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- Davoodi, Anahita, 1979-
(författare)
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Supporting evidence-based design using lighting simulations : A framework for lighting simulation of visual comfort in building design
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This research aims to integrate lighting simulation into the evidence-based design process for achieving improved lighting outcomes in built environments with a particular emphasis on visual comfort analysis in office settings. The objectives of the study include 1) understanding the current usage of lighting simulation tools, learning designers’ experiences' and needs, 2) providing a conceptual framework to integrate the use of lighting simulation in the evidence-based design (EBD) process, 3) testing the usage of the conceptual framework (named EBD-SIM) through two field studies.First, the lighting simulation tools were reviewed from multiple perspectives reflecting their current state in terms of main characteristics and applications. The usage of lighting simulation tools was investigated by conducting an online survey among lighting designers in 2014. The results showed that lighting simulation programs were widely used in Sweden, with DIALux being the most popular. The most calculated metrics were interior illuminance, glare indexes, and daylight factors. Ease of use and simulation speed were the most important factors in selecting these tools (Paper I). The changes and developments in the usage of lighting simulation tools over five years were investigated by conducting the second survey in 2019. The comparison between the two surveys revealed that DIALux remained the most popular tool though its usage slightly dropped,and the usage of Radiance-based programs was improved. In both surveys, illuminancewas the most frequently calculated metric for both daylight and electric light.In the second part of this thesis, the integration of simulation tools in the Evidence-Based Design (EBD) process was explored, leading to the development of an integrated conceptual framework, named EBD-SIM (Paper II). The application of the EBD-SIM framework with a focus on the post-occupancy evaluation (POE) step was tested with two field studies in an existing office building in Sweden (Paper III & Paper IV). Occupant visual comfort was investigated using holistic objective-subjective evaluation with different sample sizes (N=15, N=45), different times of the year (October and June), and two groups of occupants (within-subject and between-subject study). Both studies confirmed that point-in-time illuminance had the highest correlation with perceived visual comfort by occupants. The study in June showed that annual daylight performance metrics also had some degree of correlation with occupant satisfaction. It also revealed that, at least for the variables related to daylight, a POE study needs to be conducted at different times of the year to obtain a more comprehensive picture of the user perception of the lit environment. Using simulation tools also in the POE step of EBD has several advantages. The calculated performance metrics give an overview of the lit environment's objective characteristics, making it possible to document them and provide more explicit evidence for further investigation. In addition, the simulated model can be used further to generate other performance metrics should it become necessary based on further evidence.
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| 2. |
- Adamsson, Mathias
(författare)
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Non-image-forming effects of light : Implications for the design of living and working environments
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Seasonal variation in mood and subjective well-being are common at geographical locations further away from the equator. The 24-h light-dark cycle is the main time cue for synchronizing the human circadian clock to the external day and night.Nowadays, people spend more of their waking day indoors, with less exposure to the natural daylight cycle, relying on artificial lighting which differs to daylight in a number of aspects, including intensity, spectral composition and light exposure pattern.In parallel with the technology development that has been mainly driven by energy-saving reasons, it is important to investigate the non-image-forming effects of different properties of the daily and seasonal light exposure.The overall aim of the thesis was to identify characteristics of the daily light exposure that are important to support physiological and psychological needs of humans. To achieve this objective a number of research questions were posed concerning daily and seasonal light exposure, seasonal variation in physiological processes and psychological parameters, and evaluation of light exposure with respect to non-image-forming effects. The research questions were investigated in a longitudinal research design with measurements conducted each month during the year at a high latitude with large seasonal variation in day lengths.Self-report diaries and instruments for ambulatory- and static measurements were used to examine daily and seasonal light exposure in the working and living environments and for investigating the relationship between different parameters that can be used for evaluating light exposure according to non-image-forming effects of light. Seasonal variation in daily light exposure and regarding the pattern of light exposure was observed. Also, the results indicate a seasonal variation concerning the quality (i.e. spectral composition of the visible radiation) of the exposing light.Two biological markers, melatonin and cortisol, were used for investigating seasonal variation in physiological processes relating to the circadian clock. The results showed higher morning melatonin concentrations and peak level of melatonin during the winter although no seasonal change was observed concerning the phase position of the melatonin rhythm.Seasonal differences in mood and sleep-activity were studied by means of selfreport diaries and questionnaires. Seasonal variations were observed for both parameters. The results showed higher ratings of mood in the summer, particularly 6 in the evening, and a relationship between bedtime and evening light exposure and photoperiod length. Furthermore, longer sleep times was observed in the winter.Appraisal of lighting conditions in the offices during the year was rated by the use of a questionnaire. The results showed some seasonal differences concerning the perceived qualities of the light and some associations between characteristics of the lit environments and positive affect were found.Two methods, static- and ambulatory measurements, were used for recording lighting conditions in the working environments. Taken together, the results showed weak associations between the two methods.Research have demonstrated an increased need for taking non-image-forming effects into consideration when designing working and living environments, especially at geographical locations with large variations in day length where people are exposed to much of the daily light exposure at the workplace. Laboratory research has provided a good understanding of the basic concepts. However, more field research is needed. Also, current research has demonstrated that new methods of measuring and evaluating lighting conditions are needed.
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| 3. |
- Davoodi, Anahita, 1979-
(författare)
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Lighting simulation for a more value-driven building design process
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Concerns about global warming are increasing, hence, the urgency to cut carbon emissions. Reducing energy consumption, including lighting energy, is seen as the primary solution. Yet, solving the environmental factor should not come at the cost of other pillars of sustainable development. Rather, maximizing the total value of the building should be the focus. Maximizing value in the context of lighting entails improving the quality of the lighting. This study has investigated how lighting simulation could help in achieving better lighting quality. The aim of the thesis was defined as to understand the underlying architecture of lighting simulation and obtain an overview of its characteristics and applications as well as to study the use of current simulation tools.The theoretical background of lighting simulation (in the domain of Systems Engineering) was reviewed from the literature. This revealed the missing and imperfect links in the solution-to-value chain. The thesis suggests the use of a new base metric, Retinal Illuminance Map, as a solution, which in combination with black box simulation of a visual system can help repair this incomplete chain.The study of the current lighting simulation tools (Paper 1) revealed that illuminance-based metrics, luminance-based metrics, daylight availability metrics, and glare indexes are the most available performance metrics in existing lighting simulation tools. Based on usability, acceptability, availability, and previous references in the literature six software programs (Radiance, DAYSIM, Evalglare, DIALux, VELUX, and VISSLA) were selected and compared. It was found that no single tool could meet all the needs of a designer, hence, simulation tool(s) should be selected (or combined) according to the requirements of project goals and the stage of design.Building on these studies, applications of lighting simulation were identified and compiled in relation to different aspects, including performance metrics, stages of design, optimization, model integration, BIM, and parametric modeling.To obtain first-hand information about lighting designers’ experience, an online survey was conducted in Sweden (Paper 2). The results showed that lighting simulation programs were widely (90%) used in Sweden for analysis and/or rendering purposes. The majority of lighting designers considered both daylight and artificial light in their design. Factors such as ease-of use, simulation time and training had more weight than accuracy and the diversity of metrics in practitioner’s eyes. Surrogate modeling was identified as a solution for speeding up simulation time, which would also enable exploration of design solution space especially in the early design stage.
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