Development of the Annual Spectral Matrix Simulation Method and Assessment of the Effect of Spectral Discretization on Annual Lighting Energy Demand

  • As suggested by recent findings, light affects humans non-visually by impacting alertness, cognitive performance and various physiological responses. While the research about nonvisual photoreception is still ongoing, architects and designers have begun to conceive ways of integrating provisional recommendations into lighting design practices to enable healthy lighting in living and working spaces. Consequently, there has been a growing demand for annual lighting simulation tools that consider spectral properties of light for prediction and decision-making purposes. This thesis presents the annual spectral matrix simulation (ASMS) method. ASMS is based on integrating a precomputed annual spectral sky profile into the daylight coefficient approach to predict the spectral distribution of daylight. ASMS serves as the basis for evaluating annual lighting energy demand using spectral simulation of electric light. ASMS and point-in-time simulation with three-, nine-, 27- and 81-channel discretization are presented and discussed. The main aim is to examine the extent of increased accuracy of illuminance and annual lighting energy demand predictions that finer spectral discretization provides in comparison to the simulations with low spectral resolution. This investigation considers photopic as well as melanopic daylight equivalent illuminance. Finer discretization was found to be particularly beneficial for light sources with discontinuous spectral power distribution. When simulating a prototypical office room with fluorescent luminaires, annual lighting energy demand was underpredicted by 32.2 % or 16.9 kWh/m²a in a three-channel simulation in comparison to finer discretization with 81 channels. For LED luminaires with relatively continuous spectra, the difference ranged between 2.1 % and 7.8 % or 0.2 kWh/m²a and 0.7 kWh/m²a. As of today, the provision of an adequate level of melanopic equivalent daylight illuminance indoors is not required. The assessment showed that annual lighting energy demand was significantly lower when only photopic illuminance was regarded, but the minimum threshold of melanopic equivalent daylight illuminance was not met for most of the occupied hours. This finding highlights that additional consideration of melanopic equivalent daylight illuminance will lead to higher lighting energy demand. For the implementation of spectrum-based metrics in building and lighting design, high-resolution spectral simulation is therefore highly recommended.

Download full text files

Export metadata

Metadaten
Author:Margarita Alwalidi
URN:urn:nbn:de:hbz:386-kluedo-84281
DOI:https://doi.org/10.26204/KLUEDO/8428
Advisor:Sabine Hoffmann, Caroline Karmann
Document Type:Doctoral Thesis
Cumulative document:No
Language of publication:English
Date of Publication (online):2024/10/21
Year of first Publication:2024
Publishing Institution:Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
Granting Institution:Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
Acceptance Date of the Thesis:2024/07/25
Date of the Publication (Server):2024/10/22
Tag:annual lighting energy demand; daylight; electric light; multichannel spectral simulation
Page Number:VI, 143
Faculties / Organisational entities:Kaiserslautern - Fachbereich Bauingenieurwesen
DDC-Cassification:6 Technik, Medizin, angewandte Wissenschaften / 624 Ingenieurbau und Umwelttechnik
Licence (German):Creative Commons 4.0 - Namensnennung, nicht kommerziell, keine Bearbeitung (CC BY-NC-ND 4.0)