• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.8
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• pp.612-620
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• 2012

High economic growth causes increase of the building energy consumption. The energy consumption for HVAC system accounts for 40~50% of the whole building consumption. The trend for building is large-scale and high-rise. Because of the trend, the energy consumption is becoming bigger than before. Nowadays, HVAC system design are recognized as the solution for a energy-saving. This paper is focused on the energy performance evaluation of central air-conditioning system(water-based) and system air-conditioning that were applied to the office building. The systems are modeled and simulated by using EnergyPlus Software 6.0. After the Simulation, annual cooling and heating energy consumption were calculated. It was found that the system air-conditioning can reduce the energy consumption approximately 55.24% annually compared with the central air-conditioning system(water-cooled). In addition, about 46.13% of annual operating costs can be reduced by use of system air-conditioning.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.43-48
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• 2019

Since the revision of the Rationalization of Energy Use Law, the spread of new and renewable energy in buildings has been promoted. In addition, the production of electric power and thermal energy is an important issue in the change of energy paradigm centered on the use of distributed energy. Among them, geothermal energy is attracting attention as a high-performance energy-saving technology capable of coping with heating / cooling and hot water load by utilizing the constant temperature zone of the earth. However, there is a disadvantage that the initial investment cost is high as a method of calculating the capacity of a geothermal facility by calculating the maximum load. The disadvantages of these disadvantages are that the geothermal energy supply is getting stagnant and the design of the geothermal system needs to be supplemented. In this study, optimization design of geothermal system was carried out using optimization tool. As a result of the optimization, the ground heat exchanger decreased by 30.8%, the capacity of the heat pump decreased by 7.7%, and the capacity of the heat storage tank decreased by about 40%. The simulation was performed by applying the optimized value to the program and confirmed that it corresponds to the load of the building. We also confirmed that all of the constraints used in the optimization design were satisfied. The initial investment cost of the optimized geothermal system is about 18.6% lower than the initial investment cost.

• KIEAE Journal
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• v.14 no.2
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• pp.77-86
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• 2014

Plenty of efforts have been made in the traditional architecture of Korea, Hanok, to develop various elements such as restoration, the introduction of new design, and energy-saving while systemic setups on standard and evaluation of eco-friendly energy design of Hanok are lacking. If we evaluate energy performance based on current standards without reflecting unique features of Hanok on the system, Hanok will be included in the very low grade among the residential buildings being included in the approval system of eco-friendly architecture or the unique features will be modified and the burden of increased construction cost. Therefore, this study is to prepare the basic reference for the introductory evaluation system by evaluating the energy performance level of NEO-Hanok based on the current building energy rating system. The result for NEO-Hanok based on the building energy rating system, we propose the rating standard with scorecard elements of NEO-Hanok by considering the necessity of identity and standard for NEO-Hanok. As a result of infiltration test to check the tightness, it was measured as 10.81 times/h (50 ACH). As we switch from the main insulation for the wall from the glass wool 64k(0.035W/mk) to rigid polyurethane foam first class first unit (0.024W/mk), the result was slightly increased from the first demand quantity rating yield $249.8kWh/m^2{\cdot}yr$ to $235.0kWh/m^2{\cdot}yr$. Current certificate system is focused more on the heating load than the cooling load, it is disadvantageous for Hanok, which has less cooling energy consumption in summer. The rating result from the target building study is level 4.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.419-428
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• 2021

In order to develope a mobile-based greenhouse energy calculation program, firstly, the overall thermal transmittance of 10 types of major covers and 16 types of insulation materials were measured. In addition, to estimate the overall thermal transmittance when the cover and insulation materials were installed in double or triple layers, 24 combinations of double installations and 59 combinations of triple installations were measured using the hotbox. Also, the overall thermal transmittance value for a single material and the thermal resistance value were used to calculate the overall thermal transmittance value at the time of multi-layer installation of covering and insulating materials, and the linear regression equation was derived to correct the error with the measured values. As a result of developing the model for estimating thermal transmittance when installing multiple layers of coverings and insulating materials based on the value of overall thermal transmittance of a single-material, the model evaluation index was 0.90 (good when it is 0.5 or more), indicating that the estimated value was very close to the actual value. In addition, as a result of the on-site test, it was evaluated that the estimated heat saving rate was smaller than the actual value with a relative error of 2%. Based on these results, a mobile-based greenhouse energy calculation program was developed that was implemented as an HTML5 standard web-based mobile web application and was designed to work with various mobile device and PC browsers with N-Screen support. It had functions to provides the overall thermal transmittance(heating load coefficient) for each combination of greenhouse coverings and thermal insulation materials and to evaluate the energy consumption during a specific period of the target greenhouse. It was estimated that an energy-saving greenhouse design would be possible with the optimal selection of coverings and insulation materials according to the region and shape of the greenhouse.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.603-613
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• 2021

As a core policy for achieving the goal of reducing greenhouse gas emissions in the building sector, Korea has enforced the mandatory certification of zero energy buildings for new public buildings from 2020. This study suggests energy-saving technologies and economic factors that building officials can refer to for decision-making on the implementation of zero energy buildings. For this study, the construction cost for the energy item of a building was analyzed by collecting the building energy efficiency level certification data and detailed construction cost statement data from public institutions for the last three years. Based on the building energy efficiency certification data, each energy item of the baseline building was derived, and the energy performance of the zero energy building was derived through repetitive simulations by gradually increasing the energy performance value of the baseline building. By applying the analyzed construction cost, the construction cost for each energy item of the baseline and zero energy buildings was derived. As a result, the lighting equipment contributed up to 10.5% energy savings, and the increase in construction cost of the cooling and heating system was at least 9.1%.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.9-14
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• 2021

This paper discovers the energy loss factors through the insulation diagnosis of houses or buildings, and proposes directions for energy efficiency improvement. The energy efficiency factor of a building consists of insulation diagnosis, thermal bridge diagnosis, window diagnosis, airtight diagnosis, and equipment diagnosis. Among the residents and facilities in the energy welfare blind spot, an energy efficiency diagnosis was conducted for one senior citizen building located in Naju-si, Jeollanam-do, and energy efficiency diagnosis was conducted after insulation was installed. Energy measurement, diagnosis and analysis were performed using the IoT-based integrated wired/wireless energy diagnosis platform, Energy Finder. As a result of comparison, an overall energy saving rate of 16.38% was achieved. Annual heating energy consumption per unit area decreased from 333.51kWh before construction to 277.35kWh after construction, and annual cooling energy consumption per unit area decreased from 5.51kWh before construction to 5.22kWh after construction. The annual primary energy consumption per unit area decreased from 464.52kWh before construction to 403.69kWh after construction, and the annual energy cost was reduced from 3,063,307.14 won before construction to 2,641,072.49 won after construction. The additional improvement work is needed on the standards affecting energy efficiency other than insulation.