Indoor Daylight Research Articles

Revisiting the national standard of daylighting in Indonesia: A study of five daylit spaces in Bandung

The current Indonesian national standard on daylighting in buildings (SNI 03-2396-2001) proposes a number of criteria to design and evaluate daylighting condition in indoor spaces, where some of the criteria are unique to other national standards. To assess whether there is correlation between the standard and the subjective perception of the building occupants, student assessments were conducted, by using 30 engineering physics bachelor students, in five daylit spaces in the campus of Institut Teknologi Bandung in Bandung, Indonesia, during overcast days. The students were asked to draw a boundary line between daylit and non-daylit area in the given room. The results were compared to the Indonesian national standard, window-head-height rule of thumb, and contour lines yielded from simulation using Radiance/Daysim which indicated the daylight autonomy, useful daylight illuminance, and daylight factor. It is found that the fully and partially daylit areas according to the students are mostly in accordance with the areas covered with the lines of 1/3 room-depth and 1.5 window-height. The full and partial daylight boundary lines according to the students mostly overlap with daylight factor contour lines of respectively 0.4–1% and 0.3–0.7%. The 50% daylight autonomy with target illuminance of 300lx and 500lx respectively correspond to the student’s fully and partially daylit areas. Lower criteria of both static and dynamic metrics, compared to current standard and rules, might be applied to indicate indoor daylight availability in Bandung.

Using visual simulation to evaluate restorative qualities of access to nature in hospital staff break areas

Contact with nature has been found to produce multiple health benefits in diverse work environments. However, in healthcare workplaces, few studies have addressed this topic, and no studies were found comparing the restorative qualities of visual vs. physical access to the outdoors. This study used visual simulation methods to assess the restorative potential of specific design features in hospital staff break areas, investigating nature-related indoor decor, daylight, window views, and direct access to outdoor environments. The study hypothesized that staff would perceive break areas with higher levels of nature-based content as being more restorative, and that direct outdoor access would be rated as more restorative than window views. Two sets of visual assessments were developed and distributed as part of an online survey to members of the Academy of Medical-Surgical Nurses in the United States; 958 completed responses were collected and analyzed. On a scale of 1–10, nurses evaluated the restorative qualities of (a) direct access to the outdoors through a balcony, (b) an outdoor view through a window, (c) a nature artwork, and (d) an indoor plant, all depicted on images of the same two staff break areas. Statistical analyses showed that ratings increased significantly based on higher levels of nature content, from no added amenities, to indoor plants, to nature artwork, to window views, to direct access to the outdoors through a balcony. This study supports the proposition that higher levels of access to nature, daylight, and outdoor environments are perceived to have significantly more restorative potential in healthcare workplaces.

Analysis of a Translucent Insulated Triple-layer Membrane Roof for a Sport Centre in Germany

A new sport centre in Germany is presently under construction but already features an innovative and sophisticated membrane construction. It consists of a conical-shaped multi-ply membrane with an air gap and a translucent thermal insulation. The main advantages of textile construction materials are the outstanding design options and material properties, which enable to achieve large column-free spans, remarkable building shapes and -due to its light transmission- allows for high indoor daylight quality. In addition to the focus on translucent thermal insulation and membrane materials, the air and the moisture conditions within the ventilated air layer are also investigated by simulations and will be measured in-situ: The project is accompanied by a research project that will also consider monitoring of the building performances and the thermal and moisture behavior of the roof construction. The aim of the project is the methodical analysis and development of energy efficient structural measures for buildings with membrane constructions in Germany including the broad range of planning and building permission issues (due to federal fire regulations for example). The paper presents the project as a case study that offers the challenges and experiences gathered during the planning and construction, and the first simulation results with a focus on the performance of the ventilation air layer.

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.

Adaptation of Kriging in daylight modeling for energy simulation

Kriging is a group of geo-statistical techniques used to interpolate the value of a random field at an unobserved location from discrete observed values at nearby locations. Kriging has been very popular in oceanic research used for predicting the variance of geographical conditions. However, it has been difficult to find a similar application in the built environment. This paper aims to uncover possibilities of using Kriging for built environment studies, specifically focusing on indoor daylight modeling.Currently, most energy simulation tools use algorithms that are based on Daylight Factor (DF) [1] to capture the complexity of daylight behavior. However, DF has limitations in its ability to fully account for realistic daylight conditions. Thus, efficiently integrating the light domain with thermal calculations remains a major hurdle for building energy simulation tools [2].For this reason, the paper aims to find possibilities of using Kriging for daylight modeling. Kriging will use sample points to predict illuminance values of nearby locations. Kriging will considerably reduce the number of points needed to map indoor light intensity profiles. Furthermore, Kriging will be able to provide a more seamless daylight model for energy simulation tools. This proposed method can produce light distribution, such as illuminance (lux), while obtaining more realistic results than DF and at the same time reduce computational expense through statistical methods.The paper first investigates accuracy to determine whether Kriging modeling can interpolate the profile of illuminance from a select sample of data points. To validate the daylight model used in this paper, real indoor illuminance levels were measured for different days and compared with the daylight simulation model. Further, this paper tests Kriging predictions and compares them with both advanced physics-based light simulation and energy simulation to determine possibilities and limitations of the proposed method.In comparison with RADIANCE, this paper found that the proposed Kriging model was able to predict better than the energy simulation daylight model. The difference between Kriging and RADIANCE was 25.52lux. The Kriging model showed great promise since it was able to cut the full RADIANCE simulation time in half and proved to be much closer to RADIANCE predictions than other methods.

Daylight-driven photocatalytic degradation of ionic dyes with negatively surface-charged In2S3 nanoflowers: dye charge-dependent roles of reactive species

Even though dye degradation is a successful application of semiconductor photocatalysis, the roles of reactive species in dye degradation have not received adequate attention. In this study, we systematically investigated the degradation of two cationic dyes (rhodamine B and methylene blue) and two anionic dyes (methyl orange and orange G) over negatively surface-charged In2S3 nanoflowers synthesized at 80 °C under indoor daylight lamp irradiation. It is notable to find In2S3 nanoflowers were more stable in anionic dyes degradation compared to that in cationic dyes removal. The active species trapping experiments indicated photogenerated electrons were mainly responsible for cationic dyes degradation, but holes were more important in anionic dyes degradation. A surface-charge-dependent role of reactive species in ionic dye degradation was proposed for revealing such interesting phenomenon. This study would provide a new insight for preparing highly efficient daylight-driven photocatalyst for ionic dyes degradation.

Annual Performance Assessment of Complex Fenestration Systems in Sunny Climates Using Advanced Computer Simulations

Complex Fenestration Systems (CFS) are advanced daylighting systems that are placed on the upper part of a window to improve the indoor daylight distribution within rooms. Due to their double function of daylight redirection and solar protection, they are considered as a solution to mitigate the unfavorable effects due to the admission of direct sunlight in buildings located in prevailing sunny climates (risk of glare and overheating). Accordingly, an adequate assessment of their performance should include an annual evaluation of the main aspects relevant to the use of daylight in such regions: the indoor illuminance distribution, thermal comfort, and visual comfort of the occupant’s. Such evaluation is possible with the use of computer simulations combined with the bi-directional scattering distribution function (BSDF) data of these systems. This study explores the use of available methods to assess the visible and thermal annual performance of five different CFS using advanced computer simulations. To achieve results, an on-site daylight monitoring was carried out in a building located in a predominantly sunny climate location, and the collected data was used to create and calibrate a virtual model used to carry-out the simulations. The results can be employed to select the CFS, which improves visual and thermal interior environment for the occupants.

Lighting Energy Saving with Light Pipe in Farm Animal Production

The Swedish animal production sector has potential for saving electric lighting of €4-9 million per year using efficient daylight utilisation. To demonstrate this, two light pipe systems, Velux® (house 1) and Solatube® (house 2), are installed in two identical pig houses to determine if the required light intensity, daylight autonomy (DA), and reduced electricity use for illumination can be achieved. In each house, three light sensors continuously measure the indoor daylight relative to an outdoor sensor. If the horizontal illuminance at pig height decreases below 40 lux between 08.00 and 16.00 hours, an automatic control system activates the lights, and electricity use is measured.. The daylight factor (DF) and DA are determined for each house, based on annual climate data. The mean annual DA of 48% and 55% is achieved for house 1 and house 2, respectively. Light pipes in house 2 have delivered significantly more DA than those in house 1. The most common illuminance range between 0 and 160 lux is recorded in both houses, corresponding to approximately 82% and 83% of daylight time for house 1 and house 2, respectively. Further, the daylighting system for house 2 has produced a uniform DF distribution between 0.05 and 0.59. The results demonstrate that considerable electric energy savings can be achieved in the animal production sector using light pipes. Saving 50% of electric lighting would correspond to 36 GWh or 2520 t CO2 per year for Sweden, but currently the energy savings are not making the investment profitable. (Less)

Lighting and Energy Performance of an Adaptive Shading and Daylighting System for Arid Climates

Finding the proper trade-off between blocking direct sunlight, ensuring sufficient indoor daylighting and view out is a particularly delicate task especially in arid climates, due to harsh environmental conditions. As a tentative answer to this challenge, an adaptive shading and daylighting system (Shape Variable Mashrabiya – SVM) has been developed by the authors, described in an earlier paper. In this paper, we analyze how the SVM may affect annual lighting and global primary energy performance of an office building in Abu Dhabi: the SVM was applied to east and west façades and compared to external Venetian blinds, reflective and selective glazing.

Influence of WWR, WG and Glazing Properties on the Annual Heating and Cooling Energy Demand in Buildings

This investigation presents a detailed analysis in an effort of building energy performance improvement from the aspect of building envelope influence on the annual heating and cooling demand. The aim is to indicate methods of performative intervention for envelope improvement and to offer architects and practitioners useful information for decission-making in the rehabilitation and improvement process of existing office buildings. Building envelope was investigated in order to determine preferable window to wall ratio's (WWR) and window geometry (WG) in the function of indoor daylight quality in offices via numerical simulations in Radiance engine, followed by the assessment of glazing influence on the annual energy demand. A comparative analysis was performed among gathered annual building expenses and simulated heating and cooling demands from the multi-zone thermal model constructed in EnergyPlus engine. Findings from the dynamic simulations indicated the influence of glazing parameters on the annual heating and cooling demand of the multi-zone building model.

Daylighting Design for Energy Saving in a Building Global Energy Simulation Context

A study on the impact that different daylighting solutions have on the global energy demand of a space is presented. The methodology relies on dynamic simulations carried out with Daysim and EnergyPlus used in synergy to perform a parametric study to assess the indoor daylighting conditions and the energy performance of rooms with different architectural features: room depth, window size, external obstruction angle and glazing visible transmittance. Furthermore, different lighting and shading control strategies were tested. The results of the study demonstrated that optimizing daylight can lead to a reduction of up to 30% in the global energy demand for a building.

The impact of the software’s choice on dynamic daylight simulations’ results: A comparison between Daysim and 3ds Max Design®

Evaluating indoor daylight availability is extremely important in order to define the characteristics of an environment in terms of visual comfort and energy performances of lighting systems. The criticism of the static calculation approach based on Daylight Factor led to the development of the Climate Based Daylight Modeling (CBDM) one. Dynamic simulations are performed thanks to the use of specific software and the choice of a calculation tool or another could provide different output results. Therefore the aim of this paper is to compare results of dynamic daylight simulations carried out with two different software, Daysim and 3ds Max Design® and referred to a simple office located in 4 different cities and exposed according to the 4 main orientations. It demonstrates that differences in results are more or less significant depending on several factors: outdoor daylight conditions, window’s orientation and considered internal calculation point.

Validation of Computational Algorithms for Prediction of Indoor Daylight Illuminance under Sun and Sky Conditions

This study proposes computational algorithms for prediction of daylight illuminance under various daylight conditions. Five annual daylight simulation methods (ADSM) were developed for the sun and sky. Computer simulations using the ADSM were performed for a classroom with an exterior overhang. In order to validate the simulation results, the results from ADSM were compared with those by Radiance. Results indicate that the prediction by a sunmatching method and reflected daylight coefficient approach were similar to those by Radiance, when methods that consider the effect of sun were used. For the methods that consider the effect of sky, the daylight coefficient approach with four sky patches provided reliable results. The result implies that daylight coefficient approach is a useful method for the prediction of daylight illuminance under daylight conditions. Linear regression models between the results of ADSM and Radiance were acceptable with a significance level of 0.01. This implies that the ADSM can be effectively used for the prediction of indoor daylight illuminance.

Evaluation of Daylight Availability for Energy Savings

Dynamic daylight simulations are very useful instruments in daylighting design process. They allow an in depth analysis of indoor daylight availability levels and define if they are adequate to perform a particular visual task. Their results can be used to design shading devices or lighting control systems and compare different technical solutions. The use of these simulations is likely to spread in the common design practice since some regulations and green building rating systems suggest their use. This paper presents dynamic daylight simulation results related to an open-plan office, performed with Autodesk 3ds Max Design ® , which is a calculation software validated by recent researches. It is not used in academic context but it is very widespread between technicians for photorenderings production purposes. The goal of this research is to demonstrate the functionality of this software also in dynamic daylight simulations field and propose an analysis' methodology to use it.

An Evaluation of Early Education Based on Physical Environmental Guidelines

The integration of environmental policies with political support for action on these policies is of prime significance for mobilization and progression of improving indoor environments. However, state licensing agencies and local county ordinances for child care centers do not universally follow these policies and standards. As a result, most early childhood educational programs operate without proper indoor environments. Indoor air quality, temperature, ventilation, daylighting, and acoustics are crucial factors for educational settings in early childhood education. This study documents the physical environment in early childhood education centers in three counties in Maryland. Results indicate that building performance and indoor air quality standards vary according to the socioeconomic status of children who attend early childhood programs, and environmental factors correlate with educational achievement (as measured by kindergarten readiness scores).

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.

A influência dos afastamentos laterais das edificações na disponibilidade de iluminação natural no ambiente interno

Este estudo aborda os aspectos relacionados à iluminação natural no ambiente interno, sendo o objetivo principal da pesquisa analisar a influência dos afastamentos laterais entre as edificações obstruidoras, considerando a altura e a largura de via, na disponibilidade de iluminação natural no ambiente interno. Na metodologia adotada foram realizadas comparações dos percentuais de valores de iluminância do ambiente interno com os intervalos das UDI (Useful Daylight Illuminance) em um ponto selecionado no interior do ambiente com abertura orientada para Norte. Os percentuais de valores de iluminância foram gerados através de simulação na ferramenta computacional TropLux, em um ambiente de geometria retangular inserido em um cenário urbano na cidade de Vitória (LAT 20°19' S). As simulações foram realizadas para três tipos de céus padrões da CIE (Commission Internationale L´aclairage). Como principal resultado constatou-se nas localidades de céu 3 (encoberto), 7 (parcialmente nublado) e 12 (claro), que há maiores variações nas médias anuais de iluminância interna quando há modificações nos afastamentos laterais entre as edificações obstruidoras, não estando estas obstruções exatamente defronte à edificação analisada. Constatou-se também que localidades de céus 3 (encoberto), 7 (parcialmente nublado) e 12 (claro), as alterações nos afastamentos laterais entre as três edificações obstruidoras, são de pouca interferência nas variações percentuais do intervalo 100≤UDI≤500lx e 500≤UDI≤2000lx.

THE GREENING OF THE PARKING INDUSTRY –BEST PRACTICES, AND A NEW CERTIFICATION PROGRAM FOR PARKING STRUCTURES

INTRODUCTION Sustainable building design is now mainstream. The United States Green Building Council (USGBC) and the LEED Ratings Systems have moved the market, proving that “a rising tide lifts all boats.” Consumers now factor environmental effect into their buying decisions, a trend that looks to continue and intensify with the millennial generation. Renters and homeowners are willing to pay more for high-performing and better quality housing based on environmental standards. Companies recognize that indoor air quality and daylighting improve employee performance and boost retention rates. And even bottom-line businesses are investing in benchmarking and efficiency projects that have the right return on investment rates. The Urban Land Institute's Greenprint Center for Building Performance serves as a prime example of the ways developers implement benchmarking, energy efficiency, and high-performance standards in the major real estate sectors: office, retail, industrial, multifamily, and hotel. Energy e...

Evaluation of Indoor Daylight Parameters during Long–Term Observations in the Rooms Equipped with Intensive Coloured Surfaces

Examination, design and control of internal light conditions belong to important actual architectural issues. In most cases the reason is increasingly growing interest in non-visual response of human on the ambient light properties. Sick Building Syndrome (SBS) is assumed to be caused by complex of inappropriate indoor environment circumstances. Unsuitable light conditions are regarded to be one of them. This paper deals with comparison of internal light parameters such as photopic illuminance level EV, Spectral Power Distribution (SPD) and definition of peak wavelength value recorded in tested office rooms, which were scaled down to models for easier handling. Models are equipped with different selected colored wallpapers and flooring materials, whereby one model remains with all surfaces in neutral colors. The outputs of measured parameters are compared with each other and also with outdoor levels of the same light properties. There is also defined filtration efficacy of blue light component assumed to be most effective for controlling of non-visual sensoring system of human body. This observation may provide more complex overview on selection of internal surfaces colors in long-term occupied spaces, taking health and wellbeing into consideration.

The effect of hospital design on indoor daylight quality in children section in King Abdullah University Hospital, Jordan

The purpose of this study is to evaluate and analyze the indoor daylight quality in Pediatrics Ward in King Abdullah University Hospital (KAUH). It conducts an investigative analyses associated with an evaluative approach for the daylight situation in patient rooms in the children sections in KAUH. A multi-method approach was undertaken including on-site measurements, and building simulation software (RADIANCE) to develop a framework for lighting design in Pediatrics Ward.Daylight conditions were assessed in the hospital site to investigate light quality. A patient room from the Pediatrics Ward in wing A in the hospital was selected. The study considered the following variables: the differences in daylight environments (illuminance, luminance level, and daylight factor), and the physical environment properties of patient rooms in the hospital.The study found that the indoor daylight performance in terms of illuminance, luminance level and daylight factor in patients rooms are higher than the recommended values by CIBSE. Therefore, attention must be paid to the effect of the surface characteristics, reflectance values of room surfaces, and the physical properties of glazing materials on daylight quality in the hospital. In addition, sun-shading elements must be provided in patients’ rooms, to avoid excessive glare and to guarantee a good level of visual comfort for patients and staff.