• 한국환경농학회지
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• 제27권2호
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• pp.150-155
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• 2008

본 연구는 입기구가 11개이고 배기구가 9개인 무창이유자돈사에 대하여 CFD 시뮬레이션을 실시함으로써 겨울철 최적 환기를 위한 입 배기구의 위치와 개수 및 최적 공기 유입속도를 구명하고자 수행되었다. 배기팬에 가까운 돈방의 경우에는 나머지 돈방에 비해 상대적으로 음압이 크기 때문에 환기가 많이 되는 것으로 나타났고, 나머지 돈방의 경우에는 음압이 작아 환기가 적게 되는 것으로 나타났다. 이런 이유로 동일 면적의 입기구를 설치함에 있어서 같은 간격으로 배치하면 환기가 불균일하게 이루어지기 때문에, 배기팬에 가깝게 위치한 돈방에서는 입 배기구를 나머지 돈방에 비해 적게 만들어 주거나 간격을 넓게 만들어 줌으로써 균일한 환기를 할 수 있는 것으로 분석되었다. 특히 입기구가 11개이고 배기구가 9개인 무창돈사의 경우에는 동일 선상에 있는 입기구 4개를 폐쇄하며 배기구 1개는 완전 폐쇄하고 2개는 2/3를 폐쇄하였을 때 환기가 균일하게 되는 것으로 나타났다. 또한 실험돈사와 같이 돈사의 폭이 3 m 정도일 경우에는 입기구의 입공기 속도가 0.5 $m\;sec^{-1}$ 정도로 유지될 때 틈바닥 위 0.1 m 높이 위치의 풍속이 적정수준으로 유지되는 것으로 나타났다.

• 한국농공학회논문집
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• 제59권6호
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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.

• 한국농공학회논문집
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• 제57권5호
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• pp.51-60
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• 2015

In Korea, 69.4 % of duck farms had utilized conventional plastic greenhouses. In this facilities, there are difficulties in controlling indoor environments for raising duck. High rearing density in duct farms also made the environmental control difficult resulting in getting more stressed making their immune system weaker. Therefore, a facility is needed to having structurally enough solidity and high efficiency on the environmental control. So, new design plans of duck house have recently been conducted by National Institute of Animal Science in Korea. As a study in advance to establish standard, computational fluid dynamics (CFD) was used to estimate the aerodynamic problems according to the designs by means of overall and regional ventilation efficiencies quantitatively and qualitatively. Tracer gas decay (TGD) method was used to calculate ventilation rate according to the structural characteristics of duck houses including installation of indoor circulation fan. The results showed that natural ventilation rate was averagely 164 % higher than typically designed ventilation rate, 1 AER ($min^{-1}$). Meanwhile, mechanically ventilated duck houses made 81.2 % of summer ventilation rate requirement. Therefore, it is urgent to develop a new duck house considering more structural safety as well as higher efficiency of environmental control.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.702-707
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• 2008

Improving quality of life and wellbeing of the residential environment and increased interests and importance is growing confidentiality, insulation, high-rise due to a lack of ventilation and indoor air pollution. Several human diseases caused tremendously due to the indoor air which consists of formaldehyde, radon, pollutants such as volatile substances that is called the phenomenon of a new house syndrome. It has become a world-wide issue that the United States, Japan and several other countries of Europe are showing more interests. Furthermore, a lot of damages caused by the syndrome occurs in the new house should be resolved by somehow is urgent. Thus, this study would like to propose the measures based on the whether condition and the way of heating in korea against a new house syndrome via analysis of indoor contaminant Reduction comparison according to vary ventilation and humidity when operating bake-out on a new apartment.

• KIEAE Journal
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• 제5권3호
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• pp.11-16
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• 2005

The recent trends of high-density and high-rise in apartment housing have caused the problems of decrease in ventilation rates and increase of indoor pollutant contaminants. SHS(Sick House Syndrome) has now become a major issue and threats the health of residents. To solve these indoor air problems, increase in ventilation rate is considered as one of the most efficient approach. Thus, the recent housing development is pursuing improvement in the site design and the layout of apartment building blocks to promote natural ventilation is now investigated as one of the fundamental solutions. This study was focused on the air flow characteristics of outdoor environment in an apartment complex to keep the pollutants out of the site. Age of air and pressure difference have been used as indices of the outdoor air quality. Four different types of apartment building layouts have been analyzed by CFD simulation. This study again selected a real apartment housing complex as a case study model. By analyzing the pressure differences between the front and rear of an apartment building block, the ventilation performance in each individual unit was evaluated, and its impact on ventilation performance is investigated by analyzing the stagnant air around the apartment building blocks. During this process, existing patterns of apartment housing layout have been evaluated, and the most appropriate site layout has been chosen to analyze the outdoor airflow patterns. Based on the analysis of airflow patterns of site layout, the possibilities of improving ventilation performance of an individual apartment housing is proposed.

• 한국주거학회논문집
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• 제24권6호
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• pp.133-140
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• 2013

This study is to clarify the form of window and door of medieval times house which are no longer in existence, by comparative analysis between literature materials and architectural remains of united Silla and Goryo period. Particularly the window and door form change process of was analyzed, in connection with the change of term which are recorded in literature material. The form and the composition of window and door are the elements which determine the elevation design of architecture and concerned with interior environment. Therefore this study is significant in the sense that it could be used as base data for the study on the reconstruction and interior space of medieval times house. There were ho (戶) and moon (門) as door, and chang (窓) for lighting and ventilation as window. Among these, the window can be divided into fixed and openable. There were two kind of fixed window. One is called chang (窓), and it was covered by silk or paper for lighting. The other is called ham (檻), it was the form of vertical bar window and lighting and ventilation was available. And there were two kind of openable window. One is called ho (戶), which had wooden plate window leaves. And the other is called changho (窓戶), lighting was available in the condition of closing.

• 한국축산시설환경학회지
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• 제6권1호
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• pp.1-14
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• 2000

The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty nine selected farms in four provinces, Jeonbuk-do, Jeonnam-do, Gyeongbuk-do, and Gyeongnam-do, in the southern provinces, Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼98% of growing-finishing pig houses adopted the sidewall curtain systems. The sidewall curtain systems, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, 23∼35% of growing-finishing houses installed scraper systems with concrete-slat floors in Gyeongsang provinces while 52∼78% did in Jeolla provinces. The cause of a large variance in flooring between tow regions could not be academically pinpointed, rather it could be attributed to the advice of neighbors who leads local pig production circle. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to multisite operation from continuous operation was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussion section.

• 한국축산시설환경학회지
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• 제5권1호
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• pp.1-15
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• 1999

The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty six selected farms in four provinces, Gyonggi-do, Gangwon-do, Choongnam, and Chonbook, in Central Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼99% of growing-finishing curtain installation rate was lower by 10∼20%. The sidewall curtain system, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, there was quite a lot variability among provinces, with 30∼80% of the houses installing scraper systems with concrete-slat floors in comparison with 30∼60% using a slurry system. Gangwon-do and Choongbook Chungwoo-goon are the predominant regions that installed a scraper system. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to three site production from a lumped system was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussing section.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.434-442
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• 2010

This study was carried out to determine necessary conditions for optimal ventilation of small windowless piglet house (4.0 (W) $\times$ 11.0 (L) $\times$ 2.6(H) m) with corridor and attic for preheating using CFD (Computational Fluid Dynamics) simulation. The experimental weaning piglet house was consisted of a corridor, an attic, 4 rooms (3.0 (W) $\times$ 2.75(L) m), 3 fences (0.7(H) m), 5 air inlets and 2 exhaust fans (0.4 (D) m) and simulated using CFD code, FLUENT. The simulation results for the experimental weaning piglet house showed that each room was uniformly ventilated under all the experimental conditions and air velocities at 0.1 m above floor are less than 0.15 m/s for 0.75 m/s and 1.0 m/s of air inlet velocity but 0.61 m/s for 1.25 m/s. The simulation results are similar to the measured results. Considering the air flow pattern, ventilating efficiency, air velocity at 0.1 m above floor and cold stress of weaning piglets and so on, the optimum velocity of air inlet might be 1.0 m/s.

• 국제초고층학회논문집
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• 제10권1호
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• pp.73-83
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• 2021

The door open time, resulting from occupants evacuating from apartments, is an important parameter when assessing the performance of smoke ventilation systems in high-rise apartment buildings. However, the values recommended in UK design guidance appear to have limited substantiation. Monte Carlo simulations have been carried out considering variabilities in door swing time, flow rate and number of occupants. It has been found that the door open time can be represented by a lognormal distribution with a mean of 6.6, 8.7 and 11.1 s and a standard deviation of 1.7, 3.2 and 4.7 s for one, two and three-bedroom apartments, respectively. For deterministic analyses, it is proposed that the 95th percentile values may be adopted in line with recommended practice for other fire safety design parameters such as fuel load density and soot yield, giving door open times of 10 s to 19 s, depending on the number of bedrooms.