• KIEAE Journal
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• v.16 no.6
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• pp.129-134
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• 2016

Today, natural ventilation systems are widely applied in multi-family housing. However, studies using the wind data trend line of the blower door test are insufficient. Purpose: Through this study, we will propose a computational method about ventilation performance of natural ventilation systems by conducting blower door test. Method: First, we sealed the gaps between the main systems including the natural ventilation system and conducted the blower door test. Next, the natural ventilation system was opened, the blower door test was conducted, and the difference in air flow rate between when closed and when opened was checked. Blower door test was carried out with a pressure difference of 50 Pa. Result: Therefore, the ventilation performance of the natural ventilation system was checked by drawing a trend line using the data to calculate the air flow rate at 2 Pa of the natural ventilation equipment standard pressure difference.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.6
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• pp.543-550
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• 2003

In order to saving the energy for HVAC system of buildings, utilization of wind-induced cross ventilation is thought to be promising. However, utilization of natural ventilation alone is not sufficient for maintaining the human thermal-comfort such as in hot and humid regions. A hybrid air conditioning system with a controlled natural ventilation system, or combination of natural ventilation with mechanical air conditioning is thought to overcome the deficiency of wind-driven cross ventilation and to have significant effects on energy reduction. This paper describes a concept of hybrid system and propose a new type of hybrid system using radiational cooling with wind-induced cross ventilation. Moreover, a radiational cooling system is compared with an all-air cooling system. The characteristics of the indoor environment will be examined through CFD (Computational Fluid Dynamics) simulation, which is coupled with a radiation heat transfer simulation and with HVAC control in which the PMV value for the human model in the center of the room is controlled to attain the target value.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.336-341
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• 2009

In express bus which has no window, the air quality inside the bus is very critical for the passengers who staying for an extended time. Air conditioning system using natural energy is expected to significantly improve the air quality while the bus runs the suburban area. But the express buses today usually attempt to ventilate using air conditioning system, rather than natural ventilation. In this study, analysis of existing ventilation opening and the new ventilation system on roof, using computer simulation. As a result, two cases using existing ventilation device was found to be effective for partial ventilation only, while the air in front remains standstill. The new system proved to have promoted more dynamic ventilation in most of space.

• KIEAE Journal
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• v.7 no.4
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• pp.51-56
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• 2007

This study focuses on developing natural ventilation system which is able to satisfy the good indoor air quality and air speed. The natural ventilation system developed in this study is for double window façade and it has two operation modes for summer and winter. Operational sections of the devices have been analyzed by CFD simulation to calculate discharge coefficients of openings and estimated indoor air speed. For the analysis of the appropriate installation area ratio for each room and the optimum installation area, TRNFLOW simulation has been used. As the results, we could see that the natural ventilation system can provide the similar pollutant removal performance to 0.7 ACH of mechanical ventilation with appropriate installation area and installation area ratio.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.87-95
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• 2010

This study analyzed the performance of solar chimney system for natural ventilation in underground space. A mathematical model of the solar chimney was proposed in order to predict its performance under varying parameters and Korea climatic condition. Steady state heat transfer equations were set up using a energy balanced equations and solved using a inverse matrix method. Numerical simulation program to analyze system was developed by using MATLAB. As the results, the ventilation performance of the solar chimney was determined by the temperature difference of air channel and inlet, and the temperature difference was influenced by insolation, stack height and distance of air gab. Also the solar chimney system can provide $262.9m^3/h$ of annual average ventilation rate. Because seasonal differences of ventilation rate was calculated within 25%, the solar chimney system can be used for every season in Korea climatic condition. Through this study, performance of solar chimney system for natural ventilation was verified by numerical method. Consequently, the solar chimney system is proved to be effective device for natural ventilation utilizing at all times, and the additional studies should be made through the experimental method for imagineering and commercialization.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.123-129
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• 2009

In these days, the green building movement caused by the energy crisis is increasing, passive design is getting mere and more attention as it provides many possibilities for energy conservation. Moreover, with the increasing social intention for healthy life, the demand for indoor air Quality is increasing in Korea. As result, the ventilation system which can provide the sound outdoor air constantly has been obliged in Korea. So, the hybrid system which using natural power and mechanical power and makes up for the shortage of mechanical and natural ventilation attracts people's attention in Korea. As a hybrid ventilation system, in this study, the stack effect driven hybrid ventilation system in high-rise residential building will be suggested. And in this paper, the theoretical review for hybrid ventilation system suggested in this study will be addressed. Especially, the characteristics of pressure distribution and airflow caused by stack effect in high-rise residential building and the possibility of natural ventilation as results of stack effect will be described.

• Journal of the Korean housing association
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• v.14 no.3
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• pp.119-126
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• 2003

The purpose of this study is to evaluate the natural ventilation performance for variable external wind speed as a preliminary step to determining the seasonal operating modes of the Double-skin Facade System applied to apartment buildings. For this purpose, two simulation programs are used to compare the Double-Skin Facade System with the Double Sash Window. First, TAS is used to plan a schedule for natural ventilation during the intermediate season and to analyze the cooling loads. Second, CFD is used for a more detailed airflow analysis on a typical floor plan of the model building. The results of the simulations on natural ventilation performance show that the Double-Skin Facade System can reduce the cooling load by 10.5% compared to the Double Sash Window.

• Journal of Distribution Science
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• v.17 no.7
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.387-392
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• 2006

The recent on indoor air problem has led to many studies on the methods and effects of ventilation for better indoor air quality. Although natural ventilation is the most effective and energy-saving method in residental housings, the small size of openable window has been a problem in high-rise residential buildings to ventilate only through natural ventilation. Consequently, the installation of mechanical ventilation system has been a requirement in residential buildings, and has caused other problems such as increase of energy consumption and SBS. Hybrid ventilation which uses forces of both natural and mechanical power has been introduced to solve the problem of increase in energy consumption with natural ventilation. In this paper, two types of hybrid ventilation systems in residential building were introduced. One type was with natural ventilation through vent grille in the window, and another type was with natural ventilation through ceiling duct while both types used mechanical ventilation system with the outlets. The indoor temperature distribution and pollution density distribution in summer while operating the ceiling air conditioner were analyzed through CFD simulation. In this paper, the optimal location of diffusers to achieve thermal comfort would be proposed.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.689-694
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• 2009

On account of Indoor Air Quality(IAQ) deterioration by reason of high isulation and air tightness for energy saving, absence of energy efficiency ventilation system development that can be domestic existing window system, the cost increase and the energy addition loss by mechanical ventilation for IAQ improvement the ventilation obligation making design standard was prepared by a social and technical background and the necessity. In this study, open module type natural ventilation window system for energy saving included a fixed and continuous quantity ventilation was developed. The purpose that indoor thermal comfort environment evaluate of indoor resident.