Daylight Penetration Research Articles

Identifying Potential Indicators of Neighbourhood Solar Access in Urban Planning

Solar access describes the capacity of urban spaces to receive sunlight and daylight. Rapid urbanization and unbridled densification pose a threat to sustainable solar access, reducing the penetration of sunlight and daylight into cities. To effectively assess solar access at such an early design stage, at the urban planning level, it is critical that evaluation metrics are simple and reliable. This paper examines a cross section of solar metrics, from simple to more complex ones, to find potential solar performance indicators for urban planning evaluations. The metric datasets were created based on iterations of homogeneous neighbourhood designs, based on the three commonest typologies in the Swedish context: courtyard, slab, and tower. The results were validated using case studies sampled from districts of Malmö. The findings indicate that simple geometrical and latitudinal metrics may be suitable for assessing the solar access of urban designs due to high correlation with built density. Potential performance indicators aimed at indoor and outdoor evaluation of daylighting (VSC, SVF) and sunlighting (ASH_F, RD_G) in urban planning stages were suggested. Possible methods of applying the provided metric database into assessments were proposed. Future work should find evidence-based thresholds for the metric values to establish performance benchmarks.

Testing Daylight availability for cliff dwellings by adding Clerestory: A case study in Taba, Egypt

The succession of day and night affects human beings’ psychological and health status. Therefore it is essential to transfer the proper amount of daylight. The one-directional daylight source causes the most significant problem in dwellings: the deep gloom sectors. The Clerestory is an old strategy that provides daylight and air inside zones. We develop a strategy to solve daylight problems for earth-sheltered and excavated buildings. The main goal is to measure the enhancement of daylight penetration of excavated mountainous buildings settled in cliffs at various slopes after setting Clerestory. The research presents a simulation study to test Clerestory’s capability to penetrate daylight by using the DIVA plug-in as a tool. The study model is a touristic chalet with a total built-up area of 100sq—meters in Taba, Egypt. The chalet overlooks the Red Sea with a south-oriented facade. The exposed roof’s material and the Clerestory distance inward the facade control daylight penetration and cause a homogeneous daylight distribution.

IMPLEMENTING VERTICAL GREENERY ON OFFICE FAÇADE OPENING TO IMPROVE INDOOR LIGHT QUALITY

In medium-rise office building on tropical climate, façade fenestration mostly dominated by glass curtain wall. In this case, an effort should be done to control the daylight penetration and to shade glare of low sun angle especially from west orientation. The idea is utilized the vertical greenery system (VGS) on facade opening, how it performs as glare limitation as well as accommodating view. Firstly, the variable of artificial shading to light parameter are studied. Then, the previous research of VGS were explored, to find its influential variables. The last step was developed recommendation of VGS implementation on office facade opening to improve light quality. Finding from the study, the most influential variables are the plant species suitable to the climate condition, its canopy leaves area as light variable, and the placement; an integration the plants construction system with other facade elements which consider light angles of incidence and viewer’s sightlines.

Multi-Objective Optimization for Cooling and Interior Natural Lighting in Buildings for Sustainable Renovation

In order to achieve the ‘nearly zero-energy’ target and a comfortable indoor environment, an important aspect is related to the correct design of the transparent elements of the building envelope. For improving indoor daylight penetration, architectural solutions such as light shelves are nowadays commercially available. These are defined as horizontal or inclined surfaces, fixed or mobile, placed on the inner and/or the outer side of windows, with surface features such to reflect the sunlight to the interior. Given the fact that these elements can influence different domains (i.e., energy need, daylighting, thermal comfort, etc.), the aim of this paper is to apply a multi-objective optimization method within the design of this kind of technology. The case study is a student house in the University of Athens Campus, subject to a deep energy renovation towards nZEB, under the frame of H2020 European project Pro-GET-onE (G.A No 723747). Starting from the numerical model of the building, developed in EnergyPlus, the multi-objective optimization based on a genetic algorithm is implemented. The variables used are various light shelves configurations by differing materials and geometry, as well as different window types and interior context scenarios. Finally, illuminance studies of the pre- and post-retrofit building are also provided through Revit illuminance rendering.

Atrium Daylight Penetration in Dense Apartment Blocks. A case of Roysambu Nairobi, Kenya

Atrium Daylight Penetration in Dense Apartment Blocks. A case of Roysambu Nairobi, Kenya

A metamodel based on intermediary features for daylight performance prediction of façade design

In order to obtain information about building daylighting performance earlier in the design stage, recent studies have begun to develop daylight prediction models using machine learning methods. Most studies have adopted design variation parameters as the input parameters for model training, but this method greatly limits the scope of application of the daylight model. By extending application to different design possibilities, this research proposes a novel daylight model, which includes a pre-processing procedure to convert the design model into “Intermediary features” as input parameters representing daylight penetration performance. By changing geometry of one kind of parametric façade and performing daylighting simulation, we were able to generate the data for training, including Intermediary features and sDA/ASE values. The daylight model was then trained using an artificial neural network. Finally, the proposed daylight model was tested by predicting the daylight performance of other kinds of façades. The results indicated that the value of DA and ASE hours per grid were well predicted and that the daylight distribution was reproduced even with different kinds of façades. The deviations of sDA and ASE from simulation results ranged from 1.7 to 6.1% and 0.3–2.1 h respectively. The reproducibility, the predictive capability, and most importantly the extension of model applicability were all demonstrated for the proposed model. Furthermore, comparing to the daylighting simulation, the method using the proposed daylight model is estimated to save 9/10 daylighting evaluation time. This is critical for implementing the evaluation in the early design stage.

Application of light shelves in a refurbished student dormitory: Energy, lightings and comfort aspects

The transparent elements of the building envelope have a crucial role not only in term of heat and mass transfers control, but also for natural light penetration, sound insulation, thermal and visual comfort of the occupants and their health. Among passive technologies, the light shelves could be architectural solutions for improving daylight penetration and for controlling thermal loads. The available research papers usually focus on one aspect. For this reason, the aim of the present study is to analyse the application of the light shelves with multidisciplinary approach and thus, taking into account: daylight, electricity for lighting, cooling and heating needs and thermo-hygrometric comfort. The case study is a real dormitory building placed in Athens and subject to a deep energy renovation toward the nearly zero energy building target. EnergyPlus, by means of DesignBuilder interface, has been used as dynamic simulation tool.Among ten different configurations, the optimal one turns out to be the internal horizontal light shelf placed at 50 cm from the top of the window with a depth of 90 cm or 60 cm. It has been found that in some cases the reduction of electricity for lighting cannot balance the variation in heating and cooling needs.

Multi-Disciplinary Analysis of Light Shelves Application within a Student Dormitory Refurbishment

The achievement of sustainable cities and communities is closely linked to an accurate design of the buildings. In this context, the transparent elements of the building envelope have a crucial role since, on one hand, they are a bottleneck in regards to heat and mass transfers and sound propagation, while, on the other hand, they must allow daylight penetration. Thus, they are responsible for occupants’ thermal and visual comfort and their health. Considering passive solutions for windows, the light shelves can improve natural light penetration, reducing the lights’ electricity demand and controlling windows’ related thermal aspects. The scientific literature is characterized by several studies that analyze this topic, which, however, focus only on the daylight field and sometimes the energy saving for lights. Moreover, they often refer to fixed sky type for the simulations. The aim of the present study is to analyze the application of the light shelves with a multi-disciplinary approach, by means of dynamic simulations, in the EnergyPlus engine, for a whole year. A new methodological approach is presented in order to investigate the technology under different fields of interest: daylight, lighting energy, cooling and heating needs, and thermo-hygrometric comfort. The case study chosen is an existing building, a student dormitory belonging to the University of Athens. It is subject to a deep energy renovation to conform to the “nearly Zero Energy Building” target, in the frame of a European research project called Pro-GET-onE (G.A No. 723747). By means of the calibrated numerical model of this HVAC–building system, ten different configurations of light shelves have been investigated. The best solution is given by the application of an internal horizontal light shelf placed at 50 cm from the top of the window with a depth of 90 or 60 cm. It has been found that despite the reduction in electricity demand for lighting, the variation in heating and cooling needs does not always lead to a benefit.

Daylight in Buildings and Visual Comfort Evaluation: the Advantages and Limitations

Exposure to daylight significantly affects the psychological well-being of occupants by diminishing headaches, eye tensions, or stress. Daylight penetration is a matter of collaboration between building façade and perimeter zones that can be controlled through façade design features. This study reviews available daylighting systems to block or redirect natural light inside the space and their overall performance. Adaptation found to be the main key feature of daylighting systems to improve their effectiveness in indoor environments. As the main implication of such systems on the visual comfort performance of occupants, a list of quantitative indices is studied based on their mathematical equation to outline their advantages and limitations. Findings revealed a lack of agreement on acceptable indoor illuminance thresholds for most of the indices and the absence of a reliable glare index in presence of sun within the view field of the occupant. Similarly, many green building certifications propose a specific criterion to assess view out but remained a challenge for future studies.

A data-driven method to minimize sensor use for dynamic shading control

Dynamic facade systems are a promising strategy to balance the benefits and drawbacks of daylight penetration through the window in a built environment. A well-operated shading system should allow for sufficient daylight access while preventing glare in response to changing weather conditions. The dynamic shading system can also help with making use of daylight to reduce the lighting energy use when integrated with electric lighting control. This paper presented a data-driven approach to control the automated shading system. The control method allows the system to be responsive to outdoor weather conditions. With data from offline daylight simulation using typical meteorological year weather, three machine learning classification algorithms were applied to train predictive models for online shading control. The proposed method was validated using a climate-based simulation. It was found that all models had a satisfying prediction performance, with an accuracy of 0.85 to 0.92. The shading control could maintain the work plane illuminance for 97% to 99% of the time during the year. It was also associated with a potential of reducing electric lighting energy use by 40% to 43% compared to that of on/off lighting control.

A Review on Effective Use of Daylight Harvesting Using Intelligent Lighting Control Systems for Sustainable Office Buildings in India

Lighting is a fundamental requirement of our daily life. A lot of research and development is carried out in the field of daylight harvesting, which is the need of the hour. One of the most desirable attributes of daylight harvesting is that daylight is available universally and it is a very clean and cost-efficient form of energy. By using the various methods of daylight harvesting, it is possible to attain the global Sustainable Development Goals. Daylight harvesting in the most fundamental sense is the lighting strategy control of the artificial light in an interior space where daylight is also present so that the required illumination level is achieved. This way, a lot of energy can be saved. Recently, in addition to energy efficiency, other factors such as cost-efficiency, user requirements such as uniform illuminance, and different levels of illuminance at different points are being considered. To simulate the actual daylight contribution for an office building in urban Chennai, India before construction, ECO TECH software is used by providing the inputs such as building orientation, and reflectance’s values of the ceiling, wall, and floor to analyze the overall percentage of daylight penetration available versus the percentage prescribed in the Indian Green Building Council to obtain the credit points. Thus, the impact of architectural design on daylight harvesting and daylight predictive technology has experimented with office building in Chennai, India. This article will give an insight into the current trends in daylight harvesting technology and intends to provide a deeper understanding and spark a research interest in this widely potential field.

Simulation-assisted data-driven method for glare control with automated shading systems in office buildings

An automated shading system is expected to effectively prevent visual discomfort associated with glare while providing adequate daylight penetration. However, the concept of visual comfort has not been well integrated into existing commercial shading systems, leaving potential for visual discomfort and resulting in occupants’ dissatisfaction. Meanwhile, advanced methods in the academic literature are not always suitable for industrial applications due to problems associated with intensive real-time computation or privacy concerns. This research aims to address this gap by developing a simulation-assisted data-driven method for glare control with automated shades. The proposed strategy utilizes data from pre-simulated daylight analyses to develop glare predictive models using machine learning algorithms. With real-time solar irradiance measurements and the sun position as the input variables to feed the predictive models, the control algorithm can predict the glare condition and set the shades to an appropriate position that maximizes daylight ingress without causing glare. The presented method was verified using climate-based simulation to adjust the slat angle of automated venetian blinds in an office building. Its performance was compared to that of the conventional cut-off angle control for glare elimination, lighting use savings, and view access. The results showed that the proposed strategy was able to prevent 86.5%–96.9% of the glare and potentially reduce lighting energy use by 80.8% while the cut-off control only resulted in 28.9% glare elimination and 67.6% lighting energy savings. The presented method also allowed for unobstructed view more frequently, outperforming the cut-off angle control in all the examined categories.

Decision making criteria for Optimal Selection of Innovative Daylighting Systems in Buildings, Using Integrated Delphi/Dematel/AHP Approach

Nowadays, dense cities has led towards the decrease of daylight penetration into the interior space. Daylight crisis in buildings brings significant challenges to architecture, in three domains of economic, health - wellbeing and environment. "Light well" as one of the most common means of daylight tolls in building, experiences severe limitations and requires special attention. The question is which strategy is the best for increasing the daylight penetration to the depth of buildings. One of the main challenges in deep plan is to guide daylight into the building core and this can be performed through daylighting strategies, but the choice of the proper innovative daylighting system (IDS) with several parameters is the problem. This paper aims to find elements for optimal choice and selecting context-compatible tools for light well. The result shows that four macro factors were found at the interaction of building and IDS. Identifying the integration components can play an effective role in decision-making or design a new tolls consistent with the physical conditions of light well and building to overcome the daylight crisis. The present study aimed to identify, evaluate, and weigh the factors affecting the selection of appropriate and innovative daylighting systems for buildings. To this end, a three-phase study was planned and carried out. In the first phase, the factors affecting the selection of daylighting systems for the building were screened and finalized by using the Delphi method in three steps. In the second phase, interactions between criteria and sub-criteria were evaluated by the DEMATEL technique and then the network of communications and significant relationship between them were determined. The analytic hierarchy process (AHP) was employed in the third phase to evaluate the criteria and determine their importance in the selection of daylighting systems. Finally, the relevant sub-criteria were extracted and prioritized. The results indicated that structural, economic, and technical criteria were more effective than functional criteria in the selection of daylighting systems for buildings.

Enhanced Energy Savings in Indoor Environments with Effective Daylight Utilization and Area Segregation

Daylight utilization is one of the key areas for energy savings in indoor environments. An important factor often not considered by the existing daylight utilization approaches is the segregation of the floor into task areas and non-task areas. It is also observed that the inherent asymmetry in the daylight penetration pattern in most indoor environments is not given consideration while designing artificial lighting arrangements. Moreover, daily and annual daylight availability is found to have a symmetrical variation pattern, which is a significant factor often overlooked in utilizing daylight. Thus, the energy assessment can be inaccurate, leading to an incorrect or impractical evaluation of energy savings. This research proposes a comprehensive new approach to assess the energy-saving potential of daylight utilization in indoor environments. This new method combines two approaches to overcome the aforementioned issues. (1) The considered area is segmented into task area and non-task areas (or surrounding area) and considers different levels of required illuminance for each separate area. (2) The variation of available daylight at the considered location is accounted for by dividing the daylight penetration into multiple levels. For the study, the method is first applied to a simulated office space considering real-life parameters, where the annual energy savings were estimated at 83.67%. For further validation, a comparison with a case from an existing method was also carried out, and the proposed method gave an energy saving estimation of 73.45%. This indicates a 10% higher energy saving estimation as compared to the original study, against which the proposed method was compared.

Optimisation of Passive Solar Design Strategies in Side-lit Offices: Maximising Daylight Penetration While Reducing the Risk of Glare in Different Chilean Climate Contexts

Optimisation of Passive Solar Design Strategies in Side-lit Offices: Maximising Daylight Penetration While Reducing the Risk of Glare in Different Chilean Climate Contexts

Experimental demonstration and performance evaluation of a complex fenestration system for daylighting and thermal harvesting

Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Effective daylighting implementation enhances the amount of useful natural light within a space and offsets the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both of them simultaneously. This paper, describes the design and experimental demonstration of a Liquid Filled Prismatic Louver (LFPL) system, which combines both energy-saving strategies. The LFPL system was installed in a south-facing room in New York City and evaluated for indoor daylight penetration and potential for thermal energy harvesting. Daylight redirection is achieved through the prismatic louver geometry and proper orientation, whereas thermal energy harvesting is achieved through IR absorption from the liquid (e.g., water) within the prisms. Daylighting performance was evaluated by illuminance measurements at key locations within the space, whereas thermal harvesting performance was evaluated through temperature measurements and thermal imaging analysis. We show that the LFPL system, with all prismatic elements oriented at the same angle, achieve a 2-fold and 8-fold enhancement in daylight redirection to the ceiling, for prism orientations of 10° and 20°, respectively. We also demonstrate the system’s capability to adjust to specific lighting needs, within the space, through the dynamic individual orientation of prismatic elements; thus, achieving a concentrated ceiling illuminance enhancement of ~100 times and ~200 times at 2.5 and 4.3 m away from the window sill, providing workplane illuminance enhancement of 6 and 2 times more than in the case of the control room with regular windows. Furthermore, we show a reduction of potential heating loads at locations close to the window from the combination of infrared absorption in the water volume and the redirection of the incoming solar radiation, leading to a reduction of the workplane temperature by an average of 7–10 °C.

Research into the Effect of Photometric Flicker Event on the Perception of Office Workers

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.

Dynamic photovoltaic building envelopes for adaptive energy and comfort management

Current efforts to improve building envelopes mostly focus on reducing energy demand by static measures such as insulation, selective glazing and shading. The resulting envelopes are limited in adapting to weather conditions or occupants’ needs and leave vast potentials for energy savings, onsite energy generation and improvement of occupant comfort untapped. In this work, we report on a dynamic building envelope that utilizes lightweight modules based on a hybrid hard/soft-material actuator to actively modulate solar radiation for local energy generation, passive heating, shading and daylight penetration. We describe two envelope prototypes and demonstrate autonomous solar tracking in real weather conditions. The dynamic photovoltaic envelope achieves an increase of up to 50% in electricity gains as compared to a static photovoltaic envelope. We assess energy savings potentials for three locations, six construction periods and two building use types. The envelope is most effective in temperate and arid climates, in which, for the cases analyzed, it can provide up to 115% of the net energy demand of an office room. Improvements in building envelope performance and onsite power generation are key to enabling zero-energy buildings. Here, Svetozarevic et al. present an adaptive solar facade driven by soft robotic solar trackers that allow both the modulation of daylight penetration and energy generation.

리모델링에 의한 공동주택의 주광 성능 향상 분석

Purpose: Good daylighting design in buildings contributes to energy saving as well as various potential benefits, including enhancement of mood, health, the quality of the luminous environment, etc. Especially, if appropriate daylighting strategies are applied, more natural light can be brought into spaces with less-daylit areas. This work presents how daylighting could be improved in an apartment building by remodeling to allow deeper daylight penetration from its south facade. Method: Glass walls and windows instead of non-bearing walls were applied to introduce natural light through the window at the south facade by remodeling. First, daylighting performance was analyzed by taking measurements for the room facing north before its remodeling. It was, then, followed by RADIANCE simulation of the room after remodeling. Result: The results demonstrated that, after remodeling, more daylight was available indoors, which resulted in an enhanced visual environment. Also, these results could be useful as basic data to devise effective schemes for daylighting methods in the early stages of design. Well-integrated daylighting strategies enable energy savings in buildings by utilizing natural light.

EVALUATION OF LIGHT SHELF DESIGN PERFORMANCES TO THE DAYLIGHT’S SUNLIGHT PENETRATION ON SINAR MAS LAND PLAZA BUILDING TANGERANG TO INCREASE THE GREEN MARK ASSESSMENT

Abstract- Light shelf is one of the daylighting strategies used in Sinar Mas Land Plaza Tangerang. However, based on observations made on the object of research, light shelf design on Sinar Mas Land Plaza Tangerang is not optimal. This is because the purpose of a light shelf that should reflect sunlight directly to enter much deeper into the room does not occur. This is evident in the use of artificial lighting in areas close to openings, so it is necessary to evaluate the light shelf design to improve light shelf performance, which is also useful for improving the Green Mark BCA assessment.This research uses experimental research method to see daylight penetration by simulating model using Ecotect which can simulate model by ray simulation. Evaluation is done by manipulating variables from light shelf design such as ceiling design aspect, light shelf shape, and light shelf slope to see effective light shelf design to be applied to Sinar Mas Land Plaza Tangerang. Based on the research, it can be concluded that the performance of the existing light shelf design is not optimal because of the fins that are above the light shelf to block out direct sunlight. The sloped ceiling design also affects the daylight penetration distance into space. Light shelf design that effective at North orientation is a light shelf design with curved shapes, while the light shelf design that effective at South orientation is a light shelf design with a slope of 200. Improving the light shelf design can increase the Green Mark rating up to 8 points. Key Words: light shelf, daylight penetration, assessment of Green Mark, Ecotect