• KIEAE Journal
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• v.17 no.1
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• pp.69-75
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• 2017

Purpose: Heat transfer analysis of recently developed 'slim type double-skin system window' were presented. This window system is designed for curtain wall type façade that main energy loss factor of recent elegant buildings. And the double skin system is the dual window system integrated with inner shading component, enclosed gap space made by two windows when both windows were closed and shading component effectively reflect and terminate solar radiation from outdoor. Usually double-skin system requires much more space than normal window systems but this development has limited by 270mm, facilitated for curtain wall façade buildings. In this study, we estimated thermophysical phenomena of our double-skin curtain wall system window with solar load conditions at the summer season. Method: A fully 3-Dimentional analysis adopted for flow and convective and radiative heat transfer. The commercial CFD package were used to model the surface to surface radiation for opaque solid region of windows' frame, transparent glass, fluid region at inside of double-skin and indoor/outdoor environments. Result: Steep angle of solar incident occur at solar summer conditions. And this steep solar ray cause direct heat absorption from outside of frame surface rather than transmitted through the glass. Moreover, reflection effect of shading unit inside at the double-skin window system was nearly disappeared because of solar incident angle. With this circumstances, double-skin window system effectively cuts the heat transfer from outdoor to indoor due to separation of air space between outdoor and indoor with inner space of double-skin window system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.605-613
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• 2010

Double skin facade(DSF) ventilated by fans consists of a normal external and an internal envelope. In this glass layer, the installed fan replaces an air inlet for the control of air flow through the cavity. The purpose of this paper is to investigate physical theory and to analyze the applicability of fans installed in a DSF. The experiment was conducted in 2 rooms. One room has a DSF with installed fans and the other one has a typical window. The room ventilated through a DSF which fans are installed was always kept warmer than the other room, ventilated directly from the outdoors. The average increase of the supplied air temperature through the DSF ventilated by fans was $6.54^{\circ}C$ at 78CMH, $6.2^{\circ}C$ at 95CMH, and $3.7^{\circ}C$ at 120CMH. As a result, the DSF with installed fans was appropriate for installation in rooms. It supplies outdoor fresh air heated through a cavity and ventilates a constant air volume.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.276-279
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• 2007

This study aims to present the application of pv system for apartment buildings. Regarding to the domestic housing politics to improve residing environment and effective use of country land, apartment buildings have been constructed since early of 1790's. Now apartment is taking over 50% out of entire housing in Korea. PV System of apartment buildings has been developed periodically and recently gable roof or canopy is popular which pv installation is more favorable. For balcony part with double skin facade sassy window, it has a preferable condition to install on the wall depending on the window direction. In case of superhigh floor apartment buildings where facade is mostly double skin facade of curtain wall system, pv module can replace the traditional curtain wall and will reduce architectural materials and obtain various out look design thereof. So, the purpose of this research is a basic study for clean energy source and present to applicability of pv systems for apartment buildings in preliminary design step.

• KIEAE Journal
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• v.15 no.3
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• pp.43-48
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• 2015

Purpose: Recently, many countries around the world are actively looking for the ways to make full use of natural energy sources and also develop and apply an environmentally friendly system designed to save building energy consumption. Under these circumstances, this study intended to determine the applicability and energy saving effect by deriving the indoor thermal performance characteristics and the PCM temperature appropriate for a double skin façade to reduce indoor energy consumption through the application of different PCM temperatures to double skin façade and perform a performance evaluation depending on the application or non-application of PCM to a double skin façade. Method: For this study, the physical variables of the double skin façade with PCM were configured through a preliminary examination based on an experimental measurement, and experimental measurements were taken with a total of 7 types of mockup cases: Type-1 (Basic), the basic double skin façade, Type-2 (PCM $18^{\circ}C$) which was applied to the inner skin of the double skin façade depending on the phase-change temperature of PCM, Type-3 (PCM $20^{\circ}C$), Type-4 (PCM $22^{\circ}C$), Type-5 (PCM $24^{\circ}C$), Type-6 (PCM $26^{\circ}C$), and Type-7 (PCM $28^{\circ}C$) with reference to the data analysis of the basic double skin façade which preceded this study, to analyze the indoor thermal performance of the double skin façade depending on PCM temperature and the installation or non-installation of a double skin façade applying PCM based on the selected unit space. Result: Indoor thermal performance was analyzed depending on the PCM temperature applicable to double skin façade, and the analysis of heating energy reduction showed that Type-2 (PCM $18^{\circ}C$) gained 15.9% more heat compared with Type-1 (Basic) and secondly, Type-3 (PCM $20^{\circ}C$) gained 11.5% more heat. Based on these findings, it is deemed possible that the use of energy for heating can be reduced when heat coming indoors increases during the heating period, and the appropriate temperature for PCM applied to the inner skin of a double skin façade to reduce heating energy in winter, Type-2 (PCM $18^{\circ}C$) showed the highest efficiency and Type-3 (PCM $20^{\circ}C$) was also deemed appropriate.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.99-104
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• 2016

In this study, we researched the energy load according to the change of the inner window area ratio, the distance of the air gap and the azimuth of the curtain wall building, which installed the multistory double-skin facade(DSF). and we compared the results with the no double-skin facade situation as follows. With the DSF, it is better than other case, when the window area ratio is 40% and the air gap is 1.2m on the west, south-45-west, south-45-east and east. And it's best when the window area ratio is 40% and the air gap is 0.4m on the south. And on the east or south-45-east, the window area ratio is 40% and the air gap is 1.2m is better than other case with the DSF. On south, it is best when the window area ratio is 100% without DSF. On the south-45-west or west, it is best when the window area ratio is 40% without the DSF.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.59-67
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• 2011

This paper is focused on the effect of indoor temperature rise according to the use of windows and blinds in double skin facade in summer. For the experiment, we set up the mock-up of double skin facede and measuring temperature and solar radiation. Total 7 cases were used for measuring solar transmittance and indoor temperature rise. When the venetian blind was not installed, solar transmittance was 44.5%, and solar transmittance for the case that installed the venetian blind (angle 0) was 22.5%. Cases that opened inner and outdoor windows for ventilation showed lower indoor temperature rise than cases with closed windows. In addition, Case 5 (opened inner and outdoor windows with the venetian blind (angle 0) to reduce solar transmittance) indicated lower indoor temperature rise than Case 3(opened inner and outdoor windows). Consequently, Case 5 which uses inner and outdoor window for ventilation and venetian blind to reduce solar transmittance is the most effective way to reduce indoor temperature rise among all cases tested in this research.

• 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.

• KIEAE Journal
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• v.14 no.3
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• pp.71-77
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• 2014

This study aimed at developing and evaluating performance of the two logics for respectively operating two-position- and variable-heating systems. Both logics control the heating system and openings of the double skin facade buildings in an integrated manner. Artificial neural network models were applied for the predictive and adaptive controls in order to optimally condition the indoor thermal environment. Numerical computer simulation methods using the MATLAB (Matrix Laboratory) and TRNSYS (Transient Systems Simulation) were employed for the performance tests of the logics in the test module. Analysis on the test results revealed that the variable control logic provided more comfortable and stable temperature conditions with the increased comfortable period and the decreased standard deviation from the center of the comfortable range. In addition, the amount of heat supply to the indoor space was significantly reduced by the variable control logic. Thus, it can be concluded that the optimal control method using the artificial neural network model can work more effectively when it is applied to the variable heating systems.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.993-998
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• 2006

High-rise apartments have a problem using natural ventilation because of the strong outdoor wind velocity. Conventional high-rise apartments have adopted mechanical ventilation systems to maintain the indoor air quality. However, it leads to the overuse of electricity and the sick house syndrome. Double-skin facade is the alternative for the high-rise building to use natural ventilation and this study is focused on the performance of the box-window, which is a kind of double-skin facades. Indoor wind velocity and HCHO concentrations are analyzed with three types of box-windows: the diagonal type, parallel type and perpendicular type. The airflow is simulated by computational fluid dynamics program. Box-windows reduce the maximum value of indoor wind velocity about 50% compared with the single window and the HCHO concentrations do not have the big difference. Box-windows could be the alternative to enhance the use of the natural ventilation and indoor air quality of the high-rise apartment.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.265-276
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• 2022

Double-Skin Facades (DSF) on tall buildings are becoming increasingly common in urban environments due to their ability to provide architectural merit, passive design, acoustic control and even improved structural efficiency. This study aims to understand the effects of porous DSF on the aerodynamic characteristics of tall buildings using wind tunnel tests. High Frequency Force Balance and pressure tests were performed on the CAARC standard tall building model with a variable porous DSF on the windward face. The introduction of a porous DSF did not adversely affect the overall mean forces and moments experienced by the building, with few differences compared to the standard tall building model. There was also minimal variation between the results for the three porosities tested: 50%, 65% and 80%. The presence of a full-height porous DSF was shown to effectively reduce the mean and fluctuating wind pressure on the side face of the building by about 10%, and a porous DSF over the lower half height of the building was almost as effective. This indicates that the porous DSF could be used to reduce the design load on cladding and fixtures on the side faces of tall buildings, where most damage to facades typically occurs.