1,2,3 Queensland University of Technology (QUT)

2 Introduction Experiment 1 Experiment 2 Future work

3 Introduction Background

4 Introduction Background Higher degree research student office at QUT

5 Introduction Background Higher degree research student office at QUT

6 Introduction Background Heschong, L., Howlett, O., McHugh, J. and Pande, A. (2005) Sidelighting photocontrols field study,neea and PG&E and SCE.

7 Introduction Aim Using supplementary lighting, such as LED to enhance user visual comfort, as well as reducing their interventions.

8 Experiment 1

9 Experiment 1 Aim

10 Experiment 1 Method Cool-light LED strips, which have matched correlated colour temperature (CCT) to sunlight (5600 K-7000 K), were chosen. However, the proposed LED system in this study was chosen as merely an easy method to conduct the test and not for its energy efficiency.

11 Experiment 1 Method

12 Experiment 1 Method Stage 1 Stage 2 Stage 3 Stage 4 LED system off %25 luminaire power %35 luminaire power %45 luminaire power

13 Experiment 1 Method Konica Minolta LS100 luminance meter Konica Minolta T-10 illuminance meter Nikon Coolpix 8400 digital camera with a fisheye lens

14 Experiment 1 Mean window wall luminance ratio during each stage

15 Experiment 1 Results Mean indoor visual comfort during each stage

16 Experiment 1 Results Boxplot of window wall luminance ratio and feeling discomfort glare from window

17 Experiment 1 Results Survey results

18 Experiment 1 Conclusion The outcomes of this study indicated that a supplementary LED system could reduce the luminance contrast on the window wall from values in the order of 117:1 to 33:1. The results of this experiment suggested that this supplementary strategy could increase the subjective scale appraisal of window appearance by approximately 33%, as well as reducing the likelihood of users intention to turn on the ceiling lights by about 27%.

19 Experiment 2

20 Experiment 2 Experiment setting

21 Experiment 2 Experiment setting Cool-light LED strips, which have matched correlated colour temperature (CCT) to sunlight (5600 K-7000 K), were chosen. However, the proposed LED system in this study was chosen as merely an easy method to conduct the test and not for its energy efficiency.

22 Experiment 2 Questionnaire

23 Experiment 2 Method Stage 1 Stage 2 Stage 3 Stage 4 LED system off %35 luminaire power %45 luminaire power %55 luminaire power

24 Experiment 2 Instruments Konica Minolta LS100 luminance meter Konica Minolta T-10 illuminance meter Nikon Coolpix 8400 digital camera with a fisheye lens

25 Results and discussion Scatter diagram of luminance ratio between window and surrounding walls during each stage

26 Experiment 2 Results Scatter diagram of correlation between the luminance ratio on the window wall and feeling discomfort

27 Experiment 2 Results Boxplot of lighting measurement on the desk level and subjects indoor lighting satisfaction for performing laptop task

28 Experiment 2 Results Boxplot of indoor lighting level and feeling discomfort glare from window

29 Experiment 2 Results Bar chart of the association between perceiving discomfort glare from window and subjects decision to turn on ceiling lights Bar chart of the association between perceiving discomfort glare from window and subjects intention to move the blind down

30 Experiment 2 Conclusion The results of this experiment showed that the proposed LED system could increase the subjective scale appraisal of window appearance. This study also suggested that for the tested conditions, a contrast ratio of about 14:1 on the window wall was the average value below which fewer reported perceiving discomfort glare from windows. In addition, the study suggests that this contrast ratio on the window wall might enhance subjects rating for indoor lighting satisfaction while working with laptop, as well as reducing subjects intention to intervene in lighting conditions.

31 Future work Further research would be beneficial to investigate acceptable luminance ratios on the window wall through recruiting more subjects in the same test office room, as well as various test office environments with different office layouts and window types. In addition, more investigation is needed to advance the energy efficiency and efficacy of the proposed supplementary LED lighting strategy to considerably diminish energy usage of the proposed lighting design strategy.

32 Thank you