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The pattern and permeability characteristics that compose three-dimensional (3D) textiles are important as a textile shading component to the architecture, engineering and construction (AEC) industry. Moreover, due to their complex geometry, 3D fabrics require a detailed modeling for correct evaluation of performance. This paper aims to present and investigate the optical properties of six 3D fabrics proposed as an alternative to traditional roller blind shading systems, which could guarantee high daylight availability and visual comfort. The light transmission distribution for the different samples has been characterized by carrying out angular visual transmittance measurements, using integrating sphere optical benches, and virtual modeling using Radiance's genBSDF tool. The Bidirectional Scattering Distribution Function (BSDF) calculated with Radiance shows a good fit with the optical angular measurements, which were used as a benchmark and to calibrate models. The performance of the 3D textiles, in terms of illuminance, daylight availability, and glare, was assessed considering two of the set of 3D textiles as alternative materials for a movable internal roller shade system in an open office. The innovative system was compared with a traditional single layer fabric roller blind under different shading control strategies, 3D fabrics demonstrate the potential of increasing Daylight Autonomy while providing better uniformity and better connection with the outdoors due to a higher openness factor. The shading effect created by the 3D geometry of the textile can increase the openness factor while restricting glare.

Wall finishes with high solar reflectance and thermal emittance, commonly known as cool walls, can reduce the exterior surface temperatures of façades, and consequently the building cooling energy needs and power demand, and lower the sensitivity to degradation. Aging, though, may affect their performance. To investigate this risk, we exposed for four years in Milan, Italy, two series of façade finish coats, white and beige, facing north and south, in vertical and vertical-sheltered position, and we measured their solar spectral reflectance and thermal emittance before and after aging. The solar reflectance of the white finish coats drops from 0.75 to 0.55 in four years, and from 0.46 to 0.38 for the beige coats, while the thermal emittance is unchanged. Then, for a typical residential building with white walls, we computed that the cooling energy needs increase with walls aging by 5% and 11%, respectively, with or without exterior wall insulation. The exterior surface temperature is increased even by 6 °C, and the number of sudden surface temperature variations in one hour is boosted. Finally, the moisture content in the external layers is reduced, showing the impact on the heat and mass balance because of the uncertainty in solar absorption due to aging. © 2017 Elsevier B.V.

ETFE membranes are generally used in architecture for large roofing and facade systems, because of their transparency and lightness compared to glass alternatives. Multilayer ETFE panels are used to improve single membrane systems performances, reducing thermal losses, by the use of an air gap between two or more ETFE foils, generally serigraphed or surface treated to reduce solar gains. Surface temperatures and global solar radiation strongly affects mean radiant temperature (MRT), and comfort perceived by a user facing a transparent envelope as well as solar gains strongly influences primary energy use for cooling in summer conditions. In the following paper an alternative dynamic solar gains mitigation strategy is presented and applied to a double layer, non-cushions, ETFE panel for facades. We measured the effectiveness of a water spray system located in the air-gap between the parallel ETFE foils and used to reduce surface temperatures and solar access depending on different summer solar radiation values and outdoor/indoor air temperature conditions. Systems alternative with different in nozzle dimension, water spray geometry and water consumption were already tested to evaluate the best compromise between solar gains reduction and water use. The results are preliminary but we noticed that a reduction up to the 10% of the total solar gains could be achieved as well as a reduction of 10 °C of surface temperature. Comfort evaluation for a standard indoor space were already done.

Chemical and physical stress, weathering, organic and inorganic matter deposition, and microbial growth over time, or “aging”, affect the optical-radiative performance of building envelope materials. Natural exposure helps to quantify these effects, but it usually requires several years. Further, the contribution of the different degradation agents cannot be isolated, and results from different campaigns cannot be easily compared because of the variability in the boundary conditions producing aging. Here we present an adaptation of the protocol implemented by ASTM as D7897-18 “Standard Practice for Laboratory Soiling and Weathering of Roofing Materials to Simulate Effects of Natural Exposure on Solar Reflectance and Thermal Emittance”. The aim is to reproduce in the laboratory the changes in albedo (solar reflectance) and thermal emittance experienced by building envelope materials in European urban areas rather than in the United States. We tuned the spraying duration and weathering cycles, and we compared the UV–vis–NIR reflectances of naturally-aged specimens (48 months in Rome and Milan) of roofing and wall finish materials to those exposed to laboratory weathering and soiling. Excluding those materials that show early physical-chemical degradation, the mean absolute deviation between natural and laboratory exposure of roofing products is equal to 0.027 in albedo. This is a lower value than the differences between two natural exposure campaigns at the same site. We clearly defined the limits of application of the protocol, providing an appraisal of the repeatability of natural aging. Moreover, we identified possible improvements in the methodology to conduct both natural and laboratory exposure.

The aim of this paper is to explore lean retrofit strategies for transparent envelope of existing Italian office buildings, to improve their performance and to ensure low energy use and a good thermal and visual comfort.Solar and light control is necessary to prevent overheating in office buildings those generally present high internal loads. The effectiveness of solar window films use in Italian buildings context is here investigated, in comparison with other strategies like the use of internal roller blinds and the substitution of the existing window panes with high performance ones. A sensitivity analysis was assessed to evaluate the office unit primary energy use under different retrofit solution, weather conditions and window to wall ratio. A conventional existing office unit was modeled in EnergyPlus and LBNL Radiance to assess heating, cooling and lighting energy demand coupled with visual comfort parameters. Thermal comfort was evaluated hourly in accordance with ISO 7730. The results are presented with a cost - benefit analysis to understand the best retrofit solution.

Metal mesh grids and perforated screens are used in new and renovated buildings as an external second skin for the building envelope; to enhance architecture design, to filter daylight and to reduce solar gains. Their effectiveness as shading devices depends on their geometry, texture and application. In the first part of the paper six types of shadings with similar transparencies, depending on geometry and openness factor of metal mesh grid and perforated screen, were investigated. Integrating sphere measurements were collected to obtain spectral optical properties of the shading devices. The optical properties were measured for incidence angles between normal and 60°with a step of 15°. The data collected were integrated to obtain visible and solar transmittance values in accordance with ISO 9050. In the second part of the paper a parametric study on spacing and thread dimension of metal mesh grids was done using Window 6.2 models to evaluate their shading potential, defining annual different shading profiles depending on shading geometry, latitude and orientation. A conventional office unit with a curtain wall facade with a metal mesh grid shading system was modeled in TRNSYS to evaluate the solar gain profiles and their effects on the energy balance of the office unit, under different weather conditions.

Urban areas are characterized by a plurality of microclimates given by the diversity of morphologies, optical and radiative properties, solar access and air circulation in different street canyons. For these reasons, beyond strategies at urban scale, mitigation needs to be addressed at district or even at urban canyon scale, just like the design of buildings. Among different options, canopy shading has been proposed in several urban contexts, and to assess the impact of this mitigation technique on air temperature and outdoor thermal comfort conditions we performed numerical simulations for a north-south oriented urban canyon with high solar access (height to width ratio equal to 0.18) in the climate context of Milano (Italy).

This paper aims to show a new solar design tool that can be used to optimize the building's shape and solar access in existing urban areas. The presented methodology was used for the analysis of the Surfers Paradise in Queensland, where in the past the urban and buildings development changed completely the morphology of the city. Since in the medium term the Zero Energy building will be the standard for new constructions, urban development should follow the Integrated Sustainable Design approach and the principles of solar design in order to exploit solar radiation using PV modules and Solar thermal collectors in the building envelopes. The tool is based on Matlab algorithm and on RADIANCE-DAYSIM, a dynamic simulation tool, and can help urban designers and architects since the first design phase.

This paper presents an approach to measure, characterize and simulate photometric performances of light transmission efficiency of an innovative transparent concrete panel for facades. The transparency was obtained by a texture of PMMA resin insertions in the fiber reinforced concrete panel. In the first part of the paper integrating sphere measurements were collected to derive spectral optical properties of the panel. The optical properties of a specimen were measured for incidence angles between normal and 60° and the spectral results were reported. The data collected during the measures were used to: create and validate a simplified Radiance model of the panel and to optimize simulation parameters to estimate properly the total internal reflections effects thought the PMMA resin insertions.

This paper shows the results of a research aimed at assessing the amount of energy that can be produced by solar envelopes (facades and roofs) in urban contexts. A preliminary set of simulations was carried out, through dynamic yearly analyses on a sample building, to identify the main parameters influencing the availability of solar radiation and to optimize the building’s shape. The general target is to maximise solar radiation available on the external building envelope, in order to exploit it through building integrated solar systems. Furthermore, the effect of reflected solar radiation has been analysed by simulating different finishing materials (green facades, glazed facades, concrete facades and aluminium facades) on the neighbouring buildings. © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of PSE AG

Aim To analyse results obtained from radiological assessment of skeletal segments stored in the musculoskeletal tissue bank (MTB) at Rizzoli Orthopaedic Institute. Materials and methods Between January 1997 and June 2003, 891 bone segments underwent radiographic examination in two views. Two hundred and thirteen of these segments were examined by a radiologist between July 2002 and June 2003. Diagnostic evaluation was aimed at recognising relevant degenerative, traumatic and focal lesions. Focal lesions underwent histological tests. Results Twenty-two lytic lesions were found in 12 segments. Ten of these were studied between July 2002 and June 2003 and two in the period before specialist radiological assessment. In the latter cases the lesions were identified by the orthopedic specialist who had examined the X-rays before planning surgery. Histological tests showed that the bone tissue was normal or involved by degenerative phenomena. Conclusions We think donor screening should include radiological assessment of bone segments, performed according to standard parameters by a radiologist to identify bone lesions that may jeopardise the successful outcome of surgery.