• KIEAE Journal
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• v.6 no.3
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• pp.11-18
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• 2006

Attention on daylighting should be focused not so much on a simple maximization of the natural light available in a space, as on improving the quality of lighting by ensuring as even but intense distribution of illumination in inner areas. 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.7
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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.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.35-43
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• 2004

Illuminance and luminous levels in a small office space due to daylight were calculated to analyze the impact of daylight on contrast and lighting energy savings. Computer simulations were performed for four blind conditions under a clear sky condition. The blind conditions significantly impacted the illuminance an4 luminance level. Visual performance scores were calculated according to the transfer function that uses absolute contrast between target and background surface. The blind condition that had 45 tilted angle toward ground provided good contrast and performance scores. Using a control algorithm of an automated daylight dimming control system lighting energy sayings were predicted. For all blind conditions minimum lighting energy was consumed.

• Journal of the Korean Solar Energy Society
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• v.32 no.6
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• pp.11-21
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• 2012

In the normal office building, the energy consumption to maintain the reasonable intensity of illumination for the work by using the artificial illumination occupies 30% or greater of the whole building electric energy consumption. If the dependability of the artificial illumination is dropt by positively using the natural lighting from the outside, the large amount of electrical energy can be saved, in addition the more nice visual environment for work can be created. Daylight is lighting source that most closely match visual response of the human, because sunlight and skylight achieve the harmony. For this reason, the daylight of small amount than amount of the artificial lighting source also can give the same effect in work activities of human. In addition, if there is daylight at the window of the building, the energy can be saved by controlling the artificial lighting. In this paper, in the building using the photovoltaic power generation analyze the correlation between the amount of energy generated by photovoltaic and indoor illumination and this was proved through the simulation with Relux 2010. In addition, the amount of daylight inflow in the room and distribution was drawn by the equation and the ratio for the sectional dimming control of each lighting equipment was predicted and the energy saving amount according to this was calculated. As a result, the indoor illumination was satisfied with recommended illumination value of the office and consumption power could be reduced approximately with 20~70%.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.117-120
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• 2009

New shading system, which is Grating Louver System into a pair glass, is proposed for integrated lighting system between Daylight Responsive Dimming Systems and shading system in this study. The optimized distance of louvers, which is to block direct sunlight into a space, is calculated. Grating Louver System was simulated using Desktop Radiance 2.0 of lighting simulation software for comparing daylight distribution and changes of control slope by distance from window to back wall with roller shading system controlled by sun profile angle.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.167-172
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• 2005

This study based on the experimental data on the daylight responsive dimming systems performance. The purpose of this study increases the energy-saving effects by reducing excessive intensity of radiation of artificial lighting through analyzing incident daylight. The photosensor sends amounts of detected luminous flux to digital control unit(DCU) as a signal and then, it can decide dimming ratios, by received a proper dimming signal from DCU. Generally it is effective to control artificial lighting with the different control ratio of each row by setting a photosensor as same numbers and rows as artificial lighting. However, it is ineffective to do in initial costs of systems aspect in offices. By analyzing the data of this performance and finding regular ration between photosensors. we will execute different dimming ratios to each row of artificial lighting by a single photosensor.

• KIEAE Journal
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• v.10 no.6
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• pp.33-39
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• 2010

Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

• Journal of the Korean Solar Energy Society
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• v.34 no.5
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• pp.1-9
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• 2014

Daylight is very useful to control the indoor environment, and can save energy in buildings. So it is necessary to evaluate the daylighting performance of buildings. We proposed a simplified equation that can be used in the early stages of design. And we verified the equation by using the measured illuminance data from the 1/5 scale model. We compared the calculated indoor illuminances and measured illuminance including Daylight Factors of scale model in order to verify the applicability of the simplified equation, and proved the analyzed values are acceptable. When we have a target value of the Daylight Factor, we just have to determine the window area, transmittance of the glazing system, and indoor surface reflectance, then can achieve it with this simplified equation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.28-34
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• 1990

Lighting is one of the largest energy, integrated lighting system with daylight and artificial lighting has been suggested. In such system, perimeter zone can be illuminated by daylighting and the deep area of room by artificial lighting. So, the study is to develope estimation nomograph of lighting energy by turnning-off depth and lighting control systems during daytime. For the purpose, energy nomograph has been developed to apply to side-lit office guilding and the use and limitation of the nomograph has been discussed.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.45-51
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• 2006

Recently, various kinds of daylight system are recognized as an important and useful strategy in energy-efficient building designs. However, a large amount of direct sunlight can make many problems. Therefore, it is necessary to control daylighting through louver systems for high quality visual environment. The purpose of this study is to analyze daylighting performance in the reading room of a library according to different azimuths and louver systems. The results evaluated daylight performance based on the RADIANCE lighting software.