• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.925-930
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• 2008

As office automation appliances and communication equipments are adopted in office buildings, internal heat gains increase gradually. When making simulation model, internal heat gains are usually set up with standard values or ignored. Therefore, the impact of the internal heat gains has been ignored or not been focused although it is recognised as significant contributor to heating/cooling load of buildings. This study focused on the impact of internal heat gains on curtain wall buildings. the amount and schedules of heat internal gains profiles not only affect the profiles of heating/cooling loads, but also make impact on reducing the effectiveness of high performance glazing systems. It is important to identify internal heat gains profiles before considering the installation of high performance glazing systems.

• 설비공학논문집
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• 제29권3호
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• pp.97-104
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• 2017

Reinforcement of insulation in apartment buildings reduces the heating and cooling energy consumption by lowering the heat transfer in the building envelope. There are differences between internal and external insulation methods in heat transmission properties. However, some building load calculation programs cannot analysis the differences between the two. This is because these programs do no account for the timelag or thermal storage effect of the wall according to the location of insulation. In this study, the heat transmission characteristics of internal and external insulation were analyzed by EnergyPlus, and heating and cooling energy demand was compared. The results showed that external insulation system had lower heating and cooling loads than internal insulation system. Also the heat transfer rate of external insulation is steadier than internal insulation. About 13.6% of heating and cooling energy demand decreased when the outdoor wall was finished with external insulation compared to the demand with internal insulation.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.217-222
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• 2011

This study examined the cooling performance of a solar heating and cooling system for an office building using the dynamic simulation program (TRNSYS). This solar heating and cooling system incorporates evacuated tube solar collectors of $204m^2$, storage tank of $8m^3$, 116.2kW auxiliary heater, single-effect $LiBr/H_2O$ absorption chiller of 20RT nominal cooling capacity. It was found that for the representing day showed peak cooling load the annual average collection efficiency of the collector was 32.9% and coefficient of performance of single-effect $LiBr/H_2O$ absorption chiller was 0.68. And the results shows for the cooling season the solar fraction of the solar heating and cooling system was 32.2% and maximal and minimal solar fraction was 63.4% for May 17.9% for July respectively.

• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.66-72
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• 2009

As 'Low Carbon Green Building' is highly required, programs to evaluate building performance are actively and commonly used. For most of these programs, dynamic responses of buildings against external weather changes are very important. In order to simulate the programs, weather data of each region must be properly entered to estimate accurate amount of building energy consumption. To this end, the existing weather data and weather data of KSES were compared and analyzed to find out how weather changes. Energy load of Korea's standard houses was also analyzed based on this data. As a result, data corresponding to June ${\sim}$ September when cooling is supplied shows 23% of average increase with 30% of peak increase(June). On the other hand, data corresponding to November ${\sim}$ February when heating is supplied shows 29% of average decrease with 34% of peak decrease(November). Increase in cooling load and decrease in heating load in the above data comparison/analysis show that KSES 2009 data reflects increase in average temperature caused by global warming unlike the existing data. Increase in dry-bulb temperature depending on weather change of standard houses increases cooling load by 17% and decreases heating load by 36%

• KIEAE Journal
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• 제12권4호
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• pp.89-95
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• 2012

At present, many countries are trying to reduce green gas emissions to mitigate the effects of these gases on climate change. Year after year, there have been efforts to cut energy use for heating and cooling. Heating and cooling systems, common in all forms of housing, are increasing due to the constant supply of new housing resulting from improvements in economic growth and the quality of life. Thus, studies related to the design of cooling and heating systems to improve energy efficiency are expanding. Among the new designs, radiant floor cooling and heating systems which use capillary tubes are becoming viable means of reducing energy use. Radiant floor cooling and heating systems which use capillary tubes are creative and sustainable systems in which cool and hot water is circulated into capillary tube which has small diameter. In this study, the cooling and heating performance of this type of capillary tube system is investigated in an experimental study and a simulation using TRNSYS. The results of the experimental study show that under a peak load, a capillary tube radiant floor cooling system using geothermal energy can achieve desired indoor temperature without an additional heat source. The set room air temperature is maintained while the floor surface temperature, PMV and PPD remain within the comfort range. Also, this system is more economic than a packaged air conditioner system due to its higher COP. The results of the simulation show that the capillary tube radiant floor heating system maintains set temperature more stable than a PB pipe radiant floor heating system due to its lower supply temperature of hot water. In terms of energy consumption, the capillary tube radiant floor heating system is more efficient than the PB pipe radiant floor heating system.

• 설비공학논문집
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• 제15권6호
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• pp.454-460
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• 2003

In order to investigate the cooling and heating characteristics of a variable-capacity system A/C applying a digital scroll compressor, the cooling and heating capacities and COP are measured by the psychrometric calorimeter. The capacity of the system is controlled by the digital scroll compressor, which is operated by controling PWM valve and the loading vs. unloading time. In the case of unloading compared that of loading, the consumption power of the compressor is about 11% and the capacity variation of the system A/C is within about 1%. When the system A/C is operated under the cooling and heating standard conditions, COP is nearly uniform but cooling capacity and heating capacity increase at minimum, rated and maximum modes. The system A/C applying the digital scroll compressor is effective for the range with high load or the width of large load variation. When the auxiliary heater is on, at the cold region, the system A/C produces the excellent heating capacity.

• 설비공학논문집
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• 제20권4호
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• pp.245-251
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the heating-main operating mode were investigated experimentally. The system adopted a variable speed compressor with four indoor units and one outdoor unit with R-410A. In the heating-main mode, the cooling capacity was lower than the design cooling capacity due to the reduction of the flow rate in the indoor unit for the cooling, with the increase of the heating capacity. To solve these problems, the performance characteristics of the simultaneous heating and cooling heat pump in the heating-main mode were investigated by varying the flow rate to the indoor unit for the cooling and the compressor rotating speed. In addition, the adequate control methods were suggested to improve the system efficiency.

• 생물환경조절학회지
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• 제25권4호
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• pp.308-319
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• 2016

온실의 냉난방시스템 설계 기준에 적용하기 위한 외부기상조건을 설정하기 위하여 난방 설계용 외기온, 난방 degree-hour, 냉방 설계용 건구온도, 습구온도, 일사량을 분석하여 제시하였다. 우리나라 전 지역을 대상으로 현재 기상청에서 제공하는 기후평년값 기준인 1981~2010년까지 30년간의 매 시각 기상자료를 분석에 사용하였다. 표준기상데이터의 이용이 제한적이기 때문에 30년간의 전체 기상자료를 이용하여 설계용 기상조건을 구하고, 전체 자료기간의 평균값을 설계기준으로 제시하였다. TAC 방식으로 위험률 1, 2.5, 5%에 대한 설계용 기상자료를 분석하고, 설계기준에서 추천하고 있는 난방용은 위험률 1%, 냉방용은 위험률 2.5%의 기상조건 분포도를 제시하였다. 지역별, 위험률별 및 설정온도별로 최대난방부하, 기간난방부하 및 최대냉방부하의 변화를 고찰하였다. 제시된 각종 설계용 기상조건은 온실의 냉난방시스템 설계에 직접 이용할 수 있을 뿐만 아니라 냉난방 설비 보강이나 에너지 절감대책의 수립에 활용이 가능할 것으로 판단된다. 한편 기후변화로 인하여 최근 여름철 폭염이나 겨울철 이상고온 현상이 자주 발생하고 있으므로 주기적인 설계용 기상자료의 분석이 필요하고, 최소한 10년 주기로 설계기준을 개정할 필요가 있는 것으로 생각된다. 본 연구에서는 현재 기후평년값 기준인 1981~2010년까지의 기상자료를 분석하였으나 이 기준이 1991~2020년으로 바뀌는 2021년에는 즉시 이 기간의 기상자료를 분석하여 새로운 설계기준으로 제공해야 할 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• 제45권1호
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• pp.1-11
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• 2017

건축물에서 냉방과 난방에 많은 양의 에너지가 소요되고 있다. 건축은 $CO_2$ 발생을 줄이고 에너지 소비 저감을 위하여 냉 난방 부하를 최소화할 필요성이 있다. 그리고 최근 주거문화는 친환경적이고 실내 쾌적성을 중시하는 방향으로 변화하면서 단독주택의 수요가 증가하고 있다. 국내 단독주택의 구조는 크게 조적조, 콘크리트조, 목조 주택으로 구분할 수 있다. 따라서 본 논문은 세 가지 구조방식(조적, 콘크리트, 목조)으로 구성된 동일 면적 단독주택의 냉 난방 부하와 에너지 요구량을 분석하였다. 구조방식별 벽체, 지붕, 바닥 레이어를 구성하였고, 각 레이어의 열관류율(U-value)은 목조 벽체와 같이 스터드를 고려해주기 위하여 PHPP 계산법을 이용하였다. 또한 스터드 유무에 따른 차이를 비교 분석하기 위하여 목조 벽체에서 스터드를 고려하지 않은 경우(비 스터드)를 분석하였다. 분석은 엑셀을 기반으로 자체 개발한 냉 난방 부하 산출 프로그램(CHLC)과 ECO2를 이용하였다. 냉 난방 부하와 에너지 요구량 결과, 목조 구조가 가장 높은 결과를 보였고 콘크리트 구조는 두 번째로 높은 값을 유지하는 것을 확인하였다. 두 구조방식은 에너지소비 측면에서 불리하다고 판단하였다. 결론적으로, 동일한 조건에서의 조적 구조는 다른 구조방식에 비하여 냉 난방 부하 및 에너지 요구량에 있어 유리하며, 목조 구조에서 스터드로 인한 열교를 제외한다면 에너지소비를 줄일 수 있다고 판단되었다.

• 생물환경조절학회지
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• 제32권3호
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• pp.181-189
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• 2023

수소는 다양한 신재생에너지 중 환경친화적인 에너지로 각광받고 있지만 농업에 적용된 사례는 드물다. 본 연구는 수소연료전지 삼중 열병합 시스템을 온실에 적용하여 에너지를 절약하고 온실가스를 줄이고자 한다. 이 시스템은 배출된 열을 회수하면서 수소로부터 난방, 냉각 및 전기를 생산할 수 있다. 수소 연료 전지 삼중 열 병합 시스템을 온실에 적용하기 위해서는 온실의 냉난방 부하 분석이 필요하다. 이를 위해서는 온실의 형태, 냉난방 시스템, 작물 등을 고려해야 한다. 따라서 본 연구에서는 건물 에너지 시뮬레이션(BES)을 활용하여 냉난방 부하를 추정하고자 한다. 전주지역의 토마토를 재배하는 반밀폐형 온실을 대상으로 2012년부터 2021년까지의 기상데이터를 수집하여 분석했다. 온실 설계도를 참고하여 피복재와 골조를 모델화하여 작물 에너지와 토양 에너지 교환을 실시했다. 건물 에너지 시뮬레이션의 유효성을 검증하기 위해 작물의 유무에 의한 분석, 정적 에너지 및 동적 에너지 분석을 실시했다. 또한 월별 최대 냉난방 부하 분석에 의해 평균 최대 난방 용량 449,578kJ·h^-1, 냉방 용량 431,187kJ·h^-1이 산정되었다.