• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.78-97
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• 2000

Designing the industrial ventilation system is the complex and time-consuming job. It could generate some errors in the design calculations if one uses the hand-calculator or the spreadsheet program. To overcome these difficulties, VSDS(Ventilation System Design Software) had been developed a few years ago. But, it had the difficulty in designing a complex system having many branches because the user can not see the layout of the system on the screen. Another difficulty is that VSDS had been based on the assumption of the standard air condition. VSDS has thus been improved to overcome the shortcomings of the old version of VSDS.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.1
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• pp.100-107
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• 1998

Ventilation of the marine engine room is very important for the health of the workers as well as the nomal operation of machines. To find proper ventilation conditions of this engine room, numerical simulation with standard k-.epsilon. model was carried out. In the present study, the marine engine room is considered as a closed space with a heat source and forced ventilation ducts. The injection angle of air supply is found to be important. Injection with downword angle depresses recirculation flow, causing a strong steam in the wider space of the room. Ventilation and removal of the released heat are promoted with this pattern. There is a possibility of local extreme heating at the upper surface of engine when supply and exhaust ports of air are in bilateral symmetry. The effect of the increase of exhaust port area on ventilation decreases as the number of supply port increases.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.4
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• pp.552-558
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• 1999

Ventilation of the marine engine room is very important for the health of the workers as well as the normal operation of machines. To find proper ventilation conditions of this engine room numerical simulation with a standard k-$\varepsilon$model was carried out. In the present study the marine engine room is considered as a closed space with a heat source and forced ventilation ducts. The injection angle of air supply is found to be important. Injection with a downward angle depresses recirculation flow causing a strong stream in the wider space of the room Ventilation and removal of the released heat are promoted with this pattern, There is a possibility of local extreme heating at the upper surface of the engine when supply and exhaust ports of air are in bilateral symmetry.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2765-2770
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• 2008

The purpose of tunnel ventilation system for long road tunnels is to keep certain levels of Visibility Index and the concentration of CO. Additional equipments such as jet fans are used in road tunnel to discharge pollutants in the road tunnel. The control algorism of tunnel ventilation system takes the value of sensors as input, and then gives the operation method of jet fans in tunnel as output. Information on the variation of CO concentration in tunnel when jet fans are running is needed to minimize their operation time. Numerical analysis is used in this paper because of the difficulty of conducting experiments under standard condition for ventilation of road tunnel. The concentration of CO has been calculated by using 3-dimensional CFD under transient condition with speed of cars, quantity of air ventilation, and the results for various operation position of jet fans are compared.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.113-118
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• 2007

As the economic living standards are higher, the demands for more comfortable living space are also larger. In the response of this requirements, studies for improving indoor air environment have been conducted. In case of newly-built apartment buildings, the standard for the minimum ventilation to improve their indoor air quality was made. This study analysed the experimental results from the mock-up test of the hybrid ventilation system which is composed of natural and mechanical ventilation.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.243-250
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• 2019

In this study, to ensure the safety of the packaged hydrogen refueling system, the improvement plan was derived by using 3-dimensional CFD program (FLACS). We also confirmed the effectiveness of risk reduction and the suitability of safety standard. By ventilation performance evaluation according to the position of the vent, it demonstrated that the vent should be installed at the ceiling to safely ventilate without stagnation of the leaked gas. In case of ventilation system according to KGS standard, risk situation could be resolved after about 5 minutes in the worst leaked condition. The result showed that jet fire and explosion inside the packaged system could affect the surrounding facilities. This proves that the standard for installing flame detectors, emergency shut down system and protection wall is appropriate.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.268-271
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• 2006

The purpose of this study was to identify the influence of living factors on TVOC(Total Volatile Organic Compounds) concentrations for newly-built apartments. The field measurements of TVOC concentrations were made totally 30 times(5 times per one subject house) in six apartment units in which residents recently moved. Those apartments authorized its business approval before May 2004, the Act of Indoor Air auality Management for multi-use facilities. The findings were as follows: The TVOC concentrations of the measured subject apartments ranged from about 1/10 of the recommended standard for multi-use facilities($400{\mu}g/m^3$) to up to 90 times as high as the standard. Since then, the Recommended Standard of Indoor Air Quality Management for newly-built apartment house was announced in December 2005. In accordance with this standard($2390{\mu}g/m^3$) it ranged from about 1/100 to up to 15 times as high as the standard. The subject house whose TVOC concentrations reduced below the recommendation standard in the shortest period had the largest amount of ventilation (all the windows were open for ventilation in the past three months) among ail measured houses. The reason of another house whose TVOC concentrations were much higher than the rest was fronted with new furniture in the room. It's recommended that they should open all the windows for at least three months for ventilation in newly-built houses, and it would be better to avoid remodeling than needs be.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.129-137
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• 2006

The purpose of this study was to identify the influence of living factors on TVOC(Total Volatile Organic Compounds) concentrations and personal factors to reduce the Sick House Syndrome for newly-built apartments. The field measurements of TVOC concentrations were made totally 30 times(5 times per one subject house) in six apartment units in which residents recently moved. Those apartments authorized its business approval before May 2004, the Act of Indoor Air Quality Management for multi-use facilities. The Questionnaire surveys of residents' subjective responses on the Sick House Syndrome were carried out in 2nd measurement of each house. Respondents consisted of 20 residents living in the measured houses. The findings were as follows: The TVOC concentrations of the measured subject apartments ranged from about 1/10 of the recommended standard for multi-use facilities($400{\mu}g/m^3$) to up to 90 times as high as the standard. Since then, the Recommended Standard of Indoor Air Quality Management for newly-built apartment house was announced in December 2005. In accordance with this standard($2390{\mu}g/m^3$) it ranged from about 1/100 to up to 15 times as high as the standard. The subject house whose TVOC concentrations reduced below the recommendation standard in the shortest period had the largest amount of ventilation (all the windows were open for ventilation in the past three months) among all measured houses. The reason of another house whose TVOC concentrations were much higher than the rest was fronted with new furniture in the room. There turned out to be no apparent relations between the TVOC concentrations and the residents' individual responses of Sick House Syndrome. The responses were serious in those who stayed in their new houses for a long period or had disease like allergy. It's recommended that they should open all the windows for at least three months for ventilation in newly-built houses, and it would be better to avoid remodeling than needs be.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1350-1357
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• 2010

In tunnelling, temporary ventilation is very important factor in the safety of worker and the work efficiency which is affected by visibility. There are a lot of problems in the recent tunnel construction, because the longer the tunnel, the more the present design doesn't satisfy the allowable standard about dust and air pollution. Especially, In case the length of tunnel is more than 1,000m, the ventilation efficiency tends to decrease. In this study, the field measurement of the degree of contamination was performed near the face of tunnel. Based on the results obtained, the main factors of problem in temporary ventilation are the difference of temperature between outside and inside, the rate of leakage of ventilation duct and the dust and so on. It maybe helpful to the solution of problems, and also the accurate ventilation estimate.

• Journal of Mechanical Science and Technology
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• v.14 no.11
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• pp.1286-1295
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• 2000

The ventilation effectiveness is evaluated as a function of air exchange rate and supply / extract locations in a simplified model chamber using a tracer gas technique of CO$_2$ gas injected into a supply duct. Ventilation systems consist of supply and extract fans, a CO$_2$gas generator, a CO$_2$gas analyzer and a test chamber. The ventilation effectiveness is evaluated using a step-down method based on ASTM Standard E741-83. The room mean age of the model chamber is decreased with increasing air exchange rate fanged from 6to 10 air changes per hour. The ventilation effectiveness of the mechanical inlet/natural extract system is better than that of the mechanical extract system.