• Land and Housing Review
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• v.10 no.3
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• pp.9-16
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• 2019

This study aimed at developing control algorithms for operating a variable refrigerant flow (VRF) heating and cooling system with optimal system parameter set-points. Two artificial neural network (ANN) models, which were respectively designed to predict the heating energy cost and cooling energy amount for upcoming next control cycle, was developed and embedded into the control algorithms. Performance of the algorithms were tested using the computer simulation programs - EnergyPlus, BCVTB, MATLAB in an incorporative manner. The results revealed that the proposed control algorithms remarkably saved the heating energy cost by as much as 7.93% and cooling energy consumption by as much as 28.44%, compared to a conventional control strategy. These findings support that the ANN-based predictive control algorithms showed potential for cost- and energy-effectiveness of VRF heating and cooling systems.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.130-133
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• 2011

This paper reports the Survey results from a field monitoring study of office occupancy densities. The field measurement of a office in Yongin was carried out from 19 September to 30 September 2011. The survey has an aim to reveal the building energy consumption relationship between occupancy densities of a realistic office and the previous studies. The results showed that hourly occupied density of the previous studies is more higher than a field survey. we investigated the effects of difference occupancy densities on annual heating and cooling energy consumption using EnergyPlus. Heating and cooling consumption was raised because of the increased occupancy density. therefore, accurately measure the occupnacy schedule is important in order to reduce excessive building energy consumption, and is an significant element to be considered in the energy simulation.

• KIEAE Journal
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• v.14 no.4
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• pp.47-52
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• 2014

The problem of energy consumption is more serious in university buildings than primary, middle and high school buildings. Because university buildings have generally heating and cooling systems, and various incidental facilities. In university, the library is one of the building that many people use and the most energy is spent. So, investigation on energy saving is very important and urgent. This study aims finally to present the guideline for low-energy design of University library by aiding a designer to select best solution in the side of energy-saving. In this paper, composition of space, utilization schedule and performance of construction materials are grasped, some primary factors that effect to energy saving are analyzed by energy simulation. The result of this study is as follows; First, the subject library has more cooling load than heating load because of cooling load generated during middle season. Second, green roofs is the most effective to heating load saving, but not to cooling energy. Third, outdoor air cooling is the most effective to cooling energy saving among the investigated strategies included in this study.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.96-103
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• 2012

Annual energy consumption in detached houses are affected mainly by thermal performance of envelope. In particular the performance of glasses are critical due to global wanning and climatic change. Therefore, this research analyzes annual consumption of cooling and heating energy with various combination of U-value, shading coefficient and building orientation. The simulation results shows that shading coefficient of glazing contributes to the changes of proportion of heating and cooling energy demand and the optimized shading coefficient for minimizing energy consumption varies with buildings orientation.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.115-120
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• 2009

The studies for mechanical performance development have been examined to reduce energy consumption in building construction field. However, The energy consumption using in building for heating is impacted by not only system performance but also PMV particularly at temperature and clo. Most energy using in building part is mainly consumed for heating and cooling to keep comfort temperature. Heating energy consumption is bigger than cooling energy in Korea because of temperature difference in winter in comparison with summer at apartment building. This means that energy consumption can be changed by occupancy's comfort setting temperature in apartment building. This study evaluate actual comfort temperature range by clo and examined heating energy consumption by Esp-r and CO2 reduction possibility. The results show that keeping ASHRAE standards can reduce heating energy up to 23%; also, wearing underclothes with ASHRAE standard can reduce heating energy up to 47.8%. Option 4 showing Maximum CO2 emission reduction indicates that kerosene. LNG and electricity can reduce 1.5t, 1.7t, 2.46t respectively in comparison with option 2.

• KIEAE Journal
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• v.4 no.4
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• pp.19-26
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• 2004

The purpose of this study was to evaluate the thermal environment of present state and energy consumption and to verify the improvement of energy performance applying free cooling in 5ESS-2000 telecommunication equipment room. Analysis program is used the DOE-2.1E and commercial CFD code, Star-CD. The results of the simulation show that free cooling could reduce 42.1% of cooling energy, increase 48.5% of heating energy because introduced outdoor air must heating and humidification. Therefore free cooling could reduce yearly 34,609.9 kWh of heating and cooling energy and this is reaching to 21.6% of total energy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.3
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• pp.113-122
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• 2015

HVAC&R systems account for more than 50% of the energy consumption of buildings. The purpose of this study is to propose an optimal design method for the HVAC&R system and to examine the possibility for the energy conservation of a selected system. The energy demand for cooling and heating is determined by using TRNSYS and HEET. By an interaction between total system efficiency and cooling-to-heating load ratio, the optimal HVAC&R systems will be decided. The results showed that this proposed method is significantly capable of determining optimal system and building design for saving energy.

• 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.

• Journal of the Korean housing association
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• v.22 no.1
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• pp.115-122
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• 2011

This study aimed at quantifying the impact of envelope insulation on energy consumption for thermal controls in residential buildings in southern part of Korea. A series of parametric simulations for a range of R-values of walls, roof, floor, and windows were computationally conducted for a prototypical Korean detached house. Analysis revealed that the total amount of heat gain was larger than that of heat loss, while the amount of energy for cooling was smaller than that for heating due to the difference of system efficiency; the envelope heat transfer was more significant for the heat loss, thus, the increase of the envelope insulation was more effective to reduce heating load; and there were certain levels of envelope insulation after which the energy saving effect was not significant. These findings are expected to be a fundamental database for the decision of proper insulation level in Korean residential buildings.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.2
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• pp.7-12
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• 2014

Government has recently restricted heating and cooling set temperatures for the commercial and public buildings due to increasing national energy consumption. The goal of this paper is to visualize a future two way indoor set temperature control impact on building energy consumption by using TRNSYS simulation modeling. The building was modelled based on the twin test cell with the same dimension. Air source ground coupled heat pump performance data has been used for modeling by TRNSYS 17. Daejeon weather data has been used from Korea Solar Energy Society. The heating set temperature in the reference room is $24^{\circ}C$ as well as the target room set temperature are $23^{\circ}C$, $22^{\circ}C$, $21^{\circ}C$ and $20^{\circ}C$. The cooling set temperature of the reference room is also $24^{\circ}C$ as well as the target room set temperature of $25^{\circ}C$, $26^{\circ}C$, $27^{\circ}C$ and $28^{\circ}C$. For the air source heat pump system, heating season energy consumption is $35.52kWh/m^2y$ in the reference room. But the heating energy consumption in the target room is reduced to 7.5% whenever the set temperature decreased every $1^{\circ}C$. The cooling energy consumption in the reference room is $4.57kWh/m^2y$. On the other hand, the energy consumption in the target room is reduced to 22% whenever the set temperature increased every $1^{\circ}C$ by two way controller. For the geothermal heat pump system, heating energy consumption in the reference room is reduced to 20.7%. The target room heating energy consumption is reduced to 32.6% when the set temperature is $22^{\circ}C$. The energy consumption in the target room is reduced to 59.5% when the set temperature is $26^{\circ}C$.