1,721,003 research outputs found
SISTEMA DI SCHERMATURA E CONTROLLO DELLA RADIAZIONE SOLARE O DEL FLUSSO LUMINOSO DERIVANTE DA SORGENTI ARTIFICIALI, SPECIALMENTE PER APPLICAZIONE AD EDIFICI - SYSTEM FOR SHIELDING AND CONTROLLING SUN LIGHT OR THE LIGHT FLOW COMING FROM ARTIFICIAL SOURCES, ESPECIALLY FOR APPLICATION TO BUILDINGS
No full textThe patent describe an adaptive shading device actuated by shape memory alloy (SMA) springs, and stimulated by light and/or solar radiation
CLADDING ELEMENT FOR USE IN CONSTRUCTION AND METHOD FOR MANUFACTURING THE SAME
No full textThe present invention relates to a method for manufacturing cladding elements (100) for use in construction, comprising a composite cement-based structure. The method envisages providing an elastically deformable support element (2), comprising a first surface (4), a second surface (5) and a plurality of spacer elements (6) having an elongated shape positioned between said first and second surface (4, 5) so as to realize a plurality of interconnected cavities (7). The method further provides preparing a substantially fluid and water-based cementitious composition (3) and introducing the substantially fluid cementitious composition (3) into the support element (2) so as to obtain a composite structure (1) in a deformable state. After this, part of the fluid cementitious composition (3) is removed from the support element (2), so as to eliminate the excess fluid cementitious composition (3) and position the deformable composite structure (1) in a forming device. The method therefore provides for maintaining the deformable composite structure (1) in association with the forming device, until the consolidation thereof. The method further provides that said support element (2) is constituted by a three-dimensional elastically deformable fabric and that said cementitious composition (3) comprises at least one fluidifying and/or plasticizing additive and in which cement, additive and water are present according to a weight ratio variable from 1; 1/3; 1/3 to 1; 1/6; 1/6
Lean Strategies for Window Retrofit of Italian Office Buildings: Impact on Energy Use, Thermal and Visual Comfort
Get PDFThe 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 shading devices optimization by parametric approach design
No full textWindows are the most important component within building envelope to control both solar heat gain and
thermal losses, but also to guarantee an optimal daylight level.
Metal mesh are used in new and renovated buildings, especially in office building, as an external second
envelope skin to enhance architecture design, to manage daylight levels and to control solar gains.
The aim is the optimization of their position, compared to the façade raising plane, enhancing the metal
mesh systems energy performance, increasing the comfort requirements and reducing the amount of used
material to minimize costs.
In order to evaluate their performances (mesh spacing and orientation) an estimation of the primary energy
consumption for heating, cooling, lighting and daylight comfort has been carried out. The study case is a
single 3 x 4 x 3m (W x L x H) office unit placed in Milan (Italy) under a single orientation (South). It has one
wall facing outdoors, having a Window Wall Ratio (WWR) of 86%, and five surfaces, considered as
adiabatic, because facing other internal offices (three wall, ceiling and floor).
A three-step approach was carried out to assess a sensitivity analysis with Energy Plus and Radiance
engine, managed with a parametric modelling approach (Rhinoceros and Grasshopper), evaluating shading
systems performance. For all of the simulations have been calculated the total primary energy (for heating,
cooling and lighting) and the principle daylight comfort index like (Daylight Factor, Useful daylight illuminance
and Glare Analysis). In the first step the standard metal mesh system with different ratio between spacing
and characteristic diameter (d/D equal to 0.2, 0.6, 1) has been analysed and compared with a standard
façade solution such as low-e double glazing unit (DGU) alone and the same one coupled with an internal
curtain.
In a second phase the performance of metal mesh shading device with different tilt angle (-20°, -10°, 10°)
were evaluated. In the third phase, a further system implementation was assessed decomposing the second
phase system in smaller sub-systems using a hybrid solution with metal mesh and louvers.
The results shows that considering only the total energy primary energy use the system that performs better
is the metal mesh with d/D equal to 0.6 and a 10° t ilt angle (from the façade raising plane). Instead
evaluating also costs and internal comfort the hybrid system have a better behaviour
The Effect of Water Spray Systems on Thermal and Solar Performance of an ETFE Panel for Building Envelope
Get PDFETFE membranes are generally used in architecture for large roofing and façade 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 façades. 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
Metal Mesh as Shading Devices and Thermal Response of an Office Building: Parametric Analysis
Get PDFWindows are the most important part of the building façade to control solar gains, thermal losses and visual
comfort. Office buildings usually have medium-high WWR (window to wall ratio value) and high internal gains
(due to users, lighting and appliances). For this reason, they require a good balance between thermal and visible
performances of transparent façades and shading control strategies to avoid overheating, optimizing daylighting
aspects. A sensitivity analysis was assessed to evaluate primary energy use for heating, lighting and cooling for
conventional Italian single office units equipped with static metal mesh shading devices with different geometries
and openness factor values. Different location (Milan, Palermo), orientation (south and west) and WWR (33% and
100%) were analyzed. Hence shading devices alternatives as venetian blinds and sun control windows are proposed
as a comparison
Spectral light transmission measure of metal screens for glass façades and assessment of their shading potential
Get PDFMetal 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 façade 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
On the Optical Characterization of Architectural Three-Dimensional Skins and Their Solar Control Potential
Get PDFThe use of second building skins is becoming a trademark in modern architecture, opening
for innovative solutions, such as three‐dimensional (3D) systems. This paper explores the potential
of these systems to provide adequate solar protection to glazed façades by means of an advanced
optical characterization. Spectral transmittance and reflectance of fourteen samples, belonging to
several technological families, are measured with a built‐in spectrophotometer, suitable to accurately
characterize complex semi‐transparent systems. Solar and lighting properties are then calculated.
The normal optical properties strongly depend on the openness factor, thus the geometry
primarily affects the performance. A total of 11 samples exhibit normal solar transmittance in the
40–53% range; the value decreases to 20% for the plissé metal grid and increases to 70% on average
for metal meshes. The angular transmittance depends on the system texture geometry and its selfshading
capabilities. It was found that such systems underperform as static conventional shading
systems; however, one of the metal meshes, the plissé grid and the plastic grid exhibit relevant angular
selectivity, with transmittance decay at 60° in the 58–72% range compared to the normal incidence
value. The results show that some of the selected 3D systems provide adequate solar protection.
The developed dataset can be used for early‐stage design analyses, as well as for energy performance
model input and validation
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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