• Particle and aerosol research
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• v.5 no.1
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• pp.9-16
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• 2009

Pressure drop and particle removal efficiency of two commercial fibrous medium filters were measured with 20~1,000 nm sized aerosolized KCl particles. Pressure drop and particle removal efficiency were also theoretically predicted and the results qualitatively agreed with the experimental data. For this given particle removal efficiency, a filter design method for obtaining minimum pressure drop (and therefore minimum fan power) was suggested in this study by selecting solidity and fiber diameter as parameters. Therefore, by carrying out theoretical and experimental approaches together, this paper introduced a way of finding conditions for low pressure drop and high performance of a fibrous filter, especially if the filter would be used in mechanical ventilation system.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.61-66
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• 2008

Recently a certain level is required in natural ventilation for improving on the 'quality' aspect in housing. It is simulated the external flow around building which affact natural ventilation using CFD. Natural ventilation is estimated on the specific household which considered topography and not considered.

• Land and Housing Review
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• v.13 no.3
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• pp.107-113
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• 2022

With increasing airtight building construction aimed at reducing energy consumption, indoor relative humidity is increasing which can lead to condensation and moisture damage in multi-family residential buildings. This has led to increased implementation of mechanical ventilation to control indoor moisture. However mechanical ventilation systems consume additional energy and generate noise. As this leads to occupant discomfort, it is necessary to select a ventilation system that addresses the energy and noise issues. This research measured the ventilation performance, energy consumption, and noise level of mechanical ventilation devices in multi-family residential buildings. TOPSIS, a multi-criteria decision making technique was used to determine appropriate ventilation strategies in addition to occupant ventilation system operation preference.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.87-94
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• 2006

The efficiency of ventilation system is one of the most important issues of designing ventilation in high-rise apartment buildings. The purpose of this study is to analyze the ventilation efficiency of ventilation system by experimental study using CO2 gas method. The results of this paper can be summarized as follows; (1) An appropriate ventilation including opening planning, mechanical and hybrid system are required. (2) The supply diffuser of ventilation system should be located near the contaminant source. (3) The return grill should be located along with supply diffuser for proper ventilation. and the return grill should be located near or right above the contaminant source. (4) However, the supply location right above the contaminant source has to be avoided. and the supply diffuser should be installed in module with return grill increase ventilation effectiveness.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.7
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• pp.541-548
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• 2006

A hybrid ventilation system was introduced to predict the ventilation performance of the apartments. This ventilation system was composed of the natural supply-air inlet and the forced exhaust-air outlet. Analysis was conducted by CFD technique and was performed on three ventilating flow rates; 30, 60, $120m^3/h$. As the results, residents feel comfortable thermally for $60m^3/h$. In the case of $120m^3/h$, however, residents feel uncomfortable both thermally and in air currents. In this study the energy saving for space heating is also an important factor. In the case of whole region with $180m^3/h$, residents feel comfortable at each region of the model apartment. It is shown that this hybrid ventilation system is possible method for the apartment house.

• 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.

• BMB Reports
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• v.43 no.4
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• pp.257-262
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• 2010

The aim of work was to investigate changes of 7-ketocholesterol synthesis in alveolar macrophages in the dynamic of lung mechanical ventilation with injurious parameters. The goal of in vitro part of work was to observe influence of 7-ketocholesterol on iNOS and MIP1 $\beta$ production in bronchoalveolar lavage fluid (BALF) cells. We used 17 healthy domestic pigs randomly assigned into two treatment groups: group I with mechanical ventilation with physiological parameters; group II underwent injurious ventilation with high volume tidal (VT) and low positive end expiratory pressure (PEEP). Cells were analyzed for CYP27A1 protein and gene expression levels, 7-ketocholesterol production. In alveolar macrophages of group II, we obtained increase of production of CYP27A1 protein and 7-ketocholesterol, as well as the expression of the CYP27A1 gene at the 2nd hour of ventilation. In the in vitro experiments we show dose-dependent increase of MIP1 $\beta$ and decrease of CYP27A1, iNOS protein production after 7-ketocholesterol treatment.

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.19-26
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• 2016

Modern people spend much time at indoor space. So, People want to make better indoor air condition. But the facade of building is made of glass to be seen urbanely, the effect of solar radiation makes indoor environment worse. This study designs an open space affected by solar radiation with 4-way cassette air-conditioner. Using numerical simulation, this paper investigates thermal comfort and ventilation performance with discharge angles $30^{\circ}$ and $45^{\circ}$. To study thermal comfort, this paper studies distribution of velocity, temperature and effective draft temperature. Also, this paper introduces concept of air age to study ventilation performance. The flow influenced by solar radiation determines thermal comfort and ventilation performance in room space. This study shows that discharge angle of 45 degree has better thermal comfort and ventilation performance than that of 30 degree.

• Particle and aerosol research
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• v.16 no.4
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• pp.73-94
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• 2020

Particulate infectious sources, including infectious viruses, can float in the air, causing airborne infections. To prevent indoor airborne infection, dilution control by ventilation and indoor air cleaners are frequently used. In this study, the risk of airborne infection by the operation of these two techniques was evaluated. In case of dilution control by ventilation, a high efficiency air filter was embedded at the inlet of supply air. In this study, infectious source reduction devices such as indoor air cleaner include all kinds of mechanical-filters, UV-photo catalysts and air ionizers through which air flow is forced by fans. Two mathematical models for influenza virus were applied in an infant care room where infants and young children are active, and the risk reduction efficiency was compared. As a result, in the case of individually operating the ventilator or the infectious source reduction device, the airborne infection risk reduction efficiencies were 55.2~61.2% and 53.8~59.9%, respectively. When both facilities were operated, it was found that the risk of airborne infection was reduced about 72.2~76.8%. Therefore, simultaneous operation of ventilation equipment and infectious source reduction device is the most effective method for safe environment that minimizes the risk of airborne infection of respiratory infectious diseases. In the case of a space where sufficient ventilation operation is difficult, it was found that the operation of an infectious source reduction device is important to prevent the spread of infectious diseases. This study is meaningful in that it provides an academic basis for strategies for preventing airborne infection of respiratory infectious diseases.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.115-123
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• 2017

Recently there is a growing interest in the airborne spread of virus. In particular, there is growing interest in secondary infection through the air in the hospital. The distribution of air-born virus depends on ventilation system installed in a hospital. In this study, simulations were carried out to predict the move of air-born virus by ventilation system at hospital. Simulation results showed that pressure distribution was -372.05Pa ~ -3.45 Pa at 1st floor incase of only used mechanical exhaust at bathroom, shower stall, storage, kitchen etc.. if ventilation switch from used mechanical exhaust to mechanical exhaust & mechanical supply. Simulation results showed that pressure distribution was -336.44Pa at stair hall < -0.2Pa at bathroom < mean 1.19Pa at other room. So simulation results showed that using all of the mechanical supply and mechanical exhaust was more effective then the mechanical exhaust for maintain the pressure distribution in hospital. It was also showed that when using the mechanical supply and mechanical exhaust more effectively prevention of air born virus diffusion.