• Journal of the Korean Solar Energy Society
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• v.25 no.4
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• pp.119-123
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• 2005

The main purpose of this study is to define an optimum slope of the roof that demands minimum cooling load of the building, when the roof is affected by the solar and wind energy. Two different roof shapes were chosen: hip, gabled. The cooling load of building having those roof shapes was calculated through the computer simulation, using DOE program. For the simulation, the angle of the roof and angle of the orientation was changed. In the conclusion of this paper, an optimum slope of the roof which causes minimize cooling load is presented according to the roof shape and orientation. The result of this study could provide a practical design guideline for determining the roof angle for various climatic conditions.

• Journal of Bio-Environment Control
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• v.7 no.4
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• pp.290-297
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• 1998

In this study an optimization of greenhouse roof shape was performed to maximize solar light transmission which is one of the most important elements in greenhouse environment. To determine roof shape that maximize the total light transmissivity, a computer model for analysing light transmissivity was composed and the Genetic Algorithms was applied for solving optimization problems. By setting composite model as objective function(fitness function), the optimum combination of design variables(roof inclination angle, width ratio) was searched using Genetic Algorithms. The optimum combination of input variables for the maximum light transmissivity at Suwon in winter was found 40 degree root angle , 0.5 width ratio, for two span greenhouses and 37 $_。 / roof angle, 0.7 width ratio, for single span greenhouses.es.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.34.2-34.2
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• 2011

Wind guide can be installed on the top of buildings to collect wind. In this study, optimum shape of wind guide is developed, and proposed to combinate with the vertical wind turbine. Impact of parameters for wind guide is analyzed with several cases planned by Taguchi test plan. Front angle, rear angle, and roof angle are selected as key variables and changed into four different levels. By the experimental plan, totally, 64 cases are reduced to 16 cases of analysis. With optimum design of wind guide, the installed vertical axis wind turbines can be operated with maximum power output.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.135-142
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• 2011

Architectural market in the world is trying to develop Zero Carbon Buildng that doesn"t use fossil fuel. Residential building that thermal load such as heating and domestic hot water is over 70% in energy consumption is easy to make Zero Carbon Building compared with office building that is mainly electric load. So, As a preliminary for analyzing the effect of Solar thermal system in the building, an annual energy consumption of residential building and total heat loads are calculated. Based on this result, three alternatives of solar thermal system for hot water and heating are applied in the building while installation area is increasing. Solar thermal system is applied on balcony and roof of apartment building as the way to reduce thermal load. In the first case that solar thermal system for hot water is applied on the balcony, optimum installation area is $56m^2$. And you could install $40m^2$ of this system in the roof that angle is $30^{\circ}$. In the second case of solar thermal system for heating and hot water, you can install $40m^2$ on the roof. As a result of economic evaluation, the most economical application method is to install $40m^2$ of solar thermal system for only hot water on the roof of the building. At that time, you can payback the initial investing cost within 10 years. And carbon emission of this method can be reduced until about 4 ton per year.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.809-813
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• 2011

Turbulent flows are numerically simulated in the three dimensional inlet duct for heat recovery steam generator. The present study is aimed to analyze the effect of a variation in turbulent flow pattern by the change of roof angle in the transition duct. The finite volume based Navier-Stokes equations with unstructured grids are solved to make clear the flow dynamic phenomena. Reviews are made on with the data of path lines, velocity vectors, dynamic pressure, residuals for numerical convergence and so on. The k-epsilon, k-omega, Reynolds stress and RNG k-epsilon are used for generation of turbulence. Two types of roof angle are applied with and without the swirl in the duct. Turbulent flow patterns could be investigated for the optimum duct design based on the computational results.

• Journal of the Korean Solar Energy Society
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• v.36 no.4
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• pp.57-65
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• 2016

Domestic photovoltaic system for roof-top is installed towards the south at an angle of 20 to 35 degrees and the shape of PV array is divided into two kinds; a plane shape and a curved shape. This paper aims to understand an actual condition of PV facility and strengths and weaknesses of support structure production and installation and to consider the best PV surface shape by analyzing theoretical logics of these two surface shapes and architectural perspective-based realistic case studies. This study targeted 98 facilities including common houses, public institutions and education institutions. In common houses, all of 59 PV facilities have a plane surface. In public institutions, 7 of 15 PV facilities have a curved array surface and 8 PV facilities have a plane surface. In education institutions, also, 14 of 24 PV facilities have a plane array surface and 10 PV facilities have a curved surface. Most of 98 facilities have a flat roof supporting shape. However, it was found that the curved shape wasn't positive for PV generation due to the change of radial density and it was at least 10 % more expensive to produce its structure. Also, domestic general large single-plate PV facilities have problems of harmony with buildings and wind load. Therefore, it is considered that for fixed-type roof-top PV, a plane PV array shape is good for optimum generation and economic efficiency and a parallel array structure on the roof surface is favorable to wind load and snow load without being a hindrance to the building facade.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.93-101
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• 2015

Zero energy building is a self sufficient building that minimizes energy consumption through passive elements such as insulation, high performance window system and installing of high efficiency HVAC system and uses renewable energy sources. The Korea Government has been strengthening the building energy efficiency standard and code for zero energy building. The building energy performance is determined by the performance of building envelope. Therefore it is important to optimize facade design such as insulation, window properties and shading, that affect the heating and cooling loads. In particular, shading devices are necessary to reduce the cooling load in summer season. Meanwhile, BIPV shading system functions as a renewable energy technology applied in solar control facade system to reduce cooling load and produce electricity simultaneously. Therefore, when installing the BIPV shading system, the length of shadings and angle that affect the electricity production must be considered. This study focused on the facade design applied with BIPV shading system for maximizing energy saving of the selected standard building. The impact of changing insulation on roof and walls, window properties and length of BIPV shading device on energy performance of the building were investigated. In conclusion, energy consumption and electricity production were analyzed based on building energy simulations using energyplus 8.1 building simulation program and jEPlus+EA optimization tool.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.58-62
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• 2017

In this study, the design conditions for the Korean-style glass greenhouse structure has been reduced to achieve the most efficient use of natural light. The AGI program was simulated for the optimal conditions of daylight in a glass greenhouse. From the results of daylight simulation, the axis position of the glass greenhouse's roof was not an important factor in the daylight effects regarding illumination and uniformity. In summer, there were long periods of daylight and high illumination levels. The illumination value of daylighting increased with increasing glass transparency value, and the illumination value was greatest at 14:00 hours. At this time, the rate of light variation according to the glass transparency was 89 [lux/%]. In addition, the optimal design conditions for the glass greenhouse were established, which were a $30[^{\circ}]$ or $150[^{\circ}]$ installation angle and higher transmittance of glass.