• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3307-3314
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• 2012

The annual energy demand of the standard rural house models was analyzed using the DesignBuilder. Indoor temperature set-point, U-value of outer wall, type of window, and degree of ventilation were selected as simulation parameters. In all the simulation cases, heating energy demand was higher than cooling energy demand regardless of the building size. When the lower U-value of the outer wall was applied to account for the thicker insulation layer, heating energy demand was decreased while cooling energy demand was increased. However, it is better to reduce the area of outer wall which is directly exposed to outdoor air because reducing the U-value of the outer wall is not effective in decreasing heating energy demand. Among the four different window types, the double skin window is most favorable because heating energy demand is the lowest. For a fixed infiltration rate, higher ventilation rate resulted in an increased heating energy demand and had minor impact on cooling energy demand. As long as the indoor air quality is acceptable, lower ventilation rate is favorable to reduce the annual energy demand.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.1-11
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• 2017

A lot of the energy are consumed on heating and cooling in buildings. The buildings need to minimize the heating and cooling loads for $CO_2$ emissions and energy consumption reduction. In recently, also demand of detached houses were increase while the residential culture was changed. The structure of the domestic detached houses can be divided into masonry, concrete, wood frame houses. Therefore, in this study, the heating and cooling load and energy demand were analyzed on the equal area detached house consisting of three structural methods (Masonry, Concrete, Wood frame). Layer of wall, roof, and floor were composited by structure. Thermal transmittance (U-value) of each layer was using the PHPP calculation for considering stud, such as the wood frame wall. In addition, the case of without considering for studs in wood frame wall (Non-studs) was analyzed in order to compare the difference between studs or not. Analysis was performed using self-developed heating and cooling load calculation program (CHLC) based excel and ECO2. The results of cooling and heating load and energy demand showed the highest values in the wood frame structure, and the concrete structure were confirmed to maintain a high value secondly. Two structure were determined to be disadvantageous on the energy consumption. Consequently, the masonry structure have an advantage over the other structure under the identical conditions. It was determined that if the except for thermal bridges due to the studs in the wood frame structure, it can be reduced the energy consumption.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.77-86
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• 2013

This research was carried out to evaluate and raise the energy efficiency of wood frame house. The commercial solution program CE3 (Construction Energy Efficiency Evaluation) was used for simulating the energy consumption in the single-family wood frame house. The results showed that the annual heating energy demand of the house was 160 kWh per 1 $m^2$ floor area. In order to decrease the heating energy demand, the following energy efficiency methods were applied to the simulation : a) simplification of building shape, b) decrease of windows area, c) application of high performance windows (with low thermal transmittance) and d) application of heat recovery ventilator. In case of replacement of the windows with high performance one with thermal transmittance 1 $W/m^2{\cdot}K$, the lowest heating demand of 80 $kWh/m^2{\cdot}a$ was obtained. The best combination of methods, application of high performance windows and heat recovery ventilator, showed heating energy demand 34.5 $kWh/m^2{\cdot}a$.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.269-280
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• 2011

Today, global warming is one of main problems all over the world. The cause of the global warming is carbon dioxide outbreak by the rapidly increasing energy use. Therefore, it is necessary to save energy in each industrious field. It was investigated that the half of total energy consumption over the world was used for construction and building. Therefore, the saving of the building energy plays a significant role in decreasing total energy consumption. With the considerable increase in building energy consumption, a green building rating system and certification are required to reduce building energy consumption and $CO_2$ emissions. Of various elements reducing building energy, the thermal conductivity of materials affects the energy consumption as a basic element, which is directly related with reducing energy consumption. In particular, as the thermal conductivity of finishing materials is an important factor to decide heating energy efficiency of floor heating system, the investigation and development are necessary.

• KIEAE Journal
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• v.13 no.4
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• pp.43-48
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• 2013

The effect of climate change has influenced humanity and ecosystem with tremendous changes in temperature. For the past 150 years, the national annual average temperature is 0.6 degree increased and the heating degree day reduced from April to November. However, December to January, the climate change was generated and the heating degree day increased. The blackout occured in 2011 and 2012 by increasing electricity consumption of heating and cooling equipment to the effects of climate change. That is because heating load accounted for 20% of building electric use. In this study, strengthening measures to reduce heating energy consumption is presented due to climate change in winter since 1980 to prevent blackout and reliable power supply for the building energy-saving design standards by Meteorological data provided by the National Weather Service were calculated using the heating degree days in order to present eighteen cities from 1980 to 2012. Insulation standards are presented to prevent black-out by the heating degree days. the heating energy demand was reduced almost 6% including 10% in Central, 5% in South and Jeju area based on strengthening of the insulation. It is applied to the entire country an annual economic effect of 250 billion won, and black-out can be prevented.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.77-82
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• 1998

현재 온실 난방에 주로 이용되고 있는 난방기는 대부분이 화석에너지를 연료로 사용하고 있다. 따라서 생산비의 가중이 불가피하며, 또한 연소 과정에서 발생하는 배기 가스로 인하여 환경 오염이 문제시되고 있다. 따라서 태양에너지를 보다 더 적극적으로 활용할 수 있는 기술의 개발이 요구된다. 태양에너지를 시설 농업에 적극적으로 이용하기 위해서는 주간에 밀도가 낮은 태양에너지를 고밀도로 축열하여 기온이 급강하하는 야간의 보온에 활용하여야 한다. 주간의 온실내 잉여 태양에너지를 축열할수 있는 상변화 온도 3$0^{\circ}C$ 수준의 잠열축열재를 개발하기 위하여 수행한 본 연구의 결과를 요약하면 다음과 같다. 1. SCD에 Borax를 0.0~5.0wt% 첨가하여 과냉도를 25.$0^{\circ}C$에서 $1.5^{\circ}C$ 이하로 조절하였으며, Borax의 적정 함량은 3.0wt%였다. 2. SCD에 Carbopol을 0.0~3.0wt% 첨가하여 상분리량을 70.0%에서 0.0%로 조절하였으며, Carbopol의 적정 함량은 1.5wt%였다.3. 축열재 내구성 검증을 위하여 0~1,500회의 상변화 사이클을 수행하였다. 이때 상변화 온도의 변화량이 $\pm$1.$0^{\circ}C$ 이하, 잠열량 변화가 $\pm$2.0 kacl/kg 이하로서 안정된 값을 보였다. 이상의 결과로 볼 때 축열재의 수명을 10년까지는 보장할 수 있는 것으로 판단되었다.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.83-89
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• 2013

Energy consumption is closely related to our lives. As Korea has four seasons, heating and cooling system is considered as essential facilities for the residential buildings. Accordingly, the government has continuously strengthened the design criteria to improve energy for new and existing building to save energy. The most important factor in the energy efficiency analysis for apartment is the heat transmission coefficient, and the value is significantly different as the heating energy amount is greatly different according to the window area ratio versus facade area ratio. Therefore, it is time to conduct continuous set-up for goal to enhance efficiency and restriction on window area ratio versus facade area ratio.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.120-120
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• 2010

에너지 절약적 차원에서 한 대의 실외기에 다수의 실내기가 접속되는 개별공조형 멀티 열펌프에 관한 연구 및 개발과 보급이 증대되고 있다. 본 연구에서는 복수의 실내기를 갖고 가변속 압축기를 채용한 지열원 물대공기 멀티열펌프시스템을 학교 현장에 설치하여 제조사의 운전 제어 알고리즘에 따라 일일 냉난방 실증 성능 특성을 분석하였다. 2008년 9월 30일의 냉방부하가 낮은 일자에 대하여 시간에 따른 부하 변동에 따라 압축기의 용량가변으로 실내기 냉방용량은 정격용량 대비 17.1%에서 111.3%의 범위에서 변이되었으나, 열펌프 유닛의 일일 최대 COP는 6.2를 나타냈으며, 일일 평균 열펌프 유닛 COP는 4.5로 열펌프 유닛 인증 기준 이상의 성능을 나타냈다. 2008년 11월 10일 대비 2008년 12월 15일에는 시스템 가동 중의 평균 외기온도가 $9.6^{\circ}C$ 감소하였으나, 각 재실공간의 용도별 부분 부하특성으로 11월 10일 보다 난방 부하량이 작게 나타났다. 하지만, 12월 15일에는 부하량이 매우 작아서 11월 10일보다 잦은 압축기 가변에 따른 손실로 일일 평균 COP가 낮게 나타났다. 2009년 1월 12일에는 정격 용량대비 94%의 부하율로 11월 10일과 12월 15일 대비 4배 이상의 부하량으로 압축기 용량 가변율이 작아서 난방용량과 COP 변화율이 작게 나타났다. 2009년 1월 12일에는 지중순환수의 실외열교환기 유입온도가 2008년 12월 15일보다 감소하고, 시스템의 난방용량 증가로 상대적으로 응축기와 증발기 크기가 감소한 효과로 히트펌프 유닛 COP가 감소하였으나, 본 지열원 열펌프 제조사에서 생산하고 있는 본 지열원 시스템과 동일한 압축기 등을 채용한 동일 용량의 공기열원 열펌프의 1월 12일 외기온도 $-10^{\circ}C$에서의 열펌프 유닛 COP 대비 70% 우수한 성능을 나타냈다. 본 지열원 히트펌프의 2008년 11월 10일의 일일 평균 히트펌프 유닛 COP는 외기온도가 낮고 일일 부하량이 크게 나타난 1월 12일의 일일 평균 히트펌프 유닛 COP 대비 37% 높게 나타났으나, 지중순환펌프의 정속운전으로 시스템 요구 지중순환수 유량 증가에 따른 성능 향상보다 소비전력 증가 영향이 커서 1월 12일의 시스템 COP 보다 33.3% 작은 값을 나타냈다. 본 연구의 용량 가변형 압축기를 채용한 지열원 멀티 히트펌프 유닛을 지열원 냉난방 시스템의 히트펌프 유닛으로 사용할 경우 시스템 최적화를 통한 시스템 COP 향상과 연간에너지 절감을 이루기 위해서는 히트펌프의 용량 변화 시에 지중순환펌프의 순환 유량 최적화를 위한 효율적 운전 제어 알고리즘 개발이 요구된다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.830-830
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• 2015

최근 기존 도시철도역사의 환기 설비 노후화로 인해 성능과 효율이 저하되고 있다. 또한, 상황에 따른 요구 환기량을 반영하여 풍량 조절이 불가해 효과적인 환기가 이루어지지 못하고 있다. 지구온난화로 인한 기후변화에 따른 냉 난방시설의 전력 소비 증가와 화석연료의 고갈로 전력 단가가 상승함으로써 에너지효율을 높일 수 있는 방법이 연구되고 있다. 에너지 효율을 높일 수 있는 방법으로 높은 고효율 영구자석 전동기를 포함한 블로워의 도입에 대한 방안과 기존 환기설비의 on/off제어에서 가변속 운전방식에 따른 방안이 관심을 받고 있다. 본 논문은 가변속 운전 방식의 도입이 미치는 영향검토를 위해 가변속 운전 방식의 도입에 대한 에너지 절감효과를 예측하고, 기존설비와의 효율을 비교하고 검토할 수 있는 MATLAB 기반의 프로그램을 제안한다. 본 논문은 MATLAB 시뮬레이션 결과를 바탕으로 블로워 전동기 가변 속 운전방식에 대한 소비전력량 차이를 입증하였다.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.324-332
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• 2017

The comparative experiments were conducted for single span greenhouses where cucumbers were cultivated to analyze the effect of heating between a carbon fiber electric heating element heater and an oil hot air heater in terms of the inside climate, energy consumption and plant growth. In order to analyze the effect of heating capacity, 6, 9, and 16 kW of electric powers were supplied to the electric heating element for same setting temperature of 15?. As a result, as the heating capacity increased, the number of ON-OFF cycles of the electric heating element and the temperature inside the greenhouse increased proportionally. In the comparison of two heaters, it was shown that the temperature and relative humidity distributions of the electric heating element installed greenhouse was much uniform than those of the oil hot air heater installed greenhouse. The heating energy consumptions during the heating period of 79 days were 867L for the oil hot air heater and 8,959 kWh for the electric heating element heater, and the heating costs were 607 and 403 thousand won respectively. In the electric heating element installed greenhouse, the cucumber growth was slightly better and the yield was 4.3% higher than those of the oil hot air heater installed greenhouse, but there were no statically significant difference in the cucumber growth and yield between greenhouses.