• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.3
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• pp.193-200
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• 2009

The ventilation system of apartments can be divided by supply and exhaust fan, supply fan and exhaust free and supply free and exhaust fan. Recently, the individual ventilation system and central ventilation system which is combined cooling system with duct system are applied to apartment ventilation system. The airflow pattern is affected by location of supply unit and exhaust unit in indoor. This study is to investigate the proper distance between supply unit and exhaust unit using CFD. As a result of this study, the proper distance between supply unit and exhaust unit could be suggested at the interval of 3 m in supply and exhaust fan system and 2.5 m in supply fan and exhaust free.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.45-53
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• 2004

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample houses. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained the brief results as follows. Indoor air temperature at the top floor unit is $1.2\sim2.2^{\circ}C$ higher than that of middle floor unit. The evaluation of the indoor thermal comfort index at each sample rooms reveals notable thermal differences between the two units. Top floor units need more cooling load during the summertime compared to middle floor units. Therefore, solutions to reduce solar Heat gain at top floor units to be considered.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.5
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• pp.314-320
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the improved wall insulation. Hence, a multi~heat pump is required to cover heating and cooling simultaneously for each indoor unit. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the cooling-main operating mode were investigated experimentally. The system adopted a variable speed compressor using R410A with four indoor units and one outdoor unit. In the cooling-main mode, the heating capacity decreased due to reduction of flow rate to the indoor unit under heating mode operation. The EEV opening was adjusted to increase flow rate to the indoor unit under heating mode operation. The total capacity and COP in the cooling-main mode increased by 20.5% and 29.2%, respectively, compared with those in the cooling-only mode.

• Journal of the Korea Furniture Society
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• v.24 no.1
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• pp.33-41
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• 2013

As professional postnatal care systems have been rapidly supplied, there is sharp increase of postnatal care centers without legal regulations for a mother and a infant. For the quick recovery of mothers, newborn infants that have weaker immune systems are being managed in group in the postnatal care centers. Recently, the attention of the postnatal care centers has been growing because the problem of pneumonia which led to result in a casuality in a infant unit was happen. So, this research analyzed the indoor environment of infant unit through measuring formaldehyde, carbon dioxide, intensity of illumination. As a result of the data, infant units showed higher concentration of formaldehyde and carbon dioxide than Indoor Air Quality Control Law. Moreover, infant units was measured higher intensity of illumination than the range of optimum illumination for infants.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1055-1060
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• 2006

The Korean Green Building Certification System was activated from 2005. The purpose of it is to improve the quality of residential unit. Recently, people stay inside of building more than for 90% of a day Accordingly, it is really important for them to make the quality of Indoor Environmental better, in brief, to develop the indoor environmental factor in KGBC is important. One of the best way to develop the system is to do research based on POE because the area of problem can be realized. Accordingly, we get the information about POE from another research for the part of the indoor environment for residential unit to have the critical mind about the KGBC, and tried to compare the factors to another which is from foreign Green Building Certification System such as LEED, BREEAM, GBTool, After they have been analyzed, we could find that some of factor need to be revised and added. Also, there was one problem that many part of factor was created without any consideration of direction of each space in residential unit.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.115-121
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• 2008

In winter season, the survey was performed in three commercial office buildings in the metropolitan Seoul, Pusan, and Gwangju city. The purpose of the survey was to evaluate the effectiveness of ventilation for offices in commercial buildings. The data were compared to standard of applicable to the indoor ventilation in office. The results indicated that the most commercial office buildings used the air handing unit and fan coil unit as HVAC system, and the intake amount of fresh outdoor air were very inadequate to compared to the ASHRAE standard value of $0.57\;m^3/min/person$. Also the surveyed all commercial office building used the HVAC system as a meas of controlling temperature for office indoor air. Ultimately, these results presented that there were possibility of evoking indoor air quality problems by the insufficient ventilation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.447-452
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• 2009

The objectives of this paper are to study the effects of thermal and geometric conditions on the performance of indoor heat exchanger with R410A. This study carried out experimental and numerical analysis for indoor heat exchangers. In the experimental study, capacity of the indoor unit was estimated 8.3 kWh with the valve opening rate of 95% for the 50% partial operation condition. The air temperatures were measured using 80 thermocouples. This study also compared experimental data with the calculated data for the outlet temperature and the tube length. It is found that the relative errors between the experiment data and the calculated result are 4.2% and 0.5% for the outlet temperature and the tube length, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1487-1493
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• 2008

In order to investigate the cooling capacity of multi-heat pump applying an inverter compressor, the experiment on the cooling performance characteristics of heat pump with 3 indoor units was performed under the cooling standard and cooling low-temperature conditions. The system data were measured by the psychrometric calorimeter. The operation characteristics and the behavior of the cooling cycle of the heat pump with 3 indoor units were understood from the cooling capacity, COP, and P-h diagram by indoor-unit combination. The operating load and performance of the multi-heat pump depends on the indoor-unit combination. The cooling capacity and COP of the low temperature condition were larger than those of the standard one. Also the cycle was analyzed by using P-h diagram.

• Korean Institute of Interior Design Journal
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• v.14 no.3 s.50
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• pp.191-198
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• 2005

The present study is a preliminary research improving the dwelling quality of one-room type multi-family housings around the university campus. The purpose of the study is to investigate the present condition of Indoor noise level using · residents' responses and field measurements. The respondents are 104 residents living in one-room type multi-family housings. The field measurements on equivalent noise level of indoor and outdoor were carried out in 6 subject house units during the $26th\~28th$ of November 2002. The results are as follows. 1) The residents show relatively non-positive responses at evening and night on the present condition of indoor noise. 2) They answer 'living equipment foise' and 'water hammer' as major types of indoor noise of house unit. 3) Outdoor noise levels, basic factor of noise environment in 6 subject buildings were distributed $52.8\~65.3dB(A)Leq_{5min}$ and were inappropriate to the standard for environmental noise, $55 dB(A)Leq_{5min}$. 4) Indoor noise levels of subject house units were measured as $27.5\~63.5dB(A)Leq_{5min}$, the average of each house unit except one house unit was higher than the level feeling as noise, 40dB(A). 5) It was found that the differences of indoor noise levels between subject house units were caused by 'residents' living noise', 'living equipment noise', 'water hammer', and 'walking and talking noise in stairs and corridors'. 6) Therefore, it is required to plan for improving the quality of noise environment in one-room type multi-family housing around the campus. For example, soundproof construction (including double window with pair glass and balcony), outdoor garden with trees and water for increasing natural sound, interior materials with sound absorbing power to absorb living noise, soundproof pipe or double surface pipe for decreasing 'water hammer', and noiseproof floors, etc. are required.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.3
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• pp.173-182
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• 2015

A real-time, Indoor navigation systems utilize ultra-wide band (UWB), radio-frequency identification (RFID) and received signal strength (RSS) techniques that encompass WiFi, FM, mobile communications, and other similar technologies. These systems typically require surplus infrastructure for their implementation, which results in significantly increased costs and complexity. Therefore, as a solution to reduce the level of cost and complexity, an inertial measurement unit (IMU) and quick response (QR) codes are utilized in this paper to facilitate navigation with the assistance of a smartphone. The QR code helps to compensate for errors caused by the pedestrian dead reckoning (PDR) algorithm, thereby providing more accurate localization. The proposed algorithm having IMU in conjunction with QR code shows an accuracy of 0.64 m which is higher than existing indoor navigation techniques.