• KIEAE Journal
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• v.15 no.1
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• pp.53-60
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• 2015

Increase in energy consumption in building is a big concern world over. In Nepal, energy crisis is a big issue but energy demand in buildings is barely even thought about. In the southern part of Nepal, where the weather is mostly hot during the year, cooling in buildings is very important. This is an initial study regarding building design strategies which focuses on cooling energy consumption in the building. It can be seen from the study that simple passive strategies can be applied in building design which can support in decreasing cooling load. Different passive cooling strategies like orientation, building size, thermal mass, window design and two direct cooling strategies have been investigated in this study. Direct cooling strategies like shading and natural cooling helps in passive cooling. Different desing strategies have different impact on the cooling energy requirement and the study shows that thermo physical property of building materials has the maximum effect on the energy consumption of the building. Each design strategy creates and average of 20% decrease in energy consumption, whereas the thermal conductivity can have as much as 10 times more effect on the energy consumption than other design strategies.

• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.47-53
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• 2013

In order to reduce the energy consumption of the building, much effort is being made. The problems are that excessive solar radiation in summer and the heat loss in winter by the increase of window area. To prevent this problems, government limited the window area ratio or the performance of windows in new buildings. In order to reduce energy consumption of the existing buildings, the window film insulation is spotlight because the window film insulation was simple to installation. This study confirmed the performance of the window film insulation and affect to heating & cooling load of buildings. The impact of the window film insulation coating was confirmed by experiment. And this study confirmed the annual heating & cooling load by simulation. As a results, the surface temperature of coated window was higher than the surface temperature of existing window. The window film insulation was increased surface temperature of window. And this study confirmed that the increased surface temperature was slightly affected the room air temperature through experiment of the insulation box. The results of the heating and cooling load by simulation, this study confirmed that the case of coated window film insulation decreased cooling load in summer and increased heating load in winter. Also the annual total heating & cooling load was increased a little in the case of coated the window film insulation.

• Land and Housing Review
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• v.10 no.1
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• pp.25-32
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• 2019

In this study, the case analysis data on underground temperature are presented. In addition, numerical analysis of the ventilation load reduction plan was derived according to the residence schedule change for the building with cool tube. The research scope and method are as follows. The overall system principle was examined through reviewing the theory of the Cool tube system. Case study and analysis were conducted. Numerical simulation was used to examine the change in energy usage. Also, the change of load energy in case of varying amount of ventilation was derived based on actual building room schedule. When the Cool tube system was applied to the residential buildings, the cooling load was reduced from 3,331 kW to 193 kW, which showed a reduction effect of about 90%.The heating load was reduced from 42,276kW to 32,575kW by 23%.Also, result shows that the cooling load decreased by 24% and the heating load decreased by 66% when the number of ventilation according to the occupancy schedule was applied.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.3
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• pp.410-425
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• 1997

Buildings are mostly under part load conditions causing an inefficient system operation in terms of energy consumption. It is critical to operate building air-conditioning system with a scientific or optimal manner which minimizes energy consumption and maintains thermal comfort by matching building sensible and latent loads. Little research has been performed in developing general methodologies for the optimal operation of air-conditioning system. Based on this research motivation, system simulation program was developed by adopting various equipment operating strategies which are energy efficient especially for humidity control in summer. A numerical optimization technique was utilized to search optimal solution for multi-independent variables and then linked to the developed system simulation model within a mam program. The main goal of the study is to provide a systematic framework and guideline for the optimal operation of air-conditioning system focusing on air-side. For given cooling loads and ambient outdoor conditions the optimal operating strategies of a commercial building are determined by minimizing a constrained objective function by a nonlinear programming technique. Desired space setpoint conditions were found through evaluating the trade-offs between comfort and system power consumption. The results show that supply airflow rate and compressor fraction play main roles in the optimization process. It was found that variable setpoint optimization technique could produce lower indoor humidity level demanding less power consumption which will be benefits for building applications of humidity problem.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

• Architectural research
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• v.3 no.1
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• pp.53-60
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• 2001

The proposed building upgrading technique employs prestressing cables to function as bracing to improve the seismic performance during future events. A four-story reinforced concrete moment resisting frame damaged from an ultimate limit state earthquake is assessed and upgraded using the proposed technique. Both existing and upgraded buildings are evaluated in regard of seismic performance parameters performing static lateral load to collapse analysis and dynamic nonlinear time history analysis as well. To obtain realistic comparison of seismic performance between existing and upgraded frames, each frame is subjected to its critical ground motion that has strength demand exceeding the building strength supply. Furthermore, reliability of static lateral load to collapse analysis as a substitute to time history analysis is evaluated. The results reveal that the proposed upgrading technique improves the stiffness distribution compared to the ideal distribution that gives equal inter-story drift. As a result, the upgraded building retains more stories that contribute to energy dissipation. The overall behavior of upgraded building beyond yield is also enhanced due to the gradual change of building stiffness as the lateral load increases.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.4
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• pp.33-44
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• 2022

In this study, we analyze the existing heating and cooling operation method for an office-type complex building with a central heating and cooling system, and examine the effects of applying various EMS that can be applied according to the load size to save energy in the building. For this purpose, simulation analysis was performed. As a control method, reset control of chilled water, hot water, cooling water and supply air temperatures, optimal start/stop of heat source, and number of heat source control were applied according to the load size, and energy consumption was analyzed accordingly. In addition, when all of these control methods were applied, the overlapping energy saving effect was finally confirmed. As a result, it was possible to confirm the energy saving effect when EMS for reset control and heat source control were applied compared to the existing control method of the heating and cooling system, and the effect for the case of using all these control methods in combination was also confirmed.

• KIEAE Journal
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• v.17 no.3
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• pp.69-74
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• 2017

Purpose: The apartment complex constructed recently is composed of very various types of building, plan, and orientation etc. However, it is difficult to remark conclusively that these various types of buildings are designed energy-effectively, since it is difficult for architects to find useful energy design guideline for decision making. By the preceding study, the present condition and problem about this subject was grasped, apartment building types were examined and representative types were extracted. Method: Large apartment building complex having 1940 households, located in haengbok-dosi, sejong city, Korea is used as an example to conduct this study. Representative building types are extracted first. Then, heating and cooling load of households is analyzed. Lastly, effect of outdoor air cooling is investigated by computer simulation. Result: Results of this research are summarized as follows: 1. Besides solar gain, household layout of building, orientation, and plan have compositive effects on heating and cooling load. 2. The effect of outdoor air cooling in apartment can be improved by arranging windows of households.

• Journal of the Korean Solar Energy Society
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• v.34 no.5
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• pp.81-87
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• 2014

According to the domestic construction business will continue stagnant, many domestic construction companies are expanding their business into foreign countries. As results, building design guidelines including HVAC design for foreign countries considering the regional climate conditions are needed. Also, green building design strategies to minimize the heating and cooling load are key issue to win a contract in construction business in the world. In this study, peak heating and cooling loads were calculated for the representative cities in the world : Seoul, St. Petersburg, Singapore and Mecca. The analyzed building was a typical high-rise office building and the building envelope properties, indoor heat gain, residence and operating schedules were same in all cases. Only the weather conditions were different by cases.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.4
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• pp.1-7
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• 2023

In Korea, it is also mandatory for most buildings to receive energy efficiency rating certification from 2020 for the purpose of reducing greenhouse gas emissions and expanding green buildings. However, the issue of the accuracy of the ECO2 program continues to be raised, and comparisons have been made with dynamic energy analysis programs in a single type of building according to a single area. However, comparisons between multiple building types and multiple areas are insufficient. Therefore, in this study, cooling and heating loads according to multiple building types and multiple areas were analyzed through ECO2 and TRNSYS programs. The regions were supposed to be Seoul, Daejeon, Gwangju, and Busan and the building types were supposed to be office buildings and apartment houses. The annual average building load values from ECO2 were higher than those from TRNSYS. Among residential buildings across the four regions, the largest discrepancy was 41.4% in Seoul. Conversely, for commercial buildings, the most significant difference in annual average loads was noted in Gwangju, at 37.9%.