Daylight Analysis Research Articles

DESIGN OF ENERGY-EFFICIENT BUILDINGS AND BENEFITS OF ENHANCING RELIANCE ON NATURAL LIGHTING THROUGH MAXIMIZING THE EXTERNAL REFLECTED COMPONENT

Daylight can be provided via windows and glazed doors, as well as via skylights and other forms of top lighting. These glazed openings are collectively referred to as fenestration. The placement, design, and selection of materials for fenestration are extremely important and can tip the balance between a high performance and low performance building. Fenestration impacts building energy efficiency by affecting cooling loads, heating loads, and lighting loads. Visual comfort is strongly affected by the window location, shading, and glazing materials. Well-designed windows can be a visual delight. But poorly designed windows can create a major source of glare. Thermal comfort can also be compromised by poor fenestration design. Poorly insulated windows add to a winter chill or summer sweat, while windows with low U-values keep glass surface temperatures closer to the interior air temperature, improving thermal comfort. In addition, east-west windows and unshaded south windows can cause excessive cooling loads. And although windows and skylights provide opportunities for natural ventilation, they must be designed to ensure a safe, secure, and easily maintained facility. The table below specifies the recommended minimum illumination levels. Any shortage in meeting these levels should therefore be supplemented via artificial means. According to Hofman in his textbook Handbook of Lighting Design, the table below (Table 1) provides a summary of the minimum illumination levels measured in lux. The Lx value indicated for each building use is the required illumination level needed to perform the specific task. The table also provides codes that should later be used by the designer in another table(s) to aid in the final selection of an efficient lighting source. The above steps should be carried out after completion of the daylighting analysis and design. In order to establish a complete, energy efficient, and sustainable lighting design, the designer must implement an integrated approach for the entire facility. This dictates consideration of both Natural and Artificial design elements withing the Egyptian building code of lighting. یرکز البحث على الفوائد العملیة و الصحیة للمستخدم نتیجة الإعتماد على الإضاءة الطبیعیة داخل تصمیم المساحات الداخلیة بالمبانى بإستخدام معامل (ERC). و یقدم البحث عدد من البیانات التخطیطیة التى تمکن المصمم من تقدیر الإضاءة الطبیعیة إعتمادا بشکل رئیسى على معامل الإنعکاس الخارجى و ذلک لجمیع الواجهات و عند کل الأدوار.

An active sunlight redirection system for daylight enhancement beyond the perimeter zone

Over the past years, extensive research has been carried out in the creation of working environments that utilize natural light as their primary source of illumination. Transferring glare-free daylight into the core of the building can significantly increase lighting energy savings but it can increase cooling needs as well. Traditional daylighting systems mainly focus on controlling the incoming solar beam radiation, thus regulating the illuminance levels, usually near the perimeter zones. This paper proposes a sunlight redirection system that uses a number of movable mirrors, installed on a light shelf and capable of tracking the sun. Reflected sunlight is projected towards a specified, fixed target area on the ceiling. The theoretical framework for the operation of the proposed system is presented in detail, together with a daylight and energy analysis for the summer and winter solstices, representing the two extreme trajectories of the sun. Five cases were examined, representing various shading system configurations. The results indicate an increase of 99%, in the daylighting levels in the secondary (non-daylit) area during the summer solstice and a reduction of 21%, during the winter solstice, when compared to an unshaded, unobstructed reference case. If a case with a shading system (i.e. external static blinds) is used as a reference case, the proposed system increases the daily illuminance values during both solstices by 152% (summer) and 12.5% (winter). Unfortunately, there is a slight increase (<5%) in daily primary energy consumption. Simulations were performed using Radiance and EnergyPlus while the data needed as input, was created with a new algorithm capable of producing 3D models of the proposed system together with the reflected sunpatch geometry on the ceiling.

Impact of daylighting on total energy use in offices of varying architectural features in Italy: Results from a parametric study

The growing attention towards the optimization of the overall performance of a building, in terms of both indoor environmental quality and energy consumption, has brought about the need to carry out analyses, which consider the interactions of all affecting parameters. In particular, thermal and daylighting analysis should be carried out in synergy to ensure the best performance in both domains. Within this framework, the paper presents a study on daylighting and energy behavior of rooms with different architectural features. The study has been conceived to account for a broad range of possible configurations of office buildings in the climate site of Turin (Northern Italy), and has been performed through numerical simulations carried out with Daysim and EnergyPlus. The results outline the daylighting performance (in terms of spatial Daylight Autonomy (sDA)) and the energy demand for lighting, heating and cooling and demonstrate that optimizing daylighting can lead to a reduction of the total energy demand of an office.

A Design Methodology for Perimeter Block Housing Considering Day-lit Environments and Energy Performance

Perimeter block housing was introduced from the 2000s as an alternative means of urban construction that has been polarized between the large-scale development of high-density high-rise buildings and the development of small plots of land. The results of this paper allow the possibility of forming building types that satisfy the standard of two consecutive daylight hours for all households by using the properties and principles of shadows in perimeter block housing. It also provides the possibility of the combination of building forms without daylight interference from the south mass by manipulating the distances between adjacent buildings at different azimuth angles. Furthermore, comparing the energy load of residential buildings as suggested from the results of the study, it was possible to confirm whether residential buildings optimized for the day-lit environment have an effect in terms of energy usage performance, and further suggested planning directions through the analysis of daylight, sunray, and energy load. The study suggests a rational methodology for the layout of residential buildings that is optimized for the day-lit environment and also considers the issue of energy performance.

Simulation-based daylighting analysis procedure for developing urban zoning rules

ABSTRACTIncreasing urban density leads to a conflict between space-use efficiency and daylight access. Cities have traditionally relied on zoning guidelines that consist of section-based geometric evaluation techniques and/or hours of access to direct sunlight. However, it is now possible to quantify the performance of detailed design proposals before construction. Annual climate-based daylighting performance metrics for urban environments can be computed accurately, in high spatial resolution and in a timely manner. Given that massing design decisions at the urban planning level may make or break the long-term daylighting potential of a whole neighbourhood, the adoption of these tools by zoning boards, developers and urban planners seems particularly relevant. A simulation-based daylighting analysis procedure reveals the capabilities for both formulating more nuanced prescriptive zoning rules as well as for use by design teams. The procedure is used to evaluate the daylighting performance of 50 block typologies in New York City (NYC). The analysis demonstrates that certain urban massing approaches (e.g. pencil towers on a contextual base) outperform conventional massing strategies. A second case study application of an actual city block shows that innovative urban massings can improve access to daylight for the massing itself as well as for neighbouring buildings.

SYNTHESIS AND OPTIMIZATION OF LOUVER-DRIVING MECHANISM FOR INNOVATIVE DAYLIGHTING SYSTEM IN DEEP-PLAN BUILDING

Optimum usage of daylight plays a an importatnt role in high-performance architecture and planning. Innovative daylighting systems in contemporary buildings can produce various benefits such as maximizing daylight penetration, optimizing visual comfort and reducing energy consumption. This paper is to develop a new louver-driving mechanism to optimize adoption of daylight in deep-plan building in order to meet requirements of high-performance architecture. Methodology of the paper emphasize on a experimental and quasiexperimental approach for examination of different types of louver-driving mechanism. The greater city of Tehran adopted as case study of the paper. The main goal is based on searching standards to better louver design in order to optimize energy demands by using this shading device. Thus 45 different cases with different louver width and angles and different louvers’ distance from facade were chosen to analysis.Visual comfort and energy efficiency are analysed in an integrated approach. Moreover the combination of daylight and energy performances has always been an issue, as different software packages are needed to perform detailed calculations. A simplified method to overcome both issues using recent advances in software integration is explored here. All daylight, thermal and glare analysis were done in DIVA plug-in for Rhinoceros/Grasshopper which has ability to effectively calculate daylight metrics (using the Radiance/Daysim engine) and energy consumption (using the EnergyPlus engine). It can be concluded from experiments that generally, the various size of the louvers were not much different from each other and custom sizes can be selected according to the plan but any alteration in louver’s angle and distance from facade were followed by changes in lighting and thermal load of room. In the case of the using fixed louver in design in Tehran’s climate, distance between 0 and 13 centimeters and angle between 22.5 to 45 degrees are introduced as the optimum mode.

Parametric Office Building for Daylight and Energy Analysis in the Early Design Stages

This paper introduces technology analysis and optimization method. Rhinoceros, an architectural modeling program, is used, along with its graphical algorithm editor Grasshopper and its plug-in, ladybug and honeybee, with a simplified tool for building thermal evaluation for the purpose of minimizing the energy consumption and maximize the useful daylight illuminance of an office building in China Beijing. The introduction of technology analysis and optimization methods, provides a generation of practical global optimization and solution strategy for building design for different majors.

The natural light in the Italian rationalist architecture of Ex G.I.L. of Mario Ridolfi in Macerata. The virtual reconstruction and the daylight analysis of the original building

This study presents the analysis and the evaluation of indoor daylighting levels of Ex G.I.L. building (1935) in Macerata (Italy), designed by Architect Mario Ridolfi (1904–1984), according to the original composition and internal distribution, which have been deeply modified during time. The Ex G.I.L. building is a very representative example of Italian rationalist architecture. The virtual reconstruction of the original aspect of the building has been possible thanks to the study of sources and of original documents.The simulations, produced to evaluate and to represent the levels of indoor natural light, have involved a very reliable 3D virtual reconstruction of the original building about size, building components dimensions and internal distributions, allowing at the same time to provide reliable and new representations of the original building. The daylighting simulations are run, using advanced solar-lighting design tools, which use international technical lighting calculations, according to ISO/CIE standards. Finally, the data and simulations obtained are compared and evaluated with current regulatory standards.The use of current energy simulation tools on the study of this architecture of the past, shows a very high availability of natural light and optimum light distribution of indoor environments designed by Ridolfi, highlighting a specifically design attention dedicated to this purpose, where the excellent formal solution, according to the rationalist style, includes the achievement of optimum natural lighting and visual comfort.

Combined thermal and daylight analysis of a typical public rental housing development to fulfil green building guidance in Hong Kong

This paper presents a combined daylight, airflow network and building energy simulation of a Public Rental Housing (PRH) development in Hong Kong to fulfil the requirement of the local green building guidance. The numerical modelling results are partly validated by on-site measurements during the period with the highest monthly average outdoor temperature. Different ventilation control strategies are simulated to optimize natural ventilation performance. The simulation results show that the full-day ventilation strategy contributes to a lower average and peak indoor temperatures compared to the non-ventilation and night-ventilation scenarios. The indoor operative temperature of a worst-case vacant flat lies under the upper 80% acceptability limits in ASHRAE 55 during 67.5% of the modelled period in July. On the other side, at least 95.6% of the habitable area in the case buildings is predicted to experience a higher average daylight factor of 1% compared with the local green building guidance. Furthermore, the energy saving potential of the combined natural ventilation and daylight strategies is anticipated to be 51.9% for air-conditioning and 8.3% for lighting compared to a baseline building, respectively.

A study of the potential benefits of semi-transparent photovoltaics in commercial buildings

This study investigates the potential benefits of semi-transparent photovoltaic windows on the energy, daylighting and thermal performance of commercial buildings. A general simulation methodology is proposed and utilized, integrating thermal, electrical and daylighting analysis. The impact of various building design parameters on the selection of ideal optical properties of semi-transparent photovoltaics is examined. The potential performance of Poly-Si, a-Si/μc-Si and organic cell technologies is also studied. The selection of the module optical properties is shown to be sensitive on the daylight and lighting controls applied and photovoltaic cell technology utilized. The selection of a semi-transparent photovoltaic module with 10% visible effective transmittance resulted in the lowest annual end-use electricity consumption (as low as 5kWh/m2/yr). Finally, simulation results suggest that high cell operating temperatures of up to 64°C could occur that might cause accelerated degradation when organic thin film technologies are used.

Inverse opening design with anisotropic lighting incidence

In architectural design, configuring opening shapes is a crucial element of daylight analysis. In this paper we present a new method which optimizes opening shapes to meet specified lighting design purposes. This novel approach treats the problem as an inverse lighting problem considering global illumination contributions and anisotropic lighting incidence, therefore any kind of sky distribution can be used as an external source of light. The key to our technique is in exploiting coherence to formulate a compact representation that can be tailored to optimization processes. The resulting reduction in processing time and efficiency in achieving optimal shapes along with the feasibility of dealing with anisotropic light sources are our key contributions.

Climate-based daylight analysis of fixed shading devices in an open-plan office

Office buildings consume large amounts of energy and are responsible for large amounts of greenhouse gas emissions worldwide. Among building energy efficiency measures, solar shading plays a significant role in reducing building energy consumption for cooling. This study analysed the influence of solar protection on daylighting of an open-plan office. Climate-based daylight modelling was used to predict such metrics as daylight factor, daylight autonomy and useful daylight illuminances. The results obtained showed that overhangs, and horizontal and vertical louvres have similar behaviours and sidefins have no relevance to indoor daylight conditions. In all cases, it has been proven that excessive obstruction may yield an excessive reduction in a range of illuminances between 500 and 2000 lux, increasing lighting energy consumption.

Design of an Energy-Aware LED Light System (EA-LLS) for Energy Saving and User Satisfaction through Daylight, Space and User Movement Analysis in Buildings

Design of an Energy-Aware LED Light System (EA-LLS) for Energy Saving and User Satisfaction through Daylight, Space and User Movement Analysis in Buildings

Sustainable Energy Planning. Design Shading Devices with Integrated Photovoltaic Systems for Residential Housing Units

The study scopes to optimize the characteristics of shading devices (SDs) with integrated photovoltaic panels (PVs) that are designed for residential building facades. The SDs are located on the external part of a window facing south, in a distance from the external wall, in order that a semi - outdoor space is created. The research deals with the integration of solar technologies in buildings. Focusing on the optimization of the relationship between the energy technologies and the architectural design. Concerning the design process we took into consideration the definition of user's visual comfort and the optimization of the design process of the final product. This experiment focuses on the integration of flexible shadings in order to use the external space as a consecution of the internal space. Methodologically the parameters of the research are defined and the decision on the type of the experiment is taken according to the summer at three different weather conditions in Crete. So, the physical model type of experiment was preferred to the computer simulation model. The results are being categorized and the process is being evaluated according to the above mentioned parameters. The research seeks to highlight how experimental shading devices with integrated PVs can achieve better view for the users while performing as energy production and reduction machines. Finally as a result the daylight analysis value is compared with the human's comfort view to outside and the energy needed for the performance of the examined unit during the day. Our main goal is to optimize the comfort in combination with the energy generated and the best suited space for the everyday activities.

Daylight Factor Analysis for Different Types of Static Shading Devices: Case Study Location in Podgorica

Daylight analysis as a tool for energy efficiency enhancement in existing buildings is considered in this paper. Through the analysis of five types of exterior static shading devices, horizontal, as well as, vertical, the guidelines for their designing, implementation and possibilities in using of building repairing are given. Also, methods for evaluation of their impact on distribution of daily illumination, viewpoint towards the environment and thermal comfort in general are presented. In the case study, the building of Agency for Electronic Communications and Postal Services in Podgorica, Montenegro, and sophisticated software tools that enable impact analysis and precise designing of exterior static shading devices are considered. The results are presented through the examples.

Photovoltaic greenhouses: evaluation of shading effect and its influence on agricultural performances

During the last years, European government remuneration polices promoted the realisation of photovoltaic systems integrated with the structures instead of on ground photovoltaic (PV) plants. In this context, in rural areas, greenhouses covered with PV modules have been developed. In order to interdict the building of greenhouses with an amount of opaque panels on covering not coherent with the plant production, local laws assigned a threshold value, usually between 25% and 50%, of the projection on the soil of the roof. These ranges seem not to be based on scientific evaluation about the agricultural performances required to the building but only on empirical assessments. Purpose of this paper is to contribute to better understand the effect of different configurations of PV panels on the covering of a monospan duo-pitched roof greenhouse in terms of shading effect and energy efficiency during different periods of the year. At this aim, daylighting and insolation analysis were performed by means of the software Autodesk&lt;sup&gt;®&lt;/sup&gt; Ecotect&lt;sup&gt;®&lt;/sup&gt; Analysis (Autodesk, Inc., San Rafael, CA, USA) on greenhouse model with different covering ratio of polycrystalline photovoltaic panels on the roof.

A BIM Inspired Supporting Platform for Architectural Design

ABSTRACTIn conventional design processes, various kinds of design analysis made by professional consultants often arrive too late to assist architects to make strategic decisions at early design stages. The analysis is thus merely used for presentation in such cases.This paper proposes that a design “dashboard” should be integrated into modeling tools used by architects at early design stages. This dashboard should provide visual presentation for information regarding estimated construction cost, structural analysis, and building performance in real time. It is shown that in a generative modeling platform, interfaces can be developed to connect tools for modeling and design analysis, so that the mentioned characteristics of design dashboard can be implemented and customized for specific design cases.To illustrate the viewpoints, this paper presents an actual design case of an apartment building to show how the design dashboard assists the architect with prompt information on daylighting analysis at early ...

Comparative Study of Two Daylighting Analysis Methods with Regard to Window Orientation and Interior Wall Reflectance

The accuracy and speed of the daylighting analysis developed for use in EnergyPlus is better than its predecessors. In EnergyPlus, the detailed method uses the Split-flux algorithm whereas the DElight method uses the Radiosity algorithm. Many existing studies have addressed the two methods, either individually or compared with other daylight analysis methods like Ray tracing but still there is lack of detailed comparative study of these two methods. Our previous studies show that the Split-flux method overestimates the illuminance, especially for the areas away from the window. The Radiosity method has the advantage of accurately predicting this illuminance because of how it deals with the diffuse light. For this study, the EnergyPlus model, which has been calibrated using data measured in a real building in previous studies, has also been used. The calibrated model has a south oriented window only. This model is then used to analyze the interior illuminance inside the room for north, west and east orientation of the window by rotating the model and by changing the wall reflectance of the model with south oriented window. Direct and diffuse component of the illuminance as well as the algorithms have been compared for a detailed analysis.

LRT Digest 2 Tubular daylight guidance systems

Executive summaryThis Digest concerns passive tubular daylight guidance systems (TDGS), the most commercially successful method of daylight guidance. TDGS were introduced some 20 years ago and thus...

Building Information Modeling (BIM)-based daylighting simulation and analysis

Daylighting is an important aspect in designing high performance buildings. Many simulation tools have been developed to study the daylighting performance of buildings. These tools primarily use CAD environments for creating architectural models, which are then converted into daylighting models to run on the daylighting simulation engines. Once the architect defines the architectural model in CAD, a simulation expert creates the simulation input file to perform daylighting analysis. Each tool has its own rules that the architect and the engineer have to follow to prepare the simulation input files, and the complexity depends on the tools. Currently, Building Information Modeling (BIM) is widely used in the AECO industries and BIM models are used as a means of exchanging data among different professionals involved in the design and construction of buildings. The present paper discusses the use of BIM for building performance simulations and mainly focuses on how daylighting analysis can be incorporated into a BIM environment, and what challenges and benefits exist in the process of integrating BIM with daylighting simulation tools. The paper presents the development and validation of a prototype to integrate the BIM tool, Revit with the daylighting simulation tools, Radiance and DAYSIM.