• Title/Summary/Keyword: Floor heating

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An Experimental Study on the Thermal Efficiency of the Ondol House Beating System (온돌의 열효율에 관한 실험적 연구)

  • Bae soonhoon;Kang Shin-Hyoung
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.4 no.3
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    • pp.183-190
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    • 1975
  • Most Korean houses are heated by the Ondol heating system. There has been, however, no reasonable design procedure availabe yet for the system. The conventional design should be improved to have auniform floor surface. temperature distribution and to have a high thermal efficiency. Thermal efficiencies of the ondol were defined and the method of experimentation was studied. An experiment, using a life-size model which was well insulated, was performed to observe the variation in thermal efficiency as the length of fuel burning time was varied.

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Estimation of Indoor Environment using CFD of Multi-Purpose System with a Solar Collector -Part 1, focused on floor area and number of ventilation- (태양열온수기 적용 냉난방시스템의 CFD를 이용한 실내환경 평가 -제1보 바닥면적과 환기횟수를 중심으로-)

  • Kim, Jong-Ryeol;Choi, Kyang-Hyan
    • Journal of the Korean Solar Energy Society
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    • v.27 no.3
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    • pp.55-61
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    • 2007
  • This paper has been conducted to estimate cooling capacity of the dehumidification tower using hot water from a solar water heating system as a energy source of regeneration process when the dehumidification and drying system is applied to room cooling. A solar water heating system was operated and indoor temperature distributions were simulated according to weather conditions when the concerned solution was used to dehumidify room air in the dehumidification tower. Through this simulation researches we found th following results ; It was found that air velocity through supply and return diffusers should be controlled because it can cause uncomfort in dwelling area. It was found that in the sunny morning temperatures of dwelling area 1 and 2 are higher than those of dwelling area 3 and 4. In this research all the calculation results of heating and cooling system supported by solar water heater have confirmed that its cooling capacity could not reach PMV 0, thermal comfort.

A Field Study on the Facilities and Equipments of the Traditional Farmhouse in Lungching, China (중국 연변 조선족 전통농가의 시설설비 실태조사)

  • 고도임
    • Journal of the Korean Home Economics Association
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    • v.36 no.6
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    • pp.123-132
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    • 1998
  • This paper is a part of "The Study of the Traditionla Korean Ethnic Farmhousing in Yanbian, China" The purpose of this study is to investigate the facilities and equipments of the traditional farmhouse in the villages of Lungching China. The data is collected from 124 households in the villages based on the survey conducted using questionnaire and photograph. The major findings are: 1) The people in farmhouse use wood as a fuel for cooking and the method of cooking is traditional style using their iron pots. 2) Heating system of the house is ondol type of heating using. wood which is also traditional type. This means that the floor heating of the house and cooking food can be carried out simultaneously. 3) Even though pump system and running water system are the two kinds of water supply that are available in the villages, majority of people use pump system. Many houses have no drainage facilities but few houses have got bad drainage system. 4) From the planning stage of the farm house facilities and equipments for ventilation is not considered and hence it is not provided in most of the houses. 5) Farmhouses are oriented to the south and the windows and the doors are covered either with viny1 or cloth during winter time effecting the lighting system of the house. 6)Many of the houses use incandescent lights. But the switchs and the electric Outlets are short in number. 7) Sanitation facilities are worst equipped compared to other facilities present in Lungching villages of China. of China.

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The Study on Indoor Thermal Environment during Convection Heating - Thermal Comfort Sensation for Vertical Temperature Differences - (대류 난방시 실내열환경에 관한 연구 -상하온도차에 대한 온열쾌적감-)

  • Kim Dong-Gyu;Kum Jong-Soo
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.215-220
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    • 2005
  • Thermal neutrality is not enough to achieve thermal comfort. The temperature level can be the optimal, and still people may complain. This situation is often explained by the problem of local discomfort. Local discomfort can be caused by radiant asymmetry, local air velocities, too warm and too cold floor temperature and vertical temperature difference. This temperature difference may generate thermal discomfort due to different thermal sensation in different body parts. Therefore, thermal comfort can not be correctly evaluated without considering these differences. This study investigates thermal discomfort sensations of different body parts and its effect on overall thermal sensation and comfort in air-heating room. Experimental results of evaluating thermal discomfort at different body parts in an air-heating room showed that thermal sensation on the shoulder was significantly related to the overall thermal sensation and discomfort. Although it is known that cool-head, warm-foot condition is good for comfort living, cool temperature around the head generated discomfort.

An Analysis on Building Energy Load along Core Position, Area Ratio and Orientation (코어 위치와 종횡비 및 방위에 따른 건물 에너지 부하 분석)

  • Kim, Jin-Ho;Park, Woo-Pyoung;Shin, Seung-Ho;Min, Joon-Ki;Kim, Dong-Hoon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.9 no.1
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    • pp.15-19
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    • 2013
  • In this Study, effect of core position, area ratio and orientation of building on energy load is examined using TRNSYS17. This parameters are major parameters of the conceptual design stage. Reference model is square floor plan($1,444m^2$), centered core and 29% core area ratio. As the results, without considering the building orientation, the annual heating load of central building with 1:1 area ratio is lowest ($10.33kWh/m^2yr$) and the annual cooling load of off-central building with 1:1 area ratio is lowest ($59.27kWh/m^2yr$). As area ratio is bigger, cooling load is lower and heating load is higher. But if we consider building orientation, orders of heating load and cooling load are changed for area ratio and orientation.

Effects of Various Factors on the Energy Consumption of Korean-Style Apartment Houses (한국형 아파트의 냉난방 에너지에 미치는 제 인자의 영향)

  • 유호선;현석균;홍희기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.11
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    • pp.972-980
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    • 2002
  • This work is aimed at estimating the effects of various factors on the energy consumption of Korean-style apartment houses using TRNSYS. The factors considered here include the nominal size of floor area, type of remodeling, azimuth, sidewall insulation, and window type. Based on some assumptions, an actual apartment house is simplified into a model that is used for thermal load calculations. The simplified model is validated by showing a good agreement with the actual one in the predicted result. Remodeling balconies into unconditioned buffer spaces yields a favorable thermal performance in comparison with the original type regardless of the nominal size. Incorporating balconies into a conditioned indoor space leads to sharp increases in thermal loads, which must be avoided in view of energy conservation as well as structural problem. A quantitative assessment on the azimuthal effect indicates that the heating energy can be saved up to 16% by taking the south or southeast direction. Reduction in the heating load with enhancing the sidewall insulation is gradual, so that a cost-effectiveness analysis may be needed when amending the regulations concerned. Glazing appears to significantly affect the heat transfer through window. A typical case illustrates that the heating load is decreased about 25% by simply adopting triple glazing instead of double glazing.

Assessment of Utilization of Auxiliary Heating Device for Prevention of Condensation in Built-in Furniture in Winter (겨울철 공동주택에서 붙박이장 내 보조난방장치를 활용한 결로 저감 효과 평가)

  • Lee, Hyun-Hwa;Lim, Jae-Han;Song, Seung-Yeong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.33 no.12
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    • pp.99-106
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    • 2017
  • Recently, the condensation and mold problems of apartment buildings has been growing due to high insulation and high air-tightness performance for energy saving. Most of all, occupants in residential buildings has suffered from property damages due to the condensation and mold of built-in furniture. Condensation at built-in furniture were generally found in winter at the of furniture's back panels, adjacent surfaces of wall, floor and ceiling. The aim of paper is to analyze the characteristics of adjacent area around built-in furniture's condensation problem and the thermal environment around the built-in furniture in winter through the field measurements at apartment buildings. In this research, the thermal conditions and surface temperature around the built-in furniture were measured during winter season. In this research, we analyzed thermal conditions for built-in furniture which were applied and not applied auxiliary heating device. In results, it is important to consider increasing surface temperature for using heater and decreasing absolute humidity due to the occupants' behavior around built-in furniture for preventing condensation.

Energy Performance Evaluation of Apartment Houses According to Window Energy Consumption Efficiency Rating System in Korea (창호 에너지소비효율등급제에 따른 공동주택의 열성능 평가)

  • Lim, Hee Won;Kim, Dong Yun;Lee, Soo Man;An, Jung Hyuk;Yoon, Jong Ho;Shin, U Cheul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.30 no.4
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    • pp.159-166
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    • 2018
  • The Korean fenestration energy consumption efficiency rating system only considers thermal performance of the heat transfer coefficient (U-value) and airtightness excluding optical characteristics of the solar heat gain coefficient (SHGC). This study analyzed annual heating and cooling energy requirements on the middle floor of apartment by optical and thermal performance of windows to evaluate the suitability of the rating system. One hundred and twenty-eight windows were analyzed using THERM and WINDOW 7.4, and energy simulation for a reference model of an apartment house facing south was performed using TRNSYS 17. The results showed that window performance was the main factor in the heating and cooling load. The heating load of the reference model was 539 kWh to 2,022 kW, and the cooling load was 376 kWh to 1,443 kWh. The coefficient of determination ($R^2$) of the heating and cooling loads driven from the SHGC were 0.7437 and 0.9869, which are more compatible than those from the U-value, 0.0558 and 0.4781. Therefore, it is not reasonable to evaluate the energy performance of windows using only the U-value, and the Korean fenestration energy consumption efficiency rating system requires a new evaluation standard, including SHGC.

Dynamic Simulation of Ground Source Heat Pump with a Vertical U-tube Ground Heat Exchanger (수직형 U자 관 지중 열교환기를 갖는 지열원 열펌프의 동적 시뮬레이션)

  • Lee, Myung-Taek;Kim, Young-Il;Kang, Byung-Ha
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.5
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    • pp.372-378
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    • 2007
  • GHX (Geothermal Heat Exchanger) design which determines the performance and initial cost is the most important factor in ground source heat pump system. Performance of GHX is strongly dependent on the thermal resistance of soil, grout and pipe. In general, GHX design is based on the static simulation program. In this study, dynamic simulation has been peformed to analyze the variation of system performance for various GHX parameters. Line-source theory has been applied to calculate the variation of ground temperature. The averaged weather data measured during a 10-year period $(1991\sim2000)$ in Seoul is used to calculate cooling and heating loads of a building with a floor area of $100m^2$. The simulation results indicate that thermal properties of borehole play significant effect on the overall performance. Change of grout thermal conductivity from 0.4 to $3.0W/(m^{\circ}C)$ increases COP of heating by 9.4% and cooling by 17%. Change of soil thermal conductivity from 1.5 to $4.0W/(m^{\circ}C)$ increases COP of heating by 13.3% and cooling by 4.4%. Change of GHX(length from 100 to 200 m increases COP of heating by 10.6% and cooling by 10.2%. To study long term performance, dynamic simulation has been conducted for a 20-year period and the result showed that soil temperature decreases by $1^{\circ}C$, heating COP decreases by 2.7% and cooling COP decreases by 1.4%.

The verification about possibility of introducing Window to Floor Ratio as design index for building energy performance

  • Choi, Won-Ki;Lee, Yong-Jun;Lee, Hyun-Soo;Eom, Jae-Yong;Lee, Chung-Kook
    • KIEAE Journal
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    • v.17 no.1
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    • pp.23-28
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    • 2017
  • Purpose: Many design index that are using in planning phase have been developed. The most popular things among them are Window to Wall Ratio and Surface to Volume Ratio. However there are some limits. Window to Wall Ratio cannot consider building size and Surface to Volume Ratio cannot do Window to Wall Ratio. Accordingly, in this paper, the Window to Floor Ratio was proposed that it can be considered both building size and Window to Wall Ratio. And analyzed correlation of energy demand. Method: For the test, 16 modules with the size of $6m{\times}6m{\times}4m$ were used to make 35 models with the same volume. The simulation was conducted to 945 cases using the window-to-wall ratio of 30, 50 and 70 % in three areas such as Seoul, Gwangju and Jeju and three kinds of windows. And IES_VE was used. Result: The findings above show that the Window to Floor Ratio that can be considered both building size and Window area have to become as design index. It was found out that design criteria with SHGC is necessary, not with the thermal performance (U-value). It is needed to additional analysis about residential building and the effect of 24-hours heating and cooling condition. It plans to carry out research to establish design indicators for climatic conditions in the country and building applications.