• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.970-975
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• 2008

This study considers indoor thermal comfort in an ondol space by supply vent configurations to prevent cold draft in winter. A specially-designed vent cap has been investigated in comparison with a round pan-type vent and a simple opening without a cap. Numerical simulations have been conducted using CFD to analyze thermal comfort indices such as Predicted Mean Vote (PMV) and Effective Draft Temperature (EDT) as well as air distribution index i.e. Air Diffusion Performance Index (ADPI). Results show the new vent cap provides improved thermal comfort conditions especially near ondol heated floor, as the cold outdoor air spreads upwards along the vertical wall before reaching occupant region near floor. This paper includes discussions on the flow and comfort distributions created by the thermal jets from the vents.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.216-222
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• 2011

Recently, hybrid air-conditioning system has been proposed and applied to achieve building energy saving. One example is a system combining radiation panel with natural wind-induced cross-ventilation. However, few research works have been conducted on the non-uniformity of thermal comfort in such hybrid air-conditioning system. In this paper, both thermal environment and non-uniform thermal comfort of human thermal model under various air-conditioning system, including hybrid system, were evaluated in a typical office room using coupled simulation of computation fluid dynamics, radiation model and a human thermal model. The non-uniformity of thermal comfort was evaluated from the deviation of surface temperature of human thermal model. Flow fields and temperature distribution in each case were represented.

• Journal of the Korean Home Economics Association
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• v.30 no.2
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• pp.81-86
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• 1992

The purpose of this study was to investigate the psychophysical correponding to temperature and to establish the comfort zone of thermal environment for Korean in winter. An experimental investigation was carried out in climate chamber maintaining the air temperature at 20, 22, 24, 26℃ and subjects were 128 college-age Korean(64 males and 64 females) in good health. Data were analyzed by SPSS PC＋ packages. 'Neutral' on the thermal sensation ratings was most frequently indicated at 24℃ by subjects was 23.1℃ (male 24.0℃, female 22.7℃), therefore the comfort zone of thermal environment in winter was considered as 23∼24℃.

• Journal of East-West Nursing Research
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• v.26 no.2
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• pp.149-156
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• 2020

Purpose: The purpose of this study was to identify the effects of the heated-humidified breathing circuit applied on the body temperature, shivering, and thermal comfort of general anesthesia patients. Methods: The participants were patients who received general anesthesia at University Hospital K located in City B, with 25 patients in the experimental group and 25 patients in the control group. The period of this study was from Mar 19 to Apr 26, 2019. The experimental equipment included a heated-humidified breathing circuit, which connects the intubation tube with the anesthesia machine for mechanical ventilation after airway intubation in general anesthesia patients. Results: The body temperature, shivering, and thermal comfort after surgery were significantly different between the two groups (p<.001). However, the body temperature during surgery was slightly different between the experimental group and the control group. Conclusion: A heated-humidified breathing circuit may be actively used in a warming method to prevent the hypothermia of general anesthesia patients.

• 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$T^+$.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.1-7
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• 2009

In order to evaluate environmental comfort of tractor cabs, temperature, relative humidity and noise within the cab were taken from 31 tractors during plowing and rotovating operations. The temperature and humidity were evaluated with regard to the comfort zone of KS B ISO 14269-2 and PMV of ISO 7730. The noise was evaluated with regard to the permissible sound level of OSHA for daily exposure of 8 hours. The collected data indicated that thermal environment of the cabs was out of the comfort zone, which meant tractor operators worked under uncomfortable thermal conditions. Difference in the thermal comfort by tractor power and maker, and type of works was not found. However, 25% of the studied tractors showed PMV in a range of -0.5 to +0.5, which indicated their operators worked under the comfort criteria. PMV was improved when the cab was air-conditioned. Levels of measured cab noise were lower than the permissible criteria, and 76.7% of the studied tractors had cab noise ranged from 75 to 85 dBA. There was a tendency that high powered tractors, rotovating operations and locally-made tractors had greater cab noise levels. However, their differences were insignificant.

• 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 $5^{\circ})\;and\;7^{\circ}$).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.9
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• pp.610-619
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• 2011

This paper investigates the simplified comfort index and control logic for VRF (Variable Refrigerant Flow) system by using 3 environmental factors such as temperature, humidity and air flow. Indoor test under thermal load was conducted to explore relationship of each environment factors that is related to simplified comfort index. Simplified comfort function that has 3 environmental variables was proposed based on survey results. Each factor is measured and comfort preference was surveyed by more than 30 subjects in the indoor comfort test. Moreover, control logic for VRF system was developed and then simulated by using thermal load calculation method and verified with test. The proposed comfort function was in good agreement with survey results, and also verification test trend of comfort change and maintenance are quite similar with survey. Furthermore, through the additional test data analysis some differences of comfort according to position of people staying in the test room were additionally investigated by air flow. People being under an exit of air in the indoor air-conditioner feel more comfortable condition and speed of response to comfort change is relatively fast.

• International Journal of Air-Conditioning and Refrigeration
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• v.12 no.2
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• pp.108-112
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• 2004

The purpose of this study is to investigate the characteristics of thermal comfort index and to present the thermal comfort range through regression analyses and experiment in a radiant floor heating system laboratory. The results were compared to the comfort zone of ISO-7730, and the applicability of the thermal comfort index to a radiant floor heating system was studied. On comparing the sedentary posture on the floor to sitting on the chair, the comfort zone and the neutral point of comfort index showed different values. It is considered that the influence of conduction from floor to the human is sufficient. Moreover, we could find a correlation between the thermal sensation votes of subjects, and the comfort indexes were lower than those by calculation.

• KIEAE Journal
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• v.10 no.4
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• pp.67-73
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• 2010

As more and more people desire to live in an apartment complex with a comfortable outdoor space, many construction company became interested in outdoor design. In order to increase the use of outdoor space and create the most pleasant environment, outdoor thermal environment and comfort should be evaluated quantitatively from the design stage. This study utilized ENVI-met 3.1 model to analyze outdoor thermal environment in apartment complex, and evaluated outdoor thermal comfort in 6 points of apartment complex. The physiologically equivalent temperature(PET) was employed as a outdoor thermal index. Playground B had a poor thermal environment with the maximum PET $43^{\circ}C$ (Very hot). Because shading by building and tree didn't affect outdoor thermal environment of playground B. To design comfortable outdoor space from the view point of thermal environment, the factors influencing Mean radiant temperature(MRT) and wind speed should be considered in design stage. Since it is difficult to control outdoor thermal environment compared with indoor environment, we should take into account an assessment for outdoor thermal environment and comfort in outdoor design stage.