• Title/Summary/Keyword: thermal humidity

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A study on characteristics of thermal comfort for artificial environmental experiment in winter (동계 인공환경실험에 의한 온열쾌적특성 연구)

  • 박종일;김경훈;정성일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.721-731
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    • 1998
  • Recently, many researchers are studying the relation between thermal environment and human comfort. The purpose of this study was to obtain basic data which are necessary to determine the thermal comfort sensation and physiological responses for men in winter indoor environment. From January to February 1998, subject experiment was 40 times proceeded under twenty different conditions of air temperature and relative humidity with early-twenty male university students. We examined subjective evaluation, Electrocardiogram(ECG), Electroencephalogram(EEG) of subjects. The results of this study can be summarized as follows : The comfort zone of people in winter was achieved at Standard new effective temperature($SET^*$) $ 25.2^{\circ}C$, PMV range was obtained by Fanger's statistical calculation was -0.27<PMV<+0.62, TSV range obtained subjects vote was -0.76<TSV<+0.36. The largest difference of skin temperature was found at the calf area as air temperature changes. vote rate of human body presented calflongrightarrowheadlongrightarrowforearmlongrightarrowchestlongrightarrowabdo men in turn. Heart rate was decreased at low $SET^*$ and heart rate was increased at high $SET^*$ But there was no change at EEG.

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A Study on the Thermal Properties of Skirts (스커트의 열특성에 관한 연구)

  • Choi Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.4
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    • pp.388-399
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    • 1989
  • The purpose of this study was to investigate the effects of garment design, fabric type and the presence of lining on the thermal insulation value $(I_{cle}\;and\;I{cl})$ and clothing area factor $(f_{cl})$ of skirts. A standing, electrically heated thermal maninkin was used to measure the insultation value of eighty skirts-five skirt styles with eight different fabrics, with and without lining. The air temperature of the chamber was set at $22.2^{\circ}C{\pm}0.5^{\circ}C$ , air velocity was limited to less than 0.1 m/s, and relative humidity was approximately $50\%$. The results are as follows: 1) The Ic, values of gathered skirt and flared skirt, which had high $f_{cl}$ values, were significantly higher than those of other skirts, though the highest $I_{cle}$ value among five styles wer pegged skirt. 2) Insulation values of various skirts were more relevant with physical properties such as thickness, air permeability, and thermal transmission of the materials rather than fiber content. 3) The addition of lining made significant difference in the insulation values of skirts and the differences of gathered and flared skirt were significantly higher than those of othere types of skirts.

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A Study of Indoor Thermal and Air Quality in Middle and High School Classrooms during Winter (겨울철 학교교실의 실내열.공기환경 실태와 학생들의 주관적 반응)

  • Choi, Yoon-Jung;Na, Sun-Hee;Jo, Su-Youn
    • Korean Journal of Human Ecology
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    • v.18 no.2
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    • pp.509-522
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    • 2009
  • This is a basic study to improve air quality of school classrooms in winter time. The purposes are to check indoor thermal and air environment in school classrooms during winter and to analyze influencing factors on indoor environment. The measurements of students' physical elements with questionnaire surveys were carried out in a total of 6 classrooms. As a result, this research shows that the temperature of one classroom was below indoor thermal standard level, three classrooms had lack of heat, and two classrooms are heated much, which induce relatively low humidity. All of 6 classrooms had lack of ventilation, being high level of $CO_2$ concentration and 2 classrooms are in condition of high PM10 concentration. The majority of students(76%) answered that the cause of their 'heated space syndrome' is because of the lack of ventilation. Students' opening windows for ventilations is hardly carried out at normal times, except that indoor temperature is over standard. That is, we can suggest one of solutions, which is to enable students to operate heating and ventilating system by themselves according to students' physical condition.

Research on the Performance of a Solar Air Conditioning System using a Liquid Desiccant in Summer (액체흡수제 이용 태양열 공조시스템의 하계 능력에 관한 연구)

  • Choi, K.H.;Yoon, J.I.;Kim, B.C.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.2
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    • pp.33-38
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    • 2002
  • In order to find out whether solar air conditioning system could be applied to building or not, the performance and evaluation on thermal environment of the system suggested was done during summer. A solar model house was constructed to find out the performance and thermal environment evaluation when it actually operated outside. As a result, regeneration rate increased rapidly when LiCl solution temperature was over $50^{\circ}C$ and the regeneration rate was $13\sim15kg$ during 9 hours operation. Furthermore the dehumidification rate was 12kg at maximum during 10 hours operating of a dehumidifier and indoor temperature and relative humidity was $28.4^{\circ}C$ and 39.1% in average respectively. On evaluation of thermal environment during summer, PMV value was slightly high, but thermal sensation vote was 71% within the comfort zone.

Decomposition Characteristics of Cyano-compounds in Non-thermal Packed-Bed-Plasma-Reactor (충전형 저온 플라즈마 반응기에서 시안 화합물의 분해 특성)

  • Ryu, Sam-Gon;Park, Myung-Kyu;Lee, Hae-Wan
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.343-347
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    • 2012
  • The decomposition behaviors of gaseous cyanides in non-thermal plasma-catalyst hybrid reactor have been investigated with the variation of discharge power, influent concentration of cyanide, humidity of air carrier and packed materials in the reactor. Destruction of cyanides by plasma only process was very difficult compared to that of trichloroethylene. But the destruction efficiencies of cyanides were dramatically improved through packing alumina or Pt/alumina bead in the plasma discharge region. From the results, it could be assumed that thermal catalytic effect is involved simultaneously with plasma in the reaction of cyanides destruction on the alumina or Pt/alumina packed plasma reactor.

Characteristics of Thermal Comfort in Environment Chamber for Winter

  • Kim, Kyung-Hoon;Park, Jong-Il;Song, Yong-Gil
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.1
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    • pp.73-83
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    • 2000
  • The purpose of this study is to analyze and characterize the correlation of the thermal comfort sensation with physiological responses for men in winter indoor environment. A number of experiments were conducted under twenty different environmental conditions with college male students. Clinical information on each participant was reported in terms of electrocardiogram (ECG), electroencephalogram (EEG) and self-centered evaluation. The comfort zone in winter is found, throughout the study, at Standard New Effective Temperature (SET$T^+$) of 25.2$^{\circ}C$, Predicted Mean Vote (PMV) between 0.27 and 0.62, and Thermal Sensation Vote (TSV) in the range of -0.76 and 0.36. The largest difference in skin temperature is measured at the calf area with respect to air temperature changes. Skin sensitivity to environment temperature is explained as calf, head, chest and abdomen in descending order. Change in heat rate is analyzed to be in parallel with that of SET$T^+$.

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The Indoor Thermal and Air Environment of General Apartment Houses during Winter in Cheongju City (청주시 아파트 일반가정의 겨울철 실내열·공기환경 현장측정조사)

  • Cho, Jun Haeng;Choi, Yoon Jung
    • KIEAE Journal
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    • v.13 no.3
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    • pp.111-120
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    • 2013
  • The purposes of this study were to investigate the actual state of the indoor thermal and air environment in general apartment houses during winter in Cheongju City, to analyze the related factors with the indoor thermal and air environment, and to make suggestions for the improvement. A series of visiting field investigation was conducted in twenty units between 28th December, 2010, and 11th March, 2011. The field investigations included the measurement of physical indoor environmental conditions, the observation of architectural characteristics and resident's behavior, and the on-site questionnaire survey of residents. The measured values of each units were compared to evaluation standard and were categorized to group by the difference between units. Factors related to the difference of the measured values between the groups were analyzed. The findings are summarized as followed. The indoor temperature of apartment houses during winter in Cheongju City was generally suitable. The relative humidity was slightly dry, while the $CO_2$ concentration was found to be excessively high. The factors related indoor environment were analysed as heating operation, ventilation, gas range use, and hanging out the wash to dry in indoors.

Numerical Simulation of the Thermal Environment inside an Opened Tomb (개방된 고분내부의 열 환경 수치모사)

  • Lee, Kum-Bae;Youn, Young-Muk;Jun, Hee-Ho;Park, Jin-Yang;Ko, Seok-Bo
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.872-878
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    • 2006
  • In recent years the importance of the preservation of cultural artefacts like ancient tombs has been widely accepted domestically and internationally as the quality of life improves. However not much technical attention has been paid for the facilities and systems to preserve those artefacts. Even the general understanding of the preservatory environment of the underground space as tombs is poor. As a part of the present study, the temperature and relative humidity inside a selected artefact, Shinkwan-ri tomb, have been monitored for a year round by the present author to improve the understanding of the indoor thermal environment, is pursued to provide a predictive tool of numerical modelling of Shinkwan-ri tomb the opened underground space thermal environment. In this study, predictive numerical modelling of Shinkwan-ri tomb using the Computational Fluid Dynamics, calculate the velocity and temperature distribution and offer basic data which are necessary for the best fitted design of tomb air-conditioning device.

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Assessment of Utilization of Auxiliary Heating Device for Prevention of Condensation in Built-in Furniture in Winter (겨울철 공동주택에서 붙박이장 내 보조난방장치를 활용한 결로 저감 효과 평가)

  • Lee, Hyun-Hwa;Lim, Jae-Han;Song, Seung-Yeong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.33 no.12
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    • pp.99-106
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    • 2017
  • Recently, the condensation and mold problems of apartment buildings has been growing due to high insulation and high air-tightness performance for energy saving. Most of all, occupants in residential buildings has suffered from property damages due to the condensation and mold of built-in furniture. Condensation at built-in furniture were generally found in winter at the of furniture's back panels, adjacent surfaces of wall, floor and ceiling. The aim of paper is to analyze the characteristics of adjacent area around built-in furniture's condensation problem and the thermal environment around the built-in furniture in winter through the field measurements at apartment buildings. In this research, the thermal conditions and surface temperature around the built-in furniture were measured during winter season. In this research, we analyzed thermal conditions for built-in furniture which were applied and not applied auxiliary heating device. In results, it is important to consider increasing surface temperature for using heater and decreasing absolute humidity due to the occupants' behavior around built-in furniture for preventing condensation.

An Approach of Indoor thermal Environment Control and Energy Saving Using the PMV Index (PMV지표를 이용한 공동주택의 난방제어에 따른 온열환경 및 에너지소비량 시뮬레이션)

  • Seong, Nam-Chul;Yoon, Dong-Won
    • Land and Housing Review
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    • v.1 no.1
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    • pp.19-25
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    • 2010
  • Thermal comfort provide satisfaction of thermal environment and affects productivity of occupants in residential building. However, temperature control can not provide the thermal comfort at all the time. because thermal comfort is influenced by many environmental variables such as temperature, relative humidity, air velocity, radiation temperature, activity level and clothing insulation. The purpose of this study is that predicted mean vote(PMV) index is used as control. And, Thermal comfort is evaluated both PMV control and temperature control by simulation. Each other cases were compared, in which set-point temperatures of $22^{\circ}C$ and $24^{\circ}C$ and, set-point PMV index through the respective heating season in the simulation. The results show that PMV control is better to maintain comfort state and save energy than temperature control.