Facade Shading Research Articles

Comparison of Shibataea kumasasa and Equisetum hyemale as vertical greenery system for thermal and light shade in student’s architectural design studio in Surabaya

Vertical greenery system (VGS) is commonly used for facade shading. It has many advantages in its natural aesthetic, air filter, carbon sequestration, and many more. This research is the continuation of the previous research in 2019, which used Shibataea kumasasa as VGS. It was found that using Shibataea as VGS has reduced the indoor air temperature by 0.5-2°C on average, with 5°C maximum temperature difference. On the other hand, it decreased more light (in range 26-95%), made the illuminance of the room lower than the standard requirement. A studio room should have minimum 5% daylight factor or 500 lux, while on the room measurement, the lowest was 20 lux in the morning hours, the highest was only 200 lux in the afternoon. As an attempt to look for vegetation with better performance, this research uses another bamboo species, Equisetum hyemale to be examined and then being compared to Shibataea. The result is that for the thermal shade, Equisetum performs less effectively than Shibataea. As for light shade, the Shibataea reduces more illuminance than Equisetum, thus makes it a less favorable alternative. The balance of thermal-light effective performance maintained by the leaf area index can be the focus of future research.

A multi-objective optimization design method for gymnasium facade shading ratio integrating energy load and daylight comfort

The large-scale use of curtain walls in stadiums and other public buildings will cause glare and increase the burden of energy consumption, especially in summer. In the early stage of the design, the optimization of the shading devices directly affects the decision-making of the building facade. This research proposes a multi-objective facade optimization method (MOO) for stadium design, using image density atlas (IDA) to provide decision-making basis for facade shading ratio (FSR) optimization in the preliminary design process of gymnasium. In contrast to the traditional design method, the optimized design framework proposed in this study will achieve the balance optimization among contradictory goals of daylight comfort and solar radiation at the same time to optimize the daylighting performance while avoiding glare and reducing energy burden. In this study, a gymnasium in Xiong'an, Beijing was selected as the test case. Researchers took the hourly average illuminance, hourly average solar radiation accumulation, and glare index during the opening hours of the gymnasium in summer (August) as the optimization goals. Then, the genetic algorithm SPEA-2 was used to explore the Pareto frontier solution set of FSR. The optimization scheme FSR = 0.37 is formed through comparison and screening. The research results achieved a 38.5% reduction in DGP, a 54% reduction in solar radiation, and control of illuminance loss within the acceptable range. The case study reveals the importance of FSR optimization to the indoor daylight environment of gymnasium in summer, and how parameter changes affect the rules of various metrics.

Qualitative study of airflow structure across wooden louvred window panels for natural ventilation applications

Window ventilation usually used in energy-efficient buildings as an effective natural ventilation system to provide an adequate opening for fresh air to flow into the interior space. It could help to reduce the indoor air temperature and limit the contaminants in buildings. This study aimed to visualise the airflow structure across a wooden louvred window panel using the smoke flow visualisation technique at different airflow speeds of 0.5, 1.0, 2.0, 3.0 and 5.0 m/s in a closed-loop wind tunnel. Two Sony 1920 × 1080i cameras captured the airflow structure, which took the side view, rear view, front view and back view images. The wooden louvred window panel promotes optimum outdoor airflow and facilitates continuous air exchange to replace the indoor air. Results showed that smoke filled the space quickly at the highest airflow speed of 5 m/s. This study used an inclination angle of 75° for the wooden louvred window panel to avoid rain splatter. Besides, wood material could be used as a facade shading device. Therefore, installing the wooden louvred window panels could enhance natural ventilation, ensure indoor thermal comfort and reduce indoor air contaminants.

Avaliação da Eficiência Energética do Tribunal de Contas do Paraná, sediado em Curitiba

A procura por maior eficiência energética no uso da eletricidade trouxe inúmeras iniciativas louváveis, no Brasil sob responsabilidade maior do Procel, com campanhas de conscientização dos usuários, pela etiquetagem de aparelhos eletrodomésticos até o panorama atual de certificação de edificações. O presente estudo tem como objetivo principal avaliar o nível de eficiência energética por meio dos Requisitos Técnicos da Qualidade do Nível de Eficiência Energética para Edifícios Comerciais, de Serviços e Públicos (RTQ-C/Procel) do Tribunal de Contas (TC), parte do patrimônio histórico do Estado do Paraná, localizado no Centro Cívico de Curitiba. TC é composto de dois edifícios construídos e um terceiro edifício em projeto: o Edifício Sede, o Edifício Anexo e a Ampliação do Edifício Anexo. No Edifício Sede, foram analisados indicadores de possível economia energética resultante da melhoria dos sistemas de iluminação (natural e artificial). Na ampliação do Edifício Anexo, avaliou-se a aplicabilidade do sistema de sombreamento de fachadas denominado tela tensionada. Comprovou-se que os edifícios existentes apresentam grande potencial de economia energética em sistemas de iluminação e que, ao se aprimorarem os dispositivos de sombreamento da fachada no projeto de ampliação do Edifício Anexo, podem ser alcançados maiores níveis de eficiência energética no quesito envoltória.

Learning from plant movements triggered by bulliform cells: the biomimetic cellular actuator.

Within the framework of a biomimetic top-down approach, our study started with the technical question of the development of a hinge-free and compliant actuator inspired by plant movements. One meaningful biological concept generator was the opening and closing movements of the leaf halves of grasses. Functional morphological investigations were carried out on the selected model plant Sesleria nitida. The results formed the basis for further clarifying the functional movement principle with a particular focus on the role of turgor changes in bulliform cells on kinetic amplification. All findings gained from the investigations of the biological model were incorporated into a finite-element analysis, as a prerequisite for the development of a pneumatic cellular actuator. The first prototype consisted of a row of single cells positioned on a plate. The cells were designed in such a way that the entire structure bent when the pneumatic pressure applied to each individual cell was increased. The pneumatic cellular actuator thus has the potential for applications on an architectural scale. It has subsequently been integrated into the midrib of the facade shading system Flectofold in which the bending of its midrib controls the hoisting of its wings.

Comparing the energy efficiency of exterior shading by metal slats and mesh screens in an early phase design exercise for an office building in Bucharest

An early phase design exercise for shading a South facade of an office building in Bucharest is presented here. The problem to solve is deciding in a simple and quick way (not using the complicated BSDF approach), based strictly on energy-efficiency considerations, between two options in principle: the first, exterior screens, is much cheaper and the send is unmovable horizontal aluminium slats. The tool used to produce the necessary result quantities by building energy simulation is COMFEN 4.1. The conclusion is positive: if aesthetic reasons are ignored, in Bucharest and very likely many other Romanian cities having a quite similar climate, screens can be at least equally effective in saving energy by South facade shading. As they allow a flexible shading strategy (removing them during some months of the heating season), the energy-efficiency realized by having them on throughout the year can be increased further.

Exploratory Survey of Recessed Window Façade Shading in Johor Bahru Malaysia

The built environment is a major source of global energy consumption and greenhouse gas (GHG) emissions potentially exacerbating the threats of climate change. With global rising temperatures, the energy requirements for cooling and ventilating buildings in tropical nations like Malaysia will soar geometrically. Scientists around the globe are exploring several technologies to address the challenges posed by building emissions and energy consumption. One of the main methods is the application of passive design strategies such as external facade shading or self-shading. Studies indicate one of the most practical self-shading technique is recessed window facades (RWF) which can easily integrate without reducing natural light and obscuring views. However, studies on the RWF are limited in literature particularly in Malaysia. This research aimed at carrying out an exploratory survey of recessed window facade (RWF) shading in selected buildings in Johor Bahru Malaysia. The RWF buildings characteristics namely; Window-Wall Ratio (WWR), Recessed Depth (RCD), Shading Ability (SHA), Solar Heat Gain Coefficient (SHGC) and Shading Coefficient (SC) will be examined. The results indicated that the values for solar heat gain and shading coefficient are within acceptable limits. Furthermore, the high shading ability of the buildings indicated that RWF might be responsible. Further studies are required to ascertain empirical correlations between the examined characteristics. This further study will potentially improve the design of more energy efficient, low emission and thermally comfortable buildings for the future.

A multi-agent approach for performance based architecture: Design exploring geometry, user, and environmental agencies in façades

Abstract This paper presents research on the use of multi-agent systems (MAS) in architectural design with the goal of both improving and partially automating the design process as well as the design outcomes in terms of geometry and environmental performance. The work is based upon research on agent based modeling and simulation techniques (ABMS), and the combination of analytical and optimization methods with geometric modeling and user centered design. The motivation is to render more accessible the exploration of the generative aspect of bottom up design techniques when coupled with optimization and performance criteria. The objective of the work is to develop and test a design methodology, which enables designers to explore larger sets of informed solutions by coupling design requirements and generative design techniques with validated simulations (i.e., environmental analysis) based partly on the inclusion of user light preferences early in the design process. The development of the proposed methodology and the implementation of the design system for a building facade are described, while the robustness and validity of the framework is initially tested by applying it to the generation and optimization of facade panel configurations of an office building. The results show that the MAS for design system can generate unique design configurations that perform environmentally (daylight factor analysis) better than a facade with normative facade shading.

Measured daylighting potential of a static optical louver system under real sun and sky conditions

By utilizing highly specular surfaces and engineered profile geometry, optical sunlight redirecting systems integrated into the overhead “clerestory” zone of the building facade present the potential to enlarge the daylighting zone by redirecting the luminous flux incident on the window deeper into the space than conventional shading systems. In addition, by developing system geometry to redirect daylight to specific zones within the space, optical light redirecting systems have the potential to avoid the glare conditions commonly produced by conventional facade shading systems that direct significant amounts of daylight below head height into the occupant's field of view. In this case study, side-by-side comparisons were made over solstice-to-solstice changes in sun and sky conditions between an optical louver system (OLS) and a conventional Venetian blind set at a horizontal slat angle and located inboard of a south-facing, small-area, clerestory window in a full-scale office testbed. Daylight autonomy (DA), window luminance, and ceiling luminance uniformity were used to assess performance. The performance of both systems was found to have significant seasonal variation, where performance under clear sky conditions improved as maximum solar altitude angles transitioned from solstice to equinox. Although the OLS produced fewer hours per day of DA on average than the Venetian blind, the OLS never exceeded the designated 2000 cd/m2 threshold for window glare. In contrast, the Venetian blind was found to exceed the visual discomfort threshold over a large fraction of the day during equinox conditions (from 40 to 64% of the test day between August 22 and October 12). Notably, these peak periods of visual discomfort occurred during the best periods of daylighting performance. Luminance uniformity was analyzed using calibrated high dynamic range luminance images. Under clear sky conditions, the OLS was found to increase the luminance of the ceiling as well as produce a more uniform distribution of luminance over the ceiling. Compared to conventional venetian blinds, the static optical sunlight redirecting system studied has the potential to significantly reduce the annual electrical lighting energy demand of a daylit space and improve the quality from the perspective of building occupants by consistently transmitting useful daylight while eliminating window glare.

Visual Comfort Analysis of Innovative Interior and Exterior Shading Systems for Commercial Buildings using High Resolution Luminance Images

The objective of this study was to explore how calibrated high dynamic range (HDR) images (luminance maps) acquired in real world daylit environments can be used to characterize, evaluate, and compare visual comfort conditions of innovative facade shading and light-redirecting systems. Detailed (1536 × 1536 pixel) luminance maps were time-lapse acquired from two view positions in an unoccupied full scale testbed facility. These maps were analyzed using existing visual comfort metrics to quantify how innovative interior and exterior shading systems compare to conventional systems under real sun and sky conditions over a solstice-to-solstice test interval. The results provide a case study in the challenges and potential of methods of visualizing, evaluating and summarizing daily and seasonal variation of visual comfort conditions computed from large sets of image data.