The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper publi...The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper published in Journal of Power and Energy Engineering Vol.3 No.4, April 2015, has been removed from this site.展开更多
Different approaches have been introduced for the daylighting system to reduce energy consumption, but they were not populated due to complex, high cost, and insufficient designs. There has been a recent problem in ac...Different approaches have been introduced for the daylighting system to reduce energy consumption, but they were not populated due to complex, high cost, and insufficient designs. There has been a recent problem in achieving uniform distribution of sunlight at a destination deep inside the building. Therefore, we propose a system to achieve high illumination by illuminating the surface of the absorber (optical fibers) uniformly. To capture sunlight, parabolic reflector and Fresnel lens are used. Different reflectors and lenses are considered, compared, and investigated to direct uniform light, which solves the heat problem, into the optical fibers. In addition, this study includes comparison between fiber-based daylighting systems. The proposed system has been verified through simulation and experimental results.展开更多
Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through lig...Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.展开更多
In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still rel...In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.展开更多
Fiber-optics daylighting system(FODS)demonstrates significant potential for enhancing natural light utilization efficiency while enabling a more continuous visible spectrum illumination to support circadian rhythm reg...Fiber-optics daylighting system(FODS)demonstrates significant potential for enhancing natural light utilization efficiency while enabling a more continuous visible spectrum illumination to support circadian rhythm regulation.It offers a promising solution for both building energy efficiency and indoor light environment comfort improvement.However,conventional FODS face critical limitations,including low coupling efficiency at the collector-fiber interface and uneven illumination distribution,which impede its practical application.Recent advancements in optical technology present new opportunities for performance optimization of the FODS.Departing from traditional homogenization approaches reliant on optical homogenizers,this study introduces a freeform-caustics-based collector design with discretized energy distribution across the receiving plane.This innovative freeform fiber-optics daylighting system(FFODS)simultaneously addresses localized thermal accumulation and improves coupling efficiency.Furthermore,diffuse transmission materials and a freeform lens are integrated as a dual-functional diffuser to reshaping emitted light and precisely manipulate optical wave fronts,thereby achieving stable and uniform illumination in the targeted area.On this basis,a systematically simulation analysis on the thermal characteristics and photometric performance of the system was conducted.The results validate that the FFODS achieves a 98.5%coupling efficiency with a 126 times reduction in geometric concentration ratio compared to Fresnel lens collector.The diffuser maintains illumination uniformity above 0.8 under bending and adjustment conditions,while realizing 91.5%workspace illumination efficiency in the targeted area.Overall,this novel FFODS provides a transformative technique for advancing conventional FODS with high efficiency and illumination uniformity.展开更多
In order to meet the requirements of indoor illumination, a LED daylight lamp model was designed, it can replace traditional fluorescent lamp without insteading additional power supply establishment. The optical prope...In order to meet the requirements of indoor illumination, a LED daylight lamp model was designed, it can replace traditional fluorescent lamp without insteading additional power supply establishment. The optical properties of the model were simulated using optical analysis software. Its luminous efficiency is about 30.4 lm/W, and the illuminance is about 38 lux when the distance is 1.5 m between the center of the model and measured spot. With the theoretically-optimized design of LED model, experiments based on the results of the optimal simulation in the laboratory were conducted to verify the performance of the proposed LED model, it reaches a power factor of about 0.8 at 6 W. The simulation results are very similar with the measured values. It is testified that simulative method is one of the effective tools for LED lighting optical design.展开更多
Daylight is a fundamental element to obtain built environments that promote environmental comfort and energy efficiency. However, strategies that enhance the building daylight performance can affect its thermal energe...Daylight is a fundamental element to obtain built environments that promote environmental comfort and energy efficiency. However, strategies that enhance the building daylight performance can affect its thermal energetic performance. In this sense, research that addresses these aspects at the same time is considered essential. The objective of this paper was to evaluate the daylighting and thermal-energetic performance of administrative environments in a public institution, and to propose strategies that will enhance the use of daylight and lower energy consumption. Therefore, for future projects, and considering new buildings, and retrofit, this research will be an important reference. The research was developed through a case study of an administrative building model, in which the characteristics of solar orientation, light shelf use, glass type, and light and dark colors in walls were modified and combined, deriving it into models proposed. The daylighting performance evaluations were performed through dynamic simulation with the Rhinoceros for Diva software, and the thermal-energetic performance evaluations with the EnergyPlus software. The results of the work showed that a suitable solar orientation has a great impact on the automation of daylight and the energy consumption of the evaluated models, followed by the type of glass and the use of the light colors in internal walls, and that the use of artificial lighting with dimerization is fundamental as a complement to the daylight autonomy. For the boundary conditions of the study, the use of light shelves modified neither the daylight performance nor the thermal-energetic performance of the evaluated models.展开更多
Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final a...Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final architectural layout and interior design. The main aim of this study is to demonstrate how such daylighting studies can be completed at the early stages of design and, at the same time, to show the impact of window design and positioning on building indoor environments. The paper is focused on a study of window influence on room daylighting in residential buildings and computer lighting simulations in software packages： Windows Daylighting System and Autodesk Ecotect Analysis, have been carried out for different style and positioning of windows using several case studies. The main findings clearly indicated that not only the window size and style matters, but also the positioning of windows considering external walls which would make a significant influence on room daylighting levels and, therefore, such daylight studies are very important for the early stage of environmental analysis during building design.展开更多
Improving daylighting strategy is a mandatory step to achieve visual enjoyment and energy saving in buildings. Psycho, physiological effects and energy performance have to be investigated in order to define a range of...Improving daylighting strategy is a mandatory step to achieve visual enjoyment and energy saving in buildings. Psycho, physiological effects and energy performance have to be investigated in order to define a range of different daylighting strategies, thanks to daylighting devices and climate based daylight modeling. Daylighting optimization ensures indoor healthier rooms, reduces electric light consumption and cuts the risk of glare. The best way to achieve these targets is to define users lighting needs, based on visual targets and to draw up some green measures to reduce electricity demands. Involving new climate-based daylight modeling metrics aims at defining proper illumination targets, in order to drastically reduce electrical lights, as well as reducing thermal loads deriving from cooling and HVAC （heating, ventilation and air conditioning） systems.展开更多
In the subtropical zone of China, a large number of old factory buildings rich in industrial historical and cultural value have been transformed into art studios. In the existing research on building renovation, there...In the subtropical zone of China, a large number of old factory buildings rich in industrial historical and cultural value have been transformed into art studios. In the existing research on building renovation, there are still problems such as insufficient lighting, low uniformity, and ignoring the effect of glare in the lighting environment of buildings after transformation. To fill this research gap, this paper provides a daylighting design strategy for these factory buildings in subtropical zones to ensure that the transformed art studios can offer an excellent indoor daylighting environment. Through the control variable method, the window-to-wall ratio, the form of external windows, and the visible light transmittance of glass are set with quantitative and variable values, and a design strategy that meets the requirements of international general daylighting standards is obtained step by step through the simulation. The daylight factor, uniformity, daylight autonomy, and dynamic glare probability are used in this research process to measure whether the daylighting strategy meets the daylighting requirements of the CIBSE Lighting Guide for art studios. The results show that the average indoor lighting coefficient can be increased from 1.29 to 6.18, and the minimum value of the lighting coefficient can be increased from 0.4 to 4.4 by enlarging the windowed wall ratio from 1:30 to 1:3, using the combination method of the horizontal window, skylight and skylight recommended by the analysis results, and selecting veneer glass with 88% transmittance. This allows for better uniform lighting inside the building and reduces glare. This conclusion can support the lighting performance design of industrial buildings in the future.展开更多
The urgency of increasing energy efficiency in new building design and retrofits has pushed lighting simulation to play a central role in sustainable lighting design. The shape of the building and its orientation, the...The urgency of increasing energy efficiency in new building design and retrofits has pushed lighting simulation to play a central role in sustainable lighting design. The shape of the building and its orientation, the reflectances of building surfaces and glazed areas are important parameters in the daylighting design of buildings. Glazing systems can cut energy consumption and associated pollution sources, reduce peak demand, enhance daylighting performance and improve occupant comfort. This paper presents the results of a numerical and experimental comparison between the performances of an office building with and without external sunscreens. The aim was to analyse the illuminance distribution and some investigations have also been made with regards to the effect on daylight in rooms when sunscreens are used. The experimental results were obtained using an office building scale model and sky simulator. The numerical results were obtained through radiance, the ray-tracing program, to accurately predict the light levels and produce photo realistic images of the architectural space in all sky conditions： Illuminance values were obtained respectively through reference point measurements. The daylighting performances of the office building model with and without the sunscreens have been compared and analysed.展开更多
This paper explains how the optimized classrooms were selected and the results that were achieved by the optimizations carried out and finalized.The context of the research is the city of Concepción,in Chile.Virt...This paper explains how the optimized classrooms were selected and the results that were achieved by the optimizations carried out and finalized.The context of the research is the city of Concepción,in Chile.Virtual models of classrooms were evaluated using the Radiance software.We used a methodology that allowed us to determine the luminous conditions under different types of skies,seasons of the year and times of the day.The evaluation of the typologies was performed based on three defined criteria,in order to achieve the stated design objectives.We defined the optimal solutions for each orientation and,finally,we stated design recommendations for daylit classrooms to ensure the visual comfort of the students.These recommendations link all that found in the initial analysis with that found in the optimization stage.展开更多
According to Chinese daylighting climate data,combined with the standard of Commission Inernationale de l'Eclairgae(CIE) general sky luminance distribution(SLD),the sky luminance distribution of typical daylightin...According to Chinese daylighting climate data,combined with the standard of Commission Inernationale de l'Eclairgae(CIE) general sky luminance distribution(SLD),the sky luminance distribution of typical daylighting climate zones in China was studied.Through the research on reference SLD of overcast,intermediate and clear types,the standards of clear and overcast SLD are consistent with CIE general sky,and the intermediate SLD has greater error with CIE general sky.The main types of Chinese sky luminance in different daylighting climate zones were obtained,which provide the basic data for simulation and forecast of China natural light,and provide reference for using the standard amendments of China future natural light.展开更多
While the primary role of window attachments is often to moderate glare and solar heat gains,they are also able to provide additional daylight to interior spaces.For this purpose,a variety of daylight-redirecting wind...While the primary role of window attachments is often to moderate glare and solar heat gains,they are also able to provide additional daylight to interior spaces.For this purpose,a variety of daylight-redirecting window systems have been developed over the past 150 years.Fixed reflective systems(slats/light shelves)or prismatic systems that rely on total internal reflection work well under specific solar conditions,but generally sacrifice performance over a much wider range of incident solar angles and sky conditions.Dynamic systems-typically reflective slats-are more responsive to sun angles but have not been able to achieve optimal performance for glare and daylight redirection efficiency.A previous investigation into an adjustable,reflective blind concept first conceived of in the late 1970s showed promise but was not reduced to practice due to lack of adequate simulation and analysis tools.In this paper,this concept is further developed and its energy and visual comfort performance evaluated for four mid-latitude,temperate climates using ray-tracing simulation techniques.Results indicate significant potential lighting energy savings when compared with conventional automated reflective blinds(2.1-4.9 kWh/(m^(2)·a),or 14%-42%,depending on climate and orientation)or,especially,manually-operated matte white Venetian blinds(1.4-7.9 kWh/(m^(2)·a),or 9%-54%,depending on climate and orientation),while maintaining acceptable or better visual comfort conditions throughout the interior space.展开更多
Various studies have suggested several environmental,pharmacological,medical,and optical interventions and some are in use but their efficacy in myopia control may be transient,and the cellular,molecular,and biochemic...Various studies have suggested several environmental,pharmacological,medical,and optical interventions and some are in use but their efficacy in myopia control may be transient,and the cellular,molecular,and biochemical mechanisms involved unclear.Daylight exposure is currently regarded as an effective and enduring strategy in the control of myopia development and progression.However,the mechanism behind the effect of outdoor exposure and its association with genetic predisposition and other relatively more significant environmental factors on myopia is still a conundrum.This review focuses on survey-based and intervention-based studies carried out to propose a mechanism that accounts for myopia development and important for its control.展开更多
We investigated the link between ambulance transports and meteorological parameters of summer by using daily data in Osaka area, Japan. Daily observations for ambulance transports (from July 1 to September 30, 2009) w...We investigated the link between ambulance transports and meteorological parameters of summer by using daily data in Osaka area, Japan. Daily observations for ambulance transports (from July 1 to September 30, 2009) were obtained from Fire Department Service in Osaka. Data of meteorological parameters in Osaka area, Japan (from July 1 to September 30, 2009) were also obtained from Japan Meteorological Agency. Effect of meteorological parameters on ambulance transports was analyzed. A total of 49,526 ambulance transports were observed from July 1 to September 30, 2009 in Osaka, Japan. Ambulance transports were significantly correlated with mean air temperature (r = 0.298), the highest air temperature (r = 0.347), the lowest air temperature (r = 0.209) and daylight hours (r = 0.301). The higher air temperature was associated with higher ambulance transports of summer in Osaka area, Japan.展开更多
文摘The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper published in Journal of Power and Energy Engineering Vol.3 No.4, April 2015, has been removed from this site.
文摘Different approaches have been introduced for the daylighting system to reduce energy consumption, but they were not populated due to complex, high cost, and insufficient designs. There has been a recent problem in achieving uniform distribution of sunlight at a destination deep inside the building. Therefore, we propose a system to achieve high illumination by illuminating the surface of the absorber (optical fibers) uniformly. To capture sunlight, parabolic reflector and Fresnel lens are used. Different reflectors and lenses are considered, compared, and investigated to direct uniform light, which solves the heat problem, into the optical fibers. In addition, this study includes comparison between fiber-based daylighting systems. The proposed system has been verified through simulation and experimental results.
文摘Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.
基金2024 Science and Technology Commissioner Service Group's Emergency Science and Technology Research Project for Wind Disaster Relief in Hainan Province(ZDYF2024YJGG002-8)China Huaneng Group Co.,Ltd.Headquarters Technology Project,Optimization of Photovoltaic Vegetable Greenhouse Structure and Research on Planting Agronomy in Tropical Regions(HNKJ22-HF77)。
文摘In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.
基金supported by the National Natural Science Foundation of China(Grant No.52478100,No.52425801,No.52130803,No.52408102)the Natural Science Foundation of Sichuan Province(2024NSFSC0916)the Natural Science Foundation of Jiangsu Province(BK20241348).
文摘Fiber-optics daylighting system(FODS)demonstrates significant potential for enhancing natural light utilization efficiency while enabling a more continuous visible spectrum illumination to support circadian rhythm regulation.It offers a promising solution for both building energy efficiency and indoor light environment comfort improvement.However,conventional FODS face critical limitations,including low coupling efficiency at the collector-fiber interface and uneven illumination distribution,which impede its practical application.Recent advancements in optical technology present new opportunities for performance optimization of the FODS.Departing from traditional homogenization approaches reliant on optical homogenizers,this study introduces a freeform-caustics-based collector design with discretized energy distribution across the receiving plane.This innovative freeform fiber-optics daylighting system(FFODS)simultaneously addresses localized thermal accumulation and improves coupling efficiency.Furthermore,diffuse transmission materials and a freeform lens are integrated as a dual-functional diffuser to reshaping emitted light and precisely manipulate optical wave fronts,thereby achieving stable and uniform illumination in the targeted area.On this basis,a systematically simulation analysis on the thermal characteristics and photometric performance of the system was conducted.The results validate that the FFODS achieves a 98.5%coupling efficiency with a 126 times reduction in geometric concentration ratio compared to Fresnel lens collector.The diffuser maintains illumination uniformity above 0.8 under bending and adjustment conditions,while realizing 91.5%workspace illumination efficiency in the targeted area.Overall,this novel FFODS provides a transformative technique for advancing conventional FODS with high efficiency and illumination uniformity.
基金Key Scientific and Technological Research Projects of Henan Province(072102240027) Doctor Foundationof Henan Polytechnic University(648602)Postgraduate Degree Thesis Innovation Foundation of Henan Polytechnic University(644005)
文摘In order to meet the requirements of indoor illumination, a LED daylight lamp model was designed, it can replace traditional fluorescent lamp without insteading additional power supply establishment. The optical properties of the model were simulated using optical analysis software. Its luminous efficiency is about 30.4 lm/W, and the illuminance is about 38 lux when the distance is 1.5 m between the center of the model and measured spot. With the theoretically-optimized design of LED model, experiments based on the results of the optimal simulation in the laboratory were conducted to verify the performance of the proposed LED model, it reaches a power factor of about 0.8 at 6 W. The simulation results are very similar with the measured values. It is testified that simulative method is one of the effective tools for LED lighting optical design.
文摘Daylight is a fundamental element to obtain built environments that promote environmental comfort and energy efficiency. However, strategies that enhance the building daylight performance can affect its thermal energetic performance. In this sense, research that addresses these aspects at the same time is considered essential. The objective of this paper was to evaluate the daylighting and thermal-energetic performance of administrative environments in a public institution, and to propose strategies that will enhance the use of daylight and lower energy consumption. Therefore, for future projects, and considering new buildings, and retrofit, this research will be an important reference. The research was developed through a case study of an administrative building model, in which the characteristics of solar orientation, light shelf use, glass type, and light and dark colors in walls were modified and combined, deriving it into models proposed. The daylighting performance evaluations were performed through dynamic simulation with the Rhinoceros for Diva software, and the thermal-energetic performance evaluations with the EnergyPlus software. The results of the work showed that a suitable solar orientation has a great impact on the automation of daylight and the energy consumption of the evaluated models, followed by the type of glass and the use of the light colors in internal walls, and that the use of artificial lighting with dimerization is fundamental as a complement to the daylight autonomy. For the boundary conditions of the study, the use of light shelves modified neither the daylight performance nor the thermal-energetic performance of the evaluated models.
文摘Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final architectural layout and interior design. The main aim of this study is to demonstrate how such daylighting studies can be completed at the early stages of design and, at the same time, to show the impact of window design and positioning on building indoor environments. The paper is focused on a study of window influence on room daylighting in residential buildings and computer lighting simulations in software packages： Windows Daylighting System and Autodesk Ecotect Analysis, have been carried out for different style and positioning of windows using several case studies. The main findings clearly indicated that not only the window size and style matters, but also the positioning of windows considering external walls which would make a significant influence on room daylighting levels and, therefore, such daylight studies are very important for the early stage of environmental analysis during building design.
文摘Improving daylighting strategy is a mandatory step to achieve visual enjoyment and energy saving in buildings. Psycho, physiological effects and energy performance have to be investigated in order to define a range of different daylighting strategies, thanks to daylighting devices and climate based daylight modeling. Daylighting optimization ensures indoor healthier rooms, reduces electric light consumption and cuts the risk of glare. The best way to achieve these targets is to define users lighting needs, based on visual targets and to draw up some green measures to reduce electricity demands. Involving new climate-based daylight modeling metrics aims at defining proper illumination targets, in order to drastically reduce electrical lights, as well as reducing thermal loads deriving from cooling and HVAC （heating, ventilation and air conditioning） systems.
文摘In the subtropical zone of China, a large number of old factory buildings rich in industrial historical and cultural value have been transformed into art studios. In the existing research on building renovation, there are still problems such as insufficient lighting, low uniformity, and ignoring the effect of glare in the lighting environment of buildings after transformation. To fill this research gap, this paper provides a daylighting design strategy for these factory buildings in subtropical zones to ensure that the transformed art studios can offer an excellent indoor daylighting environment. Through the control variable method, the window-to-wall ratio, the form of external windows, and the visible light transmittance of glass are set with quantitative and variable values, and a design strategy that meets the requirements of international general daylighting standards is obtained step by step through the simulation. The daylight factor, uniformity, daylight autonomy, and dynamic glare probability are used in this research process to measure whether the daylighting strategy meets the daylighting requirements of the CIBSE Lighting Guide for art studios. The results show that the average indoor lighting coefficient can be increased from 1.29 to 6.18, and the minimum value of the lighting coefficient can be increased from 0.4 to 4.4 by enlarging the windowed wall ratio from 1:30 to 1:3, using the combination method of the horizontal window, skylight and skylight recommended by the analysis results, and selecting veneer glass with 88% transmittance. This allows for better uniform lighting inside the building and reduces glare. This conclusion can support the lighting performance design of industrial buildings in the future.
文摘The urgency of increasing energy efficiency in new building design and retrofits has pushed lighting simulation to play a central role in sustainable lighting design. The shape of the building and its orientation, the reflectances of building surfaces and glazed areas are important parameters in the daylighting design of buildings. Glazing systems can cut energy consumption and associated pollution sources, reduce peak demand, enhance daylighting performance and improve occupant comfort. This paper presents the results of a numerical and experimental comparison between the performances of an office building with and without external sunscreens. The aim was to analyse the illuminance distribution and some investigations have also been made with regards to the effect on daylight in rooms when sunscreens are used. The experimental results were obtained using an office building scale model and sky simulator. The numerical results were obtained through radiance, the ray-tracing program, to accurately predict the light levels and produce photo realistic images of the architectural space in all sky conditions： Illuminance values were obtained respectively through reference point measurements. The daylighting performances of the office building model with and without the sunscreens have been compared and analysed.
文摘This paper explains how the optimized classrooms were selected and the results that were achieved by the optimizations carried out and finalized.The context of the research is the city of Concepción,in Chile.Virtual models of classrooms were evaluated using the Radiance software.We used a methodology that allowed us to determine the luminous conditions under different types of skies,seasons of the year and times of the day.The evaluation of the typologies was performed based on three defined criteria,in order to achieve the stated design objectives.We defined the optimal solutions for each orientation and,finally,we stated design recommendations for daylit classrooms to ensure the visual comfort of the students.These recommendations link all that found in the initial analysis with that found in the optimization stage.
基金Project(50908239) supported by National Natural Science Foundation of China Project(2010KB14) supported by State Key Laboratory of Subtropical Building Science of South China University of Technology, China Project(CDJZR10190006) supported by the Fundamental Research Funds for the Central Universities, China
文摘According to Chinese daylighting climate data,combined with the standard of Commission Inernationale de l'Eclairgae(CIE) general sky luminance distribution(SLD),the sky luminance distribution of typical daylighting climate zones in China was studied.Through the research on reference SLD of overcast,intermediate and clear types,the standards of clear and overcast SLD are consistent with CIE general sky,and the intermediate SLD has greater error with CIE general sky.The main types of Chinese sky luminance in different daylighting climate zones were obtained,which provide the basic data for simulation and forecast of China natural light,and provide reference for using the standard amendments of China future natural light.
基金supported by the California Energy Commission through its Electric Program Investment Charge(EPIC)Program on behalf of the citizens of California and by the Assistant Secretary for Energy Efficiency and Renewable Energy of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘While the primary role of window attachments is often to moderate glare and solar heat gains,they are also able to provide additional daylight to interior spaces.For this purpose,a variety of daylight-redirecting window systems have been developed over the past 150 years.Fixed reflective systems(slats/light shelves)or prismatic systems that rely on total internal reflection work well under specific solar conditions,but generally sacrifice performance over a much wider range of incident solar angles and sky conditions.Dynamic systems-typically reflective slats-are more responsive to sun angles but have not been able to achieve optimal performance for glare and daylight redirection efficiency.A previous investigation into an adjustable,reflective blind concept first conceived of in the late 1970s showed promise but was not reduced to practice due to lack of adequate simulation and analysis tools.In this paper,this concept is further developed and its energy and visual comfort performance evaluated for four mid-latitude,temperate climates using ray-tracing simulation techniques.Results indicate significant potential lighting energy savings when compared with conventional automated reflective blinds(2.1-4.9 kWh/(m^(2)·a),or 14%-42%,depending on climate and orientation)or,especially,manually-operated matte white Venetian blinds(1.4-7.9 kWh/(m^(2)·a),or 9%-54%,depending on climate and orientation),while maintaining acceptable or better visual comfort conditions throughout the interior space.
文摘Various studies have suggested several environmental,pharmacological,medical,and optical interventions and some are in use but their efficacy in myopia control may be transient,and the cellular,molecular,and biochemical mechanisms involved unclear.Daylight exposure is currently regarded as an effective and enduring strategy in the control of myopia development and progression.However,the mechanism behind the effect of outdoor exposure and its association with genetic predisposition and other relatively more significant environmental factors on myopia is still a conundrum.This review focuses on survey-based and intervention-based studies carried out to propose a mechanism that accounts for myopia development and important for its control.
文摘We investigated the link between ambulance transports and meteorological parameters of summer by using daily data in Osaka area, Japan. Daily observations for ambulance transports (from July 1 to September 30, 2009) were obtained from Fire Department Service in Osaka. Data of meteorological parameters in Osaka area, Japan (from July 1 to September 30, 2009) were also obtained from Japan Meteorological Agency. Effect of meteorological parameters on ambulance transports was analyzed. A total of 49,526 ambulance transports were observed from July 1 to September 30, 2009 in Osaka, Japan. Ambulance transports were significantly correlated with mean air temperature (r = 0.298), the highest air temperature (r = 0.347), the lowest air temperature (r = 0.209) and daylight hours (r = 0.301). The higher air temperature was associated with higher ambulance transports of summer in Osaka area, Japan.
