• KIEAE Journal
• /
• v.5 no.4
• /
• pp.51-57
• /
• 2005

For the evaluating daylighting performance, field measurement, scale model test and a set of computer tools can be applied. For the scale model measurements, the sky simulator is a vital facility to represent the desired sky conditions consistently. Recently K university has developed a large size sky simulator, 6m-diameter and 3.7m-height, that is suitable for the international standard. To verify the reliability of the sky simulator, the luminance distribution on the inner sky surface was measured and compared with the CIE standard overcast sky model. It is found that the sky simulator can be reproduced the CIE standard overcast sky condition with 4.3% as mean difference. K university sky simulator is fully validated for usability and accuracy for daylighting researches.

• Korean Institute of Interior Design Journal
• /
• no.37
• /
• pp.110-118
• /
• 2003

Computer simulation is one of the most useful techniques to predict daylighting performance and present visual image. In architectural and interior design practice, the Lightscape is commonly used often to produce persuasive images rather than physically accurate results. Therefore, this study is to validity the Lightscape as daylighting evaluation tool, in particularly performance and realistically visualization. For the purpose, an evaluation test model (12.0m$\times$7.2m$\times$3.0m) of side lighting window with lightshelf was selected. A 1:6 scale plywood physical model was made. Under clear sky condition, illuminance of 84 Interior point were measured. Lightscape was run on a 750 MHz Pentium PC running Windows 2000 under the same sky condition. And a photography image was compared to rendering image. The physical results of interior illuminance were within 8% between the scale model and Lightscape simulation. There were no differences between the photograph image and rendering image by Lightscape in the sight. Lightscape as visualization tool for daylighting performance was validated.

• Journal of the Korean Solar Energy Society
• /
• v.24 no.2
• /
• pp.51-62
• /
• 2004

Architects may evaluate building models to see how a building will shadow itself and its neighbors at various times. A heliodon, a tilt-table which is a machine that imitates the rotation and orbit of the Earth, helps architects wanting to analyze patterns of shadow patch, passive solar heating options, site solar panels, or control solar heat gain. The heliodon swivels in three directions for setting latitude, season, and time of day. Using the device, an architect first clamps a model to the tabletop, then turns the table to the coordinates of interest. Usually, the winter and summer solstices receive strong attention, for they represent extreme cases, A more recent installation at a university adds to its heliodon a set of lamps to recreate the illumination level and more accurate patterns of shadow patch. The table holds the building model at various angles to a spotlight, which mounts in the pole. The set of scale model measurement describes the validity of various electric lamps as an artificial sun to approximate the sun's parallel rays, helping designers to distinguish between illuminated areas in and around a building and those regions falling in the shadows.

• KIEAE Journal
• /
• v.10 no.3
• /
• pp.43-50
• /
• 2010

Natural lighting is directly connected with our mental and physical health. For working or learning effect, the proper natural lighting is required for improving our living conditions. School facilities, especially, are the place where includes students' ordinary activities with learning behaviors during the school years from elementary to high school. This study was carried out for the purpose introducing a basic database in that planning a school by researching on the actual in the natural lighting system of some schools' classroom, estimating, and analyzing through a simulation, which resulted in a method of improving the natural lighting system. As a result of measuring and analyzing Daylight Factor(DF) during the time from 9 am to 3 pm when students are activating in their classroom, generally DF range of the sides near to window and aisle seats zone are not distributed well. Besides, two out of four school which are researched would not reach the standards of the law for school sanitary while rest of the schools meet the standards; Average DF 5% and Minimum DF 2%. And the result of a simulation by RADIANCE program shows the most appropriate DF range when it is applied in variable numbers about an oriehows the- South-east 15, south-east 30, south-east 45, south-west 15, south-west 30, and south-west 45 degrees. When it is applied in the variable numbers about glass transmittance - 60%, 70%, and 80% in condition facing south of a classroom, the result shows that the DF range of 80% transmittance is relatively higher than other glasses in the classroom. Thus, when a school is built, plans for an orientation is necessary for improve of elementary schools' environment with the glass installation which is made for high transmittance and is regarded with the students' activities time.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.92-97
• /
• 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.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.4
• /
• pp.136-141
• /
• 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.

• Journal of the Korean Solar Energy Society
• /
• v.37 no.1
• /
• pp.39-45
• /
• 2017

This paper presents the effect of solar collectors on the performance of solar tracking daylighting systems. A series of measurements were made for two different types of solar collectors mounted on double axis solar trackers: Parabolic dish concentrator and Fresnel Lens. Indoor light levels were measured at different locations of an office space (longitude: 126.33 E, latitude 33.45 N) as photo sensors were placed on a task plane 80 cm above the floor. To accurately monitor the applicability of the systems, measurements were performed under clear and overcast sky conditions with the roll-screen (on the south window) in the down position. Comparing the illuminance data, the system with Fresnel lens outperformed that of parabolic dish concentrator. On clear days, the former delivered the light levels of 400~600 lux on the task plane whereas the latter recorded 100~200 lux. Depending on the amount of cloud cover, on overcast days, illuminance readings fluctuated to some extent.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.148-154
• /
• 2009

By the skyscraper building, increase of skin area and expansion of curtain wall system will be the important factors of acceleration in extending supply of BIPV system. In the future interior environmental evaluation is not a necessary to the residents but an essential term which will bring enormous influence. In the interior environmental evaluation, natural light will let the residents with direct contact with outside circumstances and make them feel opened. also only the daylight has radiant energy and color rendering that will have a great influence to residents' mental, operation efficiency and advancing productivity. This research compares and analyzes BIPC system in office spaces with two general sunlight's module. In addition to natural light's efficiency for BIPC system's comfort and confirmed economical efficiency will be applied to basic research data. Hence forth, ensuring indoor intensity of illumination and controlling light system to reducing energy research data will be demanded to increase the amount of supplying BIPC system. Also continuance research in the possibility of applying BIPC system in various buildings, room temperature affected by location of windows and its condensation, and economical evaluation will be required.

• KIEAE Journal
• /
• v.16 no.4
• /
• pp.63-69
• /
• 2016

Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.108-108
• /
• 2011

공동주택에서 2025년 정부가 추진하고 있는 Zero Energy 건축물 구현과 친환경에 대한 탄소배출 저감 문제로 재생에너지 생산시스템의 추가 적용은 반드시 필요하다. 따라서 공동주택 적용 및 활용성을 높일 수 있는 BIPV시스템 개발을 통하여 설치면적 확보와 세대 활용성을 높일 수 있도록 하는 것이 필요하다. 특히 거실 창호의 경우 주방향이 남향, 남동 또는 남서향으로 배치되어 태양광을 적용하기에 적합한 특성을 가지고 있다. 그러나 창호는 건물외피의 역할과 재실자가 조망과 정보취득을 얻을 수 있는 중요한 통로가 되기 때문에 단열 문제나 시야 차폐의 문제는 발생하지는 않도록 하는 것이 필요하다. 본 연구에서는 a-si타입 모듈 2개를 10% 투과율로 Bsck Coating 색상을 달리한 모듈과 c-si BIPV 모듈을 커튼월 창호시스템으로 개발, 일반 2중 창호시스템과 비교 평가를 위해 실제 Test bed 건물에 시공하여 시환경 및 실내 창측면 온도변화 측정 분석을 진행하였다. 현재 국내외 출시되고 있는 a-si see through 모듈은 10~30%의 투과율로 창 마감재로 대체가 가능하나 건축 환경(시환경,열환경)에 대한 분석은 전무한 상태이다. 본 연구에서는 시환경과 창유리면의 열 부하, 자외선, 적외선 차폐 및 가시광선의 투과율에 대한 평가와 Back Coating에 따른 색온도 평가를 통해서 a-si BIPV의 공동주택 세대 발코니 창호 적합성에 대한 검토를 진행하였다. 연구결과는 아래와 같다. ${\bullet}$ 실내조도는 청천공 정오기준 가시성 확보 모듈의 경우 2,300 ~ 3,500lx를 나타내고 있어 대비 현상이나 창측의 급격한 조도 변화가 적은 시환경 구축이 가능 ${\bullet}$ 12시경 휘도는 창측면, 실내 벽체, 코너 바닥면을 대상으로 a-si BIPV 모듈을 적용한 경우 휘도비가 12:1로 KS나 IESNA의 광원과 근접면의 비 20:1 범위에 모두 존재, 적합한 것으로 분석되었으나 c-si의 경우는 그림자로 인한 대비 현상이 발생, 작업 시환경 문제 발생. ${\bullet}$ 이중시스템 창호와 비교하여 단열 성능 떨어짐. 발전시간대 창유리 면 온도 상승 으로 하절기 냉방부하 증가. ${\bullet}$ 자외선은 100% 가까이 차단, 적외선은 13~42%만 투과되고 가시광선은 13% 투과율을 나타내어 일반 창에 칼라 코팅을 적용하는 것과 유사한 경향을 나타냄.