• 제목/요약/키워드: Thermal-Comfort

검색결과 700건 처리시간 0.023초

여름철 실내 쾌적온도 설정 기준의 적합성 (Suitability of Setting Summer Indoor Temperature for Thermal Comfort)

  • 심현섭;정운선
    • 한국지역사회생활과학회지
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    • 제24권4호
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    • pp.583-589
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    • 2013
  • This study was to provide the information for optimum utilization of the air-conditioning system in the human health and energy saving perspective. Subjects were 17 male and female college students(7 males and 10 females) with normal weight. They wore a short sleeved shirt, knee length trousers, socks, and underwear(0.4clo). They were asked to choose the preferred temperature from different environmental temperatures($28^{\circ}C$, $25^{\circ}C$). The physiological responses were measured and the subjective sensation was voted during the step changes of environmental temperature, starting at $28^{\circ}C$ to $25^{\circ}C$ with $1^{\circ}C$ decrease every 20 minutes. The preferred temperature was $25.9{\pm}0.4^{\circ}C$ for males and $26.9{\pm}0.2^{\circ}C$ for females at $28^{\circ}C$ and $24.8{\pm}0.6^{\circ}C$ for males and $25.6{\pm}0.1^{\circ}C$ for females at $25^{\circ}C$. The preferred temperature decreased about $1.3^{\circ}C$ while the environmental temperature changed $3^{\circ}C$. During the environmental step changes, mean skin temperature decreased more in females while the oxygen uptake and rectal temperature were kept constant for both males and females. We found the preferred temperature was affected by the exposed temperature and the thermal sensation in the condition. Subjects preferred a lower environmental temperature when they were exposed to a lower temperature with cooler sensation. Therefore, in the perspective of human health and energy saving, it is recommended to start setting the air-conditioning temperature higher than the preferred temperature.

Piglets' Surface Temperature Change at Different Weights at Birth

  • Caldara, Fabiana Ribeiro;dos Santos, Luan Sousa;Machado, Sivanilza Teixeira;Moi, Marta;de Alencar Naas, Irenilza;Foppa, Luciana;Garcia, Rodrigo Garofallo;de Kassia Silva dos Santos, Rita
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권3호
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    • pp.431-438
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    • 2014
  • The study was carried out in order to verify the effects of piglets' weight at birth on their surface temperature change (ST) after birth, and its relationship with ingestion time of colostrum. Piglets from four different sows were weighed at birth and divided into a totally randomized design with three treatments according to birth weight (PBW): T1 - less than 1.00 kg, T2 - 1.00 to 1.39 kg, and T3 - higher than or equal to 1.40 kg. The time spent for the first colostrum ingestion was recorded (TFS). Images of piglets' surface by thermal imaging camera were recorded at birth (STB) and 15, 30, 45, 60, and 120 min after birth. The air temperature and relative humidity were recorded every 30 min and the indexes of temperature and humidity (THI) were calculated. A ST drop after 15 min from birth was observed, increasing again after sixty minutes. Positive correlations were found between the PBW and the ST at 30 and 45 min after birth. The PBW was negatively correlated with the TFS. The THI showed high negative correlations (-0.824 and -0.815) with STB and after 15 min from birth. The piglet's surface temperature at birth was positively correlated with temperature thereof to 15 min, influencing therefore the temperatures in the interval of 45 to 120 min. The birth weight contributes significantly to postnatal hypothermia and consequently to the time it takes for piglets ingest colostrum, requiring special attention to those of low birth weight.

고감성 의류용 Nylon/PP 온감 니트 소재의 물성 (The Physical Property of Nylon/PP Warm-up Knitted Fabric for High Emotional Garment)

  • 김현아;장홍원;허경;김승진;권상준
    • 한국염색가공학회지
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    • 제26권1호
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    • pp.22-31
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    • 2014
  • This study investigated the physical properties of warm up yarns and their knitted fabrics including the dye affinity and color fastness to washing of these knitted fabrics according to the various dyeing times and temperatures on dyeing process. The results were summarized as follows. The tenacity of Nylon/PP warm-up yarn was 4g/d and breaking strain was 4.5%. The wet and dry thermal shrinkages were higher than those of PET warm-up yarn. The maximum heat flow rate(Qmax) of Nylon/PP warm-up knitted fabric was lower than that of PET warm-up knitted fabric and heat keeping rate(a) of Nylon/PP warm-up knitted fabric was higher as 47% than that of PET warm-up knitted fabric. It was shown that the shape retention and wearing comfort of Nylon/PP warm-up knitted fabric were better than those of PET warm-up knitted fabric. The dye-affinity(K/S) of Nylon/PP warm-up knitted fabric showed maximum value at the dyeing condition of 40minute or 50minute dyeing time with $80^{\circ}C$ dyeing temperature, but PET warm-up knitted fabric showed maximum value at the 30minute or 40minute with $110^{\circ}C$ dyeing temperature. Finally, the color fastness to washing of Nylon/PP warm-up knitted fabric showed good value as between 4 and 5 grade.

온돌에서 수면시의 계절별 침실내 온열환경과 침상기후 (Thermal Environment and Bedclimate on Ondol during Sleeping in Each Season)

  • 이순원;권수애
    • 한국의류학회지
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    • 제21권7호
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    • pp.1162-1172
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    • 1997
  • The actual thermal environment and bedclimate on Ondol were investigated by the regions and housing styles in each season. The subject were sixty healthy men and women, 30 of them live in apartment, and 30 of them live in detached house. 20 of them live in Wonju, 20 of them live in Cheongju and 20 of them live in Pusan. The results are as follows: 1) The subject slept in this conditions; 23.1$\pm$2.4$^{\circ}C$ and 38$\pm$8.8% RH in spring, 27.1$\pm$1.5$^{\circ}C$ and 68$\pm$6.4% RH in summer, 27.1$\pm$1.7$^{\circ}C$ and 47$\pm$11.1% RH in autumm, and 24.9$\pm$3.3$^{\circ}C$ and 41$\pm$10.7% R.H in winter The temperatures of the floors were 38.6$\pm$5.$0^{\circ}C$ in the spring, 26.7$\pm$1.9$^{\circ}C$ in the summer, 29.4$\pm$4.7$^{\circ}C$ in the autumm, and 30.0$\pm$5.8$^{\circ}C$ in the winter. 2) Each thickness of the quilts was thinner in the summer than in any other season, but the differences in the thickness of each mattress was not significant by the seasons. 3) The differences of the bedclimate and the clothing microclimate were significant by the regions and housing in each seasons. The inside of temperature and humidity of sleepwrar were highest in summer. The bedclimate showed high correlation with the clothing microclimate. 4) The differences in the sensation which the subjects felt about temperature and comfort of the bedroom conditions were not significant by the seasons, regions, or housing styles. But the subjects felt more humid in the summer and spring than in the autumm and winter.

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내측 블라인드의 하절기 일사열 차폐 성능 비교 (Comparing Solar Heat Shading Performances of Internal Blinds in the Summer)

  • 박은미;최동호;박민용;이경희
    • 한국태양에너지학회 논문집
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    • 제34권6호
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    • pp.75-83
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    • 2014
  • Heat loss through windows and doors occupies 20 to 45% of the total heat loss in building. It accounts for a large proportion of the total heat loss in building. In order to suppress the amount of heat flow through the windows and doors were considered actions such as reinforcement of insulation performance of window, adoption of low-e glass, and installation of solar heat shading device. The Purpose of this study is to compare solar heat shading performances of 3 types of internal blinds in the summer. In order to verify the solar heat shading performances of the blinds, a roll blind, blind A(Venetian blind) and blind B(Daylight guiding venetian blind)were installed in the four rooms with the same environmental conditions. As a result of the experiment, the blind B, blind A, roll blind showed an excellent performance in that order. Its because the blind B is made of aluminum materials coated with special paints on surface. It doesn't converted to long wave by short wave light. and it is reflected to short wave to outside.

Embossed Structural Skin for Tall Buildings

  • Song, Jin Young;Lee, Donghun;Erikson, James;Hao, Jianming;Wu, Teng;Kim, Bonghwan
    • 국제초고층학회논문집
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    • 제7권1호
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    • pp.17-32
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    • 2018
  • This paper explores the function of a structural skin with an embossed surface applicable to use for tall building structures. The major diagrid system with a secondary embossed surface structure provides an enhanced perimeter structural system by increasing tube section areas and reduces aerodynamic loads by disorienting major organized structure of winds. A parametric study used to investigate an optimized configuration of the embossed structure revealed that the embossed structure has a structural advantage in stiffening the structure, reducing lateral drift to 90% compared to a non-embossed diagrid baseline model, and results of wind load analysis using computational fluid dynamics, demonstrated the proposed embossed system can reduce. The resulting undulating embossed skin geometry presents both opportunities for incorporating versatile interior environments as well as unique challenges for daylighting and thermal control of the envelope. Solar and thermal control requires multiple daylighting solutions to address each local façade surface condition in order to reduce energy loads and meet occupant comfort standards. These findings illustrate that although more complex in geometry, architects and engineers can produce tall buildings that have less impact on our environment by utilizing structural forms that reduce structural steel needed for stiffening, thus reducing embodied $CO^2$, while positively affecting indoor quality and energy performance, all possible while creating a unique urban iconography derived from the performance of building skin.

TEST CELL에서 단기측정에 의한 열성능 평가 (Thermal Performance Evaluation of a Test Cell Thru Short Term Measurements)

  • 전명석;윤환기;천원기;전홍석
    • 태양에너지
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    • 제10권2호
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    • pp.10-17
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    • 1990
  • 건물의 사양으로부터 시뮬레이션에 의해 열성능을 추출하는 기법과 실측 데이타로 부터 연역적인 방법에 의해 열성능을 추출하는 기법을 연합시켜 단기간의 측정에 의해 건물의 열성능을 간단하고 정확하게 결정할 수 있는 기법을 Test cell에 적용하였다. 실험과정 및 자료분석은 PSTAR 기법에 따라 수행했다. 각 측정기간은 3일간으로 비거주 상태에서 측정했으며, 실내온도, 외기온, 일사량, 공급열량, 풍속, 상대습도등의 자료를 측정하여 건물의 사양에 의한 시뮬레이션 모델의 재표준화에 사용했다. 아래의 3개 주요계수들이 본 분석에 의해 얻어졌다. 1) 건물 열손실계수 : BLC(표면전도율+침기에 의한 전도율); 2) 유효 건물열용량; 3) 유효 태양열 획득량. 그리고 재표준화된 식으로부터 예측된 값과 건물의 사양으로 시뮬레이션에 의해 예측된 값과 측정된 값과의 비교를 통해 재표준화된 식이 실제건물의 열성능을 잘 묘사함을 알 수 있었다. 장기간의 외삽으로 기후 자료를 이용하여 표준 쾌적도를 유지하기 위해 필요한 에너지를 계산했다.

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생활한복형 하절교복의 의복기후와 주관적 감각 (The Clothing Microclimates and Subjective Sensation for Casual Hanbok as School Summer Uniform)

  • 유정자;권수애
    • 한국생활과학회지
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    • 제21권4호
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    • pp.765-780
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    • 2012
  • This study was investigated the clothing microclimate, subjective sensation for the improvement of traditional koran high school student uniform so called "Saenghwal Hanbok". For the purpose, casual hanbok school summer uniforms were made. They were made of 4 different textiles materials - P/R, P100, P/C, P/R/S for blouses, P/W, P100, P/R, P/W/F for skirts. Then their clothing microclimate, subjective sensation were tested at room temperature $25{\pm}1^{\circ}C$ and $50{\pm}10%$ R.H. Clothing Microclimates wearing on the blouses were good matched comfort temperature range. Subjective sensations wearing on the blouses were better than those of traditional koran clothes so called "Hanbok" and quite same for western style clothes. Thermal sensations were indicated some hot condition, and moisture sensations were indicated some wet condition but tactile sensations and comfortable sensations were agreeable. The temperatures of the forehead and the breast wearing on the skirts were indicated the same results with the cases of the blouses. Leg temperatures were some lower than the mean skin temperature, the other parts' temperatures were slightly higher than blouses but the mean skin temperatures were satisfied comfortable ranges. Subjective sensations wearing on the skirts were better than those of the other traditional clothes and even Western clothes. Thermal sensations and moisture sensations were resulted the same with the case of blouses. Currently, P/R material and P/W material seemed to be cool and respectively suitable for blouses and skirts in summer among the materials of modernized Korean traditional costumes and school uniforms, since those materials lowered skin temperature. But better, physiologically pleasant materials for summer clothes should be development in consideration of clothing microclimate and subjective sensation.

Effects of Clothing Material Dyed with Astringent Persimmon Extract upon Exercise-Induced Thermal Strain and Sensory Responses in a Warm Environment

  • Park, Shin-Jung;Shin, Hye-Sun;Chung, Hee-Chung
    • International Journal of Human Ecology
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    • 제16권2호
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    • pp.1-9
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    • 2015
  • This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

멀티존 온돌난방제어를 위한 필요공급온수온도 산출법에 관한 연구 (A Study on the Required Supply Water Temperature Calculating Method for the Control of Multizone Radiant Floor Heating System)

  • 최정민;이규남;류성룡;김용이;여명석;김광우
    • 설비공학논문집
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    • 제19권1호
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    • pp.77-85
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    • 2007
  • One of the most common approaches to achieve better thermal comfort with the radiant floor heating system is supply water temperature control, which is that supply water temperature is varied with outdoor air temperature. But the application of this control method was not easy, because there has been no way to determine the supply water temperature. So in this study, a comprehensive, yet simple calculation method to find out the required supply water temperature is suggested by combining the building heat loss equation and the heat emission model of hydronic radiant floor heating system for single zone. And then using this calculation method, the multizone control method is suggested and confirmed through the thermal simulation. It is shown that indoor air temperature is stably maintained around the set point.