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• Thermochromic glazing properties have been measured under variable temperature conditions with customized spectrophotometer. • Procedure for thermochromic thin film preparation has been presented. • Building energy simulation has been implemented for impact assessment. • Optimization of the thermochromic properties has been performed for different climates. • A complete procedure for thermochromic design and optimization has been described. Thermochromic (TC) glazing could provide a significant reduction of energy consumption in curtain wall buildings. However, each application requires a design tailored to building's specifications. This paper proposes a complete approach for designing TC glaze based on building energy simulation starting from the production of thin thermochromic layers and the measurements of their optical properties by means of a customized spectrophotometer. The main focus of this work is to identify the optimal TC optical response that minimises the building energy consumption. Energy simulations have been performed for a virtual mock-up set at two locations with different climates, Italy and Poland. A set of profiles, each one determining thermochromic properties in terms of switching temperature, range of solar transmittance and transition speed, have been created with a fine step of temperature (2 °C) and used to simulate different scenarios. The outcome of the optimization provided the optimal properties to achieve the right balance between cooling energy reduction and heating energy increase due to the application of the thermochromic layer, in comparison to a standard clear glass. The fine step in switching temperature allowed to accurately estimate the subtle differences for the two different climates (25 °C Italy, 24–26 °C Poland). The highest impact has been found for the Italian location with a maximum reduction of total energy consumption of 22.8%. This was achieved with a thermochromic switching at 25 °C, with fast transition and range of transmittance between 0.1 (switched state) and 0.5 (normal state), which is a not extreme behaviour. [ABSTRACT FROM AUTHOR]

Abstract Light pollution has been recognised as a major environmental problem in urban areas at night. This study presents an investigation into the impact of seven various shading solutions on the risk of light pollution caused by indoor artificial lighting in a fully glazed office building. Radiance, a ray-tracing package, was adopted to calculate external illuminances produced by indoor lighting applications at various positions. It has been determined that: 1) A glazed façade could become a critical source of light pollution or obtrusive light (sky glow and light trespass) due to applications of indoor lighting at night; 2) A light shelf could perform well on the protection of both light trespass and sky glow; 3) A large overhang and horizontal louvre could effectively lower the risk of light trespass, but would possibly cause the deterioration of sky glow; and 4) No significant impact of short overhang and vertical louvre can be found on the two aspects of light pollution. This study exposes a significant implication; apart from their principal functions, the shading devices applied in a largely glazed building may require a new role in controlling obtrusive light in cities at night. Highlights • Investigation of night light pollution risk of glazed buildings in cities. • Impact of various shading solutions on the emitting light from glazed facade. • Ray-tracing analysis of intensities and distributions of the artificial lighting. • Comparisons of upward light and light trespass risk between various shading solutions. • Recommendation of shading applications in terms of light pollution in glazed buildings. [ABSTRACT FROM AUTHOR]

The inadequacy of highly glazed facade office buildings has been debatable for decades due to their impact on the internal environment comfort and energy consumption. One of the consequences noticed in the 50′s decade was the thermal discomfort caused by the non-uniform thermal environment. Despite the glass technology developments since then, buildings with ordinary laminated glass and unknown thermal properties became commonly accepted in Brazil's most populated cities in the low latitudes, opposing primary design recommendations. This work discusses this context based on the short-term thermal assessment of five case studies in a warm and humid climate, assuming regular occupation. The combination of the walk-through audit with thermal monitoring at the centre of office rooms and next to the facade resulted in comparing air and operative temperatures, and the PMV index, under different environment configurations. Surface temperature measurements with thermographic photos complemented the thermal analyses. The case studies confirmed different simultaneous thermal sensations between perimeter and centre zones. The perimeter zones barely reach PMV 0.5, achieved by the users' adaptations that mitigated the thermal radiation from the facades, obstructing the windows with internal shades or avoiding the window view by changing the layout. Therefore, the extensive use of window obstructions compromises other indoor environmental aspects, such as daylighting and exterior view, contradicting the architects' expectations of a transparent glass building. [ABSTRACT FROM AUTHOR]

The use of solar shading in future low energy office buildings is essential for minimizing energy consumption for building services, while maintaining thermal conditions. Implementing solar shading technologies in energy calculations and thermal building simulation programs is essential in order to demonstrate the effect of adaptive solar shading. In order to document the benefits of the shading technology, the description of the shading device in the thermal building simulation software must be described at a reasonably accurate level, related to the specific solar shading device. This research presents different approaches for modeling solar shading devices, demonstrating the level of accuracy in relation to measurement conducted in a full-scale façade test facility at Aalborg University. The research bridges the gap between increased complexity of solar shading technologies and the use of these technologies in thermal building simulation software. [ABSTRACT FROM AUTHOR]

This study presents an original method for improving the energy performance of buildings with glazed façades. For the proposed paper we analyzed using Ansys CFD software a study case for an office building with integrated heat pipes into the glazed façades. For the complete analysis of our proposed system we realized a financial study using the RETScreen 4 Software Suite. [ABSTRACT FROM AUTHOR]

This study presents a CFD Heat Transfer Analysis for Heat Pipes integration into Buildings with Glazed Façades. This consists into the introduction of heat pipes in the building envelope structure for taking over the heat from glazed façade cavity and transmission, respectively accumulating in the wall structure for achieving the indoor comfort parameters in winter and transitional seasons (autumn and springtime). [ABSTRACT FROM AUTHOR]

Double skin glazed facades (DGF) are an actual worldwide trend in new and refurbished buildings, even in warm climates with high solar radiation levels as in the Middle East and in Mediterranean climates. In such climates, overheating of indoor spaces and therefore excessive energy consumption are the main problems to be faced. These issues are commonly addressed mostly by thermal simulation or experimental evaluations on small prototypes. However, measurements on real-scale buildings with DGFs are very unusual. This information is crucial to understand and validate the predictions of the thermal behavior of the DGF technology. In this paper, thermal measurements were carried out in an unoccupied office building with a West DGF placed in the Northwest region of Argentina during 3 months in spring/summer. The air temperature exceeded in 10 °C the outdoor air and that indoor temperatures have not exceeded the outdoor levels in the hottest hours. Two correct design decisions were the use of low-e double hermetic glazing and the addition of a screenpainting to the external DGF panel. The experimental data showed that well-designed DGFs can reduce the summer energy consumption of buildings, even using West DGFs, in sunny climates. [ABSTRACT FROM AUTHOR]

Abstract: An experimental investigation of a glazed façade oriented west has been conducted utilizing the Sustainable Glazed Water Film (SGWF). The experiments involved the following three parameters namely: the water flow rate, the type of glazing, and the solar radiation intensity. Two full-scale rooms were used, one as a reference room, with a fixed configuration, and the other as a test room, which could be configured in different ways. The ability of the SGWF to reduce the passage of the solar energy during the sunny hours and hence to limit the heat passage through glazing was analyzed. The aim of this paper is to examine the improvement in thermal performance obtained by the flowing water film over glazed façades. It has been found that the flowing water film on the glazed façade lowers the glazing surface temperature by 7.2–14 °C (average) and absorbs a portion of the solar energy resulting in decreasing indoor temperature by 2.2–4.1 °C (average). However, with increased solar radiation intensity, the SGWF provides a better level of efficiency in reducing the heat transfer indoors. [Copyright &y& Elsevier]

[Display omitted] • PVGIS databases have been benchmarked against measured horizontal irradiances data. • Performance of the transposition models (horizontal to vertical) has been assessed. • Clear sky models transposed with anisotropic model are proposed as an alternative. • A filtration method for identifying the clear sky days has been proposed. • Impact of using various irradiance sources on glazing system performance is analyzed. The present study aims to benchmark the models utilized for estimating the solar irradiance on vertical planes that can facilitate the determination of critical conditions, which are utilized in the glazed facade design. Accordingly, in the first part of the study, the performance of PVGIS databases for Europe for estimating the solar irradiance components on the horizontal surfaces is compared with the on-site measurements at Bolzano airport (Italy). It is demonstrated that PVGIS-SARAH estimates both the global and diffuse solar irradiance components, compared to on-site measurements, with an acceptable error range (± 2–5%). The accuracy of isotropic and anisotropic transposition models is then compared for the same location, which demonstrates that the isotropic model tends to underestimate the global vertical incident irradiance by 6–12% of the daily peak value, while an agreement between the estimations of the anisotropic Perez model and the measurements is observed. Next, the performance of Ineichen, Solis and SPECMAGIC clear sky models, transposed with anisotropic Perez model, have been assessed utilizing field measurements on vertical facades at four different locations in Europe. The broadband version of Solis clear sky model, transposed with anisotropic Perez model, demonstrates R 2 scores between 0.85 to 0.95 for the considered locations, indicating that this approach can be utilized as an alternative to open-source/commercially available data sources to estimate the solar irradiance on vertical facades. Finally, for the case study of a triple glazing system, comparing the surface temperatures obtained employing the latter approach with those determined using other commonly utilized irradiance data sources shows a discrepancy of up to 7 °C. [ABSTRACT FROM AUTHOR]

Façade systems play an important role in fire compartmentation of a building and reducing the likelihood of fire spreading through and outside of the building walls. The use of sprinklers in building regulations often allows for smaller building separation. However, no additional benefits are usually given to additional internal sprinkler protection of the external glass façade using standard pendant sprinklers. Four compartment fire experiments were performed with non-fire-rated aluminium façades with two- and three-layered Insulating Glass Units (IGU), protected by pendant-type sprinklers (DN15, K-factor = 80, T = 68 °C). Sprinklers were in row 14–55 cm from the glazing, with 1.514–1.83 m separation distance. In all experiments, façades achieved satisfactory performance in terms of glazing integrity, insulation and reducing the thermal radiation. Under a non-uniform water distribution, parts of the glass were dry (1.7%–15.7% of IGU area), where we have observed soot deposition and local damage to fire exposed glass layer, but no loss of the structural integrity. The temperatures on the unexposed side did not exceed 86 °C, the peak measured temperature of the internal glass surface was 173 °C. The performed experiments confirmed the capability of standard pendant-type sprinklers to enhance the fire protection features of a building façade. Image 1 • Four large scale compartment fire experiments were performed. • Sprinklers may substantially improve the fire performance of building façade. • Non-uniform heat transfer through glass did not lead to loss of structural integrity. • Sprinklers efficiently cool the thermal plume from ventilation windows. • External thermal radiation from fire is shut out by the sprinklers. [ABSTRACT FROM AUTHOR]

The design of blast-resistant glazed façades can be required by building standards. The high-pressure generated by the blast wave air-front can lead to catastrophic failure of the glass panes and/or their load-bearing structure, with possible projection of fragments that constitutes a potential threat for human lives and properties. The time-dependent deformations-history is usually assessed via numerical analyses and/or experimental investigations, but it is difficult to recognize the role of each element in the complex dynamic response. As a guide to structural design, we here propose a simple analytical model that permits a synthetic but comprehensive view of the phenomenon. The dynamic interaction among the blast wave, the ensemble of glazed panels and load-bearing structure is studied in paradigmatic lumped-element models, representing glass panels supported by tensioned cables, using Rayleigh's method to reduce the response of each glass panel to a non-linear single degree-of-freedom oscillator. The dynamic equations are solved under blast pressure modeled via the Friedlander's waveform. This analytical treatment quantifies the importance of the load-bearing structure in absorbing energy from the blast wave. • An analytical model is used for a parametric analysis of cable-supported façades under blast waves. • Non-linear membrane effects in the glass panel are taken into account through Rayleigh's method. • Large deformations of the cable, with possibly a spring in series, are considered. • The dynamic equations are solved under blast pressure, modeled via the Friedlander's waveform. • A cable structure can adsorb most of the energy from the blast wave and preserve the glass panels. [ABSTRACT FROM AUTHOR]