• Title/Summary/Keyword: Illuminance ratio

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Reflector Design for LED Pedestrian Lighting Using Indirect Reflectance Type (간접 반사 방식의 LED 보안등기구 반사판 설계)

  • Chae, Sung-Gi;Jung, Dong-Hwan;Lee, Yoon-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.4
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    • pp.6-13
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    • 2012
  • In this paper, we took an indirect reflectance type that irradiates light from an LED module, which reflects light from a reflector onto the road. This LED pedestrian lighting design produces minimal glare from a relatively simple structure. Using LightTools 7.2, we conducted a study on the varying shape and curvature of the reflector. In order to further investigate this data, we researched the ratio of the DLOR and ULOR, the average illuminance, and the uniformity of the illumination. Based on this research, we selected optimum conditions to realize the actual LED pedestrian lighting using RELUX software. We found the average illuminance value to be 22[1x] and the illuminance uniformity ratio to be 0.23, which met the criteria of the proposed standards set in KS C 7658. In addition, it also satisfied the criteria of the standards set in KS A 3701 by having TI (Threshold Increment) at 7[%].

Analysis of a Night Illuminance Distribution in School Buildings (학교 건축물의 야간 조도분포 분석)

  • 박동화;성낙진;신재화;이병기
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.10 no.6
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    • pp.48-53
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    • 1996
  • In this paper, the illuminance of elementary, junior, and senior high school in Inchon was measured and analyzed to investigate their night illuminating circumstances(classrooms, science rooms, and laboratories). More than four schools were selected based on the years elapsed(l0, 20, and 30 years, etc) since the opening of the schools. It was shown that the average illuminance for the classroom and that for science room and laboratory have been improved significantly such that the former was 235.6[lx] (260[lx] for senior high school, 208[lx] for junior high school, 203[lx]) for elementary school) and the latter was 233.7[lx](248.8[lx] for senior high school, 216.4[lx] for junior high school, 207.8[lx] for elementary school). The uniformity of the illuminance was exceedingly worse than the recommended one(the average value for the classroom and that for sciense room and laboratory were 0.95 and 1.08, respectively). It was found that the maximum to minimum illuminance ratio with respect to illumination derivative(7.9 for classroom, 6.8 for scienceroom or laboratory) was very high for most school buildings and was much higher for the old ones. From the measured results, it was shown that the illuminance for the school buildings needs to be improved with regard to quality.

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Evaluation of Lighting Energy Saving Rate in a Small Office Space (소규모 사무공간의 조명에너지 절감율 평가에 관한 연구)

  • Kim, Han-Yong;Yun, Gyeong;Kim, Kang-Soo
    • Journal of the Korean Solar Energy Society
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    • v.32 no.3
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    • pp.50-58
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    • 2012
  • The objective of this study is to evaluate the lighting dimming rates with various parameters of the building skin in a small office. We compared to simulated workplane illuminance and measured workplane illuminance for the base model. After that, the five veriables(the presence of vertical wall in double skin facade, the presence of windowsill, window to wall ratio(WWR), window visible transmittance, the width of double skin facade) were applied to base model, and we analyzed the simulated lighting energy saving rates. The results are listed as below. The simulated workplane illuminance results are similar to the measurement. Simulated illuminance was smaller than measured illuminance by 16.5%(60 lx). In accordance with applicable building skin parameters, lighting energy saving rate results are summarized as follows. Lighting energy saving rate of case1(windowsill height 0.7m) is higher than that of base case(windowsill and vertical wall) by 7.3% and the lighting energy saving rate of case2(no vertical wall) is higher than that of base case by 7.6% and the lighting energy saving rate of case3(no windowsill and vertical wall) is higher than that of base case by 12.4%. The lighting energy saving rate is increased by 2.3%, when window visible transmittance is increased from 70% to 86%. The lighting energy saving rate is increased by 4.6%, when we changed the WWR 70% to 90%. lighting energy savings rate is increased by 6.5%, when the width of double skin facade is reduced from 1m to 0.3m.

Daylighting Performance of Lightpipe under Different Sky Conditions (천공상태에 따른 수직형 광파이프 시스템의 채광성능 평가)

  • Kong, Hyo Joo;Kim, Jeong Tai
    • KIEAE Journal
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    • v.8 no.3
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    • pp.101-106
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    • 2008
  • The use of daylighting has been increased recently due to energy and visual comfort. The aims of interior daylighting are to adequately illuminate visual tasks, to create an attractive visual environment, and to save electrical energy. Lightpipe can improve the distribution of light to interior spaces. This study aims to evaluate the comparative daylighting performance of lightpipe under different sky conditions with mock-up model, sized $6m{\times}6m{\times}4m$ ($w{\times}d{\times}h$). For the purpose, perpendicular lightpipe system was designed as 650 diameter, with an aspect ratio of 2. Totally 49 measuring points of and two of outdoor illuminance on the horizontal plane were monitored from 09:00 to 18:30 on April 29 and May 15 2008. Agilent data logger and photometric sensor were used. Light factor were used to analyse daylight performance under different sky condition. Under overcast sky condition and clear sky condition, the lightpipe system is suitable for KS recommendation level of illuminance.

A Study on the Experiment of Luminous Environment in Classroom of An Elementary School (초등학교 교실의 빛 환경 실측에 관한 연구)

  • Park, Kyung-Eun;Kim, Jun-Tae
    • Journal of the Korean Institute of Educational Facilities
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    • v.9 no.5
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    • pp.13-21
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    • 2002
  • Daylighting in educational environment is very important as it has an effect on students' performance as well as in their visual health. It is regarded as a good energy conservation method in saving energy used for lighting. This study conducted initial daylight measurements to analyze luminous environment in classrooms of Korean elementary school. The results indicated that the typical classroom had a reasonable level of daylight. However, it also found that the classroom had some problems of the uniformity of illuminance and the contrast of brightness of surfaces in the classroom. It is argued that daylighting design for school classroom should consider these aspects to make daylit classrooms ideal so as to provide comfortable visual environment.

The Effect of Geometric Relation between the Window and the Sun on the Interior Illuminance Distributions using a Physical Scale Model (축소모형 실험을 통한 일조창과 태양의 기하학적 위치관계에 따른 실내조도분포 특성)

  • Kim, Min-Sung;Song, Kyoo-Dong
    • KIEAE Journal
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    • v.5 no.3
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    • pp.33-40
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    • 2005
  • The existing building code regulates the minimum distance between buildings and the minimum required sunshine hours for winter solstice to ensure the right to light. Especially, the minimum sunshine hours have been guaranteed by the constitution after the right for the people to live in a healthy and comfortable environment was established. However, the existing regulation on the sunshine hours only considers the duration of sunshine hours, but ignores the minimum amount of sunlight. Therefore, the calculated sunshine hours are not coincident with the hours occupants actually feel. Therefore, the purpose of this study is to investigate the effect of solar incident angle on interior illuminance distribution, which will be used to propose a new code on the minimum sunshine hours and levels.

A Study of Microscopic Energy Simulation based on BIM - Illuminance & Energy Analysis of Illuminance Sensor Lighting (BIM 기반의 미시적 에너지 시뮬레이션에 관한 연구 -조도센서등의 조도 및 에너지 분석을 중심으로)

  • Baek, Ji-Woong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.384-390
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    • 2019
  • The importance of architecture design focused on eco-friendly and low energy continues to grow. In addition, the energy conservation design is required from a micro-perspective. Energy simulations based on BIM have attracted recent attention because of the high efficiency. On the other hand, the parameters concerned with microscopic energy are not included in BIM data. This study examined the necessity of the sensor-light parameter using a simulation of illuminance sensor light. In this study, illuminance sensors were installed into the BIM data and the operating schedule data of sensor light were generated by an illuminance simulation. The schedule data was then inputted into the simulation application, and the reduction ratio of power consumption was verified by the simulation. According to research, the power consumption and thermal load decreased by more than 20 %. Therefore, it is necessary to supplement the sensor-light parameter into BIM data for microscopic energy conservation design. This study was not confined to checking whether sensor-light parameter is necessary or not, but to ascertaining the necessary of applying a microscopic factor to generate BIM data.

Evaluation of daylighting performance of bar-type mirror reflector system in tunnel (터널 적용 바형식 반사거울시스템의 채광성능 평가)

  • Lee, Beom-Seok;Joo, Jae-Sung;Jeong, In-Young;Kim, Min-Sung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.1
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    • pp.93-105
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    • 2012
  • The basic study was preceded for reducing maintenance and power cost of lighting fixture applying daylighting because most of the tunnel lighting depend on the artificial lighting. This study aims to evaluate the daylighting performance of daylighting performance of bar-type mirror reflector system in tunnel. Illuminance and luminance was measured. As a result of horizontal illuminance measurements, it was satisfied in tunnel recommended illuminance (KSA 3703) that total average was 1,170 lx increased 6.5 times more than this system was not used. Also, as a result of evaluating driver's glare on the opposite lane, glare did not occur and the luminance ratio was 3.01 which satisfies the luminance ratio standard 10.

A Study on Visual Comfort for Light Control Method of Applied Daylighting (자연채광방식의 응용에 따른 시각적 쾌적성에 관한 연구)

  • Han, Sang-Pil;Han, Sang-Cheol
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.140-145
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    • 2012
  • The purpose of this study is to understand the change of impression by comparing the uniformity lighting with the compound lighting. In previous study, we proposed a light controlling method to harmonize daylight from a window and artificial lights from a ceiling and obtained the results to support our method. We referred this method as the Adjusted Compound-Lighting Model (AC Model). The model claims that lighting in a room with a side-window are perceived as harmonious when the overall light distribution in the room is well approximated by a compound of lights from the window and the entire ceiling. The experiment is carried out with the scaled-models and mock-up spaces that were supposed to be an office space. One is lit by the uniform lighting and the other by the compound lighting in each experimental space. In order to present varying illuminance distributions, thetwo variables were used in this study. One was the ratio of thelight from the window and ceiling in the standard and evaluation box. The standard box was provided by the ratio of 20% to 40% from the window and 80% to 60% from the ceiling as two lighting ratio patterns [Wu20(=Cu80) and Wu40(=Cu60)]. And the evaluation box was provided by the light ratio of 0% to 40 from the window and 100% to 60% from the ceiling [Wcp0(=Ccp100), Wcp20(=Ccp80) and Wcp40(=Ccp60)]. The other variable was themean illuminance level in both boxes. Two level of mean illuminance (700lx and 300lx) were used in this experiment. Each lighting condition was established at equal horizontal mean illuminance level, held constant near 700lx or 300lx in both boxes. Both of them were similar in the shape of distribution when there were same ratios of lights from the window and the ceiling. Subjects were asked to evaluate the point of difference by semantic differential rating on their overall impression after comparing with two rooms. The results showed that the impressions of compound lighting were more positive score than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open', and that there was no significant difference in impressions between two spaces on other items.

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A Study on the Actual Conditions of Living Room Lighting in Daegu and Gyeongbuk Districts (대구·경북 지역 거실 조명 실태조사)

  • Jo, Young-Mi;An, Ok-Hee;Kim, Hyun-Jin
    • Journal of the Korean housing association
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    • v.23 no.3
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    • pp.13-20
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    • 2012
  • This research study was conducted to determine the actual conditions of living room lighting in Daegu and Gyeongbuk districts. For this study, 112 households were surveyed. The results of this study are as follows: Firstly, fluorescent light was used as the general illumination of living rooms, and the ratio of not using local sources of illumination was high. Secondly, the standard illuminance was found to be 221. The illuminance was the value that satisfied the activities for togetherness and entertainment, but did not reach the illuminance necessary for other activities, such as reading, make-up, and sewing. In addition, the uniformity of brightness used as a measure of uniformity in examining the results was normal. Thirdly, both the brightness and the satisfaction of lighting in the living room space were indicated to be normal. In addition, in regard to housing lighting, 'stability', and 'brightness of lighting' were indicated as important considerations and 'brightness of lighting', 'shadow' and 'management of lighting' were indicated as problem areas.