1,720,988 research outputs found
Towards the A class: calculation methods of the energy performance in the UNI/TS 11300 Standard
No full textProblematiche di realizzazione e potenzialità di utilizzazione di un database per la scelta di soluzioni integrate appropriate negli interventi di retrofitting dell’involucro edilizio esistente
No full textProblematiche relative all’applicazione del protocollo ITACA a edifici residenziali esistenti
No full textL’importanza del sistema di regolazione nella valutazione degli interventi di riqualificazione e nella definizione della classe energetica degli edifici
No full text
The effort to bring existing buildings towards the A class: A discussion on the application of calculation methodologies
No full textThe diffusion of the energy certification in Italy is gradually making the users aware of the buildings’ energy performance, at least in some regions. For the existing buildings, the challenge is not only the energy performance calculation, but the analysis of the refurbishment strategies to obtain low energy buildings towards the A class.
Basing on European Standards EN ISO 13790 and EN 15316, the Technical Standards UNI/TS 11300 (part 1 and 2) represent the procedures defined at national level. They allow different approaches and levels of simplification in the calculation of various representative energy parameters that could bring to variations in the results.
The first aim of the work is the analysis of the most suitable solutions for existing buildings and the real possibilities to move towards the A-class requirements. Another considered aspect is the application of different calculation methods to reach this target, showing how different choices in terms of input data and methodologies (allowed by the Technical Standards) can bring to different values of the energy performance indices. This could represent a problem for the reproducibility of the calculations and their reliability in the definition of the class level reachable through refurbishment.
The research has been supported by the analysis of some representative cases of common national residential building stock, comparing the energy performance obtained with different calculation methods allowed by National Technical Standards and laws. The results show some differences which can lead to ambiguities about the class definition and the most suitable methodology to adopt. Some considerations to obtain reliable values of energy performance addressing the refurbishment towards the A class are presented
Nanoparticles released during metal-processing operations: A systematic review
No full textMetal manufacturing processes can incidentally release particles in nanosized range, increasing the likelihood of inhalation exposure to workers. Despite the widespread diffusion of these technologies, there is still a lack of standard occupational exposure values for airborne nanoparticles. Moreover, the limited and fragmented results from in-field monitoring entail a reduced level of awareness of this potential health risk. Therefore, this review aims to provide an overview of the status of knowledge dealing with occupational exposure to incidental metal nanoparticles. The main inclusion criterion was the availability of monitored data of nanoparticle incidental release in industrial or experimental settings. By applying the PRISMA workflow, 46 articles were included in the study. The main analyzed processes leading to NPs release were welding, additive manufacturing, plasma cutting and laser cutting. The analyzed works showed a noteworthy nanoparticles release, with measured concentrations significantly higher than the pre-process conditions. Variability in magnitude and pattern was affected by the features of the adopted technology, the processed materials and the monitoring conditions. In general, welding showed the highest average airborne particle concentrations among the analyzed processes. Additive manufacturing was found to be particularly critical during printing and cleaning operations, where, depending on the technology utilized, the average particle concentrations were comparable to those observed in welding. The results of the review highlight the relevance of the potential occupational exposure associated to the analyzed technologies and the importance of comparable data from in-field monitoring to define specific benchmarks for controlling the process release and to protect worker's health
New domain for promoting energy efficiency: Energy Flexible Building Cluster
Get PDFThe ongoing energy system shift-from traditional centralized fossil fuel based to decentralized renewable energy sources based-requires a strengthened control of energy matching. Smart buildings represent the latest step in building energy evolution and perform as active participants in the cluster/energy infrastructure scale, becoming energy prosumers. In this framework, the IEA EBC Annex 67 introduces the concept of 'Energy Flexible Building', defined as a building able to manage its demand and generation in accordance with local climate conditions, user needs and grid requirements. Currently, there is no insight into how much flexibility a building may offer, and this study aims to overview the theoretical approaches and existing indicators to evaluate the Energy Flexibility of building clusters. The focus on cluster scale allows for the exploitation of the variation in energy consumption patterns between different types of buildings and the coordination of load shifting for the improvement of renewable energy use. The reviewed indicators can contribute to the definition of the Smart Readiness Indicator, introduced in the European Commission proposal for the EPBD revision, in order to test a building's technological readiness to adapt to the needs of the occupants and the energy environment, as well as to operate more efficiently
Assessment of nanoparticle emission in additive manufacturing: Comparing wire and powder laser metal deposition processes
No full text: Additive manufacturing (AM), often referred to as 3-D printing, is an emerging technology with a wide range of industrial applications and process typologies. Although the release of metal nanoparticles as by-products could occur, occupational exposure limits and cogent safety standards are not currently available due to the novelty of the technology. To support the definition of benchmarks, this study aims to provide a preliminary comparison between the nanoparticle release patterns of laser metal deposition, adopting different feedstocks, namely, metal wire and metal powder. The monitored device is a university research setup, and the work presents the results of two different processes with AISI 316L as a feedstock in powder and wired form, respectively. The monitoring confirmed the outcomes of previous studies, with a high release of nanoparticles from the powder head on the device (average 138,713 n/cm3 during printing, with maximum values exceeding 106 n/cm3). Moreover, the results show a significant concentration of nanoparticles with a wire head during the printing phase (average release of 628,156 n/cm3 with a maximum of 1,114,987 n/cm3) and during pauses (average of 32,633 n/cm3 and a maximum of 733,779 n/cm3). The monitored values during pauses are particularly relevant since no personal protection equipment was used in the wire processes and the operators could access the printing room during pauses for device interventions, thus being exposed to significant nanoparticle concentrations. This study presents a preliminary evaluation of the potential exposure during laser metal deposition while implementing different technologies and provides evidence for defining effective operational safety procedures for the operators
- …
