• Journal of Climate Change Research
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• v.2 no.4
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• pp.283-295
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• 2011

Many actions against climate change have been taken to reduce greenhouse gases (GHGs) emissions at home and abroad. As of 2007, the GHGs emitted from buildings accounted for about 23 % of Korea's total GHGs emission, which is the second largest GHG reduction potential following industry. In this study, we introduced Carbon Zero Building (CZB), which was constructed by the National Institute of Environmental Research to cut down GHGs from buildings in Korea, and evaluated the main applied technologies, the amount of energy load and reduced energy, and economic values for CZB to provide data that could be a basis in the future construction of this kind of carbon-neutral buildings. A total of 66 technologies were applied for this building in order to achieve carbon zero emissions. Applied technologies include 30 energy consumption reduction technologies, 18 energy efficiency technologies, and 5 eco-friendly technologies. Out of total annual energy load ($123.8kWh/m^2$), about 40% of energy load ($49kWh/m^2$) was reduced by using passive technologies such as super insulation and use of high efficiency equipments and the other 60% ($74.8kWh/m^2$) was reduced by using active technologies such as solar voltaic, solar thermal, and geothermal energy. The construction cost of CZB was 1.4 times higher than ordinary buildings. However, if active technologies are excluded, the construction cost is similar to that of ordinary buildings. It was estimated that we could save annually about 102 million won directly from energy saving and about 2.2 million won indirectly from additional saving by the reduction in GHGs and atmospheric pollutants. In terms of carbon, we could reduce 100 ton of $CO_2$ emissions per year. In our Life Cycle Cost (LCC) analysis, the Break Even Point (BEP) for the additional construction cost was estimated to be around 20.6 years.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.1-8
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• 2005

The quantity of light available for a space can be translated in term of the amount of energy savings through a process of a building energy simulation. To get significant energy savings in general illumination, the electric lighting system must be incorporated with a daylight - activated dimmer control. A prototype configuration of an once interior has been established and the integration between the building envelope and lighting and HVAC systems is evaluated based on computer modeling of a lighting control facility. First of all, an energy-efficient luminaire system is designed and the lighting analysis program, Lumen-Micro 2000 predicts the optimal layout of a conventional fluorescent lighting future to meet the designed lighting level and calculates unit power density, which translates the demanded met of electric lighting energy. A dimming control system integrated with the contribution of daylighting has been applied to the operating of the artificial lighting. Annual cooling load due to lighting and the projecting saving amount of cooling load due to daylighting under overcast diffuse sky m evaluated by computer software ENER-Win. In brief, the results from building energy simulation with measured daylight illumination levels and the performance of lighting control system indicate that daylighting can save over 70 percent of the required energy for general illumination in the perimeter zones through the year A 25[%] of electric energy for cooling and almost all off heating energy may be saved by dimming and turning off the luminaires in the perimeter zones.

• KIEAE Journal
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• v.13 no.2
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• pp.123-130
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• 2013

The primary goal of this research is to identify the impacts of window design on the energy use in buildings which takes up about 25% of the total energy consumption. Recently, efficient use of energy is gaining more importance in buildings. Window design, especially being dependent on glazing performance choices, is an important factor for reducing energy consumption in most of the buildings. It also is influenced by the latitude of the site and window orientation. This paper aims at identifying the influence of Window performance indicators(U-value, SHGC), orientation and latitude on the building energy consumption with systematically designed simulations. Comparative study has been performed for five different locations; Greenland, Korea, Singapore, Argentina and Chile along with the different window U-value and SHGC values. The results show that optimum window system with properly coordinated window performance indicators(U-value, SHGC), orientation achieves dramatic reduction of energy consumptions. Windows with low U-value could reduce heating loads and high SHGC could reduce cooling loads. The study also verifies that the windows installed at south facade is more energy efficient in the northern hemisphere while windows facing north is more energy efficient in the southern hemisphere.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1049-1061
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• 2013

In this paper, a relative heat exchange rate is numerically compared for cast-in-place concrete energy piles with different heat exchange pipe configurations, and a new design method for energy piles is proposed. An equivalent heat exchange rate was estimated for the W-type (one series loop), multiple U-type (four parallel loops), and coil-type heat exchanger installed in the same large-diameter drilled shaft. In order to simulate a cooling operation in summer by a CFD analysis, the LWT (leaving water temperature) into a energy pile was fixed at $35^{\circ}C$ and then the EWT (entering water temperature) into a heat pump was monitored. In case of continuously applying the artificial maximum cooling load for 100 hours, all of the three types of heat exchangers show the marginally similar heat exchange rate. However, in case of intermittently applying the cooling load with a cycle of 8 hours operation-16 hours off for 7 consecutive days, the coil type heat exchanger exhibits a heat exchange rate only 86 % of the multiple U-type due to measurable thermal interference between pipe loops in the energy pile. On the other hand, the W-type possesses the similar heat exchange rate to the multiple U-type. The equivalent heat exchange rates for each configuration of heat exchangers obtained from the CFD analysis were adopted for implementing the commercial design program (PILESIM2). Finally, a design method for cast-in-place concrete energy piles is proposed along with a design chart in consideration of typical design factors.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.936-946
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• 2015

This study is aimed to analyze the reduction performance of building energy consumption according to planting base types of panel-type green walls which can be applied to existing buildings. The performance was compared to the general performance of green walls that have demonstrated effects of improving the thermal environment and reducing building energy consumption in urban areas. The number of planting base types was 4 in total, and simulations were conducted to analyze the thermal conductivity, thermal transmittance, and overall building energy consumption rate of each planting base type. The highest thermal conductivity by the planting base type was Case C (0.053W/mK), followed by Case B (0.1W/mK) and Case D (0.17W/mK). According to the results of energy simulation, the most significant reduction of cooling peak load per unit area was Case C (1.19%), followed by Case B (1.14%) and Case D (1.01%) when compared to Case A to which green wall was not applied; and the most significant reduction of heating peak load per unit area was estimated to be Case C (2.38%), followed by Case B (1.82%) and case D (1.50%) when compared to Case A. The amount of yearly cooling and heating energy use per unit area showed 3.04~3.22% of reduction rate. The amount of the 1st energy use showed 5,844 kWh/yr of decrease on average for other types when compared to Case A. The amount of yearly $CO_2$ emission showed 996kg of decrease on average when compared to Case A to which the green wall was not applied. According to the results of energy performance evaluation by planting location, the most efficient energy performance was eastward followed by westward, southward and northward. According to the results of energy performance evaluation by planting location by green wall ratio, it was found that as the ratio of green wall increased, the energy performance displayed better results, showing approx. double reduction rate in energy consumption at 100% of green wall ratio than the reduction rate at 20% to 80% of green wall ratio.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.153-160
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• 2002

As a way to assess the reliability of programs for building energy analysis, verification experiment and calculation of heating load are simultaneously conducted for a well-defined test space. Experimental conditions are carefully set to minimize uncertainties associated with radiation heating, air change, infiltration, and room-to-room interaction. Dyna- mic load calculations using TRNSYS, which are performed for two different computation domains, rely on the energy rate control that represents inherent load characteristics of a space. The predicted instantaneous heating load favorably simulates the overall behavior the measured one, though the latter fluctuates much more rapidly than the former Comparison of the accumulative load between the experiment and calculations shows a close agreement within an engineering tolerance, regardless of the computation model. It is deduced from such findings that the present experimental results along with weather information can serve as a set of reference data for validating load calculation softwares from the users'standpoint. In order to enhance the completeness of this work, a complementary study on the cooling load for the same test space is highly recommended.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.168-178
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• 2012

The objective of this study is applied to office buildings to evaluate quantitative evaluation method about performance of double-skin at design stage to establish the basis for the purpose of evaluation performance. Select the evaluation building about design plan for applying the double-skin using the dynamic heat load analysis program the annual heating and cooling load of before and after the double-skin. Using CFD to analyze wind factor and applied ventilation for realistic results. Effects of double-skin to apply, and control techniques that can be done more realistically proposed through to set and control for shade control mode of ventilator and inside cavity wall of double-skin. Apply for the building the double-skin due to interpretation of the annual heating and cooling loads applied to interpret the quantitative effect confirmed the possibility. According to the form of a double skin was confirmed cavity environmental changes.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.60-74
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• 2018

This study was to investigate the pedestrian's thermal environments in the North Sidewalk of E-W Street during summer heatwave. We carried out detailed measurements with four human-biometeorological stations on Dongjin Street, Jinju, Korea ($N35^{\circ}10.73{\sim}10.75^{\prime}$, $E128^{\circ}55.90{\sim}58.00^{\prime}$, elevation: 50m). Two of the stations stood under one row street tree and hedge(One-Tree), two row street tree and hedge (Two-Tree), one of the stations stood under shelter and awning(Shelter), while the other in the sun (Sunlit). The measurement spots were instrumented with microclimate monitoring stations to continuously measure microclimate, radiation from the six cardinal directions at the height of 1.1m so as to calculate the Universal Thermal Climate Index (UTCI) from 24th July to 21th August 2018. The radiant temperature of sidewalk's elements were measured by the reflective sphere and thermal camera at 29th July 2018. The analysis results of 9 day's 1 minute term human-biometeorological data absorbed by a man in standing position from 10am to 4pm, and 1 day's radiant temperature of sidewalk elements from 1:16pm to 1:35pm, showed the following. The shading of street tree and shelter were mitigated heat stress by the lowered UTCI at mid and late summer's daytime, One-Tree and Two-Tree lowered respectively 0.4~0.5 level, 0.5~0.8 level of the heat stress, Shelter lowered respectively 0.3~1.0 level of the heat stress compared with those in the Sunlit. But the thermal environments in the One-Tree, Two-Tree and Shelter during the heat wave supposed to user "very strong heat stress" while those in the Sunlit supposed to user "very strong heat stres" and "exterme heat stress". The main heat load temperature compared with body temperature ($37^{\circ}C$) were respectively $7.4^{\circ}C{\sim}21.4^{\circ}C$ (pavement), $14.7^{\circ}C{\sim}15.8^{\circ}C$ (road), $12.7^{\circ}C$ (shelter canopy), $7.0^{\circ}C$ (street funiture), $3.5^{\circ}C{\sim}6.4^{\circ}C$ (building facade). The main heat load percentage were respectively 34.9%~81.0% (pavement), 9.6%~25.2% (road), 24.8% (shelter canopy), 14.1%~15.4% (building facade), 5.7% (street facility). Reducing the radiant temperature of the pavement, road, building surfaces by shading is the most effective means to achieve outdoor thermal comfort for pedestrians in sidewalk. Therefore, increasing the projected canopy area and LAI of street tree through the minimal training and pruning, building dense roadside hedge are essential for pedestrians thermal comfort. In addition, thermal liner, high reflective materials, greening etc. should be introduced for reducing the surface temperature of shelter and awning canopy. Also, retro-reflective materials of building facade should be introduced for the control of reflective sun radiation. More aggressively pavement watering should be introduced for reducing the surface temperature of sidewalk's pavement.

• Solar Energy
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• v.12 no.1
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• pp.15-24
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• 1992

An hourly simulation model of a solar LiBr-water absorption cooling and heating system (for brevity, solar absorption system) is presented, based on SuperCalc spreadsheet computational procedures. This paper demonstrates the value of using spreadsheet simulation techniques by examining the thermal performances of a solar absorption system. The hourly heating and cooling coil loads for a typical office building in Tucson, Arizona are modeled and calculated using ASHRAE methods. The details of the algorithms for the components and control schemes are presented. Two case studies are also presented using real system parameters.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.6
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• pp.675-685
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• 1988

The purpose of this paper is to present the fundamental information for setting up more accurate and easier heat loads analysis method by examing and comparing Modified Bin Method with Dynamic loads calculation and Extended Degree Day Method. For this comparison, monthly and annual loads calculation are performed in perimeter zones of model office building in Seoul by the above each Method. The results of Modified Bin Method are approximated to those of Dynamic loads calculation Method, and the correlations of the methods are specifically described in this paper.