• KIEAE Journal
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• v.17 no.4
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• pp.67-74
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• 2017

Purpose: As the recent climate environment changes so rapidly, environmental problems such as hot weather and fine dust have occurred, and interest in environmental policies and technology development is increasing in countries around the world. Similarly in the Architecture, researches to reduce greenhouse gas emissions and to reduce energy application are actively conducted. Looking at previous studies, it is analyzed that the electric VRF is more energy efficient than the gas engine VRF. However, energy costs have changed due to recent price hikes and discounts on gas charges due to high electricity consumption in summer. Method: In this study, the actual building of Gas Engine VRF system was modeled using SketchUp program, and EnergyPlus was used to simulate actual building. Also, Electric VRF system was simulated, and compared with Gas Engine VRF system. Result: The total secondary energy requirement of Electric VRF system was 19.6% less than that of the Gas Engine VRF system, But when analyzing with primary energy requirement, EHP used 15.8% more energy. CO2 emissions were also estimated to be 16.9% more EHP. Energy costs were 14.8% more in Electric VRF systems, because their electricity charges are 0.6 to 160% more expensive than gas charges.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.8-18
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• 2014

Building simulation is used in a variety of sectors. In its early years, building simulation was mainly used in the design phase of a building for basic functions. Recently, however, it has become increasingly important during the operating phase, for commissioning and facility management. Most building simulation tools are used to estimate the thermal environment and energy consumption performance, and hence, they require the inputting of hourly weather data. A building simulation used for prediction should take into account the use of standard weather data. Weather data, which is used as input for a building simulation, plays a crucial role in the prediction performance, and hence, the selection of appropriate weather data is considered highly important. The present study proposed a technique for generating real-time weather data files, as opposed to the standard weather data files, which are required for running the building simulation. The forecasted weather elements provided by the Korea Meteorological Administration (KMA), the elements produced by the calculations, those utilizing the built-in functions of Energy Plus, and those that use standard values are combined for hourly input. The real-time weather data files generated using the technique proposed in the present study have been validated to compare with measured data and simulated data via EnergyPlus. The results of the present study are expected to increase the prediction accuracy of building control simulation results in the future.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.1-9
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• 2010

Apartment balcony has been remodeled since the government permitted remodeling in January 2006.But extended balcony has great impact on building heat gain and loss. Therefore It has problems such as increase of heating and cooling energy. So $\underline{t}echnical$ solutions about window solar gain in summer is an urgent matter. The Purpose of this study is to evaluate energy performance of a blind in a double-skin facade in residential buildings by using EnergyPlus program. The results show that slat angles of $90^{\circ}$ is best in energy performance if we do not consider daylight. Poorly daylighted living room needs electric light and it also causes high cooling load. On the other hand, the results show that the application of blinds controlled automatically is best for energy performance when we consider daylight. Blind slat angles of $50\sim60^{\circ}$ have best performance when blinds are controlled in this angle throughout the day on a clear day in August. Blind slat angles of $0\sim30^{\circ}$ have best performance when blinds $\underline{are\;controlled}$ in this angle throughout the day on a cloudy day (more than 7 of total sky cover) in August.

• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.54-60
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• 2019

The recent climate change is exacerbating the external thermal environment and increasing the amount of energy used in building. Energy Plus was used to evaluate low energy technology performance of buildings responding to climate change. The test types of basic building(control) and evaporative mist system + basic building(EMS), and the analysis results of each type are compared. Energy performance evaluation result, Cooling peak load were EMS reduction compared to control is about 9%. Annual cooling load per unit area were EMS reduction compared to control is about 17%. Annual energy use per unit area were EMS reduction compared to control is about 10%. Therefore, the effect of the evaporative cooling system is considered to be good through energy reduction technology of building, according to the amount and distance of the evaporative mist system in the future research on building energy performance evaluation should be carried out.

• Journal of Nutrition and Health
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• v.43 no.1
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• pp.5-11
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• 2010

We conducted comparative study on metabolizable energy content of extracts of angelica keiskei and its byproduct. Total six different groups consisting of five test groups treated with angelica keiskei and one control group were compared. Each of the five test groups were given 30% of one of whole plant, extracts, fermented of extracts, byproduct and extracts plus byproduct, respectively, mixed with AIN93M. After 3 days of adjustment period, all groups were subjected to 4 days of test period during which the amounts of feed intake and excretion were measured everyday. All feces were treated for the prevention of decomposition and changes before its energy content were measured using a bomb calorimeter. The amount of excretion was $4.8\;{\pm}\;0.3\;g$/rat/3 days in control group and 9.9-15.0 g/rat/3 days in the groups were added with extracts of angelica keiskei indicating that the angelica keiskei-treated groups produce 2-3 times more excretion. Metabolic energy of control diet was 4,133.3 kcal. This was found to be 15 to 20% higher compared with the metabolic energy content ranging from 3,117.0 kcal/kg (extracts of angelica keiskei) to 3,259.8 kcal/kg (extracts plus byproducts) angelica keiskei-treated groups. This is interpreted as the result of the decreased metabolic energy in the test diets were substituted with 30% of ngelica keiskei-treated ingredient which has low metabolic content itself. One notable finding is that the metabolic content of the group mixed with byproducts and extracts (1,763.0 kcal/kg) is 27% higher than that of extracts of angelica keiskei (1,286.8 kcal/kg) indicating that mechanical grinding increases the rate of digestion and absorption increasing, in turn, the energy content used in the body. The results of analysis of overall caloric absorption showed absorption rate in order of Whole plant < extracts < byproduct < extract plus byproduct < fermented of extract.

• Applied Biological Chemistry
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• v.8
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• pp.21-28
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• 1967

Two experiments with 32 sheep were conducted to study the effects of feeding the same amount of diet per day at different meal frequencies on ration digestibility, energy utilization, rate of gain, body composition and efficiency of gain. The results obtained are as follows: (1) The ingestion by sheep of the same amount of feed per day in 8 meals, 1 meal plus 7 ruminal inflations-deflations, and in 1 meal caused no different effect in the digestibility of the nutrients and energy, or the ME value of the diet. (2) Heat production per unit of metabolic size per unit of dietary intake was markedly lower for sheep ingesting 8 meals or administered 1 meal plus 7 ruminal inflations-deflations per day than for sheep fed 1 meal per day. (3) Body weight gain was significantly greater by sheep fed 8 meals per day or 1 meal plus 7 ruminal inflations-deflations than by those fed 1 meal per day. However, the gain in DM and energy of wool was not affected by frequency o( meals. (4) Sheep ingesting 8 meals or administered 1 meal plus 7 ruminal inflations-deflations per day gained body protein, fat and energy at a more rapid and efficient rate than sheep fed 1 meal per day. (5) Sheep fed 8 meals per day gained greater proportion of fat, protein and ash in the gained portion of the bodies than did 1 meal fed sheep. (6) An attempt was made to establish the possible explanations by which the frequency of ingesting meals exerts its effects.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1437-1446
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• 2014

This study, the urban energy used office building green roof type composition of the target by analyze building energy reductions. Green roof is total 6 types(type A~F) were selected, EnergyPlus the energy simulation programs were used. Top floor of green roof types evaluation, the reduction of the cooling peak load type E(1.26%), type D(1.30%), type C(1.37%), type B(1.45%), type F(1.49%), and heating peak load is type D(1.32%), type E(1.40%), type C(1.47%), type F(1.69%), type B(2.13%) order. Annual cooling load of heating load is reduced more than about 1% effect. The heating load reduction ratio for a maximum of 9% respectively. Cooling peak load of the building energy performance evaluation of type F > type B > type C > type D > type E in the order and in the case of peak loads heating type B > type F > type D > type E>type C order. Annual total energy use reduction of 1.07 to 1.22% and earn, type B in the best good. In primary energy use reductions in the presence of a green roof were in the 4249~4876 kWh/yr. Annual $CO_2$ emissions reductions of unapplied type A were analyzed on average 469.78 kg.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.3
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• pp.249-254
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• 2013

The integrated gasification combined cycle (IGCC) system is well known for its high efficiency compared with other coal fueled power generation system. The aim of this study is to confirm the feasibility of using bio gas in coal feeding system and syngas recirculation system. The effects of using bio gas in the gasifier on the syngas composition were investigated through simulations using the Aspen Plus process simulator. It was found that these changes had an influence on the syngas composition of the final stream and bio gas can be used in a gasifier system.

• Journal of Energy Engineering
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• v.12 no.3
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• pp.184-189
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• 2003

A study of the property of Indolene-Methanol Plus High Alcolhols (MPHA) has been completed. The study invested the measurement of fuel properties. The fuel properties investigated are distillation characteristics, heating value, flash point, specific gravity and water tolerance. The alcohol concentration was varied from 0 to 100 percent by volume in clear Indolene. The measurement of fuel properties indicated that, in general, Indolene-MPHA blends have higher water tolerance, similar specific gravity, similar flash point and different distillation characteristics compared to Indolene-Methanol blends.

• Journal of Energy Engineering
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• v.12 no.3
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• pp.190-196
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• 2003

A study of the performance effect of Indolene-Methanol Plus High Alcolhols (MPHA) has been completed. The study invested the measurement of performance parameters. The performance parameters measured are minimum advance for best torque (MBT) spark timing, power output and thermal efficiency. The alcohol concentration was varied from 0 to 100 percent by volume in clear Indolene. The performance parameters were measured using a single cylinder spark ignition engine at different compression ratios. The results of the performance measurements indicated that Indolene-MPHA blends have a higher MBT spark advance, similar power output and lower thermal efficiencies than Indolene-Methanol blends.