Assessment Of Daylight Performance Research Articles

Optimizing the Shading Device Configuration of Kinetic Façades through Daylighting Performance Assessment

When designing a façade, it is essential to consider the impact of daylight and how it can be optimized through external movable shading devices. To accurately evaluate the lighting performance of a kinetic facade, it is crucial to consider the operation of these shading devices, as they can significantly impact performance. This study proposes a high-precision methodology that utilizes digital tools and hourly data to examine the effectiveness of dynamic shading device systems in enhancing daylight performance and optimizing shading configurations using the Genetic Optimization algorithm. The study’s results demonstrate that the proposed methodology is accurate and effective, showing that the optimal operation scenario can exceed LEED v4.1 requirements while meeting daylight availability standards. Designers can achieve optimal performance by adjusting each parameter for a lighting energy-conserving kinetic façade. The limitations and applicability of this method are also discussed.

The assessment of daylight performance using indicators of Illuminance, Day light Factor and Penetration depth in the combined pattern of mosque- school- residential buildings, case study: Mansouriye Traditional Seminary in Shiraz

The assessment of daylight performance using indicators of Illuminance, Day light Factor and Penetration depth in the combined pattern of mosque- school- residential buildings, case study: Mansouriye Traditional Seminary in Shiraz

Daylighting performance assessment of a split louver with parametrically incremental slat angles: Effect of slat shapes and PV glass transmittance

Advanced shading systems, including light redirecting systems, may cause undesirable glare and affect the quality of the transmitted daylight. Therefore, it is important to integrate different building components, such as shading and glazing, to comprehensively assess daylighting performance and ensure a comfortable, luminous environment. This study proposes an advanced daylighting design based on a parametrically controlled split louver with reflective slats to redirect sunlight onto a ceiling and integrated PV glazing to control the illuminance levels. A special contoured slat design (retro shape) was evaluated and compared to different slat shapes (flat, curved, and oval) of the upper section. In addition, the effect of the PV glass transmittance (30 %, 50 %, and 70 %) on the daylighting performance was investigated. The daylight analysis was performed using Grasshopper software as a parametric tool to predict the daylighting performance through advanced dynamic metrics including Useful Daylight Illuminance (UDI), Daylight Glare Probability (DGP), and Illuminance Uniformity (Uo). It is found that the retro-shaped slat design can significantly improve the daylight distribution and level without using the common blind system for more than 90 % of the work plane area within the recommended acceptable UDI range (150 ∼ 750 lx) for a longer period of the day (including the early morning and late afternoon). Furthermore, retro-shaped slats can improve the Uo throughout the space to achieve the recommended level (0.70), while PV glazing can reduce the risk of daylight glare.

Daylighting performance assessment of traditional skywell dwellings: A case study in Fujian, China

China's rural revitalization strategy has aroused people's attention toward the preservation and renewal of traditional dwellings. Characterized by small courtyards and small top openings, traditional skywell dwellings in southern China are facing prominent daylight environment problems. However, only few studies have evaluated the visual comfort in skywell dwellings under daylight conditions using incomprehensive methods. To fill this gap, this paper systematically assessed the daylighting performance of skywell dwellings in Xingxian Village from 2D reference planes and 3D spatial interfaces. An accurate daylighting simulation model of skywell dwellings was established and validated with field measurements. ClimateStudio was used to analyze the performance metrics from the aspects of daylight quantity, daylight uniformity, and glare. Results identify insufficient daylight quantity indoors as the severest problem in skywell dwellings, which require artificial lighting throughout almost the entire daytime. Seasonal glare and inferior daylight uniformity were also observed in semi-outdoor areas. The effects of top, horizontal, and vertical spatial interfaces on the daylight environment were further investigated, and results highlight the influence of roof slope and opening setting on indoor lighting, the decay mechanism of daylight quantity on horizontal substrate interfaces, and the mismatch between daylight distribution and the positions of doors and windows on vertical enclosure interfaces. The changes in building orientation and seasons were also found to have limited effects on daylighting performance. These results can guide architects specializing in dwelling renovation, so as to improve the visual comfort of buildings and save up on living and energy costs due to artificial lighting.

Assessment of daylight performance of Advanced Daylighting Strategies in Large University Classrooms; Case Study Classrooms at JUST

Daylight in buildings helps to reduce energy consumption, lower negative impacts on the environment, improve human performance and increase the productivity. The current research aimed at studying the effect of advanced daylight technologies, like; lightshelf, anidolic systems, translucent materials and lightshelf combined with external reflectors, on daylight performance and visual environment in university classrooms. The current research was conducted on a classroom located in the lecture halls complex at Jordan University of Science and Technology (JUST). These daylight technologies were assessed for indicators; illuminance level, uniformity and energy saving. The research used real time experiments and IES-VE, the advanced simulation tool, to study how different daylight technologies would improve daylight illuminance levels and uniformity distribution. The results insured that these technologies could provide a significant increase in the illuminance levels to match the standards in the area of low illuminance level, improve the uniformity distribution and lower rates of discomfort glare. Results also indicated that energy consumption reduced in the classrooms by an average of 40–50% of energy used for lighting. Lightshelf, anidolic systems and windows in rear parts to the glazed corridor performed better in term of increasing light level in the rear part by an average of more than 100%.

Daylighting Performance Assessment of Side-Lit University Lecture Theatres in the Hot-Humid Climate of Makurdi in Nigeria

Daylighting is required to enhance visual comfort; whereas its illumination provides renewable functional interior lighting for specific programmes. Hence, this study examines the levels of daylight illumination for teaching and learning in two lecture theatres each located at the Federal University of Agriculture Makurdi (UAM) and Benue State University Makurdi (BSU) in Makurdi, Nigeria. The two buildings selected for the daylighting performance employed post-occupancy evaluation approach. A digital camera was employed to take photographs, whereas digital light meters were employed to evaluate the levels of illumination on the work plane. The results showed that 80% of the study space has inadequate indoor daylight illumination quantity and distribution as well as poor daylight ratios of 1.1and 0.9 for UAM lecture theatre and BSU lecture theatre, respectively Hence, the lighting conditions in the selected buildings fall short of the international lighting benchmarks (IESNA). Therefore, a pragmatic daylight design strategy is required to enhance daylight levels in the lecture theatres for energy-saving and visual comfort as well as onwards design and fusion in the national building code.

Assessment of daylight performance and the impact of shading devices for typical in-patient rooms in healthcare facilities in Cyprus

In the last few decades, more attention is given to design spaces with good daylight performance, either to provide useful daylight levels to the occupants which could eventually affect their health and wellbeing, or to reduce the artificial lighting use by using natural lighting. Natural lighting access in healthcare facilities has been correlated to improved physiological and psychological factors. Therefore, this makes it even more important to study daylight performance in typical in-patient rooms. This study focuses on the cases of the single room and the double room. Computer simulations were performed using the RadianceIES software in IES-VE. For the purposes of this research, fifteen different window-to-wall ratios were used, and shading devices were implemented to study the optimum design configurations. Moreover, the daylight analysis is based on dynamic metrics, such as the Useful Daylight Illuminance, the Spatial Daylight Autonomy and the Annual Sunlight Exposure. The findings suggest that the optimum scenario is achieved through the requirements set during the design process which take into consideration the useful daylight levels, the amount of time that the room can be autonomous only with natural light, and finally the probability of glare.

A human-centric approach to assess daylight in buildings for non-visual health potential, visual interest and gaze behavior

This paper introduces a novel approach for the assessment of daylight performance in buildings, venturing beyond existing methods that evaluate 2-dimensional illumination and comfort within a fixed field-of-view, to predict human responses to light concerning non-visual effects, visual interest, and gaze behavior in a visually immersive scene. Using a 3D rendered indoor environment to exemplify this coordinated approach, the authors assess an architectural space across a range of view directions to predict non-visual health potential, perceptual visual interest, and gaze behavior at the eye level of an occupant. This method allows the authors to explore and demonstrate the impact of space, time, and sky condition on three novel daylight performance models developed to predict the effects of ocular light exposure using a human-centric approach. Results for each model will be presented in parallel and then compared to discuss the need for a multi-criteria assessment of daylight-driven human responses in architecture. A parallel and comparative approach can allow the designer to adapt the architectural space based on the program use and occupants needs.

Assessment of climate-based daylight performance in tropical office buildings: a case study

The utilization of daylight can significantly affect building performance, energy efficiency, productivity, as well as occupants' comfort and satisfaction in buildings. This paper aims to assess daylight performance for tropical office buildings in a parametric approach. Thus, four passive design categories are investigated, namely interior surface reflectance, glazing visual transmittance, light shelves and shading control. The approach is exemplified using the case study of two selected offices in Singapore. This study contributed to the assessment of the daylight performance and prediction of the consequences of retrofitting alternatives toward fostering the utilization of daylight in existing buildings in the tropics.

The application of analytic hierarchy process in daylighting performance assessment

Daylighting is beneficial to humans and the environment. Various indicators have been proposed to evaluate its attributes. Studies on the weighting factors of these attributes are, however, sparse. This paper aims to develop a new daylighting performance assessment method by collecting the perceived importance of the attributes from occupants using the analytic hierarchy process (AHP) based on two equally important criteria – visual comfort and electric lighting energy saving potential. The study has two parts. In the first part, a general survey was conducted to verify the attributes affecting occupants’ visual comfort and their acceptance of not turning on electric lights in daylit cellular offices. Brightness on desktop, brightness on surroundings, uniformity on desktop, uniformity on surroundings and perceived glare from windows were found to be the attributes. In the second part, an AHP survey was conducted to examine the weights of importance of these five attributes. The results showed that they were important to daylighting performance in the order of brightness on desktop (31%), perceived glare from windows (23%), uniformity on desktop (19%), brightness on surroundings (16%) and uniformity on surroundings (11%). The findings of this study would help to develop a comprehensive performance-based daylighting assessment method in the future.

Modelling Complex Fenestration Systems using physical and virtual models

Physical or virtual models are commonly used to visualize the conceptual ideas of architects, lighting designers and researchers; they are also employed to assess the daylighting performance of buildings, particularly in cases where Complex Fenestration Systems (CFS) are considered. Recent studies have however revealed a general tendency of physical models to over-estimate this performance, compared to those of real buildings; these discrepancies can be attributed to several reasons. In order to identify the main error sources, a series of comparisons in-between a real building (a single office room within a test module) and the corresponding physical and virtual models was undertaken. The physical model was placed in outdoor conditions, which were strictly identical to those of the real building, as well as underneath a scanning sky simulator. The virtual model simulations were carried out by way of the Radiance program using the GenSky function; an alternative evaluation method, named Partial Daylight Factor method (PDF method), was also employed with the physical model together with sky luminance distributions acquired by a digital sky scanner during the monitoring of the real building. The overall daylighting performance of physical and virtual models were assessed and compared. The causes of discrepancies between the daylighting performance of the real building and the models were analysed. The main identified sources of errors are the reproduction of building details, the CFS modelling and the mocking-up of the geometrical and photometrical properties. To study the impact of these errors on daylighting performance assessment, computer simulation models created using the Radiance program were also used to carry out a sensitivity analysis of modelling errors. The study of the models showed that large discrepancies can occur in daylighting performance assessment. In case of improper mocking-up of the glazing for instance, relative divergences of 25–40% can be found in different room locations, suggesting that more light is entering than actually monitored in the real building. All these discrepancies can however be reduced by making an effort to carefully mock up the geometry and photometry of the real building. A synthesis is presented in this article which can be used as guidelines for daylighting designers to avoid or estimate errors during CFS daylighting performance assessment.

Artificial neural networks to predict daylight illuminance in office buildings

A prediction model was developed to determine daylight illuminance for the office buildings by using artificial neural networks (ANNs). Illuminance data were collected for 3 months by applying a field measuring method. Utilizing weather data from the local weather station and building parameters from the architectural drawings, a three-layer ANN model of feed-forward type (with one output node) was constructed. Two variables for time (date, hour), 5 weather determinants (outdoor temperature, solar radiation, humidity, UV index and UV dose) and 6 building parameters (distance to windows, number of windows, orientation of rooms, floor identification, room dimensions and point identification) were considered as input variables. Illuminance was used as the output variable. In ANN modeling, the data were divided into two groups; the first 80 of these data sets were used for training and the remaining 20 for testing. Microsoft Excel Solver used simplex optimization method for the optimal weights. The model's performance was then measured by using the illuminance percentage error. As the prediction power of the model was almost 98%, predicted data had close matches with the measured data. The prediction results were successful within the sample measurements. The model was then subjected to sensitivity analysis to determine the relationship between the input and output variables. NeuroSolutions Software by NeuroDimensions Inc., was adopted for this application. Researchers and designers will benefit from this model in daylighting performance assessment of buildings by making predictions and comparisons and in the daylighting design process by determining illuminance.

Comparing daylighting performance assessment of buildings in scale models and test modules

Physical models are commonly used to assess daylighting performance of buildings using sky simulators for purpose of research as well as practice. Recent studies have pointed out the general tendency of scale model assessments to overestimate the performance, usually expressed through work plane illuminance and daylight factor profiles, when compared to the real buildings. The cause of the discrepancy between buildings and scale models is due to several sources of experimental errors, such as modelling of building details, mocking-up of surface reflectances and glazing transmittance, as well as photometer features. To analyse the main sources of errors, a comparison of a full scale test module designed for experimentation of daylighting systems and its 1:10 scale model, placed within identical outdoor daylighting conditions, was undertaken. Several physical parameters were studied in order to determine their impact on the daylighting performance assessment. These include the accurate mocking-up of surface reflectances, the scale model location, as well as the photometric sensor properties. The experimental study shows that large discrepancies can occur between the performance figures. They lead, on average, to a relative divergence of +60% to +105% in favor of the scale model for different points located in the side lit room. Some of these discrepancies were caused by slight differences in surface reflectances and photometer cosine responses. These discrepancies were reduced to a +30% to +35% relative divergence, by putting in the effort to carefully mock up the geometrical and photometrical features of the test module. This included a sound calibration of photometric sensors, whose cosine-response appeared at the end to be responsible for the remaining relative divergence observed between the daylighting performance figures.