• Title/Summary/Keyword: Indoor thermal comfort

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The Characteristics of the winter season window and indoor temperature due to the indoor plant (동계 이중외피와 내부식재에 의한 실내 온도 특성에 관한 연구)

  • Yun, Young-Il;Cho, Ju-Young
    • KIEAE Journal
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    • v.15 no.5
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    • pp.107-112
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    • 2015
  • Purpose: This study desires to investigate an effect of indoor temperature, humidity, and illuminance targeting a planting system of double-skin facade and cavity space adjacent to the outside within a certain period of winter. Through this, the study suggests a basic material about an energy conservation effect of double window system using planting to reduce heating load of a building in winter, so desires to contribute to indoor thermal comfort effect and illuminance correction study of double window and indoor plant. Method: Considering effects such as day and night climatic elements and air conditions in winter, illuminance measurement was conducted through a double-skin facade of space, a subject of the measurement, on the basis of practical residence time of a resident, and this study analyzed characteristics of indoor illuminance about this. The study measured and compared a change of insolation, dry-bulb temperature, and relative humidity at each indoor-outdoor measuring point, so measured and compared characteristics of an indoor temperature effect by elements of double-skin facade and indoor plant. Result: Through this study, the researcher could determine that indoor plant within double window in winter not only blocks solar radiation but also photosynthesizes, so is somewhat disadvantageous to winter thermal comfort reducing heating load. In addition, solar radiation going through interior plays a role to bring down somewhat high humidity to about 50% of reasonable humidity, so plays a direct role of maintenance of comfortable indoor space. Although there are effects such as blocking of solar radiation and temperature reduction, this has a positive influence on humidity control and proper illuminance distribution. The researcher could determine that illuminance, temperature, and humidity by solar radiation penetration for the whole measuring time play a role to supplement indoor environment mutually.

Numerical Study on Human Model's Shape and Grid Dependency for Indoor Thermal Comfort Evaluation (실내 온열쾌적성 평가를 위한 인체 모델링 및 격자특성에 대한 수치해석적 연구)

  • Park, J.H.;Seo, J.W.;Choi, Y.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.210-217
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    • 2011
  • Recently, research on evaluating thermal comfort by using CFD has been vigorously active. This research evaluates not only distribution of temperature and air flow analysing but also thermal comfort in indoor space by applying human model. But research of human model's shape, Grid characteristic and turbulence model has not yet been studied. In this paper, human model's shape, physical characteristic of variable Grid, and change of turbulence model has been studies by CFD. In this study. FLUENT is used for analysis and PMV(predicted Mean Vote), PPD(Predicted Percentage Dissatisfied) and EHT(Equivalent Homogeneous Temperature} are used for evaluation and comparison of thermal comfort. As a result, it shows that shape of CSP and lattice features does not affect on global flow field or evaluation on PMV, PPD. However, it demonstrates more precise result from evaluation of thermal comfort by equivalent temperature when it used detailed human model considering prism grid.

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Investigation of school building microclimate using advanced energy equipment: Case study

  • Alwetaishi, Mamdooh;Alzaed, Ali;Sonetti, Giulia;Shrahily, Raid;Jalil, Latif
    • Environmental Engineering Research
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    • v.23 no.1
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    • pp.10-20
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    • 2018
  • Buildings are responsible of major energy consumption globally. In addition, they are linked to thermal comfort. The need to provide comfort becomes more crucial in schools as they are the place where students learn, and develop their skills. This research aims to investigate the energy responsiveness of new and traditional school building design, where major variation in form, amount of external walls and glazing are different. The research focused on indoor microclimate condition of selected schools in the city of Jeddah where the climate is hot and humid using advanced tools for monitoring. The research uses advanced energy equipment to measure several aspects such as floor temperature, roof temperature, globe temperature and other factors which can lead to predictable thermal comfort of users. The findings suggest that a larger area of glazing shielded from sunlight has a greater influence on both indoor condition and general thermal sensation. The finding also suggests that the glazing ratio is a major contributor on indoor thermal pattern which can result in an increase in temperature profile between from $7-10^{\circ}C$. The findings of this research can assist in the improvement in the design of the prototype school building in hot and humid climate.

Thermal Diary - 24 hours' Exposed Temperature and Thermal Comfort in Urban Life, Summer (여름철 도시의 일상생활에서 폭로되는 환경온도와 온냉감 평가)

  • 이민정;전정윤
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.333-337
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    • 2002
  • All the outdoor and indoor spaces are connected with each other. The human being moves toward those spaces and experiences temperature fluctuation between the natural and artificial temperature. We conducted an experiment which subjects are the college students wearing the data logger in urban life, and measured 24 hours' exposed temperature and thermal comfort in summer. Results were as follows. 1. Most subjects get weather information(84.6%). Fashion(46.2%) and weather (30.8%) are the reasons to select clothes. They spend their time in indoor environment for 84.92% hours of a day and have an air-conditioner(61.5%) in their houses. 2. Exposed temperature fluctuation were from 33.8$^{\circ}C$ to 15.6$^{\circ}C$. The median value of experienced temperature were 26-27$^{\circ}C$ and average temperature was 26.3$^{\circ}C$. Subjects experienced cold shock of 3.96 times in a day and 67.21% of all evaluated thermal comfort in the range of -1 and 1 by ASHRAE 7 Category Scales. Artificial environment which connected with outside let people experienced temperature fluctuation in wide range.

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Numerical Analysis on the Coupled Operation of Ventilation Window System and Central Cooling System (창호일체형 환기시스템 및 중앙냉방시스템 연계 운영에 대한 수치해석적 연구)

  • Park, Dong Yoon;Chang, Seongju
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.4
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    • pp.385-395
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    • 2015
  • This study evaluated indoor environmental characteristics in an office room equipped both with ventilation window system and central cooling system. Fresh air is supplied only by the central cooling system whereas indoor air is discharged outside through both ceiling diffuser and a ventilation window system. Numerical study is conducted by changing the volumetric flow rates of exhaust ports of each system. For estimating the performance of this coupled system, $CO_2$ concentration and Predicted Mean Vote (PMV) were calculated using Computational Fluid Dynamics (CFD) simulation. The more the ceiling diffuser exhausts indoor air, the more the $CO_2$ concentration decreases. However, when the ventilation window system exhausts more indoor air, thermal comfort level gets improved in the office room with cooling system. Therefore, when the ventilation window system is operated, the coupled operation with central cooling system should be considered for enhancing indoor air quality and thermal comfort, together.

Characteristics of thermal comfort for artificial environment experiment in summer (하계 인공환경실험에서의 온열쾌적특성)

  • 박종일;김경훈;홍희기;민병일;김창주
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.3
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    • pp.368-377
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    • 1998
  • The purpose of this study was to examine theory about indoor thermal comfort-environment as well as to determine thermal sensation and physiological responses for men in summer indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate(Electrocardiogram), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at SE $T^{*}$ 24.7$^{\circ}C$, -0.82<PMV<0.93, subject's clothing(0.41c1o)and the difference of skin temperature was found at the calf area as air temperature changes. At low SE $T^{*}$, heart rate was decreased and at high SE $T^{*}$, heart rate was increased but there was no change EEG(keeping $\alpha$-wave).wave).

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Post Occupancy Evaluation for Office Building with An Underfloor Air Distribution System (바닥공조 시스템이 적용된 사무공간의 거주후 성능평가)

  • Yoon, Seong-Hoon;Jang, Hyang-In;Jung, Hae-Kwon;Choi, Sun-Kyu;Yu, Ki-Hyung
    • Journal of the Korean Solar Energy Society
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    • v.31 no.6
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    • pp.78-85
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    • 2011
  • In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

The Effect of Indoor Temperature Change on Human Physiology for Comfort Control during Sleep Early Stage (쾌적제어를 위한 수면 초기 실내온도 변동이 인체 생리에 미치는 영향)

  • Shin, H.J.;Kim, D.G.;Jeong, S.K.;Kum, J.S.;Kim, H.C.
    • Journal of Power System Engineering
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    • v.11 no.3
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    • pp.29-34
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    • 2007
  • Existent researches about indoor thermal environment have been focused on to seek human's comfort in daytime. Also researches about thermal comfort during the sleeping time that is important for resting and recharging to modern people have been seldom existed. At present, as global warming phenomenon is being continued, most people are going through inconvenience by sultriness during the sleeping hours in sweltering summer night. Therefore we need another control method of an air conditioner to keep human's thermal comfort. Ambient temperature is a common factor of the environment, but analysis of its effect on human body physiology is still unknown. The effect of ambient temperature on human sleep has been increasingly studied in the last decade. This research investigated about optimal indoor temperature to maintain proper skin temperature and comfortable sleep when indoor air is cooled by an air conditioner in sweltering summer night.

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The Validation Study of Shaping Comfortable Environments Based on the PMV Index Using Facial Skin Temperature (안면 피부온도를 활용한 PMV 지표 기반 쾌적환경 조성의 타당성 연구)

  • Kim, Boseong;Min, Yoon-Ki;Shin, Esther;Kim, Jin-Ho
    • Science of Emotion and Sensibility
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    • v.16 no.3
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    • pp.311-318
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    • 2013
  • This research examined the validity of whether the PMV index-based comfort- or uncomfort-indoor environments could be classified by the facial skin temperature, one of the physiological indicator for human. To do this, we distinguished between a comfort thermal environment and an uncomfort thermal environment using the PMV value, and then facial skin temperatures were measured in both environments. As a result, the facial skin temperature of occupants were different between the comfort- and uncomfort-indoor environments. It suggested that the facial skin temperature could be used in shaping the comfortable indoor environment based on the PMV index. While this result suggested the PMV index-based on comfort and uncomfort indoor environments could not be valid, because the facial skin temperature was lower in the uncomfort thermal environment than in the comfort thermal environment.

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24 hours' Exposed Temperature and Thermal Comfort in Summer (여름철 도시의 일상생활에서 경험하는 환경온도와 온냉감 평가)

  • 전정윤;이민정
    • Journal of the Korean housing association
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    • v.14 no.3
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    • pp.51-56
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    • 2003
  • All the outdoor and indoor spaces are connected with each other. The human being moves toward those spaces with temperature fluctuation between the natural and artificial temperature. We conducted an experiment which subjects were wearing the data logger in urban life, and measured 24 hours' exposed temperature and thermal comfort in summer. Results were as follows. 1. Subjects controls their micro climate like this. Most of them(84.6%) get weather information. Fashion(46.2%) and weather(30.8%) are the reasons to select clothes. They spend their time in indoor environment for 84.92% hours of a day and have an air-conditioner(61.5%) in their houses. 2. Temperature fluctuation which subjects were exposed for 24 hours were from 15.6$^{\circ}C$ to 33.8$^{\circ}C$ and average fluctuation was 9.02$^{\circ}C$. The median value of experienced temperature were 26-26.5$^{\circ}C$ and average temperature was 26.18$^{\circ}C$. They experienced cold shock of 3.96 times in a day.