Daylight Simulation Research Articles

An Analysis of Permanantly Shaded Areas and the Defect Rate of Landscape Trees in Apartment Complexes Using Daylight Simulations

An Analysis of Permanantly Shaded Areas and the Defect Rate of Landscape Trees in Apartment Complexes Using Daylight Simulations

Calibration of the design of cholesterol in order to balance the light of the day with the thermal performance in order to raise the sustainability of university buildings in Syria

In a fully glazed building façade with solar inhibitors with holes (cholesters) (PSS), it is often used as an exterior casing in order to reduce energy consumption and solve other problems such as: transparency of vision. Moreover, the function of these cholesteres is not only to control the solar inhibitors entering the building, but also to control the provision of appropriate degrees of daylight, and thus we have created a balanced solution to the daytime lighting process. Nowadays, daylight simulation software applications enable us to apply scientific analyzes of daytime management in a vacuum when using cholesters (PSs). Regardless of that, current applications of sun simulation (such as: EnergyPlus) cannot deal with some engineering configurations directly, making the process of estimating the thermal factor of solar inhibitors with holes is not possible. This research provides a scientific method to achieve integrated analyzes of daytime lighting and energy consumption of voids using cholesteres during the design process on local university buildings, and such a scientific method provides us with daylight analyzes through (DIVA) and also provides thermal analyzes via EnergyPlus with DIVA / GRASSHOPPER / ARCHSIM The goal is to control the double performance of cholesters by controlling the intensity, arrangement, and shape of these perforations using the statistical method of vertical beams (DOA), and studying the simultaneous gain of daylight and the thermal efficacy of cholesters in order to provide an annual balanced and integrated solution. The (DOA) method is effective in reducing the number of simulations drawn from a mixture of the aforementioned variables and identifying the visual arrangements of these fluids. In comparison with an imperfect interface for a building located in the buildings of the University of Aleppo in Aleppo, these solar fluids with holes achieve an expectation of a decrease .The areas that are actually illuminated by daylight are (50%) and 55% less energy is needed in the building. Although this work uses the DOA method to improve the three design variables, it is possible in the future to increase these factors to include the thickness of the panels, the materials made from them and the slope of the panels.

Integrating daylight simulation in the design process: comparative analysis between two computational platforms

Daylighting presents an important role for high performance buildings. Currently, Building Information Modeling (BIM) has excelled in the Architecture and Engineering (A&E) industry as a collaboration and information exchange methodology that generates integrated computational models. Simulation plug-ins for BIM tools capable of performing daylighting simulations in a semi-automated way have been developed, thus presenting a more simplified simulation process and favoring the adoption of performance analysis since initial design stages; being a little explored subject. This article aims to investigate the Insight plug-in for Revit, focusing on its daylighting features. The workflow, input-output structure and results of Insight dynamic (sDA) and static (illuminance levels) daylighting metrics were analyzed, comparatively to the plug-in DIVA-for-Rhino, which simulation engines were considered validated by literature. Simulations on both software used the same model of a reference office space for the city of Belo Horizonte. Results indicate that Insight’s favors the daylighting analysis in the initial phases of the design process and allows the verification of code compliances, however determining materials optical properties presents some degree of complexity. Low sensitivity to glasses with low and medium values of light transmittance was noticed in the case study. Evidence of consideration of internal reflections of light rays (ambient bounces) close to 7 may leed to overestimated results in the case of low complexity models. This study intends to contribute to the understanding of the potentials and limitations of both analyzed tools, especially in regard to the specificities of BIM daylight simulation with Insight.

Sky type classification in Harbin during winter

ABSTRACT Sky type classification is a significant element in daylight simulation. As a “winter city”, the daylight climate of Harbin is distinctive, and there is therefore a particular need to determine the most appropriate sky models to establish sky luminance distribution in the city and thereby improve the accuracy of daylight simulations. To determine the closest sky type to that of Harbin during winter, sky luminance data consisting of 145 sky elements were collected by a sky scanner at 10 min intervals from June 2018 to February 2019. The sky luminance data were compared with the 15 standard sky definitions, varying from overcast sky to clear sky, proposed by the Commission International de l’ Eclairage (CIE). The sky with the lowest root-mean-square-error was selected as the most appropriate sky type. The results show that clear skies prevail in Harbin during winter, with an occurrence of 70.56%. The dominant sky type is type 12, with an occurrence of 48.57%, followed by types 11, 10, and 8 with occurrences of 17.67%, 5.81%, and 5.36% respectively. The sum of the occurrences of these four sky types exceeds 77%, which means that they can be regarded as generally representative of Harbin’s skies during winter.

파라메트릭 디자인 툴을 이용한 루버 디자인과 파라미터 고찰

Purpose: Current digital technology creates an environment in which architects can design buildings in a single design tool and simulate daylight condition without transforming data. To date, however, research on louver design through daylight simulation and analysis of data is found to be insufficient, considering the design intent of the building from an architect’s or designer’ perspective. The purpose of this study is to recognize the problem of interior space due to excessive daylight, to examine the progress of the design through the analysis of the simulations carried out to solve these problems, and to consider what the architect should consider in the simulation process. Method: Atrium space at the top of the tower where problems are expected to be caused by excessive daylight has been chosen as the simulation location for this study. For the progress of study, the methods of analyzing data, along with the concept of daylight simulation models, Constant Daylight Autonomy (cDA) and the Useful Daylight Illuminance (UDI), are understood through examples. Parametric models are built through Rhino and Grasshopper, and daylight simulations are carried out through Ladybug and Honeybee, the plug-in of Grasshopper, and the results are analyzed. Result: This study is meaningful in terms of a process to automatically execute and store results for different alternatives generated by parameters set up in conjunction with parametric tools in the initial design process. In addition, this study will provide useful information to architects or students who want to design the daylight to fit the architect’s design intent, as well as understanding the overall trend and evolutionary digital tools, as well as providing useful information about the lighting simulation process, how data is interpreted, and what needs to be considered in the simulation.

A daylight-linked shading strategy for automated blinds based on model-based control and Radial Basis Function (RBF) optimization

Addressing both daylight maximization and glare control over the entire workplace is always challenging for developing the automated shading control system. For the sake of cost and space usage, it is impractical to mount multiple sensors or cameras for real-time daylight environment monitoring to guarantee the control precision. Cut-off control is popular while it cannot attenuate the glare caused by excessive diffuse daylight. This paper introduces a model-based shading control for predetermining shading positions at each time step. A Useful Daylight Illuminance paradigm modality called rUDI is proposed as a variable criterion added to assist the cut-off strategy for further eliminating glare. The controller could be developed through real-time daylight simulations and an optimizer based on the surrogate model. This method was implemented in a full-scale office in Harbin, China. The surrogate model grounded on the Radial Basis Function Neural Network (RBF) was trained, validated and test with the experimental data sets. The control strategy was further incorporated with an adaptive light-switch model. The comparative simulations were conducted, and their corresponding results were generated for evaluating their performance in visual comfort, daylighting and electrical energy savings, demonstrating the advantages of the proposed control approach in terms of its adequate performance.

A review on machine learning algorithms to predict daylighting inside buildings

Steep increases in air temperatures and CO2 emissions have been associated with the global demand for energy. This is coupled with population growth and improved living standards that encourages the reliance on mechanical acclimatization. Lighting energy alone is responsible for a large portion of total energy consumption in office buildings; and the demand for artificial light is expected to grow in the next years. One of sustainable approaches to enhance energy-efficiency is to incorporate daylighting strategies, which entail the controlled use of daylight inside buildings. Daylight simulation is an active area of research that offers accurate estimations, yet requires a complex set of inputs. Even with today’s computers, simulations are computationally expensive and time-consuming, hindering to acquire accelerated preliminary approximations in acceptable timeframes, especially for the iterative design alternatives. Alternatively, predictive models that build on machine learning algorithms have granted much interest from the building design community due to their ability to handle such complex non-linear problems, acting as proxies to heavy simulations. This research presents a review on the growing directions that exploit machine learning to rapidly predict daylighting performance inside buildings, putting a particular focus on scopes of prediction, used algorithms, data sources and sizes, besides evaluation metrics. This work should improve architects’ decision-making and increase the applicability to predict daylighting. Another implication is to point towards knowledge gaps and missing opportunities in the related research domain, revealing future trends that allow for such innovative approaches to be exploited more commonly in Architectural practice.

Comparison and development of daylight simulation software – A case study

Working with daylight simulations on a regular basis, the authors discovered that it is increasingly challenging to achieve daylight criteria in new building projects. In addition to complex building designs, a new European Standard was published in 2018 named EN 17037:2018 Daylight in Buildings, which includes climate-based daylight simulations. These new criteria require a different type of simulation and presentation of results, compared to the simplified method of calculating average daylight factor, which is mostly used today. The authors have created, tested and validated scripts for performing climate-based daylighting simulations, using Rhinoceros and Grasshopper. The script designed for climate-based daylight simulations, showed too extensive differences between supposedly equivalent criteria for daylight factor and daylight autonomy, meaning it can’t be applied in construction projects as the only documentation of daylight availability. Further testing and investigation of the climate-based daylight script has to be done, in order to perform correct evaluations of realistic daylighting conditions.

Simulation of Different Light Well Typology by using Daylight Rules of Thumb under Overcast and Intermediate Skies without Sun

The daylight conditions that are fit for an interior can be easily achieved by applying the simple and comprehensive principles, the daylighting rules of thumb in the process design. In architecture, these rules can be expressed in a different kinds of modes and are divided into categories that based on the parameters which constitute them. Since daylighting is the control admission of natural light, one of the categories can be the light well topology. Thus, an opening plays an important role in influencing the effectiveness of daylight distribution in building. One of the categories is light well typology. This study was conducted using an existing sample of single side opening and two side opening light wells with the comparison of additives to light-well typology under under overcast and intermediate skies without sun also to proposes daylighting rules of thumb for light wells. There are several types of light wells simulated for daylighting performances in this study. Light well models were simulated by conducted using IES_VE application software. Regression analysis was then carried out to find correlation between the measurements obtained in the daylighting simulation and the calculations derived from an established daylighting formula. Thus, existing daylighting formula is modified to create new daylighting rules of thumb for light wells with reflectance mirror in single storey terrace houses. These simple equations can serve as rules of thumb to help architects and engineers in calculating daylight levels for different light well designs.

The value of daylight in office spaces

The presence of natural light in indoor spaces improves human health, well-being, and productivity, particularly in workplace environments. Do the social benefits of daylight translate into economic value as measured by what office tenants are willing to pay? Using a sample of 5154 office spaces in Manhattan, we pair urban daylight simulation with a hedonic valuation model to determine the marginal value of daylight in offices. Holding all other factors constant, we find that occupied spaces with access to high amounts of daylight (as measured by 55% spatial daylight autonomy) have a 5–6% value premium over occupied spaces with low amounts of daylight (as measured by less than 55% spatial daylight autonomy). We simulate the distribution of daylight on each office floor individually, taking into account architectural and location-specific characteristics. Then, using the hedonic model, we determine the added value of daylight in the office spaces. The results show, for the first time, that an estimated 74% of office spaces throughout Manhattan have low daylight, and that in a dense urban environment with differentiation in daylight levels, tenants value high daylight. Daylight value is independent of other building, neighborhood, and contract characteristics. By revealing the added value of daylight in commercial office spaces, we suggest that daylight is a key design driver and thus, should be considered in design, policy, planning, and project financing.

Photon mapping to accelerate daylight simulation with high-resolution, data-driven fenestration models

Data-driven modelling provides a general means to represent optically complex fenestration in daylight simulation by its Bidirectional Scattering Distribution Function (BSDF). Radiance employs the tensor tree as a compact data structure to store the BSDF at high directional resolution. The application of such models under sunny sky conditions is, however, computationally demanding, since the density of stochastic backward samples must match the BSDF resolution. The bidirectional Photon Map is proposed to rapidly forward-sample the BSDF, starting from the known sun direction. Its exemplary application shows a potential speed-up of ⩾ 98% when compared to backward ray-tracing.

Contrasting daylight simulation, measurements, and occupant’s perception in a LEED Office building in Arid Climate

Daylight is vital to building occupants as it impacts health and productivity of humans in the indoor environment. No doubt that green building rating systems contribute to the awareness of the significance of daylight in buildings, they enhances the indoor environmental quality by awarding credits to daylight harvesting in buildings. LEED as one of the predominant green building rating systems sets specific daylight criterion, and offers more than one option for project teams to assess and comply with the set criterion; either using manual calculations, using computer simulation (during design), or by daylight measurement (by substantial construction). This article presents a case study of a LEED Gold building in Cairo, Egypt. Within this specific case, three daylight assessment approaches were implemented; Daylight simulation (on design drawings), daylight measurement (after substantial construction), and Post Occupancy Evaluation (POE) (after 9 months of building occupancy). This paper contrasted the results of the assessment methods, this contrast in daylight assessment methods revealed the significance as well as drawbacks of each assessment method compared to the other, and distilled valuable insights about the reliability of each of the available assessment methods.

Relation between daylight availability and electric lighting in a single-family house

Daylight availability is an important aspect that can potentially improve both the quality and the energy performance of buildings. However, it is not always straightforward easy to assure that an increase in the daylight availability leads to a reduction of electric energy use for artificial lighting. In this study, experimental measurements and numerical simulations were conducted to analyse the relation between the uses of artificial light and the daylighting availability for different groups of users who lived for one month each in a Zero Emission Building single-family house located in Trondheim, Norway. The use of electric lighting and the outdoor environment conditions (irradiance and illuminance on the horizontal plan) were recorded through advanced daylighting simulations, carried out with DIVA-for-Rhino, the daylighting availability during the periods of occupancy was then reconstructed, using as input data the outdoor environmental variable recorded during the experimental analysis. The results show that the coefficient of correlation between daylight availability and the artificial light is in general low and the use of artificial lighting seems to be largely independent from the availability of natural light.

Perimeter Blocks in Nordic Towns - How latitude affect daylighting

One of the design principles for future sustainable towns is compactness. The densification of cities is very much needed, but it usually compromises the access of daylight. Densification is especially challenging in the Nordic region characterized by low angled sunlight, something that also limits daylight distribution and restricts its intensity. The higher the latitude, the greater is the difficulty in the distribution. Perimeter blocks give shelter from wind and often create semi-public courtyards which have been seen to be attractive in many Nordic settlements during history. In the present study, alternative design to the conventional perimeter blocks are explored and geometric options such as chamfered corners, strategically varied building heights and differently positioned openings in a broken perimeter block are analyzed. The yearly simulations as well as simulations for May 1st have been carried out for the same perimeter blocks located at four different latitudes (decimal coordinates):1. 65.0 Oulu (similar to Mo i Rana 66.3, Jokkmokk 66.6 and Rovaniemi 66.5)2. 63.4 Trondheim (similar to Reykjavik 64.1, Östersund 63.2 and Vaasa 63.1)3. 59.3 Stockholm (similar to Oslo 59.9, Helsinki 60,2, Tallinn 59.4, Saint Petersburg 59.9 and Anchorage 61.2)4. 55.7 Copenhagen (similar to Malmö 55.6, Glasgow 55.9 and Moscow 55.8)The choice of evaluation criteria is based on scientific discourse in the field of daylighting. According to the new European standard, solar radiation is included. Computer-based daylighting simulations are performed for different designs of the perimeter blocks with equal density, FAR = 1.33. The further north a city is located, the lower the houses in a perimeter block must be to maintain a certain level of daylight. The study confirms that latitude affects daylighting and that geometrical change can improve the conditions for daylight in the perimeter blocks.

Optimization of a spectrally tunable daylight simulator using four quantum dot light‐emitting diodes for visual appraisal of color

AbstractAn optimization model for luminous efficacy of a spectrally tunable light‐emitting diode (LED) daylight simulator under constraint of metamerism index was developed. It was first reported that the optimal spectrally tunable LED daylight simulator of AA grade for D50, D55, D65, and D75 standard illuminants could consist of two quantum dot‐integrated LEDs (QDLEDs) with the ultraviolet chip and two other QDLEDs with the blue chip. The optimized spectral parameters of each QDLED, as well as photometric and colorimetric performances of D50, D55, D65, and D75 daylight simulators, were obtained by maximizing luminous efficacy under the metamerism index for both a visible and ultraviolet range less than 0.25. The limit luminous efficacies of four daylight simulators using four QDLEDs under the ideal case will reach 181 lm/W to 205 lm/luminous efficacies with a radiant efficiency of both the ultraviolet and blue chips of 60%, as well as a quantum efficiency of a quantum dots layer of 90%, will reach 100 lm/W to 112 lm/W.

Photon mapping in image-based visual comfort assessments with BSDF models of high resolution

Data-driven models replicate the irregular Bidirectional Scattering Distribution Functions (BSDFs) of optically Complex Fenestration Systems in daylight simulation. RADIANCE employs the tensor tree to store the BSDF at high directional resolution. Its application in backward ray-tracing is however challenging, since the density of stochastic samples must match the model resolution. BSDF proxy and peak extraction address this problem, but are limited to cases when either the fenestration geometry, or the shape and direction of the transmission peak are known. Photon Mapping is proposed to efficiently sample arbitrary BSDFs from the known sun direction. The existing implementation in RADIANCE is extended to account for light sources and their reflections in the field of view, that are of particular importance for visual comfort assessments. The method achieves a high degree of accordance with ray-tracing, and reduces simulation times by ≈95% with data-driven models of high resolution.Abbreviations: BRT: Backward Ray-Tracing; BSDF: Bidirectional Scattering Distribution Function; CBDM: Climate-Based Daylight Modelling; CFS: Complex Fenestration System; DGI: Daylight Glare Index; DGP: Daylight Glare Probability; FPM: Five Phase Method; GPGPU: General Purpose Graphics Processing Unit; LCP: Laser Cut Panel; OoC: Out-of-Core; PM: Photon Mapping; RMSE: Root Mean Squared Error

Perimeter blocks in different forms – aspects of daylight and view

The perimeter blocks in cities are usually rectangular and follow the streets. The buildings are mostly of similar height within each block. However, perimeter blocks can be developed in many various forms. Geometric options such as chamfered corners, varied building heights and different positioned openings in a broken perimeter block are analyzed in this paper regarding the aspects of views and daylight in city planning. The choice of evaluation criteria is based on scientific discourse in the field of daylighting. As in the new European standard, “Daylight in Buildings”, the following three parameters are included in calculations: solar radiation, daylight level and view out. Computer-based daylighting simulations and calculations of view parameters are performed for different designs of the perimeter blocks with equal density, FAR = 1.33. The simulations have been carried out for Stockholm. That means roughly the same shadows as in Oslo, Helsinki, Tallinn, St Petersburg and Anchorage, all close to the same latitude (60°N). In lower latitudes, e.g. Southern and Central Europe the shadows are shorter. Nevertheless, the ranking of the alternatives will be similar. This study confirms that geometrical changes can improve the conditions for views and daylight in the perimeter blocks. The advantages in the tested urban design alternatives are considerable compared to the perimeter block of the standard type.

Occupant perception of spectral light content variations due to glazing type and internal finish

Indoor Environmental Quality (IEQ) is a key issue in the design and renovation of any indoor building environment. It is comprised of different aspects (e.g. visual, thermal, acoustic comfort, etc.), which directly affect the building occupants’ wellbeing. Studies on this topic have grown rapidly in recent years, as the time that occupants spend indoors is increasing. In this regard, indoor luminous conditions are crucial for providing sufficient task illuminance as well as to stimulate the human circadian system. Insufficient lighting conditions have been proven to be related with reduced productivity/learnability, mood swings and health disorders, thus emphasizing the necessity for further research in this field. Therefore, proper performance evaluation criteria for managing and optimizing lighting spectral composition is needed. For instance, indoor lighting conditions can be evaluated by quantity, intensity, and/or uniformity, but also by spectral content, which determines the energy conveyed and the level at which the human body is stimulated. This spectral content can vary depending on the preferred or prevalent light source, interior finishes and glazing properties generating a singular indoor lighting environment. Thus, a preliminary study on the variation of the indoor daylight spectral content is conducted using a scaled model, applying various glazing types and interior finishes. Then, daylight simulations are performed on a calibrated virtual model to evaluate the effect of various environmental conditions. Results show a considerable impact of the interior finishes as well as glazing type on the attained circadian potential of studied indoor environment.

Enhancing Validity of Green Building Information Modeling with Artificial-neural-network-supervised Learning - Taking Construction of Adaptive Building Envelope Based on Daylight Simulation as an Example

Enhancing Validity of Green Building Information Modeling with Artificial-neural-network-supervised Learning - Taking Construction of Adaptive Building Envelope Based on Daylight Simulation as an Example

Optimum Glazing Configurations for Visual Performance in Algerian Classrooms under Mediterranean Climate

Daylight quality and quantity in Algerian schools show serious problems in ensuring visual comfort of students and teachers. Some problems are due to window design, which leads to excessive amount of sunlight penetration into the classrooms. The consequences are glare and heat gain. This study investigates the effective glazing pattern for classroom to achieve optimum daylight performance and visual comfort in Algerian classrooms. Field measurements of typical classrooms were carried out in a selected school in Algeria during solstice summer (under clear sky condition) and solstice winter (under overcast sky condition). The data of outdoor daylight illuminance were used to validate Integrated Environment Solution Virtual Environment (IESVE) daylight simulation. This study used three different glazing types, namely, clear, tint and reflective glass with different glazing proportions, subsequently, seven patterns of glazing window design were used for an extensive simulation exercise. The results of the investigation from the site measurements show that the work plane illuminance was found to be beyond the range of 300 lux to 500 lux, which exceeded recommended value, except for the south-east orientation with clerestory typology, which were recorded at 2.98% of daylight factor, in contrast the daylight uniformity in tested classrooms is appropriate. Furthermore, the simulation revealed that combination of 75% clear glass and 25% reflective glass with 30% wall-to-window ratio has achieved 41.41% during winter and 47.82% during summer of Useful daylight illuminance. The use of different glazing configurations shows a significant improvement on daylight distribution and the reduction of glare comparing to the reference model. However, such improvement in the quality and quantity of daylighting was inadequate which arises the need of further enhancement.