• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.1
• /
• pp.88-93
• /
• 2005

In this study, the operational characteristics on heating performance and energy consumption for intermittent hot water heating system in apartment buildings were research by simulation. The effects of apartment inlet hot water temperature and operation time per day on energy consumption and indoor thermal environment are investigated. The strategy of energy saving and thermal environment improvement is suggested in comparison with the existing ones.

• 한국태양에너지학회:학술대회논문집
• /
• 2012.03a
• /
• pp.522-528
• /
• 2012

Currently, the energy consumption of electric lighting in an office building is accounted for more than 30% of the total energy consumption. In order to reduce the energy consumed by the indoor lighting, the daylight as a natural energy resource can play an important role in energy savings. The daylight can have positive impacts on improvement of work efficiency and productivity, and also make people feel more psychologically stable. Moreover, by using the daylight, we can definitely reduce the energy consumption in office buildings. Thus, the purpose of this study is to determine the LED dimming ratio depending on the ratio by calculating the amount of artificial illumination required according to the change of daylight by using the light simulation software that can quantify and visualize the performance of daylight. As a result, the energy savings could be obtained up to 30%.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.5
• /
• pp.39-43
• /
• 2020

In this paper, we propose the multi-channel interference cancellation algorithm for visible light communication (VLC) in smart building. The VLC system is communication technology using visible rays that come out in Light Emitting Diode (LED) device. It has energy curtailment effect and possible to use in ubiquitous network service applications. When a large number of users communicate indoors, the performance can be reduced due to channel interference. To remove interference, at the first, the minimum mean square error (MMSE) scheme as interference cancellation methods used, and then the successive interference cancellation (SIC) is applied to obtain additional diversity gain and improve interference cancellation performance. Indoor VLC channel model is employed. The performance is evaluated in terms of bit error rate (BER). From the simulation results, it is confirmed that the proposed scheme has better BER performance compared to the previous systems. As a result, the proposed interference cancellation improves the signal quality of VLC systems by effectively removing the channel noise. The results of the paper can be applied to VLC for smart building and general communication systems.

• Earthquakes and Structures
• /
• v.9 no.6
• /
• pp.1193-1219
• /
• 2015

The purpose of this study is to evaluate the seismic performance of high-rise reinforced concrete (RC) box-type wall structures commonly used for most residential buildings in Korea. For this purpose, an analytical model was calibrated with the results of the earthquake simulation tests on a 1:5 scale 10-story distorted model. This calibrated model was then transformed to a true model. The performance of the true model in terms of the stiffness, strength, and damage distribution through inelastic energy dissipation was observed with reference to the earthquake simulation test results. The model showed high overstrength factors ranging from 3 to 4. The existence of slab in this box-type wall system changed the main resistance mode in the wall from bending moment to tension/compression coupled moment through membrane actions, and increased the overall resistance capacity by about 25~35%, in comparison with the common design practice of neglecting the slab's existence. The flexibility of foundation, which is also commonly neglected in the engineering design, contributes to 30~50% of the roof drift in the stiff direction containing many walls. The possibility of concrete spalling and reinforcement buckling and fracture under the maximum considered earthquake (MCE) in Korea appears to be very low when compared with the case of the 2010 Concepcion, Chile earthquake.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.1
• /
• pp.8-15
• /
• 2011

Cooling load reduction was analysed of a ventilation system adopting a regenerative evaporative cooler. The regenerative evaporative cooler is a kind of indirect evaporative cooler which cools the air down to its inlet dewpoint temperature in principle without change in the humidity ratio. The regenerative evaporative cooler was found able to cool the ventilation air to $18{\sim}21^{\circ}C$ when the outdoor condition ranges $25{\sim}35^{\circ}C$ and 0.01~0.02 kg/kg. When the outdoor humidity ratio is lower than 0.018 kg/kg, the regenerative evaporative cooler was found to provide cooling performance enough to compensate the ventilation load completely and to supply additional cooling as well. Energy simulation during the summer was carried out for a typical office building with the ventilation system using the regenerative evaporative cooler. The results showed that the seasonal cooling load can be reduced by about 40% by applying the regenerative evaporative cooler as a ventilation conditioner. The reduction was found to increase as the outdoor temperature increases and the outdoor humidity ratio decreases.

• 한국태양에너지학회:학술대회논문집
• /
• 2011.04a
• /
• pp.133-137
• /
• 2011

Low-e glazing is classified as soft low-e glazing and hard low-e glazing. Hard low-e glazing can be temperable and its handling is comfortable because its coating film is a oxide film generated at high temperatures. But there is a fatal weakness that its insulation performance and shielding performance are lower compared to soft low-e glazing by low electrical conductivity of coating film. Soft low-e glazing is excellent because its coating film consists of Ag that is excellent electrical conductivity and it has strength that can supply various product consumers want. But soft low-e glazing has weaknesses that temperable and handling are difficult because Ag is oxidized easily. Therefore this study analyzes thermal performance of glazing by changing filling gas according to applying low-e glazing through simulation to judge performance before making sample. After this process, a comparative experimental study was done through TVS by making temperable low-e glazing.

• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.213-220
• /
• 2011

In the current construction industry where various stakeholders take part, BIM Data exchange using standard format can provide a more efficient working environment for related staffs during the life-cycle of the building. Currently, the formats used to exchange the data from 3D-CAD application to structure energy analysis at the design stages are IFC, the international standard format provided by IAI, and gbXML, developed by Autodesk. However, because of insufficient data compatibility, the BIM data produced in the 3D-CAD application cannot be directly used in the energy analysis, thus there needs to be additional data entry. The reasons for this are as follows: First, an IFC file cannot contain all the data required for energy simulation. Second, architects sometimes write material names on the drawings that are not matching to those in the standard material library used in energy analysis tools. DOE-2.2 and Energy Plus are the most popular energy analysis engines. And both engines have their own material libraries. However, our investigation revealed that the two libraries are not compatible. First, the types and unit of properties were different. Second, material names used in the library and the codes of the materials were different. Furthermore, there is no material library in Korean language. Thus, by comparing the basic library of DOE-2, the most commonly used energy analysis engine worldwide, and EnergyPlus regarding construction materials; this study will analyze the material data required for energy analysis and propose a way to effectively enter these using semantic web's ontology. This study is meaningful as it enhances the objective credibility of the analysis result when analyzing the energy, and as a conceptual study on the usage of ontology in the construction industry.

• 한국태양에너지학회:학술대회논문집
• /
• 2012.03a
• /
• pp.549-552
• /
• 2012

Recently the world is trying to reduce carbon emissions for global warming. Reducing use of fossil fuels can decrease carbon emission. In this reason the construction field has tried to reduce the use of fossil fuels relating to heating and cooling of buildings. An energy loss through the window system is about 10 to 30 percent of energy consumption of the whole building. The use of window film insulation is increasing to control the heat loss at the windows. The window film insulation absorbs solar radiation and makes the surface temperature of windows high. In this study, window surface temperature is measured, and an impact on indoor air is identified after attaching window film insulation. Finally, we found that cooling load decreases through simulation.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.16 no.4
• /
• pp.9-15
• /
• 2020

In this study, effect of reinforced insulation on heating and cooling loads were studied due to installation of PV panels on factory building roof with a floor area of 12,960 m². For PV panel installation, combination of aluminum, polyurethane, air, polystyrene and steel materials were added to the original roof, which increased thermal insulation performance. Half of the roof were covered with PV panel and the other half without. Temperature and relative humidity were measured for 8 days during summer season for both indoor spaces. PV panel showed the effect of lowering the indoor space temperature by 0.6℃. TRNSYS dynamic simulation showed that with PV panel, cooling load per area is reduced by 1.7 W/m² and heating by 10.0 W/m². PV panels installed on building roof not only generate electricity but also can save energy by reducing cooling and heating loads.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.2
• /
• pp.137-147
• /
• 2012

GRS is an effective urban ecology restoration technique that can manage a variety of environmental functions such as ecological restoration, rainwater spill control and island heat effect from a low-impact development standpoint that can be utilized in new construction and retrofits. Recently, quantitative evaluation studies, both domestic and abroad, in the areas related to these functions, including near-earth surface climate phenomenon, heavy rainwater regulation, thermal environment of buildings, have been actively underway, and there is a trend to standardize in the form of technological standards. In particular, centered on the advanced European countries, studies of standardizing the specific insulation capability of buildings with green system that comprehensively includes the green roof, from the perspective of replacing the exterior materials of existing buildings, are in progress. The limitation of related studies in the difficulties associated with deriving results that reflect material characteristics of continuously evolving systems due in part to not having sufficiently considered the main components of green system, mechanisms of vegetation, soils. This study attempts to derive, through EnergyPlus, the effects that the vegetation-related indicators such as vegetation height, FCV, etc. have on building energy load, by interpreting vegetation and soil mechanisms through plant canopy model and using an ecological standard indicator LAI that represent the condition of plant growth. Through this, the interpretations that assume green roof system as simple heat insulation will be complemented and a more practical building energy performance evaluation method that reflects numerical methods for heat fluxes phenomena that occur between ecology restoration systems comprised of plants and soil and the ambient space.