• 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.10-17
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• 2015

In this study, to examine seismic reinforcement effect of a school building constructed prior to application of seismic design, a Double I-type damper supported by wall was installed to perform comparative analysis on existing non-seismic designed RC frame. As a result of experiment, while non-seismic designed specimen showed rapid reduction in strength and brittle shear destruction as damages were focused on top and bottom of left and right columns, reinforced specimen showed hysteretic characteristics of a large ellipse with great energy absorption ability, exhibiting perfectly behavior with increased strength and stiffness from damper reinforcement. In addition, as a result of comparing stiffness reduction between the two specimens, specimen reinforced by shear wall type damper was effective in preventing stiffness reduction. Energy dissipation ability of specimen reinforced by Double I-type damper was about 3.5 times as high as energy dissipation ability of non-reinforced specimen. Such enhancement in energy dissipation ability is considered to be the result of improved strength and deformation.

• Journal of Energy Engineering
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• v.27 no.3
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• pp.28-35
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• 2018

Guidelines and institutional support for buildings are being promoted around the world as measures for environmental pollution and energy conservation. In Korea, standards are prepared according to the energy saving design standards of new buildings as amended in 2013.09.01 and the zero energy building for new buildings mandatory process is being prepared from the recommendations. Nevertheless, the government's binding power on smaller buildings is insufficient. Energy savings were analyzed for the recently constructed office buildings (application of external insulation technique) and propose a dual envelope techniques were proposed for energy reduction.

• Current Photovoltaic Research
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• v.10 no.4
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• pp.107-110
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• 2022

Lightweight and flexible photovoltaic (PV) modules are attractive for building-integrated photovoltaic (BIPV) applications because of their easy construction and applicability. In this study, we fabricated lightweight and flexible c-Si PV modules using ethylene tetrafluoroethylene (ETFE) front cover and shingled design string cells. The ETFE front cover instead of glass made the PV modules lighter in weight, and the shingled design string cells increased the flexibility. Finally, we fabricated a PV module with a conversion power of 240.08 W at an area of 1.25 m² and weighed only 2 kg/m². Moreover, to check the PV module's flexibility, we conducted a bending test. The difference of conversion power between the modules before and after bending shown was only 1.7 W, which showed a power reduction rate of about 0.7%.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.4
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• pp.51-59
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• 2023

Despite countries' efforts to reduce carbon emissions, carbon emissions have increased in recent decades along with energy use, of which building energy uses account for a large proportion. Energy savings are essential as a strategy to reduce carbon emissions in existing buildings. The field experiment on the roof of a building located in Seoul was designed to measure the temperature reduction effect of green roof with rainwater storage tank to reduce cooling energy consumption in summer. The results showed that the mean mean surface temperature under the green roof was 14.77 degrees lower than that of the non-green roof from 13:00 P.M. to 15:00 P.M., which would have a great effect on reducing cooling energy. From 01:00 A.M. to 03:00 A.M., the effect was 3.36 degrees, showing that tropical nights could be improved. The temperature reduction effect due to the rainwater storage system increased by 1.45 degrees during the day and decreased by 0.63 degrees at night. The storage system can be strategically utilized to reduce carbon emissions during the week when cooling energy increases significantly.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.349-352
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• 2015

Size of building has a direct relationship with building cost, energy use and space maintenance cost. Therefore, minimizing building size during a project development is of paramount importance against such wastes. However, incautious reduction of building size may result in crowded space, and therefore harms the functionality despite the fact that building is supposed to satisfactorily support users' activity. A well-balanced design solution is, therefore, needed at an optimum level that minimizes building size in tandem with providing sufficient space to maintain functionality. For such design, architects and engineers need to be informed accurate and reliable space-use information. We present in this paper a conceptual framework of an agent-based space-use prediction simulation system that provides individual level space-use information over time in a building in consideration of project specific user information and activity schedules, space preference, ad beavioural rules. The information will accordingly assist architects and engineers to optimize space of the building as appropriate.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1104-1105
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• 2008

This paper presents the assesment of experimented data and estimated data for electrical and thermal performance evaluation of building integrated photovoltaic(BIPV) system of cold facade type. BIPV module is used to estimate the dependence of module temperature on irradiance, ambient temperature and indoor temperature. The module temperature of no free ventilated facade PV system is higher than cold facade PV system about 13.4$^{\circ}C$. By the results on simulation, the reduction of electrical power loss is 9.57% into cold facade according to free ventilation. The annual averaged PR of BIPV system into cold facade is about 73.1%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.78-79
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• 2021

It is necessary to calculate Apparent Activation Energy(Ea) in order to apply the equivalent age formula to predict compressive strength using the maturity method. For carbon reduction, it is necessary to consider the change of Ea by condition of GGBFS concrete, which is widely used today. In this study, as a basic study for the design of the compressive strength model of GGBFS concrete, the apparent activation energy of the GGBFS mixed paste was calculated through a calorimeter. The experiment was carried out at a hydration temperature of 10 to 30℃ with a paste test specimen having a GGBFS content of 0 to 80%. As a result, the GGBFS replacement rate of the paste increased, and Ea tended to increase as the temperature decreased.

• Wind and Structures
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• v.21 no.3
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• pp.331-352
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• 2015

A series of wind tunnel tests were conducted on tapered super high-rise buildings with a square cross section by applying synchronous pressure measurement technology. The effects of global strategy of chamfered modification on aerodynamic loads and wind-induced responses were investigated. Moreover, local aerodynamic strategies of opening a ventilation slot in the corner of equipment and refuge floors were carried out. Results show that the global strategy of tapered elevation increased the vortex shedding frequency, but reduced vortex shedding energy, leading to reduction of across-wind aerodynamic loads and responses. Chamfered modification suppressed the across-wind vortex shedding effect on tapered buildings. Opening the ventilation slot further suppressed the strength of vortex shedding and reduced the residual energy related to vortex shedding in aerodynamic loads of chamfered buildings. Finally, the optimized locations of local aerodynamic strategies were suggested.

• Journal of the Korean Solar Energy Society
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• v.29 no.1
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• pp.1-10
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• 2009

This study was carried out to evaluate the Life Cycle Cost(LCC) of three types of RTPV(Building Integrated Photovoltaic) systems-Glass plus Granite. Crystalline BIPV and See through Amorphous BIPV-which were vertically installed to generate the same power output(76 kW level). Initial investment costs. cost. savings and maintenance costs had been predicted during the period of analysing the LCC of three types of BIPV(Building Integrated Photovoltaic) systems installed for the purpose of evaluating the LCC. In case of cost savings, it had been analyzed by measuring the amount of electric power generated, reduction in lighting load and heat & cooling loads through simulation. From this analysis, it was predicted that the See-through amorphous BIPV offering cost saving advantages demonstrated the economical efficiency similar to the Class plus Granite when it is backed by more than 20 years of durability.