Glass Facades Research Articles

Interconnected model with distributed thermal comfort for model based shading control

Modern buildings have a growing tendency to have large window fronts, with this design aspect leading to extensive solar heat gain and lighting in the rooms. Well-known thermal space models for control applications use simplifications of the spatial distribution of radiation and temperature. In this paper, a new modeling approach for efficient control of shading systems in rooms with large glass facades is presented and thermal comfort at multiple distributed positions in the room is more accurately captured. The idea of an interconnected system with submodels with lumped parameters and submodels with distributed parameters is introduced which can subsequently be used for model predictive control. With model-based shading control and the distributed thermal model presented, individual comfort control is possible at multiple positions in a room. The model is physically motivated, based on the material parameters and no calibration method is currently used, but realistic initial conditions are set for the simulations. Temperature variations due to incident solar radiation are included in the system part with distributed parameters and allow local thermal comfort measures. The resulting model is designed to be used in the context of model based shading control considering thermal comfort at multiple distributed locations. The introduced model is validated with simulations for temperature accuracy, distributed thermal comfort, and control characteristics. The main results are the interconnected model with additional benefits for distributed thermal comfort. Moreover, the presented modelling approach is designed for control applications, especially for model predictive control.

Simulation of Green Building Materials Uses and its Environmental Impacts: Case of Jordan

Construction is one of the most important factors affecting the environment such as global warming and carbon dioxide emissions. In addition, it represents 40% of the consumption of energy resources around the world. Jordan is one of the countries that suffer greatly from this aspect. In this research, a simulation was conducted of a multi-use building located in a university in Jordan using the ArchiCAD program, which helps us to accurately determine the construction location and obtain the results of materials and strategies that were applied to the building. Thermal insulation materials were used to show the effectiveness of their impact on the temperature difference per unit of heat flux needed to sustain one unit of heat flux (R-value) for the building. Shading means were also applied to the building’s glass facades that reduce heat loads and help the heating, ventilation, and air conditioning (HVAC) system inside the building. Finally, it was shown the difference in the environmental impact of a building that uses 100% solar energy and emits zero CO2 emissions. While a building that uses 50% solar energy and 50% oil energy emits a high amount of CO2. It becomes clear that the increasing use of green building tools helps greatly in facing the problems of the environment and the consumption of energy resources.

Validation of the PALM model system 6.0 in a real urban environment: a case study in Dejvice, Prague, the Czech Republic

Abstract. In recent years, the PALM 6.0 modelling system has been rapidly developing its capability to simulate physical processes within urban environments. Some examples in this regard are energy-balance solvers for building and land surfaces, a radiative transfer model to account for multiple reflections and shading, a plant-canopy model to consider the effects of plants on flow (thermo)dynamics, and a chemistry transport model to enable simulation of air quality. This study provides a thorough evaluation of modelled meteorological, air chemistry, and ground and wall-surface quantities against dedicated in situ measurements taken in an urban environment in Dejvice, Prague, the Czech Republic. Measurements included monitoring of air quality and meteorology in street canyons, surface temperature scanning with infrared cameras, and monitoring of wall heat fluxes. Large-eddy simulations (LES) using the PALM model driven by boundary conditions obtained from a mesoscale model were performed for multiple days within two summer and three winter episodes characterized by different atmospheric conditions. For the simulated episodes, the resulting temperature, wind speed, and chemical compound concentrations within street canyons show a realistic representation of the observed state, except that the LES did not adequately capture night-time cooling near the surface for certain meteorological conditions. In some situations, insufficient turbulent mixing was modelled, resulting in higher near-surface concentrations. At most of the evaluation points, the simulated surface temperature reproduces the observed surface temperature reasonably well for both absolute and daily amplitude values. However, especially for the winter episodes and for modern buildings with multilayer walls, the heat transfer through walls is not well captured in some cases, leading to discrepancies between the modelled and observed wall-surface temperature. Furthermore, the study corroborates model dependency on the accuracy of the input data. In particular, the temperatures of surfaces affected by nearby trees strongly depend on the spatial distribution of the leaf area density, land surface temperatures at grass surfaces strongly depend on the initial soil moisture, wall-surface temperatures depend on the correct setting of wall material parameters, and concentrations depend on detailed information on spatial distribution of emissions, all of which are often unavailable at sufficient accuracy. The study also points out some current model limitations, particularly the implications of representing topography and complex heterogeneous facades on a discrete Cartesian grid, and glass facades that are not fully represented in terms of radiative processes. Our findings are able to validate the representation of physical processes in PALM while also pointing out specific shortcomings. This will help to build a baseline for future developments of the model and improvements of simulations of physical processes in an urban environment.

A Reinforcement Learning-Based Approach to Automate the Electrochromic Glass and to Enhance the Visual Comfort

Daylight is important for the well-being of humans. Therefore, many office buildings use large windows and glass facades to let more daylight into office spaces. However, this increases the chance of glare in office spaces, which results in visual discomfort. Shading systems in buildings can prevent glare but are not effectively adapted to changing sky conditions and sun position, thus losing valuable daylight. Moreover, many shading systems are also aesthetically unappealing. Electrochromic (EC) glass in this regard might be a better alternative, due to its light transmission properties that can be altered when a voltage is applied. EC glass facilitates zoning and also supports control of each zone separately. This allows the right amount of daylight at any time of the day. However, an effective control strategy is still required to efficiently control EC glass. Reinforcement learning (RL) is a promising control strategy that can learn from rewards and penalties and use this feedback to adapt to user inputs. We trained a Deep Q learning (DQN) agent on a set of weather data and visual comfort data, where the agent tries to adapt to the occupant’s feedback while observing the sun position and radiation at given intervals. The trained DQN agent can avoid bright daylight and glare scenarios in 97% of the cases and increases the amount of useful daylight up to 90%, thus significantly reducing the need for artificial lighting.

Calibrated Numerical Approach for the Dynamic Analysis of Glass Curtain Walls under Spheroconical Bag Impact

The structural design of glass curtain walls and facades is a challenging issue, considering that building envelopes can be subjected extreme design loads. Among others, the soft body impact (SBI) test protocol represents a key design step to protect the occupants. While in Europe the standardized protocol based on the pneumatic twin-tire (TT) impactor can be nowadays supported by Finite Element (FE) numerical simulations, cost-time consuming experimental procedures with the spheroconical bag (SB) impactor are still required for facade producers and manufacturers by several technical committees, for the impact assessment of novel systems. At the same time, validated numerical calibrations for SB are still missing in support of designers and manufacturers. In this paper, an enhanced numerical approach is proposed for curtain walls under SB, based on a coupled methodology inclusive of a computationally efficient two Degree of Freedom (2-DOF) and a more geometrically accurate Finite Element (FE) model. As shown, the SB impactor is characterized by stiffness and dissipation properties that hardly match with ideal rigid elastic assumptions, nor with the TT features. Based on a reliable set of experimental investigations and records, the proposed methodology acts on the time history of the imposed load, which is implicitly calibrated to account for the SB impactor features, once the facade features (flexibility and damping parameters) are known. The resulting calibration of the 2-DOF modelling parameters for the derivation of time histories of impact force is achieved with the support of experimental measurements and FE model of the examined facade. The potential and accuracy of the method is emphasized by the collected experimental and numerical comparisons. Successively, the same numerical approach is used to derive a series of iso-damage curves that could support practical design calculations.

Energy budget in an educational building in KSA: The case of cladding with terracotta and aluminium

Buildings' façades significantly impact human thermal comfort and the energy budget of buildings. It is estimated that 73% of heat losses or gains are immediately linked to the configuration and types of materials in the buildings' envelope. Building styles in the Kingdom of Saudi Arabia witnessed a large and growing expansion in curtain walls, glass facades, metal cladding, and precast concrete. It is striking that terracotta cladding is most often associated with school building façades, especially the government ones, with very limited applications in other building types. This paper investigates the energy-related budget of using Aluminum and terracotta cladding in an educational facility in KSA. The article follows the experimental approach. Data about both cladding materials' specifications were obtained and input into the virtual model building in DesignBuilder software for simulation and analysis. The comparative analysis of energy consumption during the building's operational phase in both cases revealed that more energy budget was needed in the case of Aluminum cladding to provide thermal comfort to the occupants. The study concludes that the efficiency of thermal insulation of Terracotta is better than the Aluminum sheets. On the other hand, and in the long run, the study underscores the preference of using Aluminum cladding for its extensive reuse and recycling potential. Brittleness of Terracotta limits its prospects for recycling; therefore, it might be more energy-consuming when frequently reproduced for new applications or maintenance purposes throughout the building life cycle.

Image-based surface scratch detection on architectural glass panels using deep learning approach

Abstract As a transparent and traditional building material, glass products such as glass facade are vital components of buildings. However, the surface scratches generated in the manufacturing process or emerging in the service stage such as windborne debris impacts may lead to remarkable strength degradation of glass material. In order to assess the fracture possibility of glass components, the size and number of scratches should be monitored during their lifecycle. Automatic scratch detection of architectural glass therefore remains a necessary task for civil engineers. A pixel-level instance segmentation model using Mask and region-based convolutional neural network (Mask R-CNN) was proposed for scratches detection on transparent glass surface. Images with scratches were firstly collected by a tailor-made automated microscopic camera scanning system to build the training and validation dataset. Test results demonstrate that the trained network is satisfactory, achieving a mean average precision of 96.5% with low missing and false rate under background interference. A comparison between the proposed model and another segmentation method YOLACT indicates that the proposed model has better performance in both detection and segmentation accuracy. The proposed deep learning-based approach can better support the development of non-contact defect assessment techniques for transparent building materials such as glass.

Thermal response of low-E and float glass facades under various heating rates

Glass curtain wall has been widely employed in buildings. These glazing may easily crack and even fallout when subjected to a fire, which would influence the structural integrity and is especially vital for the interactive-external tridimensional fire development. Low-E glazing is extensively used which may bring energy conservation with potential fire risk. Here, low-E and float glazing were heated by a radiant source under various heating rates. Numerical simulation concerning the heat transfer was conducted to explore and compare the heat transfer mechanisms.

Overview of dynamic test methods for examining the glass window resistance

In recent years, glass, and glass facades are increasingly used as part of building structures. Due to its functions, glass is used in commercial, residential, or strategic buildings, such as airports, stations, or offices. However, window system is subject to several forms of the load. This can be an extreme load in the form of an explosion, an earthquake, or other types of loads, such as their wind load, or dynamic impact. In the article, we focused on an overview of several norms, standards, and research that address the issue of resilience of window systems. The aim of the article was to identify the parameters that are examined in various tests in the standards. The investigated parameters of windows in a manual attempt at burglary, impact test, and explosion were discussed in the article.

Demonstration of the Structural Resiliency of Damaged Sentryglas Laminated Heat Strengthened Glass Fins in Full Scale Testing

A unique structural design was made for the glass facade of the Co-Creation Center building in Delft. The roof is completely carried by the glass fins. The fins are laterally stabilized by being included in the triple glazed facade. To certify the safety of the design full scale tests on the fins were done at Delft University of Technology. Due to a transportation accident the fins were damaged at one end. This allowed an additional study into the effect of this pre-test damage on the residual compressive stressed induced by the tempering. It was found that the residual stresses were not significantly affected by the damage. During the compression tests no cracks developed at the damaged ends. A load of 200 kN, more than double the maximum design load did not produce failure in the prototypes. After intentionally seriously damaging all plies of the fins, the fins could still carry the 200 kN load for 30 min without buckling or other failures being noted. Measurement of the residual stress in the outer plies of the fins after damage showed that sufficient residual stress was present in the larger fragments of the prototype to provide enough stability in combination with the Sentryglass laminating foil.

Contemporary architecture with glass facades facing the energy efficiency of solar materials (VPV-IGU) in the hot climate of the Saharan region - a case study in Bechar

This paper discusses a comparative study of four types of glazing materials using in contemporary architecture. The first one is the clear and simple glazing, the double glazing, and the third one ...

Contemporary architecture with glass facades facing the energy efficiency of solar materials (VPV-IGU) in the hot climate of the Saharan region - a case study in Bechar

Contemporary architecture with glass facades facing the energy efficiency of solar materials (VPV-IGU) in the hot climate of the Saharan region - a case study in Bechar

Visual Interference in the Glass Facade

The paper analyses questions concerning the integration of architecture and art. The objective of this publication is to examine visual interferences that occur in architecture and to determine their effects on how the building is seen and on the architectural space. This phenomenon is an important artistic issue that opens the way for new compositional values in architecture. Visual interferences can occur when there are at least two layers of an image composed of repetitive elements, put in a certain order. Overlapping of graphical layers results in image concentration, and in this way compositions such as lines, circles and polygons are created, which are known as interference patterns. In art glass, it is possible to remove image layers from each other, thus obtaining an additional effect. This creates visually mobile surfaces, which react to movement of the observer. The present paper will analyse this phenomenon with the aim to determine what principles govern the occurrence of visual interferences as well as how they affect the building’s reception. The typology, classification and characteristics of each type of arrangements will be presented. An attempt will also be made to establish conditions for the design of interference arrangements, which may be used as guidelines by graphic artists and designers alike. The phenomenon will be examined based on buildings created over the past two decades. Examples will include works set both on the façade as well as in the interior of buildings. Due to the global nature of artistic phenomena, no restriction is given on the area where the examinations take place.

Risk Identification in Procurement of Glass facade in High-Rise Office Buildings in Jakarta

This study aims to identify risks at the procurement stage of the glass facade of office buildings in Jakarta. In this study, the procurement phase was analyzed using the PMBOK reference (5th edition). In this research, the most dominant risk will be discussed at the stage of glass facade procurement in high-rise office buildings in Jakarta. After the dominant risk obtained from the analysis, the prevention and recommendations will be discussed. The number of risks that occur during the procurement process can certainly hamper the project. These risks can cause to the project completion time that are not in accordance with the project schedule. Besides that, the risks could make the project cost even greater. This certainly can lead to big loss to the project. Therefore, it is very important to identify the main risks at the procurement stage from the beginning of the construction process. According to the PMBOK, the stages of the procurement is divided into 4, which consists of plan procurement, conduct procurement, control procurement and close procurement. Based on the research results, obtained 47 risks that are divided into 4 phases of the procurement. Based on expert validation, 42 risks out of 47 risks were used in the analysis. This study uses the SPSS program to determine the most dominant risk. The SPSS results show that the variables X33 and X39 are the most dominant risks in the procurement stage of high-rise office building glass facades in Jakarta. These variables are the risk of material defects (X33) and late in ordering material (X39).

Performative Design Optimization for Shading Screens

Building façade plays a significant role in architecture; it is not only a mean to express the design concepts but it is the main moderator between exterior environment and internal spaces. Ecological facades are defined as the ability to response and adapt to the changes of the environmental conditions. The geometry of the proposed screen is not a focal point of this paper, as the aim is to find a method for designing and evaluating non-conventional solar screens that improve indoor daylight quality, while the specified shading screen is installed in front of a transparent full floor to ceiling glass facade. It is assumed that by using the shading screen, the required lighting levels are being maintained, while the heat gain is being reduced. In addition, the designed patterns play a role as an architectural feature of the building. Ultimately, the presented shading screens are based on geometric ornamental patterns and arranged according to the lighting requirements. Results are indicating a multi-disciplinary approach in the design of the shading screens, which can be employed in creating similar prototypes with different climatic and loading requirements.

ORGANIZATION OF SOCIAL COMMUNICATIONS IN THE OFFICE CENTERS ARCHITECTURE OVER THE LAST YEARS

Office centers and big office parks with the comfortably organized environment are in a huge demand type of buildings over the last years.
 Research on communication in the architecture of twenty seven “A-class” office buildings in Great Britain, Denmark, Netherlands, Sweden, Norway, Finland, Estonia, France, Germany, Austria, Italy, and Portugal in years 2017-2019 is based upon these given meanings of a term «social communication»: 1) ... is a process which connects different parts of a social network with one another; 2) ...is a transmission of information, ideas, emotions, in form of signs and symbols.
 Flexible plannings of European office buildings, which can be instantly transformed, according to the company’s needs are best suited with an adhocratic type of organizational culture in Europe.
 This work consists of the analysis of the features of social communications in office centers based on: · social communications between people; · social communications between people and the environment.
 Organization of social communications: 1. External: (“office is a part of a city environment”) A) integration of a building in the city environment by using · restaurant and cafes on bottom floors; · planting of greenery; · patios and transit area spaces; entering zone, rooftop lounge-zones with open access; B) connection with the surrounding panorama by using solid glass facades, which also represents transparency of work processes; C) informing through building design about the company’s work stability with static facades. 2. Internal: A) horizontal (existence of individual space in shared space): “openoffice” system with open and semi-open spaces with constant working zones on the perimeter of the building, negotiation rooms, opened zones for the teamwork and temporary workspaces “touch down”- type; B) vertical: administration zon, talk rooms, shared communicative spaces; 3. A) planned and formal: training room, talk rooms, conference-rooms. B) random and situational: all office spaces (working zones excluded) including stairs and ramps. Office spaces also provide direct and indirect; interpersonal, intergroup and inter-organizational social communication [12].

Large deflection glass facade in typhoon area: Taikoo Place 2 podium wall

The case study presented is a 195 meters tall office tower with a raised podium made of full height glass panels, up to 15 meters high. The panels are only restrained by prestressed high-strength stainless-steel rods, lying entirely in the glass panel build-up, composed by four 12 mm thick plies, laminated with 1.52 mm thick sheets of ionoplast interlayer, with an overall thickness of approx. 52 mm. Due to the facade geometry and the high wind expected, movement joints between rods are introduced, allowing for differential movements to avoid peak stresses in the glass panels. Also, smooth transition between rod rectangular section at the interface with the glass panels to circular section at anchor points need to be ensured by CNC machining to avoid failure of the rod anchors due to fatigue. Sophisticated non-linear 3D FEM models had to be analyzed to predict glass stresses, differential movements to be accommodated by the joints and geometrical transition between rod sections. The main innovation of this facade was the use of prestressed rods in conjunction with jumbo size glass panels. As tension structures experience large movements, it was crucial to understand the effect of these deformations imposed by the rods onto the full height glass panels, analyzing steel and glass members together as a single facade entity. Furthermore, in contrast to typical cable wall facade where the prestressed elements (cables) are offset from the glass line, here the rods are located in the plane of the glass panels and completely flush with them, ensuring the thinnest possible build-up in relation to the large facade span. A rocking portal frame, moving together with the rods to avoid excessive warping in the glass panels, has been used as a solution to deal with the required opening in the facade. An additional complication was given by the high wind load (typhoon) applied on the facade which required rods’ prestress in the order of 1000 Kilonewton to limit glass stresses and deflections.

Energy consumption of hybrid smart water-filled glass (SWFG) building envelope

Thermal properties have significant impact on ecological footprint and life-cycle assessment of buildings. This is even more crucial aspect for glass buildings, which have been criticised as major factors in climate change around the world. Recent debates on glass facades, which culminated in plans for a “glass building ban” in New York City highlighted the importance of innovation in glass construction.The current solutions for mitigating energy consumption for glass facades are improving insulation (U-value) and solar heat gain coefficient (SHGC) with advanced glazing or using shading devices. A fourth approach is the recent technology of water-filled glass (WFG), which utilizes water layer to improve thermal comfort and energy performance of the façade.This paper introduces Smart Water-filled Glass (SWFG) control method, which enables the change of the opacity of the façade element by colouring the fluid over a year regarding seasonal changes. The impact of changing transparency of water layer on cooling and heating energy demand is evaluated by simulating and analysing the energy performance of a reference office room with large glazing facade in different climates.The significance of this energy evaluation is that a water-filled glass with switchable transparency is simulated and assessed here for the first time. The paper analyses the performance in seven cities from all relevant major climatic regions using LBNL WINDOW and TRNSYS (v.18) As a novel approach, the simulation study makes it possible to evaluate the overall performance of two proposed operational methods (insolation-based & storage-based) for adjusting water layer settings depending on climate conditions and reusability of the captured heat in water layer. Moreover, seven different base cases are presented in this study to compare the performance of proposed system, including conventional solutions (e.g. double or triple glazing with/without shading) and a state-of-the-art switchable technology (e.g. electrochromic glazing or EC).The results verify the hypothesis that the impact of SWFG compared to WFG varies depending on the climate with 0%-5.28% for hot climates and 0.25–3.39% for climates with heating demand. The discussion includes comparison with standard glass facades, where SWFG shows 47.41%-78.01% energy savings depending on climate. The climate-based approach of SWFG and WFG offers a significant shift in façade design that sees glass buildings as an opportunity for sustainability rather than liability for climate change.

Structural Analysis of Factors Influencing the Costs of Facade System Implementation

External facades of buildings and other structures shape the image of every building, creating the architecture of cities. Traditional concrete forms, as a symbol of durability and stability, have been replaced by lightweight enclosures—for example, in the form of aluminium–glass facades and ventilated facades. In this paper, the authors attempt to verify the strength of influence and relations between the identified factors shaping the costs of facade system implementation using structural analysis. On the basis of the collected quantitative and qualitative data obtained as a result of research on design documentation and cost estimates of implemented public buildings, as well as on the basis of interviews conducted among experts, factors which have a real impact on the costs of facade systems in the form of aluminium and glass facades and ventilated facades were identified. The indicated factors were analysed and classified using the method of structural analysis, namely the MICMAC method (refers to the French acronym for Cross-Impact Matrix Multiplication Applied to Classification). Particular influences and relations between factors were examined. Finally, six groups of factors influencing the costs of facade systems were identified, including regulatory factors that do not have a very strong impact on the level of costs, but which show a strong correlation with other factors; determinants that have a very strong impact on the costs; and a group of external factors that show the smallest influence on the estimation of façade cost.

Risk Identification in Procurement of Glass facade in High-Rise Office Buildings in Jakarta

This research aimed to identify the risk of the procurement stage of glass façade in the high-rise office building in Jakarta. In this research, the procurement phase is analyzed using the PMBOK reference (5th edition). The number of risks that occur during the procurement process can certainly hamper the project. These risks can cause to the project completion time that are not in accordance with the project schedule. Besides that, the risks could make the project cost even greater. This certainly can lead to big loss to the project. Therefore, it is very important to identify the main risks at the procurement stage from the beginning of the construction process. According to the PMBOK, the stages of the procurement is divided into 4, which consists of plan procurement, conduct procurement, control procurement and close procurement. Based on the research results, obtained 45 risks that are divided into 4 phases of the procurement.