Daylight Uniformity Research Articles

Indoor Daylighting Quality Optimization Methods of a Novel Linear Transmissive Concentrator-Photovoltaic/Daylighting System in Overcast Conditions

This study proposes a control method for improving the efficiency of natural daylighting in linear transmission-type concentrator-photovoltaic/ daylighting (LTC-PV/D) systems. The study focuses on tackling the low capacity efficiency and shading of light in LTC-PV/D systems under overcast environments. The light-harvesting performance of a proposed new dynamic trackable transmissive concentrating integrated window in an overcast environment is investigated in this study. The results indicate that, in terms of light harvesting efficiency, the percentage value of the daylight factor value of the LTC-PV/D system being more than 2% is 78.8%. Further, the maximum illuminance uniformity result reaches 0.43, which is in line with the standard of indoor illuminance demand and superior to the common results of the photovoltaic window (66.06% and 0.31), indicate a good day-lighting performance in overcast environments. For the regulation method of LTC-PV/D systems in overcast environments, the recommended control angle is 90° for using the daylight factor and uniform daylight factor indices as evaluation criteria. The trend of the indoor useful daylight illuminance is affected by different levels of outdoor diffuse radiation. For an outdoor diffuse radiation less than 280 W/m2, the optimal control angle is 90°. For outdoor diffusion radiation levels of 320, 360, and 400 W/m2, the corresponding optimal regulation angles are 55°, 35°, and 25°, respectively. This study presents a control method for the transmissive concentrating photovoltaic louver under overcast conditions, which aims to optimize and enhance the indoor natural lighting environment of buildings. The proposed method increases the maximum useful daylight illuminance by 37.3%.

Designing Intensive Care Unit Windows in a Mediterranean Climate: Efficiency, Daylighting, and Circadian Response

Hospital intensive care units (ICUs) frequently experience inadequate lighting conditions, with low daytime and excessive nighttime illuminance, which can negatively affect patient recovery and the work performance of health personnel. This study examines the impact of window design parameters—specifically, window-to-wall ratio (WWR) and window position—and interior surface reflectance on visual comfort, lighting performance, energy consumption, and human well-being in intensive care units (ICUs) in Mediterranean climates, according to orientation. Using dynamic lighting metrics, such as daylight autonomy (DA) and circadian stimulus autonomy (CSA), this research quantifies the influence of these design factors. The results suggest that a WWR of 25% is optimal for achieving sufficient DA and CSA values, with centered window configurations preferred for uniform daylight distribution and circadian stimulus. This study further emphasizes the significance of interior reflectance, recommending bright coatings to maximize outcomes, while advising against dark finishes, particularly in north-facing rooms or with smaller WWRs. Although Seville shows slightly better performance than Barcelona, the proposed configurations are effective across both locations, highlighting the prioritization of window sizing, positioning, and reflectance over Mediterranean geographical differences. These findings offer practical guidance for ICU design to enhance natural lighting, supporting patient recovery and overall well-being through improved circadian alignment.

A Review of Factors Affecting the Lighting Performance of Light Shelves and Controlling Solar Heat Gain

In areas with a deep floor plan, the distribution of natural light is not uniform. Consequently, relying solely on daylight may not suffice to meet the space’s lighting requirements, necessitating the use of artificial lighting in darker areas. Therefore, a lighting system is needed that not only controls the glare near the windows but also increases the light at the end of the room and provides uniform daylight. One of the widely used systems is the “light shelf”, which has three main functions: shading, increasing the depth of light penetration, and reducing glare. Review articles about light shelves were published in 2015 and 2017, while more than 80% of the studies have been carried out since 2016, and light shelves with more diverse forms and dynamic elements and many consolidations have been proposed. Therefore, there is a need for a more comprehensive review. The main question of this research is how different parameters (including climate, material, ceiling, and integrated systems) can help to increase the efficiency of light shelves. By using a systematic review, studies in the past three decades were classified in order to determine the effect of these parameters on improving lighting performance and controlling solar heat gain.

Daylight Comfort Performance of a Vertical Fin Shading System: Annual Simulation and Experimental Testing of a Prototype

This study aims to develop and evaluate a vertically rotated fin shading system for an energy-efficient, user-friendly office space. The system was designed to protect a 4 × 8 m office room with a south-facing facade from excessive solar radiation and glare. The shading system was modelled and simulated using Rhino/Ladybug 1.6.0 software with Radiance engine, based on real-weather data (*.epw file) for Wrocław, Poland at 51° lat. The simulation calculated the useful daylight illuminance (UDI) for 300–3000 lux and the daylight glare probability (DGP) for ten static and four kinetic variants of the system. The optimal angle of the fin rotation for the static variant was found to be α = 40°. The kinetic variants were activated when the work plane illuminance exceeded 3000 lux, as detected by an internal sensor “A”. The simulation results show that the kinetic system improved the daylight uniformity in the office room, achieving UDI300–3000 values above 80% for more than 40% of the room area. A prototype of the system in a 1:20 scale was built and tested on a testbed at Wrocław University of Science and Technology, using TESTO THL 160 data loggers. The measurements were conducted for a week in early November 2023, and three clear days were selected for analysis. The measurement results indicate that the low solar altitude on clear days causes high illuminance peaks (15–18 Klux) and significant contrast in the room, leading to unsatisfactory DGP values consistent with the simulation outcomes. Therefore, the study concludes that the proposed system may need an additional shading device to prevent glare during periods of low solar altitudes.

Sensitivity Analysis and Multi-Objective Optimization of Skylight Design in the Early Design Stage

Building geometry design decisions are important for energy efficiency and daylight performance. Sensitivity analysis, coupled with optimization, is an important approach to investigate and optimize building geometry in the early design stage. Incorporating skylights is an important daylighting strategy in commercial buildings; however, skylight-to-floor ratio (SFR) is often the only design variable evaluated in precedent studies. More design variables related to skylight geometry, clerestory geometry, skylight material, and building geometry need to be evaluated. This study investigates the skylight design of a 2000-square-meter commercial building. Eighteen design variables are evaluated according to their influence on building energy and daylight performance. One-at-a-time (OAT), linear regression, and Morris sensitivity analysis approaches are utilized to identify the most influential variables. Seven of the twelve building geometry variables and two of the six building material variables are considered as important. Then, a multi-objective optimization with genetic algorithms is processed to find out the optimal design solution. The three objectives are energy use intensity (EUI), daylight autonomy (DA), and daylight uniformity (DU). After the optimization, five candidate design options are picked from the Pareto front. Discussions are made on the features of these designs, and one design is selected as the optimal solution.

Performance of secondary skin on optimizing the distribution of natural lighting in building

The high intensity of sunlight in Bangka Belitung Islands has a potential to get natural lighting throughout the day. Previous research found that facades with wide glass dimensions in the Asian Region with a tropical climate, on average, are not equipped with shading devices. This causes an uneven distribution of sunlight in the room and makes users feel visual discomfort. Natural lighting should be able to work optimally utilizing secondary skin on building facades. The secondary skin can be more optimal in energy use compared to a single skin to control the entry of direct sunlight. This plays a role in creating visual comfort. The secondary skin can also work in an aesthetic part to give an attractive image, such as an element of the locality. This study aims to obtain optimal secondary skin modules. The method used is a quantitative experiment to see the daylight uniformity in the lecturer’s workspace through the application of patterns on secondary skin and simulation software Velux Daylight Visualizer 3.1 and doing descriptive analysis to get the optimal module to achieve uniformity. Through this research, it was found that the percentage of different modules affects the distribution of light entering the building.

The impact of aspect ratio of buildings implementing Horizontal light pipe and shading systems on daylight performance

ABSTRACT Deep-plan buildings limit daylight use in spaces far from the building perimeter, leading to uneven daylight distribution. Integrating a Horizontal Light Pipe (HLP) as an optical daylighting system, reflective light shelves, and blinds as shading systems can reduce excessive daylight levels at the perimeter area of a building and improve daylight uniformity. Earlier investigations of HLP daylight performance concentrated on fixed building geometries, but few studies focused on the building aspect ratio, one of the design variables of building geometry that greatly influences daylight performance. This study aims to investigate the impact of the aspect ratio of buildings implementing HLP and shading systems on daylight performance. The research method was experimental, using IES-VE simulation as a tool. The daylight factor (DF), uniformity daylight factor (UDF), and useful daylight illuminance (UDI) of various aspect ratios and depths of office buildings implementing HLP and shading systems were analyzed. The results show that increasing the building aspect ratio from 1:1 to 2.1:1 sequentially increased the average DF and UDF values by 18.47% and 17.2%, respectively. Improving the building aspect ratio from 1:1 to 2.1:1 along the east-west axis improved the UDI by 3%, whereas the north-south axis decreased it by 10.2%.

Assessing Window Design's Impact on Daylight Uniformity in Classrooms in Patna, India

Windows play a vital role in daylight infusion, significantly impacting indoor visual comfort. Various metrics exist for evaluating visual comfort in which the uniformity ratio falls under the distribution category and is as crucial as illuminance levels. This ratio effectively reduces the likelihood of glare and the need for artificial lighting. The primary objective of this research is to assess the impact of window design on daylight uniformity ratio in a classroom setting. In pursuit of this objective, a study investigated the uniformity ratio (Uo) of north-oriented and south-oriented classrooms of Kendriya Vidyalaya (KV) Khagual, Patna. The study considered five common shapes of windows (excluding the existing base cases) at different window-sill levels. Ninety simulations were run in the DesignBuilder software under overcast, intermediate, and clear sky conditions. To assess the uniformity ratio on three dates: March 21st, June 21st, and December 21st, which correspond to the highest, equinox, and lowest solar availability during the year under intermediate and clear sky conditions at three distinct times. The omission of the specific time and date for overcast conditions and the particular year for clear and intermediate sky conditions is justified as the outcome remains consistent throughout all years. The results show that the window design and sill level significantly affect the uniformity ratio. The research findings show that window design in Case 9 at a sill of 1230 mm and lintel of 3050 mm (just below the slab) consistently produces the best uniformity ratio across all sky conditions, independent of classroom orientation. This paper offers valuable design recommendations by comparing the uniformity ratio for five commonly used window designs. This is one of the first studies of window design and position to evaluate the uniformity ratio in the classrooms at Patna.

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.

Solar Angle Model for Daylight Redirection in Prismatic Panel

An advanced complex fenestration system can utilize uniform daylight. Nonetheless, an inefficient design would increase solar heat gain and indoor temperatures, besides uneven light distribution that would cause the "cave effect." Prismatic panels are widely used as complex fenestration systems, providing uniform daylight. This paper proposes a computational model that integrates optical principles like Snell's law with environmental variables and visualizes the performance of prismatic panels in terms of redirection angle while encountering the prism refractive index and geometry at the specified geographic location. The proposed model entails a prismatic panel as a daylight system for redirecting daylight. In contrast to detailed modeling needed for simulation in software programs like Radiance, this computational tool provides a more straightforward and efficient solution for the initial design of light redirection panels that rely on the principle of refraction and evaluate their annual performance based on the angle of deviation. The model's applicability has been demonstrated by utilizing various triangular prism design examples with diverse materials in Frankfurt and Helsinki.

Optical evaluation of a smart transparent insulation material for window application

Thermotropic (TT) materials can provide dynamic regulation of solar energy and daylight, thus achieving building energy saving and indoor environment improvement. Parallel Slats Transparent Insulation Materials (PS-TIM) when integrated into the cavity of a double-glazed window can increase the thermal resistance of the window system, thus reducing building heating energy consumption. In this study, these two advanced technologies are combined to form a novel TT PS-TIM window system for adaptive daylighting control and enhanced thermal insulation. To achieve this, thermotropic hydrogels such as hydroxypropyl cellulose (HPC) and poly(N-isopropylacrylamide) (PNIPAm) are proposed for integration within polymethyl methacrylate (PMMA) slats between double glass panes. The optical properties of the PMMA-TT slats have been firstly investigated by optical simulations and experiments. Windows integrated with the PMMA-TT slats have been developed and predicted for their daylight performance under different solar incident angles, slat tilt angles and concentrations of HPC/PNIPAm polymer within hydrogel. It was found that the TT PS-TIM window can effectively reduce visible and solar transmittance when the TT material switches from clear (at low temperatures) to translucent (at high temperatures). In addition, the translucent TT PS-TIM window allows less light to be transmitted into the interior space when the slat tilt angle is increased from horizontal to inclined. More uniform daylight distribution in the indoor space can be achieved by increasing the slat tilt angle. The optical investigation results of this research will provide guidance for the further development of this system.

Daylighting Performance of Integrated Venetian Blinds with Horizontal Light Pipe System for Deep Plan High-Rise Office in Tropical Climate

A substantial amount of daylight is received by tropical countries like Malaysia. There are advantages and disadvantages to using this renewable resource in a high-rise office building. Such buildings' deep plan spaces make it difficult to create a uniform daylight distribution across the space. A solution for this issue is the usage of an integrated Venetian blind (VB) with a horizontal light pipe (LP). Using an overcast and intermediate sky in South orientation, seven (7) distinct types of VB angle configurations were simulated using the Integrated Environment Solution Virtual Environment (IESVE) to evaluate how well they performed in daylight with an integrated LP. The findings demonstrated that the daylight uniformity throughout the room was improved by the integration of the VB and LP systems. When compared to a room with only a LP installed, VB with 0o and -15o angles had the best performance. The combination of LP and VB allowed for the shading of the front portion of the space and at the same time, illuminating the rear portion of the space. The results of this study encourage building designers to utilise the integrated VB and LP in the deep open-plan high-rise office building and reduce the use of non-renewable energy resources.

Daylighting performance improvements using of split louver with parametrically incremental slat angle control

Different shading device systems and control strategies can be employed in different parts of a window system to perform different functions, particularly for fully glazed façades. A split louverwith various improvements was proposed in this studyas an innovative daylighting device to improve daylighting distribution and uniformity. An 8 m deep office room in Jordan was chosen for a case study, where it is south-oriented with a high window-to-wall ratio (WWR: 95%). The split louver system features two sections with different functions that can affect the quality and quantity of daylighting performance in the deep room space. Four types of parametrically controlled reflective slats, i.e., unanimous, incremental, fully parametric, and parametrically incremental, were investigated for the upper section of the split louver. While the daylighting performance of the four systems is extremely similar in terms of illuminance level but different in distribution, the parametrically incremental control is the preferred one attributed to its practicality and distribution performance. The upper section of the split louver includes blind integration, and different slat surface materials (diffuse, semi-mirrored, and mirrored) were evolved through various improvement phases. Simultaneously, the lower section of the split louverwas investigated in order to adjust the overall illuminance level. The proposal of scheduled angles of split louver in both sections presented the most optimal combinations to achieve balanced daylighting levels in both the front and back of the space. This resulted in a free-glare indoor with accepted daylight uniformity levels of up to 0.60 and high percentage coverage within UDI150∼750 lx for most of the working hours throughout the year are realized (between 90% and 100% at noontime and no less than 50% along the rest of the working hours).

Daylighting Performance of Integrated Light Shelf with Horizontal Light Pipe System for Deep Plan High-Rise Office in Tropical Climate

Tropical countries such as Malaysia receives a significant amount of daylight. The utilisation of this renewable resource in a high-rise office building leads to opportunities and challenges. Deep plan spaces in such buildings provide challenges to create a uniform daylight distribution across the room. An integrated light shelf (LS) with horizontal light pipe (LP) offers a solution to cater to this problem. Seven (7) different types of LS angle configurations were simulated through Integrated Environment Solution Virtual Environment to assess their daylight performance with integrated LP using overcast and intermediate sky with four orientations. The results showed that the integration of LS to LP improved the daylight uniformity across the room. LS5 with an angle of -15° performed best when compared to a room with only LP installed for all the design days and orientations. The integration of LP and LS5 was able to shade the front portion of the room while providing illumination at the rear spaces. The findings of this study promote the use of integrated LS and LP in deep open-plan high-rise office buildings for building designers.

Performance of combined daylighting strategies in varied sky conditions: post occupancy evaluation of lecture rooms in a tropical climate

Due to the inadequate attention given to daylighting in lecture rooms in tropical wet and dry climate, this study, using field measurement, evaluates combined daylighting strategies in three lecture rooms labelled LLH, BMS and ANB with distinct bilateral glass louvre windows, window floor ratio, orientation and shading strategies. It determines the difference in illuminance in varied sky conditions, and the relationship between the strategies. Results revealed that under the clear sky condition, combined strategies in LLH and BMS rooms were effective in illuminance performance except during evening hours while the one in ANB was ineffective. Both rooms recorded poor daylight uniformity. Similar performance was obtained under overcast sky but they produced effective daylight uniformity. An effective daylighting was obtained throughout the process in the intermediate sky condition, however, the strategy in ANB room was ineffective in the evening hours. Only ANB room had an effective daylight uniformity in the intermediate sky. The strategy in LLH room had a strong positive relationship with BMS’s. The strategy in LLH had a weak positive correlation with ANB’s, but ANB’s strategy had strong positive correlation with BMS’s. Overall, the study contributes to the performance of combined daylighting strategies in tropical wet and dry climate.

Integration of Shading Device and Semi-Circle Horizontal Light Pipe Transporter for High-Rise Office Building in Tropical Climate

The blooming of a deep open plan in office buildings is accelerated due to economic profit reasons. This hinders the utilisation of daylight despite having abundance of daylight in tropical climate. Although a light pipe (LP) provides a means to illuminate the deep interior of the space, non-uniform daylight distribution still occurs due to the high illumination contrast across the room. The integration of a shading device (SD) in a room with an LP offers a solution to create a uniform daylight distribution. In this study, daylighting performances of 5 different types of an SD with different angles were analysed through a computer simulation software, namely Integrated Environment Solution Virtual Environment. The simulation was done using overcast and intermediate sky with sun conditions. The results showed that all SD cases improved the daylight uniformity across the room. A horizontal Venetian blind with an angle of +45o and −45o showed the best qualitative performance among all the cases. However, further shading and illumination are needed respectively to increase the potential daylight utilisation in an open plan office room. This study also concluded that a vertical Venetian blind did not provide a good daylight uniformity due to the vertical nature of the SD. A design recommendation guide for building designers is proposed at the end of this study to promote the integration of an SD and an LP in deep open plan high-rise office building.

Switching daylight: Performance prediction of climate adaptive ETFE foil façades

This paper reports on the daylighting performance of switchable ethylene-tetrafluoroethylene (ETFE) foil in double-skin façades (DSF). In contrast to conventional glazing or static ETFE façades, switchable ETFE moderates incident daylight and controls internal light distribution by actively responding to weather conditions and solar light intensity. To better understand the light control function of ETFE and the impact of parameters such as climate, latitude and window-to-wall ratios (WWR), a validated optical model was used to evaluate different DSF designs. ETFE façades were modelled with a Bidirectional-scattering distribution-function (BSDF) and spectral data, obtained from experimental measurements, to accurately represent specular and diffuse light transmittance. Based on the five-phase method, a parametric climate data-driven simulation of an office room with different façade designs was conducted for three climate scenarios (Oceanic, Mediterranean, Sub-Tropical). When employing switchable ETFE in façades with different WWRs (30–90%), an annual increase of useful daylight illuminance (UDI) from 11 to 69% in the range of 500–2000lx was recorded. The calculated glare probability (DGPs) declined 59% in the best-case scenarios, providing working conditions with imperceptible glare for 94% of the scheduled time. Simultaneously, the daylight uniformity ratio (UR) increased up to 19% compared to a room with a conventional double-glazed façade. Significant improvements of daylight quality were achieved for façades with large windows in climates with abundant solar light available all year long. Overall, this study contributes to expanding the knowledge on adaptive membrane façades, demonstrating their capacity to enhance the daylighting performance of indoor spaces in different climates.

Predictive models for daylight performance of general floorplans based on CNN and GAN: A proof-of-concept study

A daylight performance evaluation at the early design stage is essential for a building morphology design and optimization, having a tremendous influence on energy consumption and indoor environments. Considering the complicated input parameters, time and computational cost of the simulation tools, although proxy models based on various machine learning algorithms have been developed, they are limited to certain building forms described based on the selected parameters. In this study, proxy models of a daylight simulation for general floorplans are proposed based on convolutional neural network (CNN) and generative adversarial network (GAN). ResNet (CNN) and pix2pix (GAN) are applied to predict static and annual daylight metrics (uniformity, mean lux, success rate, sDA, and UDI) and illuminance distribution in space, respectively. Geometry information is embedded in the image structure, and a grid-based simulation are conducted as the ground truth. Two datasets composed of real floorplan cases and parametric rooms were tested in the experiments. ResNet obtains the best R2 of 0.959 and an MSE of 0.008 on the real case dataset for daylight uniformity. In addition, pix2pix generates visualization results close to the simulation with an SSIM of 0.90 in the test set within a period of 1 s and provides real-time intuitive feedback for designers. The results show the possibility of using deep neural networks to extract features from general building forms and build predictive models, which can be integrated into automatic form-finding and design optimization.

Optimizing daylight utilization of flat skylights in heritage buildings

IntroductionAdapted reuse in old historical buildings has been a real challenge since the state of deterioration is usually found severe, and suggested retrofitting is applied with high delicacy to preserve the building originality. Additionally, on altering the potential users’ activity, special considerations are required to fulfill the new needs. Daylight in historical buildings has a special significance in conceiving the massive artistic content within the interior spaces, in providing visual comfort for users, and affecting the total energy performance. ObjectivesThe main goal is to meet the new daylight requirements in heritage building spaces, and to rely on relaxing daylight instead of artificial light sources during the day. MethodsThe research is implemented in Tosson Palace, a historical palace in Egypt, where a top-lit space’s daylight performance is assessed using Rhino + Grasshopper’s Diva package, then the skylight is parametrically configured to optimize daylighting conditions using Radiance, and Daysim engines in high intensity solar climate. Optimization of skylight glazing technologies and skylight size is conducted by changing optimization parameters including the number the two perpendicular mullions grid, and mullions’ depth, which also acts as a shading element. These parameters are genetically optimized using a multi-objective octopus plugin and the optimized configuration is evaluated using LEED v4.1 in SpatialDaylightAutonomy(sDA), and Annual Sun Exposure (ASE) criteria that show both the daylight adequacy, and the comfortable daylight exposure percentages in the skylight covered space. ResultsThe outcomes offer guidance for heritage adapted reuse in hot climatic conditions with minimum design interventions to meet the original design and provide potential users’ comfort conditions. Furthermore, enhancement of both visual, and thermal conditions through the skylight configurations is to be studied. ConclusionThe selected optimum case succeeded in compromising the assessing metrics such that ASE was reduced by 38% from the base-case, avoiding unpleasant direct daylight, and providing protection for interior artifacts from sunlight and achieving a moderate uniform daylight distribution on both affected floors levels.

Daylighting Performance of Light Shelf Photovoltaics (LSPV) for Office Buildings in Hot Desert-Like Regions

Visual comfort and energy consumption for lighting in large office buildings is an area of ongoing research, specifically focusing on the development of a daylight control technique (light shelf) combined with solar energy. This study aims to investigate the optimum performance of light shelf photovoltaics (LSPV) to improve daylight distribution and maximize energy savings for the hot desert-like climate of Saudi Arabia. A radiance simulation analysis was conducted in four phases to evaluate: appropriate height, reflector, internal curved light shelf (LS) angle, and the integrated photovoltaic (PV) with various coverages (25%, 50%, 75%, and entirely external LS). The results revealed that the optimum is achieved at a height of 1.3 m, the addition of a 30 cm reflector on the top of a window with an internal LS curved angle of 10° with 100% coverage (LSPV1, LSPV2). Such an arrangement reduces the energy consumption by more than 85%, eliminates uncomfortable glare, and provides uniform daylight except for during the winter season. Hence, the optimization of the LSPV system is considered to be an effective solution for sustainable buildings.