• 설비공학논문집
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• 제16권3호
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• pp.303-309
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• 2004

In order to improve thermal comfort in the Rotunda, which is high and wide visiting space of the new national museum of Korea, eight ventilating fans were installed near the ceiling of Rotunda. It has been analyzed thermal comfort of Rotunda with/without ventilating fans by numerical simulation. To evaluate thermal comfort of the Rotunda, well-known indices, PMV and PPD were introduced. The results of present investigation show that temperature distribution of the case with fans is closer to target temperature than the case with-out fans at the breathing zone. In the case without fans, thermal stratification with 16$^{\circ}C$ of temperature difference occurs along the height of the Rotunda which makes the thermal environment worse and the PPD values reach up to 50% in the 6th floor connection passage. In the case with fans, however, the vertical temperature difference were reduced to 9$^{\circ}C$ and the PPD values were lower below 20%. Consequently, the ventilating fans adopted on this study are effectively used for improving the thermal comfort in large space structure with thermal stratification.

• 대한전기학회논문지:전력기술부문A
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• 제55권10호
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• pp.399-409
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• 2006

This paper presents a novel method for satisfying the thermal comfort of indoor environment and reducing the summer peak demand power by minimizing the power consumption for an Air-conditioner within a space. Korea Electric Power Corporation (KEPCO) use the fixed duty cycle control method regardless of the indoor thermal environment. However, this method has disadvantages that energy saving depends on the set-point value of the Air-Conditioner and direct load control (DLC) has no net effects on Air-conditioners if the appliance has a lower operating cycle than the fixed duty cycle. In this paper, the variable duty cycle control method is proposed in order to compensate the weakness of conventional fixed duty cycle control method and improve the satisfaction of residents and the reduction of peak demand. The proposed method estimates the predict mean vote (PMV) at the next step with predicted temperature and humidity using the back propagation neural network model. It is possible to reduce the energy consumption by maintaining the Air-conditioner's OFF state when the PMV lies in the thermal comfort range. To verify the effectiveness of the proposed variable duty cycle control method, the case study is performed using the historical data on Sep. 7th, 2001 acquired at a classroom in Seoul and the obtained results are compared with the fixed duty cycle control method.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1213-1219
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• 2008

This experimental study was to analyze thermal comfort and indoor air quality(IAQ) with ventilation and humidification in the classroom when system air conditioner was operated. The thermal comfort was estimated by the PMV index and the concentration of $CO_2$ and total suspended particle(TSP) were measured and compared with ventilation and humidification. As a result, the class room temperature distribution was $2{\sim}5^{\circ}C$ low during operating ventilation system and humidification. At 60% RH, PMV values of measuring points were ranged from +0.5 to -0.5 indicating optimal the range of thermal comfort. The average concentration of $CO_2$ gas and TSP were reduced 645 ppm, 0.17 mg/$m^3$ respectively, during operating the ventilation system. From the results, to maintain comfortable environment in the heated classroom, the ventilation and humidification were needed in winter season.

• 한국자동차공학회논문집
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• 제20권5호
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• pp.120-129
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• 2012

As the recent advancement of automobile industry, there has been a great interest in the thermal comfort of the passengers inside the cabin of an automobile. Thermal comfort is affected by temperature, velocities, and mean radiation temperature of air, thermal resistance of clothes and physical active level of human. The present study performed computational analysis to select the location of air-conditioning vent that improves thermal comfort inside the cabin. In order to do this, we considered various air vent positions, and thermal flow analysis of each case is performed using CFD for the cabin with four passengers. The thermal comfort is evaluated using the computational results and the optimum location of air vent is suggested.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.11-21
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• 1999

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

• 설비공학논문집
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• 제12권9호
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• pp.810-816
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• 2000

Thermal comfort plays an important role in modern office buildings. Four major factors affecting thermal comfort are air temperature, velocity, humidity and radiation temperature. Distribution of these thermal factors in indoor space depends largely on the air flow which is related to the method of supplying and extracting air. In this study, an experimental analysis on indoor thermal comfort is conducted to study the difference between a ceiling supply cooling system and a floor supply one. The two cooling systems are applied to an office space during summer season and the distributions of temperature, velocity, radiation temperature and PMV are measured. Results show that the floor supply cooling system is superior in terms of thermal comfort and energy saving. Studies need to be done, however, to reduce the vertical temperature difference of a floor supply air conditioning system.

• 설비공학논문집
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• 제21권7호
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• pp.402-408
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• 2009

In this paper, the effects of ventilation and humidification on thermal comfort and indoor air quality(IAQ) were evaluated in a classroom when a heat pump system was operated in winter. Thermal comfort parameters, such as temperature, relative humidity, globe temperature and air velocity, were measured at 9 points in the classroom. The concentration of $CO_2$ and total suspended particles(TSP) in the classroom were measured in order to analyze IAQ. Temperature distribution in the classroom was decreased by $2{\sim}5^{\circ}C$ when the ventilation system and the humidifier were operated. When the relative humidity was adjusted to 60% by operating the humidifier and the ventilation system, the predicted mean vote(PMV) in the classroom was within the comfortable range of $-0.5{\sim}0.5$. When the ventilation system was operated, the average concentration of $CO_2$ and TSP were decreased by 645 ppm and 0.17 $mg/m^3$, respectively. This paper suggests the humidification and ventilation conditions to maintain the comfortable environment in the school classroom in winter experimentally.

• KIEAE Journal
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• 제15권1호
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• pp.97-102
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• 2015

Recently many buildings are airtight, deterioration takes the high stage. As this room ventilation is increasingly difficult, the importance of indoor air was emphasized. And Got a few provisions on the indoor ventilation, the building is used for other purposes also requires a lot of careful research. In this study, consisting of floor heating ventilation in the room and wants to know the impact on the human body react with the carbon dioxide concentration in the indoor air were investigated PMV. We have get the data through the experimental study like this. It can be inferred correlations of ventilation and temperature according to human comfort that you should consider when using the work of residential buildings in accordance with the changing social conditions and social. It is also determined that in the future through additional experiments related data can be established basic experimental data.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.115-123
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• 2010

Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

• 한국조경학회지
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• 제38권5호
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• pp.12-20
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• 2010

본 연구는 도시 소공간의 열환경을 개선하기 위한 방안을 모색하고자 공간 구조별 열특성을 평가하여 분석하였다. 도심 내 위치한 고려대학교 캠퍼스를 연구 대상지로 선정하였으며, 대상지 내에 공간 유형을 대표하는 각각의 장소에서 열환경을 조사하였다. 기상장비를 활용한 미기상 및 바이오 기상 측정, 어안렌즈 촬영사진(Fish-eye lens photography)를 활용한 공간구조 및 특성 분석, 그리고 온도나 습도와 같은 기상정보 및 이미지 정보를 활용한 열쾌적성 모델링의 순서로 공간의 열환경 및 인체 열쾌적성을 분석하였다. 열환경 평가 결과, 인체 열쾌적성의 정도는 캠퍼스 공간의 유형에 따라 차이가 나타났다. 건물이나 수목 등에 의해 위요된 폐쇄형 공간 유형에서 개방형 공간 유형에서 분석된 평균 복사온도, PMV, PET 지수보다 더 양호한 것을 알 수 있었다. 이러한 결과는 수목과 건물에 의한 태양복사열의 차단 및 그림자의 영향을 받기 때문이라고 할 수 있다. 그러므로 공간을 계획할 때 개방성이나 통풍성을 높이기 위한 수목의 배치를 고려하고 복사열을 차단할 수 있는 바닥포장이나 건물 외장재 종류를 선택할 필요가 있다. 본 연구는 도시 공간의 이용자가 실제적으로 느끼는 열쾌적성의 정도를 정량화하고 이를 평가함으로써 이용자를 고려한 공간계획 방안을 제안하였다.인체 열쾌적성을 평가하는 정량적 평가 방법 및 그에 따른 연구결과는 향후 도시 공간의 쾌적한 환경을 조성하는데 기여할 수 있을 것으로 판단된다.