• Title/Summary/Keyword: Thermal sensation

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Subjective Responses to Thermal Stress for the Outdoor Performance of Smart Clothes

  • Kwon, JuYoun;Parsons, Ken
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.3
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    • pp.169-181
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    • 2017
  • Objective: The aim of this study was to explore the influence of outdoor weather conditions on subjective responses during physical activity. Background: The largest difference between indoor and outdoor conditions is the existence of the sun. The heat load from the sun has an influence on the heat gain of the human body and the intense degree of solar radiation affected thermal comfort. Method: Thirty eight people were exposed to a range of climatic conditions in the UK. Weather in England does not have extremely hot and cold temperature, and the current study was conducted under warm (summer and autumn) and cool (spring and summer) climates. Measurements of the climate included air temperature, radiant temperature (including solar load), humidity and wind around the subjects. Subjective responses were taken and physiological measurements included internal body temperature, heart rate and sweat loss. Results: This study was conducted under four kinds of environmental conditions and the environmental measurement was performed in September, December, March, and June. The values for sensation, comfort, preference, and pleasantness about four conditions were from 'neutral' to 'warm', from 'not uncomfortable' to 'slightly comfortable', from 'slightly cooler' to 'slightly warmer', and from 'neither pleasant nor unpleasant' and 'slightly unpleasant', respectively. All subjective responses showed differences depending on air temperature and wind speed, and had correlations with air temperature and wind speed (p<0.05). However, subjective responses showed no differences depending on the radiant temperature. The combined effects of environmental parameters were showed on some subjective responses. The combined effects of air temperature and radiant temperature on thermal sensation and pleasantness were significant. The combined effects of metabolic rate with air temperature, wind speed and solar radiation respectively have influences on some subjective responses. In the case of the relationships among subjective responses, thermal sensation had significant correlations with all subjective responses. The largest relationship was shown between preference and thermal sensation but acceptance showed the lowest relationship with the other subjective responses. Conclusion: The ranges of air temperature, radiant temperature, wind speed and solar radiation were $6.7^{\circ}C$ to $24.7^{\circ}C$, $17.9^{\circ}C$ to $56.6^{\circ}C$, $0.84ms^{-1}$ to $2.4ms^{-1}$, and $123Wm^{-2}$ to $876Wm^{-2}$ respectively. Each of air temperature and wind speed had significant relationships with subjective responses. The combined effects of environmental parameters on subjective responses were shown. Each radiant temperature and solar radiation did not show any relationships with subjective responses but the combinations of each radiant temperature and solar radiation with other environmental parameters had influences on subjective responses. The combinations of metabolic rate with air temperature, wind speed and solar radiation respectively have influences on subjective responses although metabolic rate alone hardly made influences on them. There were also significant relationships among subjective responses, and pleasantness generally showed relatively high relationships with comfort, preference, acceptance and satisfaction. Application: Subjective responses might be utilized to predict thermal stress of human and the application products reflecting human subjective responses might apply to the different fields such as fashion technology, wearable devices, and environmental design considering human's response etc.

A Experimental Study for Developing of the Dry Double Floors Hydronic Ondol System (건식이중바닥온돌시스템 개발을 위한 실험적 연구)

  • Kim Nan-Haeng;Sohn Jang-Yeul
    • Journal of the Korean housing association
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    • v.17 no.3
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    • pp.1-7
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    • 2006
  • The aim of the research was to evaluate the characteristics of thermal environment and thermal comfort in the Dry Double floors Hydronic Ondol System. Physical indoor thermal environments (the floor surface temperature, the vertical temperature, etc.) and skin temperature have especially been measured. Physical features conditions, sensation, thermal comfort, humidity sensation, comfort of body were investigated for the survey. As a result, (1) During the operation of the boiler (12 hour), the average indoor temperature is appeared to be $21.6^{\circ}C$. The floor surface temperature showed peak value of $31.4{\sim}40.6^{\circ}C$ after 8hours 30minutes after the start-point of the heating. The vertical difference of temperature was turned out to be not uniform. (2) While the skin temperature showed a narrow distribution of temperature in the Dry Double floors Hydronic Ondol system. (3) The response to thermal comfort which people felt was satisfactory, and most of them felt dry during the test.

Evaluation of Thermal Comfort on Temperature Differences between Outdoor and Indoor Thermal Conditions in Summer (여름철 실내외 온도차에 따른 인체의 온열쾌적성 평가)

  • 금종수;김동규;최광환;이낙범;임재중;최호선;배동석
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.11
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    • pp.890-896
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    • 2002
  • Purpose of this study is to clarify the evaluation of thermal comfort based on temperature differences between outdoor and indoor thermal conditions in summer. The experiments were performed to evaluate temperature difference between indoor and outdoor thermal conditions (29, 31, $33^{\circ}$) by physiological and psychological responses of human. According to physiological responses, TSV (thermal sensation vote) and CSV (comfort sensation vote) and psychological responses, ECG (electrocardiogram), MST (mean skin temperature) of human, it was clear that the optimum temperature difference is about $5^{\circ})\;and\;7^{\circ}$).

A Study on the Thermal Sensation Vote of the Log House in Winter Season (통나무집의 동절기 실내 온열감 평가에 관한 연구)

  • Min, Byeong-Cheol;Jeon, Ji-Hyeon;Shin, Yong-Gyu;Kang, Sang-Woo;Kook, Chan
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.297-300
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    • 2006
  • Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially the building made by the wood, which has environmental characteristics that the reinforced concrete and brick doesn't have, are acknowledged with its superiority. Then, studies on indoor thermal control capability of the wooden building and influence of its indoor environment to sensory environment of occupants are not enough proceed. Thus, there were proceeded 24 hours measurements for indoor and outdoor thermal environmental elements of Log Cabins and the hourly subjective tests to evaluate indoor amenity of occupants in this study. The results of the study are following: 1) Upon evaluation on thermal environment elements, indoor and outdoor dry bulb temp were 22.0$^{\circ}C$ and -2.9$^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8%and 52.7%. Differences of indoor and outdoor temperature and humidity were 24.9$^{\circ}C$ and 26.9%. 2) Upon contrastive analysis between the results of subjective tests, warm and cold sensation vote, and PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfaction), values of subjective tests W.9

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Optimal Heating Location for developing the Heating Smart Clothing based on Thermal Response of Body (발열 기능 스마트 의류를 위한 인체 온열반응 기반의 최적의 발열위치 연구)

  • Cho, Hakyung;Cho, Sangwoo
    • Science of Emotion and Sensibility
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    • v.18 no.3
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    • pp.93-106
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    • 2015
  • In accordance with escalating demands for advanced technology products, the smart clothing that includes embedded ICT technology have expanded into fields of daily life. As a result of this trend, interest in smart clothing with digitally controllable heating has rapidly grown and the market for smart heated clothing has also expanded. Increasing of prospect in smart heated clothing market, the effectiveness and thermal sensation research of the location on the pad attached is insufficient. This study was conducted to find the optimal location of heated clothing via experimental research on changes in skin temperature and subjective thermal sensation when heating pads were placed on different areas of the body. For this experiment, the subjects consisted of 10 males in their 20's of standard physique. The skin temperature at 11 different areas of the body, rectal temperature, and subjective thermal sensation were taken at different stages (before testing, after a 20 minute rest period, 20 minute treatment period, and after a 40 minute recovery period) in an artificial-climate chamber at $-5^{\circ}C$. As a result, the optimal location for heating pads in smart clothing was estimated and suggested.

Sportswear Physiological Optimization: Effects of Clothing ease, local heating and materiales (운동복의 기능성과 쾌적성에 관한 연구)

  • Lee Young Suk;An Tae Whan
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.2 s.38
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    • pp.127-138
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    • 1991
  • The aim of the present stud)r has been to obtain new and additional data allolwing a better design of sports garments as well as a better choice among some materiales, through measure-ment of body surface changes in the upper trunk in movement, measurement on the effects of local heating on other parts of the body and measurement of the thermal resistance of 6 types of materials applied on a manikin. In the first experiment, the upper trunk was divided in 32 Parts, the surface of which was measured by the tape method for two upper limb positions: extension at $90^{\circ}$ and $180^{\circ}$. In the second experiment, skin temperature, local thermal sensations and whole body thermal sensation were measured every 5 minutes during 40 minutes. The four areas of the shoulder, abdomen, hande and feet were heated with the hot pack at $50^{\circ}C$. In the third experiment, the regional thermal resistance of the various materials selected, in two different cases of clothing ease, have been measured by using a thermal manikin. Resultes of experiments were: 1. Extensions cause the upper front part of the trunk surface to lengthen vertically while the back tends to stretch in width. 2. Skin temperatures of the upper limbs are influenced by the abdomen and shoulder boatings. The correlation between the whole body thermal sensation and the upper trunk thermal sensation is significantly asserted. 3. Ceramic and aluminium coated materiales offer the most effective thermal resistance; ease in clothing increases the thermal resistance at the breast and the abdomen as well as the clo value of the materials.

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A Field Survey on the Standard Establishment of Thermal Indoor Climate - with the effect of thermal environmental factors, and clothing to the thermal sensation - (표준실내기후 설정에 관한 기초조사연구 -열환경요소와 착의량이 온냉감반응에 미치는 영향-)

  • Choi Hei Sun
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.16 no.6
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    • pp.590-605
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    • 1987
  • The purpose of this study was to investigate thermal environmental factors, thermal clothing properties, and thermal sensation of the office workers in four selected office buildings in Seoul, and to determine the effect of thermal environmental factors and clothing insulation to the thermal sensation of the subjects. The subjects selected from each office were 5 males and 5 females at a time. Thermal environmental factors(DBT, GT, RH, MRT, $ET^{\ast}$) and clothing variables such as clothing weight per body surface $area(g/m^2)$ and estimated clothing insulation values(clo) were significantly different among each seasons(p<0,001). Means of $ET^{\ast}$ and estimated clothing insulation values of each season were as follows; Winter; $20.84^{\circ}C$ $ET^{\ast}$ with 0.72 clo for male and 0.79 clo for female Spring and fall; $23.65^{\circ}C$ $ET^{\ast}$ with 0.59 clo for male and 0.68 clo for female Summer; $26.00^{\circ}C$ $ET^{\ast}$ with 0.47 clo for male and 0.53 clo for female. In comparison these data with ASHRAE Standard, the subjects were predicted to feel comfort-able in spring and fall, and slightly hot in summer and slightly cold in winter because of high and low clo respectively. But the result of this survey showed more than $80\%$ of the occupants were thermally comfortable at a given environmental temperature and clo.

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Evaluation of Thermal Comfort in Ceiling Cooling System (천장복사냉방의 온열쾌적성 평가에 관한 연구)

  • Lee, Ju-Youn
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.4
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    • pp.287-293
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    • 2008
  • The purpose of this study was to clarify the effects of air and ceiling temperatures on a type of ceiling cooling system that involves cool water circulation. The experiment is conducted in summer. The subjects (11 young females) are exposed to the following conditions: combinations of air temperatures $(27^{\circ}C,\;29^{\circ}C,\;31^{\circ}C)$ and ceiling temperature of $(22.7^{\circ}C,\;23.7^{\circ}C,\;24.7^{\circ}C)$ in still air and RH 50%. The following results were obtained; the thermal sensation vote is neutral at a mean skin temperature of $34.5^{\circ}C$. The ceiling temperature affected different parts of the body. For example, the forehead, scapula and abdomen produced different skin temperatures. Thermal comfort vote was rated as comfortable at high temperature environment. The satisfaction from the ceiling temperature was valued comfortable zone in this experiment. Mean skin temperature showing higher thermal neutrality temperature than existing studies for floor and wall radiation cooling results.

A Study on the Room Temperature Control Methods Considering Human Thermal Comfort Under Hot and Humid Condition (인체의 온열환경 적응을 고려한 여름철의 실온 쾌적변동 제어에 관한 연구)

  • Lee, Ju-Youn
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.5
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    • pp.334-341
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    • 2008
  • The purpose of this study is to investigate the effects of changing air temperature and the changing on/off periods of the air-conditioner system. Adding to that, this paper discuss is to consider the effects of air temperature with the air-conditioner system upon the human thermal comfort. The experiment is conducted during the summer. The subjects(6 young females) are exposed to the following conditions: combinations of 2 Swing and 2 Linear air control Conditions. (2 Swing during 40 min, 4 Swing during 40 min, Linear 40 min, Linear 60 min in still air and RH 50%). From the experiment, the following results are obtained; the thermal sensation vote is neutral after 90 minute. The mean skin temperature ranged about $34^{\circ}C$ at all conditions. The skin temperature was greatly affected by 2 Swing big amplitude condition.