• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.101-108
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• 2014

The performance of the daylighting in buildings depends on building site and shape. As an energy saving design strategy, daylighting is a key issue in green building design. In this paper, the influence of the adjacent or obstructed building on daylighting performance of the office building in urban area was analyzed. A typical office building about 20 storeys with obstructed buildings has been modeled and simulated using Radiance. The parametric simulations have been performed to analyze the influence of the daylighting performance (illuminance, luminance) of the analyzed office. The results show that the possibility of the glare was decreased when the obstructed building is located in south, also the illuminance level was significantly decreased. When the obstructed building is located in north, the changes of the illuminance level and luminance possibility were somewhat small compared to the unobstructed condition. The daylighting performance of the analyzed building was most affected by the obstructed building in winter season.

• KIEAE Journal
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• 제9권1호
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• pp.23-30
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• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.

• 조명전기설비학회논문지
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• 제19권6호
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• pp.1-8
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• 2005

건물 내에 존재하는 자연광은 조명원으로 국한되지 않고 시각적, 심리적 자극을 통한 실내 환경의 질적 향상에 이르기까지 에너지절약 및 공간의 쾌적성에 큰 영향을 미친다. 유입되는 자연광량에 비례적으로 연동되는 건물에너지는 전기조명에너지를 절감시키고 난방 기간동안 일사열의 유입에 따른 난방에너지를 절감시킨다. 여름철에는 전기조명의 소등으로 인한 조명원의 발열량이 감소됨으로써 냉방부하의 감소에 이르기까지 포괄적인 영향을 미친다. 조명개발분야의 선진국에서는 에너지 절약형 광원의 대체와 아울러 자연채광과 통합된 최적 조명제어 기술의 운용만이 건물이 가지고 있는 에너지 절약의 잠재력을 현실화시킬 수 있다고 판단하고 있다. 따라서 본 연구는 일반적인 사무소 모델 공간의 에너지 절약형 인공조명을 대상으로 자연광 유입에 따른 연동적 조명제어 기법을 적용하는 경우를 대상으로, 인공조명의 소등량에 따른 조명에너지의 절감량과 이에 수반되는 냉방에너지의 점감량 및 일사열 취즉에 따른 겨울철 난방 부하 절감량을 분석함으로써 자연채광의 건물에너지에 대한 연간 기여도를 통합 분석하였다. 특히 자연채광의 성능은 실험을 통한 측정 데이터를 이용하고 에너지 해석 프로그램을 재구성하여 실질적인 절감량을 도출하도록 시도하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.92-97
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• 2009

It is more necessary to consider the various factors for developmenting visible PV module of alternative window than traditional PV module. It must have sufficient performance which is Tvis, daylighting, daylight factor, glare index. so that more needs to consider suitable plan and total evaluated technology. Under the this background. For using commonly a combination BIPV module system and Daylinghting that can alternative architectural window, our goal on this study is drawing proper window area ratio as the window by analyzing lighting performance and glare index depending on transmittance of DSSC. On this study, we drew the result about window area ratio that can apply in the building when applying DSSC in the window. In situation that window is alternated as curtain wall in atrium that has big Widow area, if applying red 15.8% DSSC of low transmittance, it is expect to proper because it is suitable illumination standard and doesn't occur a discomfort glare. In case of office, we propose to apply red 33.2% or blue 35.2% DSSC of high transmittance for no affecting lighting load. we expect to contribute to select proper and effective window when applying the window in the building by drawing the window area ratio that can apply in thee building depending on transmittance of DSSC and offering the glare index data.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.136-141
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• 2011

The lightshelf system reduces intense illumination levels of indoor from direct sun light and reflect to lead diffused light into indoor deeply. This study aims to design acurved-lightshelf by a ray tracing method and evaluate the daylighting performance of window integrated with the curved-lightshelf by computer simulations. For this purpose, evaluation test model was designed for the experiments to validate the simulation model, and the curved-lightshelf was designed by the ray tracing method using Ecotect. After the office model was designed using 3D simulation, the average indoor illuminance, luminance and distribution of illuminance were evaluated by simulation which has a algorithm of Radiosity and Ray-Tracing method under four different cases(case1;no lightshelf, case2; Flat board, case3; tilted at $30^{\circ}$ angle, case4; the curved-lightshelf). As results, it turns out that case1 showed higher average illuminance and case4 was more uniformly distributed than case2 and case3, In addition average luminance of case1 was also lower. indicating that the curved-lightshelf would reduce the possibility of the glare, while maintaining the sufficient daylight level.

• KIEAE Journal
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• 제11권5호
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• pp.137-143
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• 2011

An atrium space, unlike ordinary office rooms, accommodates variety of activities such as moving and resting of people and usually houses variety of vegitation to improve amenity and indoor environment. Many atrium buildings in Korea have been designed by considering the environmental criteria for human beings, not for the vegitation in the atrium space. Especially the daylighting designs are mostly focused on the required illuminances for various visual tasks of the occupants and glare controls. As a result, some atrium spaces do not provide sufficient light to the interior plants. Consequently, these atrium spaces require a high level of electric lighting to compensate the deficit of natural light for the photosynthesis of the vegitation. The purpose of this study was to suggest design guidelines for 4-sided atrium spaces having different well indices (WI), plan aspect ratio (PAR), and cardinal orientation. The findings from this study might be referenced by building designers when designing or selecting canopy systems by considering the daylight performances of the uncovered atrium spaces. In the study, the daylight performance was evaluated in terms of daylight autonomy (DA).

• KIEAE Journal
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• 제13권4호
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• pp.21-26
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• 2013

Shading devices have become an integral part of the daylighting strategy for sustainable classroom design. The louver type is newly designed shading devices which provide more view to the outside and protect from outside condition such as snow or rain. The purpose of this study is to compare the daylight performance of traditional and louver type overhang and lightshelf. The room dimension was $7.5m{\times}9.0m{\times}3.0m$. The length of shading devices was calculated by Palmero's study. The length of the traditional and louver type overhang was 455mm, 1210mm and lightshelf was 350/810mm, 625/555mm respectively. For the study, the Radiance 2.0 was used to evaluate the illuminance and uniformity ratios. And scale model were used to evaluate sunpatch area on the floor in model was calculated. The results showed that the louver type lightshelf was suitable for spring and summer, and louver type overhang was suitable for winter.

• 한국태양에너지학회 논문집
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• 제35권6호
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• pp.1-7
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• 2015

This paper deals with the design and operation of a hybrid daylighting system that uses natural and artificial lighting to enhance visual comfort in buildings. The system was developed using an AVR micro controller for solar tracking in conjunction with dimming controls, which, acting together, enables the maximum use of natural daylight and also improves energy efficiency in buildings. Experimental results clearly demonstrates the usefulness of the present system capable of enhancing indoor lighting conditions when sufficient daylight is available and distributed appropriately in harmony with artificial lighting.

• KIEAE Journal
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• 제6권4호
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• pp.25-32
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• 2006

Mock-up model can be applied to measure accurate performance data but difficult to apply the variables in experiment. There can be a slight experiment errors in Scale model, but various parameters can be applied for a objective experiment. This paper aims to compare the daylighting performance in 1, 1/5, 1/10 scale model of offices and analyze the experiment errors to certificate the influence of model experiment. To analyse daylighting performance, a comparison of a Mock-up model, sized $12.0m(w){\times}7.2m(l){\times}3.7m(h)$, designed for experimentation of daylighting systems and its 1:5, 1:10 scale model. It has an identical configuration of reference room and the test room. For the test room, the lightshelf system was designed as Micro-4 reflective material. To assess work plane illuminance and light factor, photometric sensors of each room were installed at work-plane(6 points) and exterior horizontal illuminance (1 point). And luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio and luminance are discussed.

• KIEAE Journal
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• 제4권4호
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• pp.61-68
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• 2004

Daylight is a critical factor in architecture, as it helps enhance the working efficiency and pleasantness of the people working inside, in addition to reduce the power consumption in heating and cooling and make the interior space brighter. There are many kinds of glazing and daylighting systems. At present, research and efforts for their development are carried out, alongside quantitative evaluation. This study aims to present basic materials to be used to design proper glazing and daylighting systems in architecture based on a quantitative evaluation by scale models of existing office buildings. The result of the study can be summarized as follows. 1)As a result of the experiment, it appeared that the ratio of the interior illumination (i.e. at the working table, ceiling and wall) against the outdoor illumination increases at a constant rate, as the transmittance of the glazing goes up. 2) It was found that the SIR(Sunlight Illuminance Ratio) of a separated window system goes up by 20-50% at the rear part than in the case of an ordinary window system.