• Journal of KIBIM
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• v.2 no.2
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• pp.17-26
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• 2012

This paper presents the results of a theoretical energy analysis of a research test bed called the Zero Net Energy Test House (ZNETH) in Omaha, Nebraska in U.S.A. The ZNETH project is being designed and built with the goal of consuming a negligible amount of energy by offsetting remaining usage after energy conservation. The theoretically consumed and generated energy levels were analyzed using energy modeling software programs. By integrating a highly graphical and intuitive analysis with a Building Information Model(BIM) of the house, this investigation introduces strategies to include sustainable materials and systems to predict energy generation with a case study of ZNETH. In addition, this paper introduces parametric analyses for better envelope design and construction material selection by analyzing simulated energy consumption with various parametric inputs, e.g., material types, location, and size. It was found that the current design of ZNETH does not meet its goal of zero net energy. Sugeestions are presented to assist ZHETH in meeting its net zero energy goal.

• Journal of the Korean Solar Energy Society
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• v.38 no.4
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• pp.55-66
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• 2018

nZEH (net-Zero Energy House) is defined as a self-sufficient energy building where the sum of energy output generated from new & renewable energy system and annual energy consumption is zero. The electricity generated by new & renewable energy system with the form of distributed generation is preferentially supplied to electrical demand, and surplus electricity is transmitted back to grid. Due to the recent expansion of houses with photovoltaic system and the nZEH mandatory by 2025, the rapid increase of distributed generation is expected. Which means, we must prepare for an electricity-power accident and stable electricity supply. Also electricity charges have to be reduce and the grid-connected should be operated efficiently. The introduction of ESS is suggested as a solution, so the analysis of the load matching and grid interaction is required to optimize ESS design. This study analyzed the load matching and grid interaction by expected consumption behavior using actual data measured in one-minute intervals. The experiment was conducted in three nZEH with photovoltaic system, called all-electric houses. LCF (Load Cover Factor), SCF (Supply Cover Factor) and $f_{grid}$ (Grid Interaction Index) were evaluated as an analysis indicator. As a result, LCF, SCF and $f_{grid}$ of A house were 0.25, 0.23 and 0.27 respectively; That of B house were 0.23, 0.23, 0.19, and that of C were 0.20, 0.19, 0.27 respectively.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.276-284
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• 2009

As an on-going research project, Zero Net Energy Test Home (ZNETH) project investigates effective approaches to achieve whole-house environmental and energy goals. The main research objectives are (1) to identify energy saving solutions for designs, materials, and construction methods for the ZNETH house and (2) to verify whether ZNETH house can produce more energy than the house uses by utilizing Building Information Modeling (BIM) and energy analysis tools. The initial project analysis is conducted using building information modeling (BIM) and energy analysis tools. The BIM-driven research approach incorporates architectural and construction engineering methods for improving whole-building performance while minimizing increases in overall building cost. This paper discusses about advantages/disadvantages of using BIM integrated energy analysis, related interoperability issues between BIM software and energy analysis software, and results of energy analysis for ZNETH. Although this investigation is in its early stage, several dramatic outcomes have already been observed. Utilizing BIM for energy analysis is an obvious benefit because of the ease by which the 3D model is transferred, and the speed that an energy model can be analyzed and interpreted to improve design. The research will continue to use the ZNETH project as a testing bed for the integration of sustainable design into the BIM process.

• Journal of the Korean Institute of Educational Facilities
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• v.25 no.4
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• pp.11-18
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• 2018

Global warming is happening now and inevitable. Everyone knows that immediate action should be taken to slow it down, but uncertain about the effective solution. Despite global efforts to reduce greenhouse gas emissions, sea levels are rising gradually. In 2013, Cornell University announced the Climate Action Plan(CAP) to make the campus greener, to reduce waste, and to ensure efficient use of resources. In particular, they set a goal of reducing energy use by 2050 and making carbon emissions to zero. Accordingly, the purpose of this study is to analyse the case of the master plan of Cornell Tech campus and its major buildings. Mainly, The House, faculty and student housing of Cornell Tech and the world tallest certified passive house, will be the main precedent that shows the architectural planning of passive house. Passive house technology, which was thought to be possible only in single-family houses, can be applied to high-rise buildings. If any passive house technology of The House project is actively introduced into the dormitory projects of domestic universities that are about to be built or renovated, it will be a good opportunity for the university to take the lead in preparing for global warming.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.397-405
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• 2023

As interest in greenhouse gas reduction has increased in all sectors, the discussion of the International Maritime Organization (IMO) to regulate pollution by ships is attracting attention in international shipping. At the 80th IMO MEPC held in July 2023, the 「2023 IMO Strategy for the Reduction of Green House Gases from Ships (MEPC. 377(80))」 was adopted, which included the net-zero target around 2050, and a firm intention to the decarbonization of the international shipping sector showed. In particular, energy, fuel and technology targets for zero or near-zero greenhouse gas emissions by 2030 were added as new targets, and total greenhouse gas emission checkpoints for 2030 and 2040 were added as an indicator for achieving the 2050 target. The IMO's goal setting for 2030, which is about seven years away, will impose a lot of technical, economic, and political burden despite the decarbonization technology of international shipping, which has grown to a significant level in a short period of time. Accordingly, this paper presents the comprehensive impact of the 2023 IMO GHG Strategy on international shipping.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.4
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• pp.27-38
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• 2023

The Government the Republic of Korea is showing a lot of interest in net zero-energy buildings (NZEBs) to reduce energy consumption of buildings and to promote green growth policy in construction sector. The application of building passive technologies and renewable energies is essential to achieving NZEBs. Green remodeling reinforced the insulation of the exterior walls and roofs of the buildings and replaced high-efficiency windows and doors. In this study, the energy performance before and after green remodeling applied in a detached house was comparatively analyzed for baseline scenario and three different ones, ALT 1, ALT 2 and ALT 3. A building modeling and simulation software (DesignBuilder V7.0) with EnergyPlus (V9.4) calculation engine was used to calculate the energy demand and energy consumption for each scenario. Based on the calculation results of the building's energy demand for baseline, it was determined that the target building required more heating energy than cooling energy. The simulation results also showed that the implementation of building envelope performance improvement technologies (ALT 1) could notably decrease the heating energy consumption of the building. After the remodeling (ALT 1), the source energy consumption per unit floor area was assessed to be reduced by 65.2%, compared to prior remodeling of 338.7 kWh/m² -y. Meanwhile, ALT 2 can achieve energy savings of 67.7% and ALT 3 can achieve savings of 73.1%. Following completion of the remodeling project, actual construction costs, and on-site measurements and verification results will be gathered and compared with the simulation results. Additionally, economic analysis including construction costs and payback period will be conducted using actual site data.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3255-3267
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• 2024

This paper presents a high-fidelity simulation of the Organization for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) 3D whole-core Watts Bar benchmark using the UNIST in-house STREAM3D (Steady State and Transient Reactor Analysis code with Method of Characteristics) neutronic code. The benchmark encompasses various whole-core exercises, including single physics problems, multiphysics simulations, and depletion problems. When comparing parameters during the zero-power physics tests, including ITC, DBW, CRW, and criticality tests, STREAM3D results indicate a strong agreement with the measured data and KENO-VI. The comparison with the MC21/CTF code in 3D HFP BOC condition demonstrated strong agreement, with only a 0.42% difference in the normalized radial power distribution, a 0.38 K difference in the RMS of the assembly coolant exit temperature, and a mere 4 ppm difference in CBC.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.543-550
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• 2022

The U.S. Department of Energy conducts the Solar Decathlon competition as a student-based achievement that encourages sustainable design with energy efficiency and solar energy technologies. In the 2020 competition, the University of Nevada, Las Vegas (UNLV) team designed, fabricated, and constructed a net-zero modular house that applies innovative and highly efficient building technologies. This paper focused on the lessons learned during the early phases of this ongoing modular project. The research methodology included obtaining feedback from key project participants using a well-structured questionnaire. The results showed that the major items/challenges in the project's planning phase included selecting the modular size, planning the construction system, planning the materials and procurement, estimating costs and duration, selecting a fabricator, collaboration and communication, safety, and planning module transportation. These findings will help modular practitioners and future Solar Decathlon competition participants better understand how and what factors they should consider most during the early phases through the lessons learned.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.615-623
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• 2012

Humanity is facing a number of serious issues associated with increased energy consumption and environmental pollution. Various studies/guidelines concerning sustainable building construction have suggested solutions to these disastrous problems, including: net-zero energy buildings, the green building certification system, and others. Sustainability pursues three expected effects: environmental, social, and economic merits. Korean Green Building Council (K-GBC) has also announced the Korean Green Building Certification System (K-GBCS) since 2003 based on sustainability. Some positive social and environmental aspects of the K-GBCS have already been reported. However, it is somewhat difficult to verify its economic merits, which are crucial to ensuring the validity of the K-GBCS. This research aims to verify the economic merits of the eco-friendly Korean-style condominiums accredited by K-GBCS. Following this, the expected economic effectiveness of K-GBCS will be examined in terms of sustainability. The underlying assumption is that the potential economic effect should reflect the actual economic merits, and should reflect the value of the housing in particular. According to the analysis of the variance, it can be concluded the value of green certified buildings is statistically higher than the value of non-certified buildings. Furthermore, it was also observed that this tendency was more dominant in Gyeonggi Province than in the City of Seoul. This may be caused by one of the variables: the proximity to downtown. In future studies, this variable should be studied in greater detail.