• Title/Summary/Keyword: Indoor Air Temperature

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Performance Analysis on Combined Horizontal Ground Source Heat Pump with Earth tube using EnergyPlus (EnergyPlus를 이용한 수평형의 지열 히트펌프와 어스튜브를 조합한 시스템의 성능 검토)

  • Cho, Sung-Woo
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.13 no.2
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    • pp.22-29
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    • 2017
  • This study is performed to performance of the combined system the GSHP (Ground Source Heat Pump) system with the Earth tube system using EnergyPlus program. The Earth tube system using fan is characteristics as supply lower (higher) air temperature than outdoor air temperature in cooling and heating seasons, the GSHP system is characteristics as small indoor air temperature variation range. As the results of Earth tube + GSHP system simulation, GSHP power can be reduced than the GSHP single operation as 17.3% in cooling seasons and 32.5% in heating seasons, the GSHP design capacity can be replaced more small size.

Characteristics of Thermal Environments and Evaluation of Thermal Comfort by Human Reponse Experiment in Winter (동계체감실험에 의한 온열환경 특성 및 쾌적성 평가)

  • 고경태;정성일;박종일;김경훈
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.291-295
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    • 1998
  • The purpose of this Study was to determine thermal sensation and physiological responses for men in winter indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate Variability(HRV), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at 50% R.H., 24$^{\circ}C$, and the difference of skin temperature was found at the calf area as air temperature changes. At low air temperature and low humidity, heart rate was decreased, but there was no change at brain wave, keeping ${\alpha}$-wave.

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An Experimental Study on the Thermal Environmental Measurements and Subjective Reponses in Summer Season for the Korean Traditional Houses in Chonnam Province (전남지방 전통주택의 하절기 온습도 측정 및 주관평가에 관한 실험적 연구)

  • Kim Sun-Woo;Lee Tai-Kang;Kim Hyung-Ryul
    • Journal of the Korean housing association
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    • v.17 no.2
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    • pp.41-46
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    • 2006
  • This study aims to analyzed thermal comfort characteristics and subject response for thermal environment of Korean traditional houses.. The air temperature and humidity in the living area of the residence were measured in during a day. And the subject response were surveyed to evaluate of controling the thermal environment factor (temperature, humidity, comfort) of the korean traditional houses. As a result, the variation of air temperature and humidity of most rooms are considerably static while condition of outdoors are much varied, it is showed that indoor climate has been controled with traditional soiled walls. And environmental control for the air temperature and humidity is estimated considerably satisfactory.

Evaluation of the operating reliability on the concurrent heating-cooling system air conditioner for different refrigerant flow rates with high-head and long-line conditions (동시냉난방 시스템 에어컨의 냉매량 변화에 따른 고낙차 장배관 운전 신뢰성 평가)

  • Lee, Seung-Chan;Kim, Tae-An;Tae, Sang-Jin;Jung, Gyoo-Ha;Moon, Je-Myung;Kim, Youn-Jea
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.304-309
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    • 2008
  • The heating and cooling performances of system multi-air conditioner for various refrigerant flow rates with high-head and long-line conditions are experimentally investigated. The maximum head and tube length were 110 m and 1000 m, and the two different adjustments of refrigerant flow rates were +20 % and -20 %, respectively. The experimental system was composed of 4 outdoor units with module systems, and 13 indoor units which were joined with the mode change unit by single-tube circuit. Field tests without indoor and outdoor temperature control were performed in a general office building with two different refrigerant flow rates. Especially, the oil level in the compressor was normally maintained at the safety zone. Experimental results were prepared on the p-h diagram.

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Development and Evaluation of Ultraviolet C Sterilizer for Air Conditioning (공기 조화를 위한 자외선 C 살균기의 개발 및 평가)

  • Yun, Jung-Hyun;Sun, Ki-Ju;Cheon, Min-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.12
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    • pp.1018-1022
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    • 2011
  • Nowadays, with improvement of economical income and life qualities, life pattern changes have been brought such as increasing of avocational activities. Consequently, following those life trends, utilization of car is getting increased. Thus, the perceptions of car have been changed from the only means of transport in the past to a 2nd residental space. that is why the car's endo environmental factors are getting so important. Air conditioner regulating air ventilization in vehicle's indoor automatically sets the right temperature based on the differences of indoor and outdoor's temperature with development of advanced functions to provide better environmental qualities in vehicle. However, even those advanced techniques for functional development are got so diverse though, the essential technique for preventing the growth of bateria and mold inside of the air conditioner are not even severals. Especially, evaporator one of the vehicle air conditioning equipments generates cooled air by vaporizing refrigerant in liquid state with the water as the adduct for this reactions. It has structural difficulties for water vaporation then cause the growth of germs. That's why this reseach was focused on the way of eliminating germs in the vehicle air conditioner efficiently. Direct air sterilizer by using UVC(Ultraviolet C) is manufactured and that performances are evaluated.

A Study on Environmental Standards of School Building (교사환경기준에 관한 연구)

  • Hong, Seok-Pyo;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.1 no.1
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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A Prediction Model for TVOC and HCHO Emission of Paint Materials (페인트에서 방출되는 TVOC 및 HCHO 방출량 예측모델)

  • Kim, Hyung-Soo;Lee, Kyung-Hoi
    • KIEAE Journal
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    • v.3 no.1
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    • pp.13-20
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    • 2003
  • It is highly recognized that there is need for protection against indoor air pollution, as we realize environmental pollution is growing, For example, in an indoor environment, a person spends more than 80 percent of their time inside the building. Thus, concern about indoor decoration materials is growing, since they cause pollution in the rooms of an apartment, as well as in offices. As the indoor decoration materials become more diverse and lusurious, so the effect of VOCs(Volatile Organic Compounds) and HCHO(Formaldehy) is growing. The indoor decoration materials cause the Sick Building Syndrome, such as headaches, dizziness, or lack of concentraion, and they in turn cause serious deterioration in people's health. In this study, I probed the status of the indoor air pollution and carried on an investigation and analysis about the prevention technique. In doing so, I performed experimental tests and an assessment of the indoor decoration materials of an apartment. I also examined elements of the emitted and the emission. Finally, I examined the character of emissions, by changing environmental conditions, such as the temperature, humidity, and ventilation. With respect to VOCs tests, I applied the method of solid state adsorption using the adsorptive tube, based on the measurement of the American EPA TO-17, ASTM 5116-97, and the measurement of the Japanese Wall Decoration Industrial Association. The tested sample was analyzed by High Performance Liquid Chromatography, after going through the process of dissolvent extraction. As subjects of the test, Paint were selected. The process of this test is as follows; first, I figured out the character of the emission, by measuring the emitted concentration of VOCs and HOHC from the indoor decoration materials of an apartment. Second, I made a small-scale chamber and the test was processed in the chamber in order to suggest an environment-friendly prediction modlel development.

Correlation Analysis of Parameters affecting Pressure Distributions in Vertical Shafts by Design of Experiments (실험계획법에 의한 수직샤프트내 압력분포에 영향을 미치는 인자간 상관관계 분석)

  • Han, Hwa-Taik;Shin, Chul-Yong
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.883-888
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    • 2008
  • Various effluents generated in cooking processes contribute a great deal to indoor air pollution among many other indoor pollutants such as dusts from outdoor and carbon dioxide from human body. Kitchen exhaust hoods are not believed to exhaust indoor contaminants properly in many cases, while generating too much noise. Instead of focusing on individual products of kitchen hoods, we should address the problem by attacking the ventilation system as a whole including vertical shafts and building air-tightness. In this study, it is intended to investigate the pressure distribution along the vertical shaft depending on various system parameters, such as shaft size, concurrent hood usage rate, roof fan, inlet pressure loss, and outdoor temperature. The maximum static pressure in the vertical shaft has been obtained using the method of design of experiments and analyzed by the analysis of variance. The results can be used for the design of kitchen exhaust systems by analyzing the pressure distributions in vertical shafts.

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A study on an improvement of indoor cooling tower efficiency (지하역사 실내형 냉각탑 성능개선 연구)

  • Bae, Sung-Joon;Hwang, Sun-Ho;Shin, Chang-Hun;Pyo, Soo-Chul
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1726-1735
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    • 2008
  • Seoulmetro has operated the air cooling equipment for 57 stations to improve services focused on our customers who use Seoulmetro during the summer season and has established every year. However, a new set of problems has arisen with the cooling tower to support a heat exchange of cooling water. The most important matter is loss of efficiency in the cooling tower. The leading cause of this problem is that we use an indoor type. As the cooling tower room is located in the underground of the city because of the residents near the station. Therefore It is difficult to establish the cooling tower on the ground. But it is unsuitable for the location requirements of the underground type because it has a limited space to set up the air cooling equipment, for example, the cooling tower and a ventilating opening. As a result of such an unfavorable condition, the cooling tower doesn't work efficiently and the warmth of cooling water because of insufficiency of a heat exchange and a refrigerator's technical obstacle such as a high-temperature and a high-pressure has arisen. To prevent this situation, the operator tend to reduce refrigerant. Accordingly, the efficiency of the air conditioning is getting lower and lower. Study wishes to analyze the matter to improve indoor cooling tower efficiency and recommend a best practice for a person who manage the establishment.

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Estimation of Indoor Environment using CFD of Multi-Purpose System with a Solar Collector -Part 1, focused on floor area and number of ventilation- (태양열온수기 적용 냉난방시스템의 CFD를 이용한 실내환경 평가 -제1보 바닥면적과 환기횟수를 중심으로-)

  • Kim, Jong-Ryeol;Choi, Kyang-Hyan
    • Journal of the Korean Solar Energy Society
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    • v.27 no.3
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    • pp.55-61
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    • 2007
  • This paper has been conducted to estimate cooling capacity of the dehumidification tower using hot water from a solar water heating system as a energy source of regeneration process when the dehumidification and drying system is applied to room cooling. A solar water heating system was operated and indoor temperature distributions were simulated according to weather conditions when the concerned solution was used to dehumidify room air in the dehumidification tower. Through this simulation researches we found th following results ; It was found that air velocity through supply and return diffusers should be controlled because it can cause uncomfort in dwelling area. It was found that in the sunny morning temperatures of dwelling area 1 and 2 are higher than those of dwelling area 3 and 4. In this research all the calculation results of heating and cooling system supported by solar water heater have confirmed that its cooling capacity could not reach PMV 0, thermal comfort.