Zhao, Chengpeng;
(2025)
The effects of spectral power distribution with high melanopic efficiency on visual and atmosphere perceptions of offices.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
Recent investigations into the effects of spectral power distributions (SPD) have largely kept separate the impact on the human’s circadian system from impressions of interior lighting. When daylight is insufficient, blue-enriched electric light sources are considered as an alternative to deliver a stronger stimulus to circadian system of occupants in offices. However, such light sources may not always be desired. At present, it is still not clear how to balance the non-visual effects of light on circadian rhythm and user satisfaction of office lighting. Therefore, this research aims to explore the influences of SPD with high Melanopic Daylight Efficacy Ratio (M-DER) on visual and atmosphere perceptions in the context of Integrative Lighting design for offices. Three objectives were proposed to achieve this aim. The first objective seeks to test can cold white light sources be more acceptable if they have SPDs closer to the daylight. The second objective is to examine if increasing melanopic efficiency by shifting peak wavelength of blue primary affects visual and atmosphere perceptions. The third objective is to explore how Duv affects atmosphere perceptions of office lit by SPDs with melanopsin stimulating peak wavelengths. Three psychological experiments were conducted with a multi-channel LED lamp which can closely resemble the SPD of daylight. The results suggest neither using SPD of daylight nor changing Duv improve user satisfaction of electric lighting. Metameric approaches can increase melanopic efficiency of SPD without significantly affecting visual and atmosphere perception, but the colour matching functions should be selected with care. There was evidence suggesting melanopsin may play a role in colour vision. It is anticipated that these results will assist lighting designers and manufacturers in selecting the most beneficial light spectra for the health and well-being.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | The effects of spectral power distribution with high melanopic efficiency on visual and atmosphere perceptions of offices |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of the Built Environment UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of the Built Environment > Bartlett School Env, Energy and Resources |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10204586 |
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