• Architectural research
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• 제19권4호
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• pp.101-108
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• 2017

The use of the air conditioner is increasing due to the rise of the outdoor temperature during summer, and the problems of the fire and the cooling performance deterioration are caused due to lack of maintenance of the outdoor unit. In particular, overall performance of cooling system and efficiency in outdoor units have been degraded due to an intake of high-temperature outdoor air thereby increasing cooling energy and operating cost. Thus, this study aimed to increase efficiency of outdoor units by evaporating and cooling intake air through mist spray at the intake port surface in the outdoor unit. The measurements results showed that total power consumption of misting outdoor unit compared to that of conventional outdoor units was reduced by 21% approximately, and total power consumption of the entire system including pump was reduced by 16.7%. In addition, the operating cost including water use was reduced by 13.5% approximately. In summary, if a mist-spray nozzle kit is installed in air-cooled outdoor units, the reduction in the usage of cooling energy and operating cost will be achieved without replacement of existing cooling systems or a large scale of repairs.

• 대한기계학회논문집B
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• 제29권7호
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• pp.868-877
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• 2005

We performed the experimental and the numerical study on the comparison of thermal comfort performance indices for cooling loads in the lecture room for 4 cases: Fan coil unit(FCU) or 4-way cassette air-conditioner is respectively operated with the ventilation system or without. We measured the velocity, the temperature distribution and predicted mean vote(PMV) value in the lecture room for 4 different air-conditioning methods. Effective draft temperature(EDT) and PMV were investigated to analyze the characteristics of two thermal comfort indices in the lecture room and to compare their values each other. From the results we knew that there is the similarity between PMV values and EDTs when the room is air-conditioned for cooling loads. It turned out that definition of the control temperature is very important when the EDT is calculated. Finally EDT should not be used to predict the accurate thermal comfort in case that the temperature and humidity are suddenly varied and the zone affected by the solar and inner wall radiation.

• 설비공학논문집
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• 제15권9호
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• pp.738-743
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• 2003

In the present study, the heating and cooling characteristics of system air-conditioner using a PWM compressor or a BLDC inverter compressor are investigated by the psychometric calorimeter using air enthalpy method. Cooling and heating capacities, power inputs and COPs are measured at the low, moderate, high loads under the cooling and heating standard conditions. At cooling conditions, the capacity of the PWM system is larger than that of the inverter case. Due to large power input, however, low COPs are measured under total load ranges. At heating conditions, the capacity of the PWM method is a little larger than that of the inverter case, except high load range. Since power input is low, large COPs are measured at moderate and high load ranges, which are different from cooling data. This shows that the PW system compared with the inverter case has good energy consumption efficiency at moderate and high load ranges except low load range. And when the system A/C is operated under the cooling and heating standard conditions, COPs are nearly uniform at total load ranges.

• 설비공학논문집
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• 제23권8호
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• pp.580-586
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• 2011

In this study, 3 cooling systems of apartment which are air-cooled air conditioner with indoor unit, water-cooled air conditioner with indoor unit and small capacity absorption chiller-heater with FCU have been evaluated by Multi-Criteria Decision Making Analysis. Weights of 7 selected factors which are economics, space, billing, constructability, human comfort, visibility and reliability are determined by expert group of 30 system designers and 30 construction engineers. Final weights were derived for 101 and 166 $m^2$ apartments. Analysis shows that small capacity absorption chiller-heater with FCU is the most favorable system for apartment cooling system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.334-339
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• 2007

This paper is concerned with economic analysis and comparison between hybrid and central air conditioning system by TRNSYS simulation and Life Cycle Cost(LCC) analysis. Hybrid air conditioning system that is using VAV for interior zone and system air-conditioner for perimeter zone is installed in building A. Central air conditioning system is composed of VAV and convector. The simulation was carried out in mode temperature level control using TRNSYS 16. From the result of simulation and LCC analysis, hybrid air conditioning system was better than central air conditioning system in initial cost and energy consumption.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권2호
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• pp.117-124
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• 2015

최근 생활수준의 향상으로 인해 가정용 에어컨의 보급률이 꾸준히 증가함에 따라 품질에 대한 소비자의 눈높이 또한 점점 높아지고 있다. 과거에 소비자의 요구는 제품의 효율성에 집중되었지만 점차 저진동/저소음에 대한 부분으로 확장되고 있다. 에어컨의 압축기는 제품의 효율을 결정하는 주요한 부분이면서 동시에 진동/소음의 주된 원인을 제공하고 있다. 압축기에서 발생한 진동/소음은 압축기 케이스와 배관을 통해 주위 구조물로 전달되고 이들은 다시 구조기인 소음이나 2 차적인 진동을 유발하게 된다. 본 연구에서는 RecurDyn 을 이용해 압축기의 진동/소음에 영향을 미치는 모터의 가진력이 고려된 MFBD(Multi Flexible Body Dynamics) 해석 모델을 개발하였다. 개발된 모델을 이용하여 압축기의 진동/소음 특성을 조사하고 압축기에서 발생하는 진동을 계산하여 실험 결과와 비교하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제30권2호
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• pp.267-274
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• 2006

There are no solar loads through windows and heat transfer from outer walls of the building to the interior This study analyzes indoor air temperature and air flow distribution for the interior of buildings or vessels occupying space. Numerical method is adopted to visualize the indoor side environmental situation. that is without heat transmission to outside the building in various cooling load conditions; supply ventilation lighting. occupancy and infiltration in conditioned spaces. Reaching time of an air conditioner is predicted theoretically by cooling load variations. Theoretical modelling of the reaching time shows good agreement with experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.88-89
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• 2010

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 하계학술발표대회
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• pp.166-166
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• 2005

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 하계학술발표 논문집
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• pp.9-9
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• 2004