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The purpose of this paper is to compare light fastness assessments by exposure of fabric dyes with various dyes in daylight and an artificial xenon arc lamp.

Cotton fabric dyed with 66 reactive, vat, azoic and direct dyes dyed in different depths were exposed to daylight and Xenon arc lamp for assessment of light fastness by standard methods. The light fastness rating and fading hours by the two methods were analysed and compared statistically.

The correlation between the corresponding light fastness rating (LFR) measured in Xenotest and daylight is quite high (0.93). The logarithmic correlation coefficients between fading hour (FH) and LFR in Xenotest and daylight are 0.95 and 0.88, respectively. For Xenotest, the assessed LFRs are same as those predicted from geometric progression up to LFR of 5.5, and thereafter, the former is higher. On the other hand, in the case of daylight, the assessed LFR is lower. Assessments for three successive seasons showed high repeatability in case of Xenotest and moderate repeatability in case of daylight. Assessments for three successive seasons showed high repeatability in case of Xenotest and moderate repeatability in case of daylight.

The exposure conditions in daylight cannot be controlled or standardised, whereas the exposure in Xenon arc lamp in the accelerated fading instrument can be strictly controlled. These differences in exposure control may affect the repeatability of experimental findings.

Inconsistent ratings may be because of little deterioration of samples during storage, as well as seasonal variation of daylight.

There are no direct social implications.

The researches on the comparison of the two light fastness assessment methods have not been reported in any recent publication to the best our knowledge.

Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial lighting, increase workers productivity, customers’ satisfaction and consequently improve sales. However, excessive use of glazing and absence of lighting controls can contribute greatly to higher energy need for heating and cooling and cause undesired glare effects. Thus, optimizing the size, position and materials of external glazing, with the addition of deflectors and dynamic artificial lighting, can become key aspects in the design of sustainable low energy buildings. The purpose of this paper is to analyze daylight potential and energy performance of a hall-type commercial building, situated in the cold climate of Finland, by utilizing different combinations of skylights, windows and lighting controls.

The authors have used computer simulations to estimate daylight and energy performance of a single floor commercial building in relation to various combinations of skylights and windows with variable glazing materials, light deflectors and zonal lighting controls.

The results show that electric light energy saving potential ranges from a negligible 1.9 percent to a significant 58.6 percent in the case of glass skylights and wall windows using multi-zone lighting control. Total delivered energy ranges between increase of 1.5 and 21.2 percent in the cases with single zone lighting control and between decrease of 4.5 percent and increase of 4.5 percent in the cases with multi-zone control. The highest decrease in primary energy consumption was 2.2 percent for single zone and 17.6 percent for multi-zone lighting control. The research underlines the significant potential of electric light energy savings using daylighting strategies that, including the control of direct solar access for glare and internal gains, can be more than 50 percent.

This research combines accurate daylight and energy assessment for commercial hall buildings based in cold climate region with multiple design variations. The novelty of this work is the consideration of interior elements, shelves and deflectors, in the calculations. This is made possible through the combined use of validated simulation platforms for detailed annual daylighting and electric lighting calculation (Radiance and Daysim) and energy analysis (IDA-ICE, Equa Simulation AB). This method allows to obtain a reliable assessment of the potential of using natural light sources in buildings.

Daylight plays a crucial role in the attainment of building energy savings. Harnessing daylight in building designs will require the need for daylight illuminance data. However, daylight illuminance data are scarce due to few measuring stations. Aside from being sparse, illuminance measuring stations can be expensive to set up, thus making the luminous efficacy model a better alternative. Hence, this study attempted to model horizontal luminous efficacies under the 15 Commission internationale de l'éclairage (CIE) standard skies. Therefrom, daylight illuminance was estimated from a proposed vertical luminous efficacy model.

Measured solar irradiance, daylight illuminance and luminance distribution data were gathered from the local measuring station in Hong Kong. The luminance distribution data were used to classify the skies into the 15 CIE standard skies. Next, the solar irradiance and daylight data were used to derive the horizontal luminous efficacies under each standard sky. Furthermore, a vertical luminous efficacy model developed using the measured data was described, and this was used to predict vertical illuminance.

It was observed that Skies 1, 8 and 13 seem to be predominant in Hong Kong. Also, the result showed that constant luminous efficacies could be used for deriving illuminance data. Furthermore, horizontal luminous efficacy ranged from 40 to 190lm/W, indicating that daylight can provide sufficient visibility during working hours. The vertical luminous efficacy model proves to offer reasonable estimations of vertical illuminance data.

Further work needs to be done with more measured data to cover for spring seasons. The described model still needs to be fitted with different world climates to ascertain its universal applicability. The evaluations need to be done under obstructed sky conditions to cater for dense and clustered urban centres.

The discussed luminous efficacy model could be used to derive illuminance data in the absence of measured daylight illuminance data, especially in the subtropical region. Also, the comparative advantage of daylight over artificial lighting was highlighted in this study.

Unlike previous studies, this paper discusses the luminous efficacies of global, direct and diffuse components under the 15 CIE standard skies. Furthermore, the described luminous efficacy analysis provides an approach for deriving vertical and horizontal illuminance data. Such vertical data will be required for analysing building lighting requirements, sensible heat from electric lighting, and energy savings from daylighting controls. Also, the information on horizontal luminous efficacies will help evaluate solar roof and skylight designs.

The purpose of this research is to investigate natural illumination properties of one of the classrooms in the School of Architecture at Izmir Institute of Technology, located in Turkey, which is the northern hemisphere.

In this study, the definitions of the basic terms in daylighting, such as daylight factor, illuminance, glazing ratio, are given first. Then, a luxmeter and a lighting simulation software, Velux, are used in order to calculate variable lighting factors during daytime, at different storeys, at different directions, for the classes. Velux is a proprietary software and it enables natural lighting analysis practically.

Chosen classrooms are examined regarding their having sufficient natural illumination. The height of windows from the floor is changed, and the resultant effects on natural lighting in the classrooms are determined by using the lighting simulation program, Velux. The study shows that daylight factor and illumination near the window decreases as the height of the window above the floor increases. However, the illumination increases away from the window, giving greater uniformity to the lighting. At the same time, the usable depth of the classroom increases. The tall and narrow windows bring the daylight near themselves.

Practical window design decisions can help architects to provide effective and healthy natural lighting for interiors.

Adjustment of the dimensions of the windows is important in order to balance the energy consumption of buildings. This study investigates natural lighting depending on both experimental measurements and simulation software, Velux.

In performative architectural design, daylighting is a crucial design consideration; however, the evaluation of daylighting in the design process can be challenging. Immersive environments (IEs) can create a dynamic, multi-sensory, first-person view in computer-generated environments, and can improve designers' visual perception and awareness during performative design processes. This research addresses the need for interactive and integrated design tools for IEs toward better-performing architectural solutions in terms of daylighting illumination. In this context, building information modeling and performance simulations are identified as critical technologies to be integrated into performative architectural design.

This research adopts a design science research (DSR) methodology involving an iterative process of development, validation and improvement of a novel and immersive tool, HoloArch, that supports design development during daylighting-informed design processes. HoloArch was implemented in a game engine during a spiral software development process. HoloArch allows users to interact with, visualize, modify and explore architectural models. The evaluation is performed in two workshops and a user study. A hybrid approach that combines qualitative and quantitative data collection was adopted for evaluation. Qualitative data analyses involve interviews, while quantitative data analyses involve both daylighting simulations and questionnaires (e.g. technology acceptance model (TAM), presence and system usability scale (SUS)).

According to the questionnaire results, HoloArch had 92/100 for SUS, a mean value of 120.4 for presence questionnaire (PQ) and 9.4/10 for TAM. According to the simulation results, all participants improved the given building's daylighting performance using HoloArch. The interviews also indicated that HoloArch is an effective design tool in terms of augmented perception, continuous design processes, performative daylighting design and model interaction. However, challenges still remain regarding the complete integration of tools and simultaneous simulation visualization. The study concludes that IEs hold promising potentials where performative design actions at conceptual, spatial and architectural domains can take place interactively and simultaneously with immediate feedback.

The research integrates building information modeling (BIM), performative daylighting simulations and IEs in an interactive environment for the identification of potentials and limitations in performative architectural design. Different from existing immersive tools for architecture, HoloArch offers a continuous bidirectional workflow between BIM tools and IEs.

This paper aims to raise awareness on how a simple action by the occupant can significantly influence building energy efficiency, cost and CO₂ emissions to the environment. Classrooms in schools are the primary energy consumers (45.4%) due to the use of artificial lighting, despite Malaysia's tropical climate being ideal for daylight exploitation. This paper focuses on assessing the workplane daylight distribution quality and quantity in baseline and existing conditions of a typical pre-school classroom in Kuala Lumpur as a model-based exploration strategy towards nearly Zero Energy Buildings.

The adopted method is based on the calculation of average daylight factor (DF), daylight illuminance level (IL) and uniformity ratio (UR) parameters affected by the internal fixed drapes through computational and in situ measurements according to the requirements of the law and respective standards comprising the MS1525:2019, GBI and BREEAM.

The results show how user behaviour can turn a well-daylit area (Net Lettable Area>90%) into a poor-daylit area (NLA<5%) by sacrificing natural daylight. All the parameters' values were significantly decreased from 10% (UR) up to 88% (ADF). Full dependency on artificial lighting has imposed a total of RM18858.90 and CO₂ emissions of 25,362 kg for all pre-schools' classrooms in the country per day.

The paper develops the occupants' awareness on their contribution to climate change and global warming through the information and transparency provided.

The evidence indicates that a simple action by the occupant can significantly influence visual comfort, EE, cost and CO₂ emissions to the environment.

This study aims to identify the optimal configuration to enhance the environmental conditions of a terrace house courtyard space in a hot and humid climate. The use of the courtyard has declined in new housing developments although it is an effective element to bring in light and wind to promote passive ventilation to occupants. To achieve the comfort level, the courtyard needs to be open, but some occupants modify it with enclosures, such as polycarbonate, to increase the useable and shaded area. This affects bringing in daylight but deters the passive ventilation from happening. Thus, this research is important to create a courtyard that brings in daylight and wind as well as shades from the harsh sun of the tropics and to educate the occupants on the role of the courtyard as a passive ventilation system.

The research method employed is a simulation study. A terrace house with a courtyard design in Penang was chosen as a case study of the baseline model. The courtyard configurations of the case study were evaluated, and 4 settings based on the literature review were established for simulation. The effects of the courtyard configurations were tested through daylight and CFD simulations. Daylight and ventilation requirements from Malaysia Standard were used to evaluate and compare the effectiveness of the proposed settings.

The results suggested that the semi-enclosed courtyard feature with a shading device could provide the optimal environmental conditions of the courtyard space in a terrace house in a hot-humid climate. This paper will benefit the architectural community in which it is intended to implement courtyard design in modern terrace houses and will also contribute to the discovery of the most suitable courtyard typology in a hot-humid climate.

The study does not include studies on thermal comfort, energy performance, or use behavior of occupants in this courtyard. The study only focuses on the influence of different courtyard configurations in improving the courtyard space's daylight availability and indoor air movement.

The data from this study reveal that alteration of courtyard design needs to suit comfort level that should not alter the functions of the courtyard as a passive design. The simulation method offers data for microclimatic conditions according to the changes in design. This study attempts to design influence on multiple parameters of shading, daylighting and ventilation to optimize the use of tropical climatic conditions.

The terrace house with courtyard would create a passive design strategy that would naturally ventilate, provide daylight, and will save on energy usage. The courtyard then with its enhanced comfort for the user will be able to function as a useable space to foster family relationships.

The study on courtyard design using the simulation method mostly have been conducted using a single parameter. This study highlights the analysis and process of identifying the optimal configuration for the architectural feature of a courtyard to provide a comfort level for occupants in hot and humid climates using the simulation method using data from two pieces of software.

Optimisation of daylight admission through window is crucial for alleviating glare while maintaining useful daylight levels in order to enhance occupants' health, visual comfort and moderating lighting energy consumption. Amongst various solutions, fixed external shade is an affordable solution for housing spaces that need to be sophisticatedly designed, especially during the period of increasing home spaces as working environments. In the humid subtropical region, daylight control plays an important role in indoor comfort, particularly with areas with a high window to wall ratio (WWR). Due to the insufficient amount of such study on non-office spaces in Australia, shading-related standards are not addressed in Australian building codes.

The chosen methodology for the research is a quantitative data collection and analysis through field measurement and simulation simultaneously. The first step is a multi-objective optimisation of shading elements through a non-dominated sorting genetic algorithm (NSGA-II) on parametric modelling via Rhino3D CAD and simulation engines (DIVA and ClimateStudio). In the second phase, the Pareto front solutions are validated by experimental measurements within a room with a single north-facing window (the most probable for the daytime glare in Sydney) for the seven most common local window configurations.

Through the simulation of ten genes, 1,560 values and 2.4 × 1,019 of search space, this study found an optimum shade for each local common window layout, resulted in +22% in (UDI) and −16% in views with discomfort glare on average. Moreover, an all-purpose polygonal shade showed an average of 4.6% increase in UDI and a 5.83% decrease in the percentage of views with discomfort glare.

The findings are subject to the room dimensions, window dimensions and layouts, and orientation of windows for selected residential buildings in Sydney.

The study contributes to the development of highly accurate fixed external shading systems with rectangular and tapered-form external shapes. A real-time measurement by luminance-metre sensors and HQ cameras located at six eye levels is conducted to corroborate simulation results of the visual comfort.

The purpose of this paper is to propose building code changes that would benefit both architectural design and the potential of achieving nearly zero energy goals by analyzing the architectural implications of the energy system boundaries within the Swedish code.

The analysis is driven by three questions that relate the national implementation of EU directive on nearly zero energy 2020 to the premises set out in the guidelines for revising the Swedish building code aiming at a performance-based regulation. A crucial part of the research is a comparative analysis of the design implications of the code to research findings in scientific articles on near-zero energy or low-energy design.

The energy system boundaries in the Swedish code are steering the architectural design and energy consequences of offices towards using less heat but more electricity. The energy section is also limiting the architectural design choices by ignoring the positive energy aspects of daylight. A proposal of a new comprehensive energy section taking all architectural design related energy aspects into account is presented, in order to support design of nearly zero energy buildings.

A building code that relates the energy system boundaries to form will help integrated design choices that are more likely to support the strive towards nearly zero energy buildings.

The paper reveals the design implication of the Swedish energy section to be counterproductive regarding energy efficiency as well as limiting architectural design choices.

The purpose of this paper is to present a methodology to quantify the solar energy potential for applying photovoltaic systems and find an efficient geometry for urban blocks to obtain a better quality of daylighting in terms of continuous daylight autonomy (DA) and spatial DA with less energy consumption.

The paper is based on a complete simulation of the topography and micro-climate of the area under study. Simulations were performed using ArcGIS and Rhinoceros and urban daylight (UD) and urban modeling interface plugin for a neighborhood in the region of Narmak in Tehran, Iran. Five configurations of a neighborhood were compared using simulations.

It was found that the impact of the geometrical form on daylight gain and energy consumption is significant and the terraced model is the most suitable form for obtaining a constant floor area ratio. Furthermore, it is an optimal form of urban blocks to gain the most energy through photovoltaic systems in the neighborhood as it would be able to satisfy about 42 percent of the energy needs.

Planning to achieve sufficient energy factors in cities is a difficult task, since urban planners often do not have adequate technical knowledge to measure the contribution of solar energy in urban plans and this paper aims to introduce a comprehensive modeling methodology by which the urban energy planning can be used and understood in the urban context to make it completely clear as a strategy of implementation.