• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.61-71
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• 2017

The tracer gas method has an advantage that can estimate total and local ventilation rate by tracing air flow. However, the field measurement using tracer gas has disadvantages such as danger, inefficiency, and high cost. Therefore, the aim of this study was to evaluate ventilation rate in pig house by using the thermal distribution data rather than tracer gas. Especially, LMA (Local Mean Age), which is an index based on the age of air theory, was used to evaluate the ventilation rate in pig house. Firstly, the field experiment was conducted to measure micro-climate inside pig house, such as the air temperature, $CO_2$ concentration and wind velocity. And then, LMA was calculated based on the decay of $CO_2$ concentration and air temperature, respectively. This study compared between LMA determined by $CO_2$ concentration and air temperature; the average error and root mean square error were 3.76 s and 5.34 s. From these results, it was determined that thermal distribution data could be used for estimation of LMA. Finally, CFD (Computational fluid dynamic) model was validated using LMA and wind velocity. The mesh size was designed to be 0.1 m based on the grid independence test, and the Standard $k-{\omega}$ model was eventually chosen as the proper turbulence model. The developed CFD model was highly appropriate for evaluating the ventilation rate in pig house.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.683-690
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• 2021

The ventilation system of the engine room of a ship is generally installed to supply the combustion air necessary for the internal combustion engine and to remove the heat source generated in the engine room, and it must satisfy the international standard (ISO 8861) for the design conditions and calculation standards for the ventilation of the ship engine room. The response delay of the ventilation system including the fire detector is affected by the airflow formed inside the area and the location of the fire detector. In this study, to improve the initial fire detection response speed of a fire detector installed on a fishing vessel and to maintain the sensitivity of the installed detector, the smoke behavior was simulated using the air flow field inside the engine room, the amount of combustion air in the internal combustion engine, and the internal pressure of the engine room as variables. Analysis of the simulation results showed that reducing the flow rate in the air flow field and increasing the vortex by reducing the internal pressure of the engine room and installing a smoke curtain would accelerate the rise of the ceiling of the smoke component and improve the smoke detector response speed and ventilation system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.1
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• pp.60-72
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• 2021

Objectives: This study was performed to investigate the level of participation in and satisfaction with training courses at job training institutions and to improve participation and satisfaction through changes in the training method for industrial ventilation subjects. Methods: The results were analyzed for the mean and standard deviation by t-test and ANOVA, (p=0.05). Participation rates were examined for three courses: specialization, job training, and supervisory. The participation inthe education was 428 people, and the result of satisfaction with the change of education method was 878 people. Satisfaction was investigated for the specialized curriculum and job training curriculum,but not the supervisor curriculum. The satisfaction results for six items(contents, quality, skill, level, degree of understanding, degree of practical) were analyzed according to the change in the training medium and the method among people in one occupational ventilation subject. Results: The participation rate was similar in the job training and specialized training courses, but the lowest rate was in supervisory courses(p=0.05). In general, there was the lowest participation on the first day of education, and the participation rate improved after the second day. Satisfaction with the course was high for the specialized education course with a number of practical education assignments(p=0.278). The satisfaction level for the teaching method in the industrial ventilation subjects was high in a mixed group which combined lecture and practice. The industrial ventilation course in the basic job training course showed a difference between lecture and mixed education(p=0.111), but there was no significant difference. However, the industrial ventilation course in the advance job training course showed a clear difference between lecture and the mixed education(p=0.036). Conclusions: Therefore, the first day of training should start in the afternoon so that more trainees can participate, and it is recommended to assign important subjects after two days. In addition, it is suggested that job competency-enhancing education utilize various educational methods and media.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.154-159
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• 2005

The markers for Environmental Tobacco Smoke(ETS) a.e necessary to obtain, to interpretate and to provide the data of quantitative exposure assessment. The purpose of this research is to evaluate Indoor environment using the concentration of ETS and the correlations between markers(RSP, nicotine, 3-EP) and environmental conditions(smoking density, ventilation rate). The mean ACH(air change per hour) in smoking rooms showed non-compliance with ASHRAE standard value. The concentrations of RSP, 3-EP, nicotine showed log-normal distributions, and became different statistically depending on smoking condition(p<0.01). The geometric mean concentration of RSP in smoking room was 441.7 ${\mu}g/m^3$ that is far exceeded environmental standard(150 ${\mu}g/m^3$). The correlation coefficients between RSP and SI, 3-EP and SI, and Nicotine and SI were 0.67, 0.84, 0.74 respectively. The correlation coefficient between nicotine and 3-EP, Nicotine and RSP, and RSP and 3-EP were 0.76, 0.78, 0.57 respectively.

• Journal of the Korean Society of Safety
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• v.13 no.2
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• pp.65-75
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• 1998

The cases of welders illness by welding fume generated during arc welding are recently reported, which makes the legal regulation in the welding work place. Also, this situation makes the employers and welders be concerned about the welding fume seriously. At this point of time it is necessary that a standard testing method is developed as a fundamental tool for the evaluation of Fume Generation Rate(FGR) required for making progress in the development of low fume electrodes and welding process technology and also constructing the ventilation system in welding area. However, the current standard(KS D 0062) is only applicable to the manual covered electrode arc welding. In this study the evaluation procedure for the FGR is established by developing the fume collection chamber which can be applicable to semiautomatic and automatic arc welding as well as manual arc welding. This evaluation system and procedure can be used as a tool not only to develop the low fume welding electrode and welding process technology but also to construct the equipment controlling the welding workshop atmosphere.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.302-309
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• 1999

This paper is intended to provide a method to design control software fur the TCMS, train control and monitoring system. The TCMS with this control software will be applied KOREA Standard EMU. The control software is designed by SCADE Case tool to concern safety and reliability. The function for the EMU is implemented in software easily programmed, using a functional block, graphic programming language. the control software has modular design and each module is tested with SCADE simulator. This time we focus a HVAC(heater, ventilation and air conditioner controller) control module, present a design method and a simulation method for that module.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.3
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• pp.397-412
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• 1996

This study aims to present the fundamental strategies to improve the Indoor Air Quality (IAQ) in apartment buildings. To investigate the concentration of indoor air pollutants such as radon, formaldehyde, and VOCs, both the document survey and the field measurement were conducted. In addition, to identify the source of the air pollutants, the laboratory experiment was carried out for various building materials. Finally, the minimum period to be reserved befor3e building occupation to ensure healthy IAQ, which largely depends on the ventilation rates, was simulated using a simple compuer program. The results of this study can be summarized as follows: 1. In case of newly-constructed apartment houses, concentrations of formaldehyde, VOCs and radon were found to exceed the standard. Meanwhile, at existing apartment houses, concentrations of VOCs, particularly toluene and xylene, highly exceeded the standasrd level. Concentrations of formaldehyde and radon, however, had been lowered according to the duration of occupation. 2. The laboratory experiment of concentration of pollutants per square meter of building material surface area showed that radon gas was much emitted from the gypsumboard; formaldehyde from flooring and wallpaper; and VOCs from paints and kitchen furnishings. The emission rates of formaldehyde and VOCs were proportional to air temperature. 3. According to the simulation of the minimum period to be reserved before occupation, newly-constructed airtight houses required about 190-200 days, and naturally ventialted houses with fully-open-windows required about 20-45days, in order to keep the level of radon gas lower than standard. Therefore, with the current practice, the date of occupation should be delayed for about 15 days.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.87-93
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• 2011

This study was carried out to determine more effective way in eave structure between lengthening roof just as standard plan and replacing 3 types of vertical rain roof facility by using computational fluid dynamics (CFD) simulation to reduce the heat stress of Hanwoo, increase the effect of dryness of room floor, rain proof and ventilation efficiency. The simulation which did with mean wind velocity (1.2 m/s) result showed that the case of lengthening of roof just as standard design was more effective than the cases of vertical establishment of rain proof facility.

• Clean Technology
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• v.13 no.4
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• pp.281-286
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• 2007

VOCs from the heat recovery ventilation system (total heat exchanger) are measured in this study. Two different types of element (L and M type) from heat recovery ventilating system are tested to study the intial release characteristics of VOCs under KS cooling and heating standard conditions. VOCs are measured for the various flow rates and different operating times. Considering errors in the test method and the measuring instrument, the tested heat recovery ventilating systems was found to release 6 major VOCs, such as acetic acid, 2-butanone (MEK), 2-(methylthio )ethylamine, toluene, styrene, and x-acids (Ion 57). The concentrations of released VOCs are not quite much affected by operating conditions. The results show much larger VOCs concentrations in the cooling mode than in the heating mode, due to the high operating temperatures.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.1
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• pp.1-12
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• 2020

The main purpose of the research is to prevent residents who are using underground parking lot from being exposed to pollusion, and to allow them to enjoy clean indoor environment. The study subject for the research are underground parking lots in 20 different apartments, 4 of them were constructed before 2000, 10 were constructed from 2000-2010, and the rest were constructed after 2010. By analyzing the air quality in these underground parking lots, we found out that O3, NO2, CO, PM10, Radon in all parking lots were not excessive compared to the standard limit. TVOC rate was measured with the value in between 312 ~ 2,137㎍/m3, with CO2 value in between 193~1,824 ppm, and HCHO with the value in between 0.01~1.52ppm. The lightning system in underground parking lots in apartments constructed before 2000 were using manual light control system, while automatic light control system was used in all apartments constructed after 2000, and the brightness of parking lots in apartments constructed before 2000 was quite low. The apartments constructed after 2000 are performing cleaning and ventilation due to management agreement, while the apartments constructed before 2000 are not performing regular cleaning and there was no mechanical ventilation system installed. The difference of indoor air quality was significant seasonally, daily, and yearly (year of construction), while illuminance was significantly different yearly.