• KIEAE Journal
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• 제7권1호
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• pp.65-72
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• 2007

As ecological design elements, daylighting can be applied to provide adequate illumination on visual tasks to create an attractive visual environment and to save electrical energy. Daylighting control systems reject direct sunlight and penetrate it onto the ceiling or to deep into the room. This study aims to evaluate the luminance environment of sloped light guide with automated venetian blind systems according to sun angle changes. For evaluation, a mock-up model was used and the south facing side-window mounted between the clerestory window and the view window. To assess luminance performance, 3 view points of luminance were monitored. As results, the conventional and lightshelves show ideal luminance ratio between workplane and surroundings(3:1) and workplane and darkness area(2:1) due to total ratio of surroundings and darkness area has lower ratio than workplane. Compared to the lightshelves window, conventional window shows unrelieved effect in between the workplane and brightness area(1:5). It means that there has low deviation according to the required standards. Also, compared to the ratio between the brightness area and darkness area(2~6:1) conventional window with high deviation(10~20:1) provide discomfort glare due to the excessively strong contrast, while lightshelves window shows a required luminance ratio that provide a three-dimensional effect to occupants. Therefore, luminance distribution indicate that application of a lightshelves and blinds not only has a significantly positive effect but also offers higher luminance quality in a daylit room

• KIEAE Journal
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• 제4권3호
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• pp.27-35
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• 2004

The conventional way to acquire sufficient amount of daylight in interiors is to provide large openings with clear glass. The use of clear glass on the whole facade, however, might cause a sort of visual problem because of the harness of direct sun and brighter sky surface than expected. They should be filtered in opticalway or bounced in the architectural. One of the common solutions for the problem might be the use of photometric glasses with various transmittances for the glass walls. This paper deals with performance data related to the impact of various transmittal glazing materials for window systems in terms of daylighting. A series of scale model measurements was carried out with the fundamental configuration of a commonly used all-glass facades. Additionally some experimental performance index was issued for the better expression of the need of natural lighting.

• 설비공학논문집
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• 제19권7호
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• pp.491-499
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• 2007

An architectural means of optimal daylight distribution is by using so-called light shelf systems, horizontal shading and redirecting devices. The overall performance of the daylighting system can be improved by the incorporation with electric lighting control devices. This paper aims to exemplify the benefit of daylighting in term of economic consideration. In such a case a reasonable technique to compare system costs is by life-cycle costing. Stated simply, a life-cycle cost represents the total cost of a system over its entire life cycle, that is, the sum of first cost and all future costs. Four different electric lighting system designs are proposed and a lighting control system that is continuously operating according to the level of daylight in the space has been adapted. The result shows clearly that although denser layout of lighting fixtures might be more effective to interface to the level of daylight ceaselessly changeable, its economic benefit may not meet the expected criterion the reason of increased initial investment and maintenance cost for the fixtures and control devices.

• KIEAE Journal
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• 제13권5호
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• pp.59-66
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• 2013

Current Architectural Facade Designs have been trending to increased glass areas resulting in increasing impact on interior lighting and daylighting. In regards to indoor environmental quality, the increase in window space has a large impact on the daylighting received which ultimately impacts the liveability of a space. Especially when considering seasons, in the summer, excessive daylighting can result in glare as well as put an increased load in conditioning the air space further reducing energy efficiency. As a result, in order to improve the sustainability performance of a building, it is important to limit the natural lighting exposure to properly meet the needs and conditions of the building occupants. One of the most representative features to limit excessive sunlight exposure, is to incorporate operable blind systems. To this end, this research has been based on simulations performance through the Radiance Program. Radiance is capable of analyzing performance of daylight and impact of sunlight. Through analysis of different slat angles and blind shapes, impact and minimization of energy usage was evaluated. Furthermore, seasonal analysis was performed in order to understand the effects of seasonal climate factors. Ultimately this research provides an analysis of operable blinds optimization and effects of blind shape, control factors and angle of shading.

• 한국태양에너지학회 논문집
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• 제37권1호
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• pp.39-45
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• 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.

• 교육시설
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• 제13권2호
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• pp.25-33
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• 2006

Majority of elementary school in Korea are built by standard plan in 1980s. Being deteriorated and uniform, they have lots of problems to meet the new education curriculum and generate environmental problems in terms of its performances. This research intends to review the conditions of classroom units related with the environmental issues and provide the directions of sustainable renovation to meet the updated curriculum focusing on daylighting and ventilation systems for the classroom built by standard plan in 1980s.

• KIEAE Journal
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• 제13권1호
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• pp.39-45
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• 2013

The daylighting control system has to be applied to prevent the excessive incident daylight and reduce energy use. As the one of the most useful daylighting control systems, the blind system is simple and easy to install on the window for small office buildings. This study aims to evaluate the summer energy performance of small office buildings by venetian blinds and energy saving strategy of ministry of knowledge economy in korea. For the study, the simulations have been executed on blind installation conditions and lighting control methods. As results, the energy loads cut down 22 to 25(%) by using blind energy. Also, the efficient shows high on EMS system and low on $45^{\circ}$ slat angles. Also, using energy saving strategy can reduce about 13(%) energy load.

• KIEAE Journal
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• 제11권6호
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• pp.139-149
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• 2011

This study focuses on design tendencies in office buildings of public institutions after tightening up Korea's building energy performance criteria. Important office design criteria and recommendations pay attention to the issues such as building orientation, greening buildings, building form, space and envelop by intensifying building energy performance related laws, government guidelines and evaluation systems. The design tendencies explored in this research are as follows. Office buildings mainly face south and have various types of indoor and roof green spaces not for ecological reasons but for the rest. Building depth becomes thinner and atria are inserted into office buildings to improve daylighting and natural ventilation. Building cores are located on north or west and east sides acting as buffer spaces to reduce heat loss and to block solar radiation. Office building envelop design includes various creative ideas to control or utilize solar energy as like three dimensional or double structured skin and window size variation to cope with the intensity of solar radiation. Further, solar energy generation systems are integrated with building component such as roofs, sun screens and windows. This study demonstrates that government's reinforcement of the building energy performance criteria drives the change in design methods and approach.

• 조명전기설비학회논문지
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• 제21권3호
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• pp.18-26
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• 2007

투과체는 기본적으로 외부환경과 접촉할 수 있는 친화적이고 생태학적인 기능을 가지고 있으며, 이를 통해 유입되는 빛은 실내공간에 다양한 분위기를 연출할 수 있도록 해준다. 이에 본 연구는 투과체가 적용된 사무소건물을 대상으로 채광유입을 증대시킬 수 있는 채광방식을 설계하여 적용 시 실내의 색도와 색온도에 미치는 영향을 분석하였다. 이를 위하여 1/10축소모형을 제작하였으며, Prometric 1421이라는 측정기기를 이용하여 실험을 수행하였다. 측정결과 투과체가 갖는 파장대별 투과특성이 실내의 색도에 영향을 미치는 것으로 나타났으며, 빛의 유입을 증대시키는 채광방식을 설치할 경우 천정면의 색온도에 많은 영향을 주었으며, $5{\sim}20[%]$정도의 색온도를 증가시키는 것으로 나타났다. 따라서 채광시스템을 설치할 경우 활동적인 분의기의 공간이 연출될 수 있을 것으로 기대된다.

• KIEAE Journal
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• 제2권1호
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• pp.63-68
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• 2002

Solar sunlighting systems are useful to apply for most buildings. This study aims to analysis the development and architectural application of solar sunlighting systems. For the purpose, abroad developing situation of solar sunlighting systems were investigated and analyzed literally. And, by case studies, architectural application methods are analyzed. As results, light pipe systems are mainly used for small building and houses. Also solar mirror systems are used for atrium and underground spaces. Lens-fiber systems are applied for high rise buildings and office buildings which internally have no influx of sunlighting. Some application suggestion in our country are discussed.