• Title/Summary/Keyword: Thermal-Comfort

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Evaluation of Comfort and Hand Characteristics of Lining Fabrics (안감용 직물의 태와 착용 쾌적성 평가)

  • Shim, Huen-Sup;McCullough, Elizabeth A.
    • Fashion & Textile Research Journal
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    • v.10 no.4
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    • pp.537-543
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    • 2008
  • The purpose of this study was to evaluate the comfort and fabric hand characteristics of selected lining fabrics made of acetate and polyester. The comfort of the linings was determined by human subjects wearing suit blazers constructed with different lining materials in an environmental chamber controlled at $30.6^{\circ}C$ air temperature and 50% relative humidity. The hand characteristics of the lining fabrics were determined by five trained panelists using standard fabric reference samples. The effect of lining fabrics on the subjects' thermal sensations was not statistically significant. But the subjects voted warmer when wearing the polyester surah lined blazer or the polyester taffeta blazer than wearing the acetate blazers. The results of the subjective comfort evaluation indicated that, in general, the subjects rated the acetate linings significantly less sticky, clammy, damp, and non-absorbent than the polyester linings. Acetate surah was rated a little higher than the other acetate fabrics on these comfort descriptors. The results of the subjective hand evaluation indicated that the lining fabrics rated low on the geometric and mechanical hand characteristics and rated moderate on noise. Acetate surah scored the highest on most of the hand characteristics, whereas, polyester taffeta scored the lowest.

A Study on the Thermal Comfort Zone and Energy Use of Radiant Floor Heating by Residential Style and Clothing Level (생활특성과 착의량에 따른 바닥복사난방 공간의 열쾌적 범위 및 에너지 사용량에 관한 연구)

  • Kim, Sang-Hun;Chung, Kwang-Seop;Kim, Young-Il
    • Journal of Energy Engineering
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    • v.24 no.1
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    • pp.24-31
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    • 2015
  • The purpose of this study is to provide the thermal comfort range according to the residential style and clothing level at radiant floor heating space, and compare the annual energy consumption and energy cost for each condition. Lower neutral point temperature has been stood for floor sitting style than chair sitting style, which appears that the thermal sensation was affected by local heat transfer between floor surface and the human body. The result of research indicates that neutral point temperature was in inverse proportion with the clothing level. It is interpreted that the increasing of clothing level results decrement of heat loss from human body, and is available to achieve same thermal comfort at lower room temperature. It was analyzed that the floor sitting style is more economical residential style than the chair sitting style, because the energy consumption of the floor sitting style is saved by 6.0% in average to compare with that of the chair sitting style. It is analyzed that energy consumption has been decreased by 13.5% with the clothing level of 1.2 Clo than with that of 1.0 Clo, and decreased by 18.0% than with that of 0.8 Clo, which explains that the energy saving can be achieved with the variation in life habit to increase the clothing level.

Wearing Comfort Evaluation of a Summer Flight Suit to Improve Ventilation (통기성 향상을 위한 하계비행복 설계 및 착용쾌적성 평가)

  • Jeon, Eun-Jin;Park, Sei-Kwon;You, Hee-Cheon;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.16 no.3
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    • pp.485-491
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    • 2014
  • This study verified the effect of summer flight ventilation developed in a previous study based on wearing comfort evaluation. Seven healthy males in their twenties volunteered for this experiment conducted in aclimatic chamber. The experiment consisted of three consecutive periods of rest (20 minutes), running on a treadmill (10 minutes) and recovery (20 minutes). A comparative evaluation was conducted on the general flight suit which had no ventilation holes and summer flight suit that use subjective satisfaction measures and objective measures. The subjective satisfaction was evaluated according to the criteria of temperature sensation, wet sensation, thermal comfort and fatigue sensation. The objective satisfaction was measured by skin temperature, microclimate (temperature and humidity), sweat rate and thermography. The comparative wearing evaluation identified the summer flight suit decreased the temperature between skin and suit by $0.42^{\circ}C$ (upper arm), $0.9^{\circ}C$ (calf) and the skin temperature by $0.3^{\circ}C$ (shoulder), $0.4^{\circ}C$ (upper arm), $0.5^{\circ}C$ (calf) as compared to the general flight suit. The humidity inside the summer flight suit decreased at head (7.73%), shoulder (5.86%), upper arm (5.26%), and calf (8.73%) compared to the one inside the general flight suit. Thermography showed that the air flowed through ventilation holes (neck and armpit). The design of ventilation holes applied to the summer flight suit can be applicable to overall clothing that requires thermal comfort such as dust-free garments, mechanical clothing and combat uniforms.

A Study on the Relationship between Structural Characteristics of Cotton Fabrics and their Cool-and-Warm Felling (I) - at $65\%$ Relative Humidity- (면직물의 구성특성과 냉온감과의 상관성에 관한 연구( I ) -상대습도 $65\%$하에서-)

  • Chang Jee Hye
    • Journal of the Korean Society of Clothing and Textiles
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    • v.14 no.2
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    • pp.152-163
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    • 1990
  • The purpose of this study is to experimentally analyze the relationship between structural characteristics of cotton fabrics and their cool-and-warm felling in order to develop more comfortable fabrics. Comfort in textile products has been emphasized as consumers preferred performance to fashion of clothing. Thermal comfort of clothing is a basic parameter of the comfort sensation which is usually represented by the cool-and-warm feeling felt by human skin. Cloo-and-warm feeling is perceived by the heat flux which transfers heat energy stored in an object to skin. We feel warm (cool) if the temperature of nerve extremity in skin ascends (descends). As cool-and-warm feeling determines the comfort sensation of clothing, it is important to develop new comfort fabrics. Although considerable works have been made on the body, clothing, and environment, there has been no research study on the structural characteristics of fabrics and their cool and warm feeling. Cool-and-warm feeling is closely related to the transient heat transfer property. This research study used the cotton fabrics manufactured in Korea as sample and measured $q_{max}$ value with thermal property measuring instrument (Thermo-Labo II type). $q_{max}$ values estimated by polynomial regression equation were compared with those observed in this study. This study also identified the structural parameters of cotton fabrics for a specific range of $q_{max}$ values. The findings of this study can be summarized as follows: 1) As the thickness, porosity and air permeability of cotton fabrics increase, $q_{max}$ value decreases. 2) As the fabric count and over factor of cotton fabrics increase, $q_{max}$ value also increases. 3) $q_{max}$ values have been estimated by simple and polynomial regression equations developed in this study. Regression curves which have been plotted by polynomial regression equations also provided with the range of structural parameters for a specific range of $q_{max}$ values of cotton fabrics. This study would be significant in that it has identified the structural Parameters for the cool-and-warm feeling of cotton fabric at $65\%$ relative humidity.

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Analysis of the Influence of Street Trees on Human Thermal Sensation in Summer (여름철 인간 열환경지수에 미치는 가로수의 영향 분석)

  • Jo, Sang-man;Hyun, Cheol-ji;Park, Soo-kuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.5
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    • pp.105-112
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    • 2017
  • In order to analyze the effect of street trees on human thermal sensation(thermal comfort) in summer, microclimatic data were measured and analyzed at sunny and shaded locations of two deciduous broadleaf and three broadleaf evergreen species of street trees. As a result, the mean differences by species in air temperature, relative humidity and wind speed were small: $0.2{\sim}1.5^{\circ}C$, 0.9~5.3% and $0.1{\sim}0.5 ms^{-1}$, respectively, but the mean difference in the mean radiant temperature was great, $27.1^{\circ}C$. In the results of physiological equivalent temperature(PET) and universal thermal climate index(UTCI), which are human thermal sensation(thermal comfort) indexes, the shaded locations by the trees showed mean reduction rates of 21.2~31.3% in the PET compared with the sunny location, which are equivalent to 1.5~2.5 levels of thermal perception. Also, 12.7~20.0% in the UTCI was reduced by the trees' shadows, which is equivalent to 1~1.5 levels of heat stress. In addition, although the broadleaf evergreen trees had 5% greater mean reduction in PET than that of the deciduous broadleaf trees, the Zelkova serrata that belonged to the deciduous broadleaf trees showed the equivalent thermal reduction effect as the broadleaf evergreen trees because of the high density of branches and leaves. Therefore, the mean radiant temperature and the density of the crown(branches and leaves) were the main influences in thermal modification by these street trees in summer.

A Study on Verifying the Effect of Thermal Environment Control of Street Canyons based on Application of Green Wall System (거리협곡 벽면녹화 조성유형에 따른 미기상 변화 및 열환경 평가)

  • Kim, Jeong-Ho;Choi, Won-Jun;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.25 no.2
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    • pp.311-322
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    • 2016
  • This study reduced and built Street Canyons created by skyscrapers in order to verify effect of Street Canyons by green wall within the city centre and analysed influence factors on temperature reduction according to applicative types of green wall in the lab. Applicative types were divided into three types such as non- greening type(Case A), one-side greening type(Case B), both side greening type(Case C). The result of analysis of each types showed that average temperature of Case B and Case C is respectively $1.0^{\circ}C$ and $1.7^{\circ}C$ lower than Case A. The result of analysis of WBGT was that the highest temperature was given by Case A($40.2^{\circ}C$) and second one was from Case B($39.8^{\circ}C$) and third one was from ($39.1^{\circ}C$) and in UTCI Case A records the highest temperature of $34.7^{\circ}C$ and Case B provided the second highest temperature of $33.9^{\circ}C$ and Case B gave the lowest temperature of $32.7^{\circ}C$. In PMV the highest temperature of 2.65 was from Case B and second one of 2.61 was from Case A and third one of 2.54 was from Case C. Duncan analysis of each types based on solar radiation and thermal comfort generated that there was analytical significance between Case A and Case B and Case B in terms of each types of average temperature reduction. The significance of thermal comfort in WBGT, MRT, PMV showed non-significance but, In UTCI it was analysed that there was significance between Case C and Case A.

Prototype Intelligent Thermal Mountain Climbing Jacket Embedded with a Two Way Shape Memory Alloy (이방향 형상기업합금을 이용한 지능형 보온성 등산용 자켓의 프로토타입 개발)

  • Lee, Ji-Yeon;Shin, Yeon-Wook;Kim, Hee-Jung;Baek, Bum-Ki;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.1
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    • pp.92-101
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    • 2010
  • This study reports on the development of intelligent clothing using a shape memory alloy (SMA) that forms a still air layer and provides thermal insulation depending on the environment temperature. SMA springs were prepared with Nitinol and have an original length of 6mm and a latent length of 20mm with a response temperature of $24.5^{\circ}C$. Hysteresis was evaluated at a temperature between $0^{\circ}C$ and $40^{\circ}C$. An experimental outdoor jacket that was attached with 30 springs was compared with a commercial jacket in terms of the microclimate temperature, humidity, and comfort properties by human subject tests in the microclimate chamber set at $5{\pm}0.5^{\circ}C$. The results showed that the microclimate temperature of SMA embedded clothing system from the wear trials was higher than the commercial ones during the rest period after exercise, especially on the skin side. In addition the thermal, humidity, and comfort sensations of SMA embedded clothing were better than the commercial ones.

Basic Study on Creating Ecological Residence Space - A thermal environment study of the aged - (생태 공간 조성에 관한 기초 연구 -고령자를 대상으로 한 열환경 연구-)

  • Kim, Dong-Gyu;Ha, Byeong-Yong;Kum, Jong-Soo;Chung, Yong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.23 no.2
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    • pp.153-161
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    • 2011
  • Creating standards on thermal environment has been organized traditionally based on the youth and the manhood who are in mainly active layer of a society. However, traditional creating standards have differences from the physiology of the aged who have weak physical ability than younger person. As a result, it causes a health problem of the aged. Therefore, In this study, we had a basic study to create a comfortable thermal environment which had considered to a physical ability and a physiology of the aged, and build a ecological residence space to maintain health. We had several experiments with the aged; Experiment, Comfort Sensation Vote, Mean Skin Temperature and Analyzing HRV. The result have following by: 1)For the aged, the summer recommend temperature, $26^{\circ}C$, is appropriate within first 30 ~ 40 minutes, but it should be increasing the temperature after that time. 2) By considering PMV status and thermal feeling of the aged, they are prefer to higher temperature than normal setting of air-condition system. 3) In the condition of the summer recommend temperature, $26^{\circ}C$, they had answered in neutral or comfort with the comfort sensation vote. However, we had figure out that they had stress in a lower temperature by analyzing the result of HRV.