• 설비공학논문집
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• 제21권5호
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• pp.273-281
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• 2009

In recent semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems represents about 45% of the total air conditioning load required to maintain a clean room environment. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery from the exhaust air is therefore useful for reducing the outdoor air conditioning load for a clean room. In the present work, an energy-efficient outdoor air conditioning system was proposed to reduce the outdoor air conditioning load by utilizing an air washer to recover heat from the exhaust air. The proposed outdoor air conditioning system consisted mainly of a preheating coil, an air washer, two stage cooling coils, a reheating coil, a humidifier and two heat recovery cooling coils inserted into the air washer and connected to a wet scrubber. It was shown from the lab-scale experiment with outdoor air flow of $1,000\;m^3/h$ that the proposed system was more energy-efficient for the summer and winter operations than an outdoor air conditioning system with a simple air washer.

• 설비공학논문집
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• 제24권4호
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• pp.297-305
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• 2012

In recent large-scale semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems to heat, humidify, cool and dehumidify incoming outdoor air represents about 45% of the total air conditioning load required to maintain a clean room environment. Therefore, the energy performance evaluation and analysis of outdoor air conditioning systems is useful for reducing the outdoor air conditioning load for a clean room. In the present study, an experiment was conducted to compare the energy consumption of outdoor air conditioning systems with a simple air washer, an exhaust air heat recovery type air washer and a DCC return water heat recovery type air washer. It was shown from the present lab-scale experiment with an outdoor air flow of 1,000 $m^3/h$ that the exhaust air heat recovery type and DCC return water heat recovery type air washer outdoor air conditioning systems were more energy-efficient for the summer and winter operations than the simple air washer outdoor air conditioning system and furthermore, the DCC return water heat recovery type one was the most energy-efficient in the winter operation.

• 설비공학논문집
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• 제14권3호
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• pp.240-246
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• 2002

Bypass air conditioning systems are divided into three types; an outdoor air bypass, a mixed air bypass and a return air bypass system. What makes the return air by pass system more effective is that it directs all of moist outdoor air through the cooling coil. The bypass air conditioning system can maintain indoor R.H (Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. When a design sensible load (the ratio of sensible load to total sensible load) is 70 percent (at this time, RSHF (Room Sensible Heat Factor) . 0.7), indoor R.H was maintained 59 percent by the return air bypass system, but 65 percent by the conventional CAV air conditioning system (valve control system). The bypass air conditioning system can also improve IAQ (Indoor Air Quality) in many buildings where the number of air change is high.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.591-596
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• 2008

The present study has been conducted to study the performance of dedicated outdoor air handling unit in central and personal air-conditioning. With conventional central and personal air-conditioning systems which are designed according to the maximum load, humidity increase above comfort level can not be avoided as the cooling load decreases. The adoption of dedicated outdoor air handling unit, however, can solve this problem. Moreover, the dedicated outdoor air handling unit has the characteristics of anti-bacteria due to dry coil, energy saving and good indoor air quality. During cooling seasons, dedicated outdoor air handling unit can save energy up to 30% than the conventional cooling+reheating system for controlling both temperature and humidity.

• 설비공학논문집
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• 제29권2호
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• pp.43-50
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• 2017

The purpose of this study is to develop a control algorithm for outdoor air cooling based on the prediction of cooling load, and to evaluate the building energy saving using outdoor air cooling. Outdoor air conditions such as temperature, humidity, and solar insolation are predicted using forecasted information provided by the meteorological agency, and the building cooling load is predicted from the obtained outdoor air conditions and building characteristics. The air flow rate induced by outdoor air is determined by considering the predicted cooling loads. To evaluate the energy saving, the benchmark building is modeled and simulated using the TRNSYS program. Energy saving by outdoor air cooling using load prediction is found to be around 10% of the total cooling coil load in all locations of Korea. As the allowable minimum indoor temperature is decreased, the total energy saving is increased and approaches close to that of the conventional enthalpy control.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1306-1311
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• 2009

In recent semiconductor manufacturing clean rooms, in order to improve clean room air quality, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from the outdoor air introduced into clean room. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery is therefore useful for reducing the outdoor air conditioning load for a clean room. Therefore it is desirable to recover heat from the exhaust air and use it to reheat the outdoor air. In the present study, numerical analysis and experiment was conducted to simulate the amount of energy reduction of exhaust air heat recovery type air washer system. The present numerical results showed good agreement with the results of the experimental data.

• 설비공학논문집
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• 제25권2호
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• pp.55-63
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• 2013

For a large-scale semiconductor manufacturing clean room, the energy consumed in an outdoor air conditioning system to heat, humidify, cool and dehumidify incoming outdoor air is very large. In particular, the energy requirement to humidify outdoor air in the winter season is generally known to be high. Recently, in order to overcome the high energy consumption nature of a steam generator in a conventional steam humidification type outdoor air conditioning system, an air washer is often introduced instead of the steam generator in the outdoor air conditioning system, which can be called a water spray humidification type outdoor air conditioning system. Therefore, the assessment and comparison of the annual energy consumed in the steam humidification type and the water spray humidification type outdoor air conditioning systems deserves to be examined in order to reduce the outdoor air conditioning load of a clean room. In the present study, a numerical analysis was conducted to obtain the annual electric power consumption of the two outdoor air conditioning systems. It was shown from the comparison of the numerical results that the water spray humidification type outdoor air conditioning system can reduce about 30% of annual electric power consumption of the steam humidification type outdoor air conditioning system.

• 대한기계학회논문집B
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• 제35권12호
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• pp.1249-1255
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• 2011

최근의 반도체 제조용 대규모 클린룸에서는 도입 외기를 가열가습 및 냉각감습하는 외기공조시스템의 에너지소비량이 클린룸 환경을 유지하기 위해 필요한 전체 공조에너지의 약 45 %를 차지하고 있다. 특히 동기(겨울철)의 경우 외기를 가습하기 위한 에너지소비량은 매우 높다. 따라서 에너지절감을 통한 제조비용 절감 및 온실가스 감축을 위해 외기부하와 관계되는 공조에너지의 사용효율 증대 및 철저한 사용합리화가 요구되고 있다. 따라서 반도체 클린룸용 외기공조시스템의 핵심 가습방식인 증기가습과 수분무가습 방식에 대한 소비전력량을 분석하는 것은 에너지절약적 측면에서 상당히 가치가 있다고 판단된다. 본 연구에서는 전극봉식 가습기에 의한 증기가습방식 및 에어와셔에 의한 수분무가습방식 외기공조시스템들의 공조프로세스 및 소비전력량을 외기량 1000 $m^3$/h의 경우 기흥지역의 동기 및 하기의 피크부하에 대해 비교하는 실험을 수행하였다. 실험결과들로부터 에어와셔 수분무가습 외기공조시스템이 전극봉식 증기가습 외기공조시스템보다 연간 소비전력량이 적어서 에너지절약적임을 보여주었다.

• 대한설비공학회지:설비저널
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• 제1권1호
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• pp.3-11
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• 1972

The outdoor design conditions for the locality are the basic problem in the design of air conditioning system. The ideal solution to the basic problem is to design a building that has a capacity at maximum output just equal to the load which develops the most severe conditions for the locality occur, but in most cases, economics interferes the attainment of the ideal. Studies of weather records show that the most severe conditions do not repeat themselves every year. The weather conditions of principal cities such as Seoul, Inchon, Suwon, Taegu, Chonju, Ulsan, Kwangju, Pusan and Mokpo in Korea have been analyzed to determine the probability of occurrence of certain temperatures according to recent 10 years $(1960\∼1969)$ weather records. The outdoor conditions for winter air conditioning design are shown on Table 2. The outdoor conditions for summer air condioning design are shown on Table 7. Heating degree days are shown on Table 10 and 11.

• 설비공학논문집
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• 제24권11호
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• pp.759-766
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• 2012

To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.