• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.328-333
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• 2007

The purpose of this study is modelling of system air-conditioner for TRNSYS. System air-conditioner is operated by a variable capacity compressor and accommodated by multiple evaporators. By reason of these feature, realizing performance of system air-conditioner for TRNSYS was incomplete. In this study performance data of system air-conditioner and control logics are used to make system air-conditioner module for TRNSYS. Performance data contains total capacity, power input and capacity index of system air-conditioner. The simulation was carried out in a mode of temperature level control using TRNSYS 16. The simulation shows that the system air-conditioner model operate variable capacity and can compute capacity index and power input of system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.862-865
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• 2004

The system air conditioner has an outdoor unit and a number of indoor units, which connected by several long pipes. In comparison with building HAVC system, the system air conditioner doesn't need lots of facilities, such as control of room, cooling tower, etc. At the beginning stage for the market of the system air conditioner, its main application was a school which size is small to use the building HAVC and large to use home air conditioning system, such as PAC (package air conditioner), RAC (room air conditioner). Therefore, because of the advantages of the system air conditioner mentioned above, the market is expanded rapidly. Since it is difficult to evaluate the noise caused by the system air conditioner because it has to be implemented before the finish of construction, the prediction or estimation of the noise by using CAE technology should be very important. In this research, using a commercial code, RAYNOISE, the noise is estimated to improve the design of building.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.10-15
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• 2016

This paper is to analyze and study the failure examples of refrigerant gas in automotive air conditioner. The first example, the air conditioner compressor continually operated that the refrigerant was leaked in air conditioner system. By lubrication shortage, the piston was partially sticked on cylinder of air conditioner compressor inner part. This was caused the phenomenon of engine operation trouble by load increasing with engine rpm variation during engine running. The second example, it sought the fact that the air conditioner refrigerant gas was leaked from air conditioner compressor to condenser high pressure pipe toward rear air conditioner checking with the lines of air conditioner. The third example, the refrigerant gas of air conditioner found that was leaked imperceptible from condenser inner by crack that was generated on the fins of air conditioner condenser. Therefore, the air conditioner system that maintain the air conditioner by decreasing the in-car temperature must meticulously manage to not leak the air conditioner refrigerant gas.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.427-432
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• 2005

This study developed a program for detecting charged refrigerant amount in system air-conditioner. System air-conditioner is an air-conditioning system with multiple indoor units. Due to the complexity of the system, it is more difficult to detect the refrigerant amount charged in system air-conditioner than in a general single air-conditioner. Experiments were performed for 6 HP outdoor units with 3 indoor units in a psychrometric calorimeter. The experimental amount of charged refrigerant were ranged from 60% to 140% with 10% increasement. Fuzzy algorithm were emploeed for detecting the charged refrigerant amount in a system air-conditioner. The experimental data were used for curve fitting for general ranges for indoor and outdoor temperature conditions. membership function were determined for whole ranges of experimentally measured data and rulebase were defined for each amount of refrigerant charge. Developed program successfully predicted the measured data within 10% resolution range.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.176-179
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• 2005

A case-study in classroom acoustics was conducted and the effects of two types(system air conditioner and packaged air conditioner) of air conditioner were investigated. Acoustical measurements were made in two different classrooms. Each classroom has different acoustics showing sound quality of air conditioner. Mental concentration test was conducted to evaluate the effects of air conditioner noise with different sound presure level(dBA). Speech intelligibility test was also planed with adopting Korean phonetic balanced words.

• Journal of Power System Engineering
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• v.12 no.4
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• pp.32-38
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• 2008

The improvement of cooling ability for the air conditioner is the most efficient method of application of its system. Therefore, this study has been investigated the improvement of cooling ability for the air conditioner using automotive by attached of a thermoelectric module. According to the result of test, capacity of the thermoelectric module make temperature range from $-75^{\circ}C$ to $+300^{\circ}C$ possible to cooling and exothermic. In addtion to, the reduction effect of energy revealed and the effect of liquid hammer remained with safety by attached the thermoelectric module. It was found that the air conditioner system by attached thermoelectric module have better cooling ability than the air conditioner system of existing vehicle.

• Journal of Power System Engineering
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• v.6 no.4
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• pp.16-22
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• 2002

This study was conducted to find performance evaluation method for automobile air conditioner. Experimental facilities were constructed to simulate wide range of operating condition for the automobile air conditioner. Compressor speed was controled by variable speed electric motor and the power was measured through torque transducer and tachometer was used to measure compressor speed. Parametric studies were conducted in this study, to figure out effect of environment variables on the performance of the automobile air conditioner. The environmental variables are inlet air temperature, relative humidity and air flow rate for the evaporator and inlet air temperature and air flow rate for the condenser. Compressor speed is also changed. The results of this study shows that air flow rate of the evaporator is more sensitive to the performance of the automobile air conditioner than the other variables. However relative humidity of the inlet air of the evaporator strongly affects capacity rather that COP.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.4
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• pp.315-322
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• 2012

In these days, importance of HVAC system in office building is steadily growing in terms of thermal comfort and energy savings. As a energy efficient heating and cooling system, system air-conditioner which can be controlled distinctly and has a high COP is more widely adopted nowadays. However, the features and advantages of system air-conditioner were not reported well because system air-conditioner did not describe yet by conventional simulation methods such as TRNSYS, e-Quest, Energyplus, etc. In this study, by using the TRNSYS program which is able to show module implementation and building energy consumption analysis, system air-conditioner module will be proposed and validated through comparison between the simulation results and measurement results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.172-179
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• 2006

This study developed a program for detecting charged refrigerant amount in system air-conditioner. System air-conditioner is an air-conditioning system with multiple indoor units. Due to the complexity of the system, it is more difficult to detect the refrigerant amount charged in the system air-conditioner than in a general single air-conditioner. Experiments were performed for a 6 HP outdoor unit with 3 indoor units in a psychrometric calorimeter. The experimental amount of the charged refrigerant was ranged from $60\%\;to\;140\%\;with\;10\%$ increasement. Fuzzy algorithm was employed for detecting the charged refrigerant amount in the system air-conditioner. The experimental data were used for curve-fitting for the general ranges of indoor and outdoor temperature conditions. Membership function was determined for the whole ranges of experimentally measured data and rule-bases were defined for each charged refrigerant amount. Developed program successfully predicted the measured data within $10\%$ resolution range.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.298-303
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• 2008

PMV, $CO_2$ and the energy consumption performance were numerically investigated in a large space with air-conditioning systems of four type. The numerical results showed that thermal comforts in the occupied zone are nearly similar in three systems except 3-way wall type system air-conditioner with ventilation system installed 2.2m height from the bottom. In case of 3-way wall type system air-conditioner the energy consumption for cooling loads was reduced about 25.5% compared to other air-conditioning systems. From the viewpoint of IAQ, it was turned out that system air-conditioner with ventilation system became worse about 20% compared to central air-conditioning systems for cooling load. The PMV, $CO_2$ concentration and energy consumption of all systems for heating loads were similar in a large space considered.