• 한국입자에어로졸학회지
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• 제9권2호
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• pp.59-67
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• 2013

One of purposes in this study was to confirm the behavior of coughed particles under different ventilation conditions. Three types of ventilation systems were applied for this experiment and the properties of coughed particles were measured using computational fluid dynamics (CFD) in an intensive care unit. The changes of total airborne particles for each case showed different trends according to the ventilation type and time, but the deposited particles were similar in all conditions. Although the time taken for 50% of the particles to be deposited was the fastest in case 2, the portion of deposited particles after 300 seconds was only 5% in all conditions. In case 1, a relatively small number of particles were deposited on the wall, but the particle exhaust and deposition on the occupants were the highest. In case 3, the downward ventilation was applied as that recommended by the US Center for Disease Control and Prevention (CDC) and showed different exhaust efficiencies according to the particle size.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.76-81
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• 2007

The shopping center in underground passage increased for efficient space utilization in urban area. This study describes operation characteristics of all air type and hybrid type with local ventilation and fan coil unit fixed to ceiling. In order to compare energy saving, thermal environment and installation space, etc., integrated simulator with heat production and indoor distribution system is designed and constructed. Energy saving of the hybrid system is calculated as over 30% compared to conventional all air type. And also the results showed that humidity decreased about 6%, also indoor thermal distribution is improved as temperature variation of around $1^{\circ}C$.

• 한국농공학회논문집
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• 제65권1호
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• pp.61-72
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• 2023

The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

• KIEAE Journal
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• 제4권3호
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• pp.103-107
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• 2004

This paper aims for evaluating the wind-driven ventilation in basement parking lots of apartment. Wind tunnel tests coupled with tracer gas method were conducted, and classified by wind directions and opening types. The test results showed that, as for wind-driven ventilations, stack type openings were more successful than scuttle vent. Finally, according to Weibull distribution in Seoul, yearly averaged wind-driven ventilation rate was calculated.

• 설비공학논문집
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• 제15권6호
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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.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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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.

• 토지주택연구
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• 제10권3호
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• pp.1-7
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• 2019

Indoor particulate matter(PM) is a carcinogen and needs to be removed and managed. It is generally reduced and removed through ventilation and filtration. Owing to the recent occurrence of high-concentration fine dust and yellow dust in the atmosphere, however, it is difficult to expect the purification of indoor air through the simple introduction of the outside air. For residential buildings, in particular, they are highly dependent on natural ventilation but the lack of natural ventilation is worsening because concerns over the inflow of external pollutants are increasing. Therefore, this study designed and manufactured a window ventilation system that does not require a duct to improve the maintenance and management problems of general ventilation system, and constructed indoor PM concentration change data through performance evaluation.

• 설비공학논문집
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• 제19권2호
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• pp.202-211
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• 2007

Ventilation system is being recommended as an effective tool to improve indoor air quality (IAQ) in apartment houses. Recently, in Korea, apartment house suppliers must establish ventilation system in apartment houses in law. In this study, improvement of IAQ by establishing mechanical ventilation system at apartment house was investigated by mockup test. Seven apartment houses were arranged for the test and improvement of IAQ was examined under the various conditions of ventilation rates, ventilator type and duct works. The results of this study show that IAQ in the test houses which were established mechanical ventilation system was improved about from 30% to 40% compared with IAQ in the apartment house which was not established ventilation system. However, there were no apparent concentration differences between the cases of changing ventilation rates, ventilator types and ductworks.

• 한국터널지하공간학회 논문집
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• 제18권3호
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• pp.291-303
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• 2016

최근 도시부 지하도로 건설에 따른 터널내 다양한 형태의 분기부가 설계되고 있으며, 이는 기존의 일자형 터널에서의 환기해석 방법과는 다른 해석방법을 요구하고 있다. 그러나 국내외 터널환기 해석방법중 네트워크형 터널에 대한 환기해석에 대한 방법은 설계기준으로 제시되지 않고 있으며, 주로 네트워크용 수치해석 프로그램에 의존하여 설계가 진행되고 있다. 본 연구에서는 수치해석적 방법이 아닌 특성화 방정식에 기초한 네트워크형 터널에 대한 환기해석 방법 중 설계기준으로 적합한 네트워크 모형을 고찰하였다. 기존의 Hardy-Cross 방법은 계산방법이 비교적 간단하고 수계산이 가능한 장점이 있어, 광산통기 및 터널환기 분야에서 폭넓게 적용되어 왔다. 그러나 Tayler 정리에 따른 절단오차 문제 및 대규모 네트워크 환경에서 mesh의 선택 알고리즘에 따른 수렴성 문제가 보고되고 있다. 따라서 본 연구에서는 비 hardy-cross 방법 중 mesh의 구성이 없이도 유량과 압력을 동시에 해석할 수 있는 gradient method로 네트워크형 터널에 대한 환기해석의 적용성을 고찰하였고, 더불어 네트워크형 터널에 대한 환기해석이 가능한 간편한 방법을 제시하는데 그 목적이 있다.

• 터널과지하공간
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• 제20권2호
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• pp.92-96
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• 2010

본 연구에서는 지하공간에서 화재 발생시 배연장비의 연기배출 성능을 평가하기 위하여 실험을 실시하였다. 배연장비로는 이동식 송풍기를 사용하였으며 가연물질로는 에탄올을 사용하였다. 한 변의 길이가 80cm의 정사각형 화원을 사용하였으며 최대 열방출률은 약 460 kW이다. 급기방식 배연의 영향을 평가하였다. 급기방식의 경우 실내의 가시도 향상 및 온도감소 효과를 확인할 수 있었다.