• Title/Summary/Keyword: Predicted mean vote

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Characteristics of Thermal Environments and Evaluation of Thermal Comfort in Office Building in Summer (여름철 사무실내 온열환경 특성 및 쾌적성 평가)

  • Lee, C.H.;Bae, G.N.;Choi, H.C.;Lee, C.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.3
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    • pp.206-217
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    • 1994
  • In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 212 occupants were questioned to evaluate Korean thermal comfort in office building in summer. Thermal and comfort sensations were estimated using PMV(Predicted Mean Vote) and ET* (New Effective Temperature) which are most widely used nowadays. Comparing this experimental result with international standards and that of other research, Korean thermal responses were discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained: TSV=0.461ET*-11.808 and neutral temperature is $25.6^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $24.0{\sim}26.8^{\circ}C$, which is about $1^{\circ}C$ higher than that of ANSI/ASHRAE Standard.

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A Study on the Comparison of Thermal Comport Performance Indices for Cooling Loads in the Classroom (학교건물에서 냉방부하에 따른 열적 쾌적성 평가지표 비교 연구)

  • Noh, Kwang-Chul;Oh, Myung-Do
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1274-1279
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    • 2004
  • We performed the numerical study on the comparison of thermal comport performance indices for cooling loads in the classroom when the 4-way cassette air-conditioner is mounted on the ceiling. We investigated the velocity and the temperature distribution of the classroom as with respect to the variation of the air diffusion angle of the air-conditioner. Air diffusion performance index and Predicted mean vote were used for analyzing the characteristics of the thermal comport in the classroom and comparing their values each other. From the numerical results, we knew that the thermal comport is largely affected by the air diffusion angle and velocity of the air-conditioner. And we also found out that the qualitative tendency of the distribution between Air diffusion performance index and Predicted mean vote is very similar in all occupied zone.

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Characteristics of Thermal Environments and Evaluation of Thermal Comfort in Office Building in Winter (겨울철 사무실내 온열환경 특성 및 쾌적성 평가)

  • Bae, G.N.;Lee, C.H.;Lee, C.S.;Choi, H.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.2
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    • pp.310-318
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    • 1995
  • In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 138 occupants were questioned to evaluate Korean thermal comfort in office building in winter. Thermal sensation was estimated by using PMV(Predicted Mean Vote) and ET*(New Effective Temperature) indices. Comparing present experimental result with international standards and that of other research, Korean thermal responses were discussed. Seasonal difference between summer and winter was also discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained; TSV=0.432ET*-8.814 and neutral temperature is $20.4^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $19.4{\sim}22.4^{\circ}C$.

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Evaluation of Korean Thermal Sensation in Office Buildings During the Summer Season (여름철 사무실내 한국인의 온열감 평가)

  • Bae, G.N.;Lee, C.H.;Lee, C.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.2
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    • pp.341-352
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    • 1995
  • In this study, thermal parameters were measured and 213 occupants were also questioned in three office buildings located in Seoul during the summer season. Predicted mean vote-predicted percentage of dissatisfied(PMV-PPD) and standard new effective temperature(SET*) were used for evaluating Korean thermal sensation. The distribution of thermal sensation vote(TSV) and percentage of dissatisfied(PD) is very similar to that of PMV and PPD. By regression analysis, the following regression equation was obtained; TSV=0.339SET*-8.583. In this case, neutral temperature and comfort range are $25.3^{\circ}C$, $23.8{\sim}26.8^{\circ}C$ respectively. Present experimental results obtained from the field study is less sensitive to the temperature change than those obtained from the climate chamber study in Korea. But, thermal sensations are similar to each other near the neutral point. The neutral temperature and comfort range obtained by this experiment are higher than those of ANSI/ASHRAE Standard 55-1974 about $1.4{\sim}1.8^{\circ}C$.

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Effects of relative humidity on comfort sensation by comparison between the young and the aged (여름철 냉방시 상대습도가 쾌적감에 미치는 영향(청년과 고령자의 비교를 중심으로))

  • 김동규;금종수;최광환;박희욱;김종열;주익성
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.4
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    • pp.381-388
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    • 1998
  • Hot and humid weather in summer generally brings about discomfort. Experiments on which relative humidity makes effects on the comfort sensation were performed to the young and the aged using sensation vote. From July to October 1996, seven college students and eleven aged people were exposed for 2 hours under six different conditions in the Pukyong National University test chamber so as to determine the effects of relative humidity on thermal and comfort sensations. Subjects were wearing same clothes, and the mean clo value was 0.5. The mean radiant temperature was equal to the air temperature and air velocity in the occupied zone around 0.lm/s. In the experiments, it was found that discomfort could be largely reduced when the humidity is controlled to low values in the settled high temperature.

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Characteristics of Thermal Comfort in Environment Chamber for Winter

  • Kim, Kyung-Hoon;Park, Jong-Il;Song, Yong-Gil
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.1
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    • pp.73-83
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    • 2000
  • The purpose of this study is to analyze and characterize the correlation of the thermal comfort sensation with physiological responses for men in winter indoor environment. A number of experiments were conducted under twenty different environmental conditions with college male students. Clinical information on each participant was reported in terms of electrocardiogram (ECG), electroencephalogram (EEG) and self-centered evaluation. The comfort zone in winter is found, throughout the study, at Standard New Effective Temperature (SET$T^+$) of 25.2$^{\circ}C$, Predicted Mean Vote (PMV) between 0.27 and 0.62, and Thermal Sensation Vote (TSV) in the range of -0.76 and 0.36. The largest difference in skin temperature is measured at the calf area with respect to air temperature changes. Skin sensitivity to environment temperature is explained as calf, head, chest and abdomen in descending order. Change in heat rate is analyzed to be in parallel with that of SET$T^+$.

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Assessment of Thermal Comfort in a General Hospital in Winter Using Predicted Mean Vote (PMV) (Predicted Mean Vote(PMV)를 이용한 겨울철 종합병원의 실내 온·열 환경의 평가)

  • Lee, Boram;Kim, Jeonghoon;Kim, KyooSang;Kim, Hyejin;Lee, Kiyoung
    • Journal of Environmental Health Sciences
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    • v.41 no.6
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    • pp.389-396
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    • 2015
  • Objectives: A hospital is a complex building that serves many different purposes. It has a major impact on patient's well-being as well as on the work efficiency of the hospital staff. Thermal comfort is one of the major factors in indoor comfort. The purpose of this study was to determine thermal comfort in various locations in a hospital. Methods: Various indoor environmental conditions in a general hospital were measured in February 2014. The predicted mean vote (PMV) and carbon dioxide ($CO_2$) concentration were measured simultaneously in the lobby, office, restaurant, and ward. Results: The ward was the most thermally comfortable location (PMV=0.44) and the lobby was the most uncomfortable (PMV = -1.39). However, the $CO_2$ concentration was the highest in the ward (896 ppm) and the lowest in the lobby (572 ppm). The average PMV value was the most comfortable in the ward and the lowest in the lobby. In contrast, for concentration of carbon dioxide, the highest average was in the ward and the lowest in the lobby. Due to air conditioner operation, during operating hours the PMV showed values close to 0 compared to the non-operating time. Correlation between PMV and $CO_2$ differed by location. Conclusion: The PMV and concentration of carbon dioxide of the hospital lobby, office, restaurant and ward varied. The relationship between PMV and carbon dioxide differed by location. Consideration of how to apply PMV and carbon dioxide is needed when evaluating indoor comfort.

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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Thermal Comfort Range of Radiant Floor Heating System by Residential Style (생활특성에 따른 바닥복사난방 공간의 열쾌적 범위에 관한 연구)

  • Kim, Sang-Hun;Chung, Kwang-Seop;Kim, Young-Il
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.11 no.1
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    • pp.7-14
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    • 2015
  • This study has been purposed to provide thermal comfort range in accordance with the residential style of radiant floor heating space, and to compare it with the thermal comfort range at predicted mean vote. The survey for the thermal sensation vote to the subjects and the measurement of environmental factors has been executed, and regression analysis has been performed. It is interpreted that the combination of the physical factor and the psychological factor results lower neutral point of the floor sitting style than that of the chair sitting style. There are some difference between the measured predicted mean vote and the thermal sensation vote via survey, which appears to be caused by distinctive heat transfer characteristic of floor radiant heating space, such as, high radiant temperature and contact thermal sensation of floor surface.