• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.256-263
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• 2011

Recently, curtain wall structure is constructed according to increasing high rise building. Glass is usually used in opening of curtain wall structure and window area ratio is finally increased. Excessive Daylighting and solar radiation by large window area ratio cause discomfort glare and add to cooling load in the case of office that is heavy on lighting and cooling. Therefore, this study suggests to use low transmittance window for solve those problems. Indoor lighting environment and building energy performance were analyzed by increasing transmittance from 10% to 90% and comparing fixed venetian blind. Consequently, the range of transmittance that is possible to daylighting and prevent discomfort glare. Secondary energy consumption is efficient in the case that transmittance is the range of from 20% to 50%, primary energy consumption is nice on from 20% to 40%. If those result put together, the range of window transmittance from 30% to 50% is proper in the office in lighting environment and energy consumption aspects.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.2
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• pp.82-95
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• 1992

It has been known that the application of an airflow window system reduces the energy consumption compared with conventional double pane window in a building. But how to analyze thermal load in a building with an airflow window system has not been well known. so two kinds of method (Mode 1 and Mode 2) to analyze time dependent thermal load of the building with an airflow window system are presented in this study. The results of load analysis about the model building(total area : $4521m^2$, 3 floors) by Mode 2 show that the maximum cooling and heating load in a building with an airflow window system are decreased about 12-17% and about 19.5% than with double pane glass window, and yearly energy consumption with an airflow window system is saved about about 20% than with double pane glass window.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.557-560
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• 2008

Window system is an essential component for ventilation, lighting, and thermal environment in buildings. However, window system has the lowest insulation performance and may cause high energy consumptions, if it is not properly designed. Thus, performance of window systems play an important role in built environment. This study proposes a new window systems for balcony, which has double vents and analyses the thermal performance using an intergrated simulation method with Therm 6.1 and Widow 6.1. The result shows higher U-factor than conventional window systems. It is expected that the double vent window system can increase thermal performance and save energy in apartment houses.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.211-220
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• 2012

In study to investigate losing energy of building in window, we analyze the heating loss parts in the material of structure throughout modeling of window system. Also, by making modeling in the building using simulation, we investigate the heating load variation of building in window. According to the type of windows and the material of structure, we analyze the energy variation of building and a temperature variation.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.156-161
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• 2011

In case of newly constructed buildings, the construction type is almost Curtain-wall system or large window in building skin. However, these kind of buildings have problems with regulations on building energy efficiency. And national regulations on building energy efficiency limit only the V-factor of window(except infiltration), it is hard to predict energy consumption of Curtain-wall buildings which gain large solar energy in summer. In this study, the influence of LSG(Light to Solar Gain) on energy performance was theoretically analyzed with simulation. LSG is the value of VLT divide SHGC and represents the optical performance of the glass or glazing. The Window & Therm program developed in LBNL was used to analyze window systems and EnergyPlus was used to building energy. Cases of glazing are three types; single coated Low-e clear glazing, tripple coated Low-e clear glazing, tripple coated Low-e tinted glazing. The results of this study are follows; 1) The building energy consumption of Alt-l, 2, 3 were about 300, 253, $259kWh/m^2{\cdot}yr$ respectively. Therefore, improvement of LSG could save the energy up to 16%. 2) The saved energy could be converted 1 billion won as annual benefit of total energy costs 3) SHGC and LSG more influence on cooling energy than heating energy in office buildings.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.205-210
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• 2009

Generally, the building's windows and ventilation for the purpose of mining and the vista and windows by emotional engineering design area is a growing trend. According to the flow of energy is lost from the building, will be achieved through the walls and roof and windows. Among these, the window through the loss of about 45% of the entire building is big enough to rate. In addition, the building regulation U-value Limitation of window is $3.3W/m^2$ K in southern regions, while U-value Limitation of wall is $0.35{\sim}0.58W/m^2$ K. It means that the energy loss through windows is six times more than it through wall. Therefore, the purpose of this study is to evaluate the environmental performance of the super window system by verification experiment. The results of this study are as follows; 1)Thermal performance of insulated Super Window measured as $1.44W/m^2$ $^{\circ}C$ 2)Required energy for heating was cut down about 5.3% from 266.99 $MJ/m^2$ yr to 252.85 $MJ/m^2$ yr 3)Super Window's reduction rates increased 4.1% from 31.48% to 35.58% when it is compared to normal windows. 4)Building energy efficiency rating elevated from 2nd rating to 1st rating.

• KIEAE Journal
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• v.13 no.3
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• pp.91-96
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• 2013

The purpose of this study was to analyze the annual energy demand including heating, cooling and lighting according to kind of windows with transparent thin-film a-Si Building Integrated Photovoltaic(a-Si BIPV) for office building. The analysis results of the annual energy demand indicated that the a-si BIPV window was reduced by 8.4% than the clear gazing window. The base model A was combinate with a-Si BIPV window area of 67% and clear window area of 33% among the total exterior area. The model B is to be applied with low-e clear glass instead of clear glass of the base model A. The model B was reduced to annual energy demand of 1% more than the model A. Therefore, By using a-si BIPV solar module, the cooling energy demand can be reduced by 53%(3.4MWh) and the heating energy demand can be increase by 58%(2.4MWh) than clear glazing window in office building. Also, Model C applied to the high efficient lighting device to the model B was reduced to annual energy demand of 14.4% more than the Model D applied to the high efficient lighting device to the model A. The Model E applied with daylight dimming control system to the Model C was reduced to annual energy demand of 5.9% more than Model C.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.85-92
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• 1984

It is a esperimental report to investigation for optimum window-width on radionuclides $^{131}I\;and\;^{198}Au$ The obtained results were as follow; 1. In case of $^{131}I$, 1) The lowest counts produced at the window-width of 10KeV and 20KeV. 2) The count rate, more increased, when the window-width more opened, but the counting efficiency is very good between 70KeV and 130KeV window-width (19.23% -35.71% about the peak energy). 3) The heighest counting rate per KeV of window appeared at 130KeV window-width. 4) BKG counts increased proportionally to the wider window as 5.473 + 0.016 cpm. 2. In case of $^{198}Au$ 1) The lowest counts appeared at 10KeV and 20KeV window. 2) Count rate more increased, when window-width more opened, but the counting efficiency is very good between 80KeV and 140KeV window (19.46% - 34.06% about the peak energy). 3) The highest counting rate per KeV of the window appeared at 140KeV window. 4) BKG counts increased proportionally to the wider window-width as 4.74 + 1.09 cpm.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.429-435
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• 2010

Although recently revised building code requires 15~20% increased thermal insulation performance for window systems, since the code is focusing on winter heat loss, it is not satisfactory to contribute on reducing rapidly rising cooling load in summer. Window systems have great impact on building heat gain and loss. Therefore technological development for window system specialized in shading solar gain in summer is an urgent matter. This study evaluates the performance of sun shading and thermal insulation for blind integrated window system. Also, computer simulation evaluates the effect of heating and cooling energy consumption reduction for an individual unit(floor area of $85m^2$) of a multi-family housing. Physibel Voltra, a heat transfer analysis software, was used to analyse the effect of energy consumption reduction, and the energy load was converted to the cost to compare the actual effect of economical benefit.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.471-474
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• 2020

In recent years, the challenge of higher energy efficiency has emerged as urban buildings have become taller, and the area of window glasses has increased. To address the problem of energy efficiency in buildings, research on smart windows is being actively conducted. In this study, an accelerated experiment for thermal stability was conducted to fabricate a liquid crystal cell applicable to external windows. It was confirmed from the study that the function is maintained even in a high-temperature external environment through the change in transmittance by voltage. Compared with the initial transmittance, after the passage of time, the smart window cell to which the sealant was applied showed a small change in transmittance of 1~2%. This result confirmed the thermal stability of the liquid crystal-based smart window.