• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.198-198
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• 2011

Cooling and Heating system using Geothermal energy in the country has shown rapid development in the research and business field during about 10 years. However, like other renewable energy sources, high initial construction cost is acting as an obstacle to apply widely. Therefore Energy pile system(Heat Exchanger inserted inside the structure pile) that can save about 25 % initial construction cost has been studied in European countries and recently being studied in our country. Therefore, KPECO(Korea Electric Power Corporation) is also studying energy pile system to improve cooling & heating system in substation that install about 200 pile. KPECO is aimed to make energy pile design, construction and maintenance standards because substation has good applicability. In this study, we studied to make new grout material and design program to make optimized design & counstruction method of energy pile system. And planing to peform field test for energy pile system in a 154 kV substation to obtain long-term behavior and efficiency of the system.

• 설비공학논문집
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• 제28권3호
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• pp.103-109
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• 2016

The purpose of this study is to perform comparative economic evaluation for the systems of ground source heat pump (GSHP) and district heating and cooling (DHC) by focusing on the analysis of operation case of GSHP. The adapted research object is a public office building located in Seoul. The capacity of ground source pump is about 3,900 kW. Ground heat exchanger is closed loop type. The analysis period for life cycle cost is 30 years. Economic evaluation is assessed from the viewpoints of the following four parts: initial cost, energy cost, maintenance and replacement cost, and environment cost. The total life cycle cost of GSHP is approximately 8,447 million won. The cost of the DHC System is approximately 3,793 million won. The cost of the DHC is approximately 46% lower than GSHP system under the condition of current rate for GSHP and DHC.

• 한국조경학회지
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• 제27권2호
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• pp.19-28
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• 1999

This study quantified shading, evapotranspiration and windspeed-reduction effects of trees on use and cost of heating and cooling energy in two residential neighborhoods of Chuncheon different in tree cover. Annual savings per residence of heating energy were approximately 1,210 MJ(1%) and those of cooling energy, 130 kWh(10%) in study district 1 having tree cover of about 10% . For district 2 with tree cover of about 20%, annual heating and cooling savings were 2,130 MJ(2%) and 180 kWh(19%) per residence, respectively. Trees annually saved energy costs by approximately ￦31,000 ($26, $1=￦1,200) per residence in district 1 and by ￦49,000($41) in district 2. One tree taller than 3 m resulted in annual energy savings of ￦8,000($7) in the study districts. Energy savings by trees in district 2, which had higher tree cover by 10% difference than district 1, were about 2 times greater than those in district 1. This implies that more tree plantings could enhance energy saving effects. Of the total costs saved, 58% was attributed to windspeed reduction and 47%, evapotranspiration. However, shading increased energy costs by 5% due to tree plantings at the wrong locations. Full tree plantings on the west and north of buildings and avoidance of shade-tree plantings of use of solar-friendly trees on the south are recommended to increase building energy savings efficiently.

• 한국태양에너지학회 논문집
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• 제33권1호
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• pp.96-105
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• 2013

This study aims to investigate the energy performance of apartment in respect of complex design, building type and generation house layout and finally to produce the guide line for energy saving design. To grasp the present condition and problem about this subject, apartment building types were examined and representative types were extracted. Considering azimuth angle, private area, and generation number, building type of the subject apartment was classified in detail, energy simulation was conducted, and the effect to energy cost was compared. In the research, using VE energy simulation program, the heating and cooling load were calculated and converted to energy cost. It is expected that this analysed results will be basic data for the more integrated study. Research consequence can be summarized as follow: 1) Energy cost is compared according to several azimuth in plank '一' type apartment. As the results, calculated gas cost is the best in $49^{\circ}$, but total cost is in $-31^{\circ}$. 2) Apartment buildings of tower types are compared, it is resulted that 'Y' type (azimuth $-7^{\circ}$, $-20^{\circ}$) is the best in gas cost, but the total cost is worst because of high cooling load.

• KIEAE Journal
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• 제5권3호
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• pp.25-31
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• 2005

Computer simulations were performed for Heating Ventilating and Air-Conditioning (HVAC) systems to figure out more efficient maintenance methods for the building used for adolescent trainees. This study aims at suggesting design alternatives for optimum operation and performing life cycle cost (LCC) for each alternative. First, the capacity of the heat source equipment was determined using annual maximum heating and cooling loads. Annual loads were calculated and applied to the alternative for the purpose of calculating annual energy cost. Second, several types of data were collected to predict energy cost. Finally, the pay back period for each alternative was calculated using total cost estimation during standard duration period. This study indicates that the absorption chiller that does not occupy most part of a mechanical room, and does not need much operation cost was most economical.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.53-60
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• 2005

The purpose of this study is to improve energy efficiency of windows in office buildings through the evaluation of their heating, cooling and illumination load. Energy efficiency is influenced by window size which is determined at the early stage of building design. The process of this study is as follows. First, energy performance is analysed according to the various rates of windows through computer simulation (ECOTECT). Then, the annual heating, cooling and illuminating loads according to the different window sizes are compared one another. Results indicated that the optimal window size considering energy efficiency is 50% of the surface area. When the window size is 50% of the surface area, annual maintenance expense is also smallest. Since the cost of cooling is larger than that of heating, too low indoor air temperature in summer is unfavorable based on the reasonable annual maintenance expenses.

• 조명전기설비학회논문지
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• 제30권3호
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• pp.94-105
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• 2016

The objective of the work was to evaluate the impact of lighting energy to cooling and heating consumption in medium scale office building, when currently installed fluorescent lights were replaced with various LED lighting fixtures. This evaluation comes from an integrated approach combining the proper indoor lighting environment and the thermal aspects of cooling & heating consumption in office building. These simulations were performed by coupling an appropriate luminaire analysis for energy consumption and a dynamic thermal simulation software (TRNSYS). To analyze comparative study of effects on the heating, cooling loads, and energy consumption of an LED lamp application, 2 types of LED lamp with low light power watt(LPW) 24W and high LPW 7.5W and a fluorescent lights(FL) with 37W are used respectively. Integrated building energy consumption decreased up to 3.2% when fluorescent lamps were replaced with LEDs. Thus, the high LPW of LED(7.5W) replaced with the same number of FL shows an effective energy saving and cost- effective luminary.

• 한국지역사회생활과학회지
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• 제27권2호
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• pp.281-294
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• 2016

This study was conducted to promote consumer interest in Geothermal Heat Pump (Ground Source Heat Pump, GSHP) and district heating and cooling (District Heating & Cooling, DHC) systems, which are competing with each other in the heating and cooling field. Considering not only the required cost data of energy itself, but also external influence factors, the optimal mix ratio of these two energy systems was studied as follows. The quantitative data of the two energy systems was entered into a database and the non-quantitative factors of external influence were applied in the form of coefficients. Considering both of these factors, the optimal mix ratio of GSHP and DHC systems and minimum Life Cycle Cost (LCC) were obtained using an algorithm model design. The Optimal Energy Mix of GSHP & DHC (OEMGD) algorithm was developed using a software program (Octave 4.0). The numerical result was able to reflect the variety of external influence factors through the OEMGD algorithm. The OEMGD model found that the DHC system is more economical than the GSHP system and was able to represent the optimal energy mix ratio and LCC of mixed energy systems according to changes in the external influences. The OEMGD algorithm could be of help to improve the consumers' experience and rationalize their energy usage.

• 설비공학논문집
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• 제23권11호
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• pp.747-753
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• 2011

The purpose of this study was to quantify the impact of the ventilation rate on heating and cooling energy consumption in a detached house. For it, a series of simulations for the application of the diverse ventilation rate (ACH) were computationally conducted for a prototypical detached residential building in the cold climate (Detroit, Michigan) and hot/humid climate (Miami, Florida) of USA. Analysis revealed that ventilation is a significant heat losing source in the cold climate; thus, the higher ventilation rate significantly increases the heating energy consumption and energy cost in the cold climate; while the impact on energy increase for heating and cooling energy consumption is similar in hot/humid climate with less significancy compared to cold climate. The research outcome of this study could be a fundamental data for determining the optimal ventilation rate in terms of indoor air quality, but also building energy performance well.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.579-585
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• 2009

Recently, Vertical-Closed Loop system using geothermal which is the most efficient among the building cooling and heating systems is coming into wide spread due to assistance of domestic policies. However, there is a limitation that a design of ground heat exchanger taking 60% of construction cost is done by GLD and GLHEPRO programs without specific guidelines and consideration on Entering Water Temperature(EWT). For getting an optimal EWT, we analyzed the costs for construction of ground heat exchanger and cooling and heating for 15 years. In the results, reduction of construction costs as the length of ground heat exchanger shortens was much greater than increase of the electrical power consumption as COP gets low. EWT that COP of heat pump can be 3.76 or above was below $31^{\circ}C$ in cooling and was over $5^{\circ}C$ in heating.