• Wind and Structures
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• 제35권3호
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• pp.213-227
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• 2022

The design of a building is a complex process that encompasses different fields: one of the most relevant is nowadays the energetic one, which has led to the introduction of new typologies of building envelopes. Among them, the Permeable Double Skin Façades (PDSF) are capable to reduce the solar impact and so to improve the energetic performances of the building. However, the aerodynamic characterization of a building with a PDSF is still little investigated in the current literature. The present paper proposes an experimental study to highlight the modifications induced by the outer porous façade in the aerodynamics of a building. A dedicated wind tunnel study is conducted on a rigid model of a prismatic high-rise building, where different façade configurations are tested. Specifically, the single-layer façade is compared to two PDSFs, the former realized with perforated metal and the latter with expanded metal. Outcomes of the tests allow estimating the cladding loads for all the configurations, quantifying the shielding effects ascribable to the porous layers that are translated in a significant reduction of the design pressure that could be up to 50%. Moreover, the impact of the PDSFs on the vortex shedding is investigated, suggesting the capability of the façade to suppress the generation of synchronised vortices and so mitigate the structural response of the building.

• Journal of the Korean Wood Science and Technology
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• 제43권6호
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• pp.876-883
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• 2015

국립산림과학원에서는 한옥의 전통건축기술을 바탕으로 한국형 기둥-보 목조주택인 ?그린 프로젝트를 2006년부터 진행해오고 있다. 최근에는 에너지 절약 기술요소를 적용하여 건물의 에너지성능을 개선하고자 하였다. 본 연구에서는 강화된 단열기준에 따른 기둥-보 목조벽체의 단열상세를 제시하고 그에 따른 건물 에너지 절감 효과를 평가하고자 하였다. 건물외피의 열관류율은 현행법 수준과 저에너지주택인 패시브하우스 수준인 두 단계로 나누었으며 건물에너지 성능을 평가하기 위하여 건물의 기밀성능은 국내 신축 목조주택 수준인 $3.0h^{-1}$과 패시브하우스 수준이 $0.6h^{-1}$ 두 단계로 나누어 열관류율과 기밀성능의 조합에 따라 4가지 경우에 대한 건물에너지 성능 평가가 이루어졌다. 대상건물은 서울에 위치하였으며 에너지 성능은 상용 건물에너지성능 평가 프로그램인 CE3가 사용되었다. 강화된 열관류율에 따라 시뮬레이션을 진행한 결과 연간 난방에너지 요구량은 $14kWh/(m^2{\cdot}a)$ 절감효과를 나타냈다.

• 국제초고층학회논문집
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• 제4권1호
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• pp.85-90
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• 2015

Advances in the technology of computational design are giving architects and engineers the opportunity to analyze buildings with complex geometries. This study explores the optimization and automation process using the parametric design method, and uses digital tools to achieve surface representation and panelization for curved shaped office buildings. In this paper, we propose parametric algorithms of dimensional and geometric constraints using the Knowledge-ware scripts embedded in Gehry Technologies' Digital Project. The knowledge-based design methods proposed in this study can be used to systemize the knowledge possessed by experts in the form of data. Such knowledge is required to promote collaboration between designers and engineers in the process of CAD/CAE/CAM. The aim of this study is to integrate the process into design, which establishes an integrated process. This integration enables two-way feedback between design and construction data by combining the methods used in designing, engineering, and construction.

• Journal of Construction Engineering and Project Management
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• 제5권4호
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• pp.16-22
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• 2015

This paper presents an automated computer vision-based system to update BIM data by leveraging multi-modal visual data collected from existing buildings under inspection. Currently, visual inspections are conducted for building envelopes or mechanical systems, and auditors analyze energy-related contextual information to examine if their performance is maintained as expected by the design. By translating 3D surface thermal profiles into energy performance metrics such as actual R-values at point-level and by mapping such properties to the associated BIM elements using XML Document Object Model (DOM), the proposed method shortens the energy performance modeling gap between the architectural information in the as-designed BIM and the as-is building condition, which improve the reliability of building energy analysis. Several case studies were conducted to experimentally evaluate their impact on BIM-based energy analysis to calculate energy load. The experimental results on existing buildings show that (1) the point-level thermography-based thermal resistance measurement can be automatically matched with the associated BIM elements; and (2) their corresponding thermal properties are automatically updated in gbXML schema. This paper provides practitioners with insight to uncover the fundamentals of how multi-modal visual data can be used to improve the accuracy of building energy modeling for retrofit analysis. Open research challenges and lessons learned from real-world case studies are discussed in detail.

• Wind and Structures
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• 제28권6호
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• pp.389-404
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• 2019

In coastal regions, it is common to witness significant damages on low-rise buildings caused by hurricanes and other extreme wind events. These damages start at high pressure zones or weak building components, and then cascade to other building parts. The state-of-the-art in experimental and numerical aerodynamic load evaluation is to assume buildings with intact envelopes where wind acts only on the external walls and correct for internal pressure through separate aerodynamic studies. This approach fails to explain the effect of openings on (i) the external pressure, (ii) internal partition walls; and (iii) the load sharing between internal and external walls. During extreme events, non-structural components (e.g., windows, doors or rooftiles) could fail allowing the wind flow to enter the building, which can subject the internal walls to lateral loads that potentially can exceed their load capacities. Internal walls are typically designed for lower capacities compared to external walls. In the present work, an anticipated damage development scenario is modelled for a four-story building with a stepped gable roof. LES is used to examine the change in the internal and external wind flows for different level of assumed damages (starting from an intact building up to a case with failure in most windows and doors are observed). This study demonstrates that damages in non-structural components can increase the wind risk on the structural elements due to changes in the loading patterns. It also highlights the load sharing mechanisms in low rise buildings.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.532-536
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• 2015

This paper presents an automated computer vision-based system to update BIM data by leveraging multi-modal visual data collected from existing buildings under inspection. Currently, visual inspections are conducted for building envelopes or mechanical systems, and auditors analyze energy-related contextual information to examine if their performance is maintained as expected by the design. By translating 3D surface thermal profiles into energy performance metrics such as actual R-values at point-level and by mapping such properties to the associated BIM elements using XML Document Object Model (DOM), the proposed method shortens the energy performance modeling gap between the architectural information in the as-designed BIM and the as-is building condition, which improve the reliability of building energy analysis. The experimental results on existing buildings show that (1) the point-level thermography-based thermal resistance measurement can be automatically matched with the associated BIM elements; and (2) their corresponding thermal properties are automatically updated in gbXML schema. This paper provides practitioners with insight to uncover the fundamentals of how multi-modal visual data can be used to improve the accuracy of building energy modeling for retrofit analysis. Open research challenges and lessons learned from real-world case studies are discussed in detail.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.434-439
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• 2008

Dome stadiums give thermal unpleasant feeling to occupants because of the radiant heat and the indoor and outdoor haet exchange from roogs or lightweight building envelopes of sidewalls. This study analyzed the indoor temperature and velocity distribution according to various air supply and return sustems in dome stadiums in summer.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.801-806
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• 2008

The best plan is that the insulation performance should be improved because the insulation and airtight of building envelopes have an effect on the energy consumption basically. New insulation materials, which have the high performance and are above insulation standard, have been developed steadily. Because there are not studies on the building energy rating system and economic evaluation considering new insulation materials, these matters should be studied. In result alternatives, which applied 6 high performance material each, influence, reduce the annual heating energy and raise the building energy rating. Applying the vacuum insulation material(Case1,2) and vacuum or triple glazing can retrieves the investment with $120 and $$140{\sim}150$ per barrel each.

• Wind and Structures
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• 제13권2호
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• pp.191-206
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• 2010

Windborne debris is a major cause of structural damage during severe windstorms and hurricanes owing to its direct impact on building envelopes as well as to the 'chain reaction' failure mechanism it induces by interacting with wind pressure damage. Estimation of debris risk is an important component in evaluating wind damage risk to residential developments. A debris risk model developed by the authors enables one to analytically aggregate damage threats to a building from different types of debris originating from neighboring buildings. This model is extended herein to a general debris risk analysis methodology that is then incorporated into a vulnerability model accounting for the temporal evolution of the interaction between pressure damage and debris damage during storm passage. The current paper (Part I) introduces the debris risk analysis methodology, establishing the mathematical modeling framework. Stochastic models are proposed to estimate the probability distributions of debris trajectory parameters used in the method. It is shown that model statistics can be estimated from available information from wind-tunnel experiments and post-damage surveys. The incorporation of the methodology into vulnerability modeling is described in Part II.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.190-195
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• 2008

The objective of this research is to determine overall heat transfer coefficients (K-value) of exterior wall, floor, and roof of Nakseonjae, a Korean traditional residence via field measurement of transient heat flow and temperature difference across each envelope component. Heat flow sensors and T-type thermocouple were attached on the internal and the external surface of each building component, and real-time measurement data were collected for the three consecutive summer days. The K-values determined in this research showed good agreement with other results from open literature. Peak and annual thermal loads of the traditional residence estimated by a commercial energy simulation program were compared with those for a current apartment house. The traditional house showed lower annual cooling load than that of the current building. It may caused by the fact that the traditional building has less air-tight envelopes and no fenestration passing direct solar radiation into the space.