• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.1
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• pp.44-55
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• 1998

The evaluation of aluminum flat tube and louver fin heat exchangers for a condenser in residential air-conditioning applications has been conducted. A series of tests for two-different brazed aluminum heat exchangers was performed and the results were compared with conventional fin and tube heat exchangers for residential air-conditioning system. Refrigerant charge amount for a window-system air-conditioner with the brazed aluminum condenser is decreased by 35% and the volume and material of heat exchanger can be reduced by 50% compared to the conventional fin and tube heat exchangers.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.2 no.1
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• pp.57-60
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• 1973

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.3
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• pp.159-165
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• 2003

The fault detection and diagnosis technology may be applied in order to decrease the energy consumption and the maintenance cost of the air-conditioning system. To detect partial faults of the air-conditioning system, a neural network algorithm may be used. In this study, the neural network algorithm using normalized input data by the standard deviation was applied. And the [7$\times$10$\times$10$\times$1] neural network structure was selected. Test results showed that the neural network algorithm using normalized input data was very effective to detect the condenser fouling and the evaporator fan fault of an air-conditioning system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.3
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• pp.134-141
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• 2017

The purpose of this study was to analyze physiological changes via a cold air reaction experiment to generate basic data that are useful for the development of an automobile active air conditioning system to prevent drowsiness. The $CO_2$ concentration causing drowsiness in vehicle operation was kept below a certain level. Air was blown to the driver's face by using an indoor air cooling apparatus. Sleepiness and the arousal state of the driver in cold wind were measured by physiological signals. It was evident in the EEG that alpha waves decreased and beta waves increased, caused by cold air stimulation. The ${\alpha}/{\beta}$ ratio was reduced by about 52.9% and an alert state confirmed. In the electrocardiogram analysis, the efficiency of cold air stimulation was confirmed by the mean heart rate interval change. The R-R interval had a delay time of about one minute compared to the EEG response. The findings confirmed an arousal effect from sleepiness due to cold air stimulation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.1
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• pp.75-80
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• 2008

The objective of this research was to investigate the enhancement of heat transfer by mesh in water/air direct contact air conditioning system. Mesh is inserted as a turbulent promoter in front of the water injection nozzle. The heat transfer characteristics with and without mesh and the effect of the number of inserted mesh and mesh porosity size have been studied experimentally. Inserted mesh improves heat transfer efficiency compared to non~inserted mesh system and heat transfer efficiency increased as the number of mesh is increased. Meanwhile, heat transfer efficiency decreased as the porosity of the mesh is increased. With inserted mesh, inlet and outlet temperature difference of air increased more than 50%. Heat exchange time of water/air to reach the 100% humidity decreased less than 30%. This result shows inserted mesh can enhance the performance of the water/air direct contact air conditioning system.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.2 no.4
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• pp.265-270
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• 1973

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.73-79
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• 2015

In this study, a thermal storage performance and characteristics of daily operation were investigated when the air and the liquid were heated simultaneously by a hybrid solar air-water heater that can make hot water as well as heated air. The hybrid solar air-water heater is kind of a flat plate solar collector that can make hot water and heated air by installing air channel beneath absorber plate of traditional flat plate solar collector for hot water. As a result of daily operation, maximum water temperature reached in a thermal storage was shown $44^{\circ}C$ on 73kg/h of air mass flow rate and about $40^{\circ}C$ on 176kg/h of air mass flow rate. Thus, the necessity of heating water in thermal storage by operating only liquid side was confirmed when the temperature of liquid in thermal storage is lower than we need. In case of efficiency investigated on daily operation, the thermal efficiency of the liquid side was decreased with increment of the inlet liquid temperature and decrement of the solar radiation, but efficiency of the air side was increased with increment of inlet liquid temperature difference as the traditional solar air heater. Total thermal efficiency of the collector was shown from 65.85% to 78.23% and it was decreased with increment of the inlet liquid temperature and decrement of solar radiation same as the traditional system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.146-152
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• 2000

As an improvement in the standard of living and economic growth the demand for air conditioning equipment is increasing rapidly. Nowadays air conditioning equipments are being used for industry large building house and car. Thess equipments was concentrated on improving heat efficiency of economic aspects while they design heat exchanger for cooling and heating,. These air conditioning equipments using heat exchanger cause a discomfort to user due to generating mist at the beginning of operating. Therefore the user demand air of high class and quality. In this experimental study to acquire elementary data for development of heat exchanger which be able to supply air of high quality that is to say possess a restraint effect of mist generation. We estimate an effect on cooling plate kind supply air velocity supply air temperature cooled plate temperature and supply air relative humidity which have an influence on outlet air condition of heat exchanger.

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.106-106
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• 2006

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.2
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• pp.103-108
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• 2003

The common accumulator was designed for solving the maldistribution problem of oil at the air conditioning system with two compressors. The oil level inside two compressors was visualized by using a common accumulator on the various operating conditions. As a result of the visualization, oil distribution inside two compressors was achieved appropriately according to the capacity of each compressor. Uniform distribution of oil was also accomplished at on and off operation condition.