• KIEAE Journal
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• v.11 no.4
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• pp.71-78
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• 2011

The goal of this study is to analyze the impact of load factors on building energy consumption by using EnergyPlus program. We selected a campus building and monitored energy consumption from January 2009 to November 2010. First, we simulated energy consumption basically with weather data, building heat gain and EHP performance data. And then we simulated energy consumption with three additional parameter(infiltration, OA control and schedule). Simulation results are verified by MBE and Cv(RMSE) proposed by M&V guideline 3.0. Simulated total energy consumption was 104.3% of measurements, 4.33% of MBE, and 13.62% of Cv(RMSE). Results show infiltration and schedule were revealed as the most dominant factor of heating energy consumption and of cooling energy consumption, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.43-50
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• 2017

The purpose of this study is to develop a control algorithm for outdoor air cooling based on the prediction of cooling load, and to evaluate the building energy saving using outdoor air cooling. Outdoor air conditions such as temperature, humidity, and solar insolation are predicted using forecasted information provided by the meteorological agency, and the building cooling load is predicted from the obtained outdoor air conditions and building characteristics. The air flow rate induced by outdoor air is determined by considering the predicted cooling loads. To evaluate the energy saving, the benchmark building is modeled and simulated using the TRNSYS program. Energy saving by outdoor air cooling using load prediction is found to be around 10% of the total cooling coil load in all locations of Korea. As the allowable minimum indoor temperature is decreased, the total energy saving is increased and approaches close to that of the conventional enthalpy control.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.1-8
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• 2011

In this paper, inverse building modeling was applied to building perimeter zones which have different window orientation. Two test zones of east-facing and west-facing zones in ERS(Energy Resource Station) building, which is representative of small commercial building, was used to test performance of cooling load calculation and peak cooling load reduction. The dynamic thermal load model for the east and west zone was validated using measured data for the zones and then it was used to investigate the effect of peak cooling load reduction by adjustment of indoor cooling temperature set points during on-peak time period. For the east zone, the peak load can be reduced to about 60% of the peak load for conventional control even without any precooling. For the west zone, PLR is nearly independent of the start of the on-peak period until a start time of 1pm. Furthermore, PLR has a small dependence on the precooling duration. Without any precooling, the peak cooling load can be reduced to about 35% of the peak load associated with conventional control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.10
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• pp.553-558
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• 2009

Energy demand characteristics of hotel, hospital, and office building are compared to provide guidelines for combining building in community energy system design. The annual, monthly, and daily energy demand patterns for electricity, heating, hot water and cooling are qualitatively compared and important features are delineated based on the energy demand models. Key statistical values such as the mean, the maximum are also provided. Important features of the hourly demand patterns are summarized for weekdays and weekends. Substantial variations in both magnitudes and patterns are observed among the 3 building types and smart grouping or combination of building type and size is essential for a successive energy supply.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.4
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• pp.137-144
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• 2016

Commercial buildings account for a significant proportion of the total building energy use in Korea, and cooling energy, in turn, accounts for the largest proportion of total energy consumption in commercial buildings. Under this circumstance, chiller staging is considered to be a reasonable and practical solution for cooling energy saving. In this study, the part-load ratio and the operating characteristics of a vapor compression chiller were analysed within an office building. In addition, energy consumption among different chiller staging schemes was comparatively analysed. As a result, significant proportions of total operating hours, cooling load and energy consumption turned out to be in the part load ratio range from 0% through 50%, and thus energy consumption was significantly affected by the chiller COP at low part-load conditions, indicating that the chiller operation at the part-load is an important factor in commercial buildings. In addition, utilizing a sequential chiller staging scheme can reduce the annual cooling energy usage by more than 10.3% compared to operating a single chiller.

• Journal of the Korean Solar Energy Society
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• v.29 no.3
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• pp.66-72
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• 2009

As 'Low Carbon Green Building' is highly required, programs to evaluate building performance are actively and commonly used. For most of these programs, dynamic responses of buildings against external weather changes are very important. In order to simulate the programs, weather data of each region must be properly entered to estimate accurate amount of building energy consumption. To this end, the existing weather data and weather data of KSES were compared and analyzed to find out how weather changes. Energy load of Korea's standard houses was also analyzed based on this data. As a result, data corresponding to June ${\sim}$ September when cooling is supplied shows 23% of average increase with 30% of peak increase(June). On the other hand, data corresponding to November ${\sim}$ February when heating is supplied shows 29% of average decrease with 34% of peak decrease(November). Increase in cooling load and decrease in heating load in the above data comparison/analysis show that KSES 2009 data reflects increase in average temperature caused by global warming unlike the existing data. Increase in dry-bulb temperature depending on weather change of standard houses increases cooling load by 17% and decreases heating load by 36%

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.135-142
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• 2011

Architectural market in the world is trying to develop Zero Carbon Buildng that doesn"t use fossil fuel. Residential building that thermal load such as heating and domestic hot water is over 70% in energy consumption is easy to make Zero Carbon Building compared with office building that is mainly electric load. So, As a preliminary for analyzing the effect of Solar thermal system in the building, an annual energy consumption of residential building and total heat loads are calculated. Based on this result, three alternatives of solar thermal system for hot water and heating are applied in the building while installation area is increasing. Solar thermal system is applied on balcony and roof of apartment building as the way to reduce thermal load. In the first case that solar thermal system for hot water is applied on the balcony, optimum installation area is $56m^2$. And you could install $40m^2$ of this system in the roof that angle is $30^{\circ}$. In the second case of solar thermal system for heating and hot water, you can install $40m^2$ on the roof. As a result of economic evaluation, the most economical application method is to install $40m^2$ of solar thermal system for only hot water on the roof of the building. At that time, you can payback the initial investing cost within 10 years. And carbon emission of this method can be reduced until about 4 ton per year.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.11
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• pp.567-573
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• 2015

Commercial buildings account for significant portions of the total building energy in Korea, and thus, a variety of research on chiller operation has been carried out. However, most of the studies were carried out on the chiller itself, i.e., the part load ratio characteristics and the corresponding electricity energy consumption patterns were not analyzed in existing studies. In this study, the part load ratio and the operating characteristics of the vapor compression chiller were analyzed within an office building equipped with the conventional variable air volume system. As a result, significant portions of total operating hours, cooling load, and energy consumption turned out to be in the part load ratio range of 0 through 50%. Thus, energy consumption was significantly affected by the chiller COP at low part load conditions, indicating that chiller operation at the part load is an important factor in commercial buildings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.6
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• pp.609-615
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• 2000

The energy conservation is one of the most important issues in recent years. Especially, the energy conservation through improved control strategies is one of the most highly possible area to be implemented in the near future. The energy conservation of the ice storage system can be accomplished through the improved control strategies. A real time building load prediction algorithm was developed. The expected highest and the lowest outdoor temperature of the next day were used to estimate the next day outdoor temperature profile. The measured dry bulb temperature and the measured building load were used to estimate system parameters by using the on-line weighted recursive least square method. The estimated hourly outdoor temperatures and the estimated hourly system parameters were used to predict the next day hourly building loads. In order to see the effectiveness of the building load prediction algorithm, two different types of building models were selected and analysed. The simulation results show less than 1% in error for the prediction of the next day building loads. Therefore, this algorithm may successfully be used for the development of improved control algorithms of the ice storage system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.1
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• pp.1-13
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• 2023

Many government in the world have conducted building energy performance certification program to reduce building energy consumption. In this study, a reference building and its HVAC system was modeled, and the energy load and consumption were estimated by the ECO2 program. The software is a simple building energy simulation program based on monthly calculated method. The building energy efficiency rating the the reference building was 1+ under baseline condition. The simulation results showed that the insulation performance slightly affected building energy load and consumption, but light density had a significant effect on them. The application of geothermal heat pumps gave improvement of building energy efficiency rating but it could not make it possible to get zero energy building(ZEB) certification. The ZEB 5 certification could be achieved by using photovoltaics, however getting better grade was difficult. The simulation results showed that the ZEB 4 certification, one grade higher than ZEB 5, could be attained by using more than one renewable energy source such as geothermal and solar energy in this study.