• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.50-57
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• 2006

This study describes to analyze the cooling load characteristics for a room air conditioner as a function of supply ventilation air when an air conditioner is running An experimental apparatus consists of a test room, a room air conditioner, a humidifier, an electrical heater a supply fan and a controller The reaching time to the inside setting temperature of the room air conditioner with is evaluated theoretically and experimentally in a conditioned space cooling loads such as supply ventilation air, lighting, occupancy and infiltration. In the conditions of cooling loads for the supply ventilation air of 9.5 L/s(0.98 ACH). lights. one Person, and infiltration, the reaching time to the inside setting temperature ($27\;^{\circ}C$ dry-bulb) increases up to $35\%$ more than for no supply ventilation air condition. Theoretical modelling of the reaching time shows good agreement with experimental results.

• 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.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.301-305
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• 2006

An electrical bill is one of the various factors that influence on energy use of residents. This study focused on electrical bills and searched that whether electrical bills affect resident behavior of operating air conditioner and their controlled indoor climate. We surveyed two groups for field study ; the one is residents who live in a studio apartment in Seoul and they are charged for electric as energy consumption they used, and the other is residents who live in a university dormitory and they are not charged for their energy consumption. We measured how long they used the air conditioner for cooling, on/off temperature of air conditioner and room temperature for these two groups. Residents were interviewed about their cooling needs, decisions about when to turn on their air conditioner and so on. We found that dormitory group has much amount of time used the air conditioner than studio apartment group and there are differences of room temperature between two groups when they turn on or off air conditioner. The result shows that perception of money affects resident behavior of operating air conditioner and their acceptable thermal range.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.3
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• pp.160-166
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• 2001

A numerical analysis has been performed for natural convection in an air conditioner duct system. The governing equations were solved a finite volume method using a SIMPLE algorithm. In the calculation mode of duct, the room temperature was preserved at $25.0^{\circ}C$ and duct wall temperature had a temperature of 15, 20.0, 22.5, 23.75, 26.25, 27.5 30 and $35^{\circ}C$. The results of velocity vectors and contours have been represented for various parameters. Based on the numerical data, the relationships between temperature difference and flow rate into room was represented. In the case of $T_\gamma>T_\omega$, the equation for temperature difference and flow rate was $Q=0.0285\triangleT^0.4005$, and in the case of $T_\gamma>T_\omega$, the equation was $Q=0.0099\triangleT^0.4752$. The duct system has an important relation to room temperature and duct wall temperature.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.11
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• pp.1079-1087
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• 2005

In this paper, thermal comfort and ventilation performance characteristics in the lecture room with the ventilation system and two different air-conditioning systems, system air-conditioner or fan coil unit, were evaluated by experimental and numerical methods. We compared the measured data with the computational results of the predicted mean vote and carbon dioxide concentration. Additionally the ventilation effectiveness was calculated numerically. From a viewpoint of the uniformity of PMVs in the lecture room, the thermal distribution performance of the system air-conditioner was more effective than the fan coil unit. Carbon dioxide concentration and ventilation effectiveness were barely affected by the type of the air-conditioning system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.577-582
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• 2012

Recently, noise reduction of air-conditioner is one of the important design factors for high quality product. Especially, customer complaints arise due to noise problem of the outdoor unit. After the operation of air-conditioner start, noise level of outdoor unit is increased gradually and sometimes abnormal noise occurs until it reaches steady state condition. The aim of this paper is to investigate the relation between noise of outdoor unit and thermodynamic properties of cycle at transient condition of room air-conditioner. In order to find out the noise characteristics of outdoor unit, noise and vibration measurements are carried out. Also, the thermodynamic properties of compressor and heat exchanger are measured by using temperature and pressure sensors and experimental results are discussed. Finally, we find out the relation between noise and cycle properties at starting of room air-conditioner and the improvement method to reduce noise level is proposed.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.786-798
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• 2007

As we go about our daily lives, people often collect surrounding information and adapt to the situation. Computer development trends show that one wants computers to work like human beings, i.e. computers can sense its context and adapt corresponding to context changes. To implement this expectation, a context aware service layer is needed. In this layer, sensors capture its environment and send this information to the service center. Considering received information as its context, the service center seeks the suitable operation according to the context. Tills paper presents a context aware service which is applied in controlling air-conditioner. The air-conditioner includes sensors which are installed at some special positions in a room. Each of these sensors gathers comfort-influenced information like temperature, humidity and sends them to air-conditioner. The air-conditioner adapts its operation to the environment according to the sensed information. To control the air-conditioner effectively, we use a genetic algorithm which is suitable in adaptation issues. The simulation shows that the room condition can be maintained at a comfortable level by using context-aware services in the operation of the air-conditioning system.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.31-37
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• 2012

This paper describes to analyze the ventilation performance of a room air conditioner for indoor comfort control. An experimental apparatus consists of a test room, the room air conditioner, a tracer gas measurement system, a supply fan and a controller. Ventilation performance as a function of human occupancy is evaluated with supply ventilation air using a tracer gas technique of CO2 gas in the test room. The ventilation performance is evaluated in a step-down method based on ASTM Standard E741-83 and is found to increase with increasing supply ventilation rate. The CO2 gas concentration is decayed rapidly without human occupancy. The ventilation performance without human occupancy increases up to 55% and the ventilation performance with one person increases up to 25% at the supply air of 570 lpm comparing with a natural reduction after one hour. A modeling for ventilation performance of a room air conditioner in a test room is presented using experimental datum.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.3
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• pp.204-216
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• 1992

In most cases, EER(Energy Efficiency Ratio) is available to present energy efficiency of air-conditioners. But, EER is not adapt to measure energy efficiency at actual life environment because it is based on fixed temperature and humidity contditions. To overcome this disadvantage, there is need to introduce SEER(Seasonal Energy Efficiency Ratio) established at time varient temperature and humidity conditions. In this paper, SEER measurement method and conditions based on actual life environment of the country is introduced, and discussed SEER value about two air-conditioner type, that is, non inverter air-conditioner and inverter air-conditioner. As a result of, inverter air-conditioner was superior to non inverter air-conditioner at cooling seasonal energy efficiency.

• Journal of the Korean Home Economics Association
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• v.35 no.5
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• pp.239-248
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• 1997

to design nature-affinitive, reasonable and effcient thermal environment plannings and facilities, the holding patterns of heating-cooling facilities·accessory devices and residents' evaluation in Cheju Province were surveyed as well as residents' understanding for them. Major findings of this study are summarized as follows: 1) In the cooling system, the percentage of air-conditioner possessor was 19.4%, which was lower possessive rate than mainland's. The location of air-conditioner was mainly public area. That is, 55.3% of the location is livingroom, and the rest was Anbang. the general cooling accessory device was a fan. It was frequently used at the children's room and the dining room. The possessive patterns of air-conditioner depend on the characteristics of residents, such as the academic carrier and the average monthly income. Characteristics of house for air-conditioner possess depend on the location, house type, the size of floor space. 2) In the heating system, individual heating system reached to 57.3%. Heating accessory devices were oil stove and electric heating blanket. Only 32.2% of survey population were holders. 3) Residents preferred better ventilated room arrangement, which was characteristic of subtropical areas. 4) The preferred condition for heating-cooling facilities and accessory devices were strong solidity, less air pollution, and less noise.