• Title/Summary/Keyword: Thermal Comfort Condition

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Physiological Responses and Subjective Sensations by Age through Seasonal Condition (환경온도에 따른 착의 생리반응과 주관적 감각의 연령별 비교)

  • Lee, Jung-Sug;Song, Min-Kyu;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.11 no.5
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    • pp.833-839
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    • 2009
  • This study was to investigate the human's physiological responses and subjective sensations with wear trial through seasonal condition by age. Climate chamber was set $5^{\circ}C$, RH 45% for winter and $30^{\circ}C$, RH 65% for summer condition. Thirty male subjects were volunteered consisted of 10 people in their 20s, 40s, and 60s. In this study physiological responses such as rectal temperature, skin temperature, clothing microclimate, heart rate and blood pressure were measured. As for age, 60s was the highest in rectal temperature regardless of seasonal condition. In skin temperature, 40s was the highest in winter and 20s was the highest in summer. In clothing microclimate temperature and heart rate, 20s was the highest regardless of seasonal condition. And blood pressure was appeared the highest in 20s regardless of seasonal condition. Subjective sensations such as temperature sensation, wetness sensation and thermal comfort were measured. The subjects revealed that temperature sensation was higher 20s than 60s. Compare of other age group, 60s felt colder in the same environment and clothing. It suggested that temperature susceptibility in 60s became weakened showing no change sensation during the cold exposure. Wetness sensation was higher 20s than 60s. Thermal comfort of 60s was felt more discomfortable than any other age group. This means require the supplement of a suitable clothing in order to adjust to change of environmental conditions.

Evaluation of Thermal Comfort during Sleeping in Summer - Part III : About Indoor Air Temperatures Rise - (여름철 수면시 온열쾌적감 평가 - 제3보 : 실내온도 상승에 관하여 -)

  • Kim Dong-Gyu;Kum Jong-Soo;Kim Se-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.7
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    • pp.535-540
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    • 2006
  • This study was performed In evaluate sleep efficiencies and conditions for comfortable sleep based on the analysis of Physiological signals under variations in thermal conditions. Five female subjects who have similar life cycle and sleep patterns were participated for the sleep experiment. It was checked whether they had a good sleep before the night of experiment. EEGs were obtained from C3-A2 and C4-A1 electrode sites and EOGs were acquired from LOC (left outer canthus) and ROC (right outer canthus) for REM sleep detection. Sleep stages were classified, then TST (total sleep time), SWS (slow wave sleep) latency and SWS/TST were calculated for the evaluation of sleep efficiencies on thermal conditions. TST was defined as an amount of time from sleep stage 1 to wakeup. SWS latency was from light off time to sleep stage 3 and percentage of SWS over TST was calculated for the evaluation of sleep quality and comfort sleep under thermal conditions. As result, the condition which raise a room temperature provided comfortable sleep.

Subjective Hand and Physical Properties of Tricot based Artificial Suede according to Raising Finish (기모가공 조건에 따른 트리코 기포 인조 스웨이드의 태와 물성)

  • Roh, Eui Kyung;Oh, Kyung Wha
    • Fashion & Textile Research Journal
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    • v.16 no.1
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    • pp.153-159
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    • 2014
  • This study evaluates the changes of the subjective hand, preference, comfort and mechanical properties of tricot based artificial suede made from sea-island type micro fibers according to raising condition. The subjective hand and the preference of raised suede for jacket were rated by the 20's and 30's women experts according to raising cycles. Comfort properties were evaluated by air permeability, water vapor transmission, and thermal transmission. Mechanical properties were measured by the KES-FB system. The subjective hand of artificial suede was categorized into three hand factors: smoothness, warmness and thickness. Smoothness, warmness and thickness perception increased with raising cycles which affected hand preference and luxuriousness perception. The thickness and wale density of suede increased with the number of raising. Suede became more compact and less pliable and less stretchable due to increased fabric thickness; in addition, the surface of suede became smoother and compressive since the surface evenness of suede improved with smaller fiber fineness and an increased amount of naps covered the base fabric. Furthermore, water vapor transmission decreased and thermal insulation increased. The best raising conditions for artificial suede was four cycles in which artificial suede was preferred without changes in physical properties.

A Study on the Ventilation Improvement of Diesel Locomotive Engine Load Test Building using Computational Fluid Dynamics (전산유체역학을 이용한 디젤엔진 부하시험장의 환기 개선에 관한 연구)

  • Park Duckshin;Jeong Byungcheol;Cho Youngmin;Park Byunghyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.2
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    • pp.227-242
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    • 2005
  • The aim of this study is to relieve the poor ventilation problem of the diesel locomotive engine load test building, located in an urban area. This paper evaluates the ventilation performances of the studied load test building based on the temperature measurement experiment and the computational fluid dynamics (CFD) during the engine load test. The temperature rise caused by the radiator blower of the building was turned out to be the main cause of disturbing the thermal conditions of the building. The indoor temperature distributions simulated by Fluent were validated with the temperature measurement results obtained from the studied building. The simulation results indicated that the comfort condition of this building was poor We suggested several remedial changes in the duct structure of this building for the improvement of the comfort conditions. In addition, a prototype drawing combining several improved design options was proposed. and then the simulation of the temperature distribution in the proposed prototype was performed. The result indicated that the indoor thermal condition of this proposed building was improved when compared with that of the current building.

A Study on the Application of the Radiant Floor Cooling System in Residential Building (주거 건물의 복사냉방시스템 적용에 관한 연구)

  • 임재한;여명석;김광우
    • Journal of the Korean housing association
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    • v.15 no.3
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    • pp.73-82
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    • 2004
  • The objective of this study is to demonstrate the potential of radiant cooling systems using Ondol as an alternative cooling system in residential buildings. For this purpose, computer simulation and model experiments have been performed for the system performance analysis regarding comfort, floor surface condensation, and supply water temperature. The results of this study is the following: In radiant floor cooling system, room air temperatures were maintained within the set temperature range of $\pm$1$^{\circ}C$ without any discomfort condition. And taking into account only the condensation occurrence, it was possible to achieve radiant floor cooling for a period of about 77% of the total cooling period in weather condition of Seoul. The minimum supply water temperature is about 15$^{\circ}C$, so renewable energy system such as ground heat exchange system can be used as an alternative in cooling source. Also, floor surface condensation can be prevented by integrating with the dehumidification system.

A Study on the Operational Strategy for Hybrid Ventilation System in Apartment unit focused on Indoor Air Quality (실내공기질을 고려한 공동주택의 하이브리드 환기 시스템의 운영에 관한 연구)

  • Lee, Yong-Jun;Leigh, Seung-Bok;Lee, Kyung-Hoi
    • KIEAE Journal
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    • v.4 no.3
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    • pp.203-210
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    • 2004
  • This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

Suggested and Preferred Amount of Clothing in a Winter Indoor Condition

  • Shim, Huen-Sup;Jeong, Woon-Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.12
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    • pp.1418-1424
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    • 2011
  • This study proposes the suggested amount of clothing (SAC) and examines the preferred amount of clothing (PAC) for thermal comfort in mild cold conditions. Six male and nine female college students were systematically exposed to mild cold conditions by reducing the amount of clothing (Step I, 1.2clo ${\rightarrow}$ Step II, 1.0clo ${\rightarrow}$ Step III, 0.8clo ${\rightarrow}$ Step IV, 0.7clo). The subjects were then asked to adjust the amount of clothing to attain overall thermal comfort until they maintained thermal comfort for 10 minutes without changing the amount of clothing (Step V). The experiment was carried out in a climatic chamber at $19.5^{\circ}C$, 50%R.H. Body composition was measured and individual cold climate adaptability was surveyed before starting the experiment. Rectal temperature ($T^{re}$), skin temperature ($T_{sk}$), and oxygen consumption ($\dot{V}O_2$) were measured and the overall thermal sensation was voted in each step. PAC was obtained from the garments weight selected by each subject in Step V. SAC was proposed based on the change of oxygen consumption (${\Delta}\dot{V}O_2$). As a result, males showed higher $\bar{T}_{sk}$ and greater $O_2$ than females (p<.01). SAC obtained from $\dot{V}O_2$ were 652.0 (SE 3.9) g/$m^2$ for males and 766.0 (SE 2.5) g/$m^2$ for females and it was significantly different between groups (p<.01). PAC of males and females were 1.6 and 1.5 times heavier than SAC. In conclusion, females were more sensitive to the cold stress and recommended larger amount of clothing than males.

A Study on the Convergence of Renovation Measures for Urban Ecological Park Considering the Thermal Environment in Summer - With a Case of Gildong Ecological Park - (여름철 열환경을 고려한 도시생태공원 리노베이션 방안 융합 연구 - 길동생태공원을 사례로 -)

  • Kwon, Ki Uk
    • Korea Science and Art Forum
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    • v.36
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    • pp.11-22
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    • 2018
  • This study recent changes in urban thermal environment caused by climate change generate diverse problems such as urban heat island effects, heat wave, and drought. Under this condition, with the increased perception and expectation of the quality of life, the urban citizens' desire for outdoor activities is increasing. This study conducted the thermal environment analysis focusing on the urban ecological park used by many urban citizens, and also suggested the renovation measures for urban ecological park considering the thermal environment. As the research site, the ecologically-favorable Gildong Ecological Pak with diverse space composition was selected. The measuring items were measured and analyzed by dividing them into thermal environment index and thermal comfort index. In the results of analysis in each type of park space, the forest zone showed the most favorable result. Based on such results, total three kinds of renovation measures for urban ecological park considering the thermal environment were suggested. Through this, the urban ecology park renovation plans were presented in three ways. The results of this study are meaningful in that it can be used as a base material for creating an ecological park considering the thermal environment.

A Study on Examination of Indoor Thermal Environment Elements and Thermal Sensation Vote of Log Cabins in Winter Season (통나무집의 동절기 실내 온열환경 요소의 측정과 온열감 평가에 관한 연구)

  • Min, Byeong-Cheol;Jeon, Ji-Hyeon;Kook, Chan
    • Journal of the Korean housing association
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    • v.18 no.2
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    • pp.21-27
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    • 2007
  • Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially as the wood has distinctive ecological merits in comparison with reinforced concrete and brick, the buildings made by the wood are acknowledged with its superiority of ecological value. Enough field studies for their thermal environment, however, haven't been done. In this study, to investigate indoor environmental condition and occupants' response to it of Log Cabin in Gyeongsangnam-do Hamyang Country Jirisan Natural Recreation Forest, examination of indoor thermal environment and field subjective evaluation have been done in that fundamental information of thermal environment characteristics can be suggested. The results are following; 1) Thermal environment of the Log Cabins; Indoor and outdoor mean dry bulb temperature were $21.9^{\circ}C$ and $-3.1^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8% and 52.1%. These results are below ASHRAE; dry bulb temp. $22.0^{\circ}C$, humidity 30%, and above domestic standards; dry bulb temp. $18{\sim}20.0^{\circ}C$, humidity $40{\sim}60%$. 2) Result of subjective evaluation; Thermal sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. And humid sensation and its comfort were evaluated as 'slightly uncomfortable' because of 'slightly warm'. 3) Result of vertical temperature and humidity; Vertical temperature difference from head to ankle was $0.54^{\circ}C$ which means most occupants may feel comfortable.

A Study on the Analysis of Indoor Thermal Environment in Large Enclosure through Actual Measurement (실측을 통한 대규모 실내경기장의 온열환경 분석에 관한 연구)

  • Chae, Mun-Byoung;Yang, Jeong-Hoon;Choi, Dong-Ho;Seok, Ho-Tae
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.3-8
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    • 2007
  • The purpose of this study is to grasp the characteristic of indoor thermal environment from large enclosures in connection with heating and cooling condition. This study has measured indoor thermal environment in winter and summer season. We examined indoor thermal environment of the large enclosures in this study which include vertical, horizontal temperature distribution and thermal comfort environment.

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