1,721,187 research outputs found
Beccali M., Progettazione, realizzazione e monitoraggio di un impianto Solar Desiccant and Evaporative Cooling (DEC)
No full textElectricity Consumption Analysis of Tertiary Buildings: An Empirical Approach for Two University Campuses
No full textAn empirical approach for the analysis of energy consumption of existing buildings of the tertiary sector is presented in this study. It allowed the organization and management of large amounts of data according to different timeframes and helped to focus on leading issues about energy uses, and dealt with compatibility with tariff structure. The analysis method, which implied a powerful graphical representation of the results, allowed us to detect critical issues in electricity energy management for public buildings and improve their energy performance. Furthermore, the authors proposed a set of electricity consumption indexes (ECIs) that gave useful insight into the main hotspots. The basis of the proposed method was an automated spreadsheet based data processing procedure. The main advantage of the method was its applicability with a small charge due to the purchase and installation cost of simple data loggers instead of more complicated and expensive technical building management systems. The method was tested exploiting data measured for more than 2 years in several buildings of the Politecnico of Milano (Italy) university
Mapping Seasonal Variability of Buildings Electricity Demand profiles in Mediterranean Small Islands
Full text linkIn communities with a high tourist influx and warm climate, such as Mediterranean small islands, the energy demands for space cooling and domestic hot water are expected to significantly increase during summer. Considering the current energy context, for succeeding energy transition and reducing the dependency on not endogenous fossil fuels, it is paramount to increase the deployment of renewable sources of energy, especially wind and solar which, however, are aleatory and unpredictable. Hence, to reduce the high costs for energy supply in these contexts, the analysis of the variation of energy consumption is fundamental. Moreover, mapping the spatial distribution of energy profiles can be useful to have an overview at a large scale of the considered building stock. Within this frame, a Geographic-Information-System-based procedure was implemented to estimate the residential buildings energy demand profiles, focusing on the seasonal variation. The adopted method can provide a valid supporting tool for decision makers that have to implement smart energy strategies in contexts with a high variation of the energy demand and evident electricity summer peaks. The method for mapping the energy demand profiles, implemented on the small island of Pantelleria, can be applied to other similar contexts, also supporting energy policies in the implementation of renewable energy communities
Special issue "Smart Urban Lighting Systems"
Full text linkThe design and operation of multifunctional infrastructures for public lighting as well as their impact on the urban environment and citizens' life is today of great interest. The cost of energy for public lighting is often an issue for the budget of municipalities. Furthermore, researchers' and designers' attention is increasingly focused on aspects of public lighting not directly valuable through economic factors. Starting from the "quality" of the light environment, looking at citizens' visual comfort, the light has to be considered as an instrument to improve the urban context and objects therein (including buildings). Indeed, urban degradation (lack of infrastructures, maintenance, services, etc.) is linked to the poor quality of everyday issues, such as traffic, pollution, noise, lack of information, long times to access focal points, and the lack of safety. Simultaneously, in many areas, the potential related to the valorization of historical heritage is often underexploited. The installation of efficient lighting systems coupled with the implementation of ICT solutions can provide economic, social, and health benefits, energy efficiency, and visual comfort. On the other hand, as for indoor lighting, these systems can be expensive, not easy to maintain, and not as efficient as expected. The aim of this Special Issue was to investigate the problems and advantages of smart urban lighting systems in more detail. This Special Issue included 6 papers of the 10 submitted papers
FREESCOO facade 3.0, a compact DEC thermally driven air-conditioning system for apartments
Full text linkFREESCOO is an innovative Desiccant Evaporative Cooling air conditioning system designed for ventilation, cooling, dehumidification and heating of buildings in residential and tertiary sectors. This paper presents the third generation of the façade version, which will be tested on field in Milan (Italy) within the Merezzate+ project supported by Climate-KIC. The adsorption bed used by the system is a finned heat exchanger packed with silica gel grains, which allows simultaneous dehumidification and cooling of the process air. The direct evaporative cooling process, operated downstream to the dehumidification, is realized using a rotary plate humidifier. The regeneration of the adsorption bed is done through low-grade heat around 60 °C and the only electrical consumption is for the fans and water recirculation. The unit has been designed in order to be integrated in the loggia of small apartments of roughly 47 m2. The result is a Seasonal Energy Efficiency Ratio around 10.7. From the primary energy savings perspective with respect to a conventional air conditioning, they can be up to 36% if the electricity generation is not renewable heavy or the district heating has a renewable energy quota
On the impact of safety requirements, energy prices and investment costs in street lighting refurbishment design
No full textStreet lighting is an indispensable feature for the night landscape of cities. It is important for road safety, users visual comfort, crime prevention and to augment the perceived personal safety. Realize and maintain an adequate street lighting service is very expensive for municipalities with significant impact on their budgets. For this reason, special attention should be paid to the design of new street lighting systems and to the refurbishment of existing ones, since many of them are inadequate. In light of this it is very important to implement street lighting designs that fulfil lighting requirements avoiding energy waste and light pollution and, at the same time, result economically sustainable for municipalities. In this paper, an original step by step methodology for the lighting, energy and economic analysis of street lighting refurbishment designs has been introduced and explained in detail. The methodology is suitable for use in cities of different sizes. As an applicative example, the methodology has been tested in the town of Pontedera (Italy) and the results are discussed, also providing a sensitivity analysis of the economic feasibility with respect to the variations of electricity prices and investment costs
Building Integrated Solar Thermal Design: Assessment of Performances of a Low Cost Solar Wall in a Typical Italian Building
Full text linkPresent work deals with the topic of building integration of solar thermal collector (BIST) as a refurbishment measure. Such equipment, more than its main function as heating generator, plays a specific role as a building component (envelope finishes, thermal insulation layer, roof cover etc). Consequently, from a heat transfer point of view, an integrated component affects twice the global building balance: supporting the thermal plant (i.e. providing heat for final uses) and modifying the wall heat-transfer pattern (i.e. reducing thermal losses). In turn, the collector performance itself is influenced by the wall structure (back losses reduction). Present work proposes a method for evaluating the yearly performance of a low cost BIST by means of a Trnsys model on a reference building. This model arises from previous studies based on experimental validation of a FEM model that was implemented in order to describe the collector-wall system efficiency
Assessment of the technical and economic potential of offshore wind energy via a GIS application: A case study for the Sicily Region according to Italian laws and incentive frameworks
No full textThis paper presents a technical and economic analysis of the possible exploitation of offshore wind resources using spatial analysis methods based on GIS tools. The study assessed the magnitude and distribution of the main constraints on installation of wind farms by taking into account the relevant technical factors and local laws on nature protection issues in a specific area, i.e., Sicily. Specific cost functions were defined for several components of the total cost of construction and maintenance of a wind farm. Several scenarios were implemented according to wind turbine size, hub height, total wind farm power, and distance from the coast, and the levelised production cost was assessed for a total of 12 scenarios. The main economic performance outputs were calculated and represented on maps, thus demonstrating this approach as a useful tool for decision makers, stakeholders and planners
Electrical hybrid heat pumps assisted by natural gas boilers: a review
No full textIn this paper, a comprehensive review is performed on hybrid systems using electrical Heat Pumps for Heating, Ventilation & Air Conditioning systems and Domestic Hot Water production using case studies from 2016 to 2022. This work particularly focuses on studies that investigated systems with electrical Heat Pumps assisted by a gas boiler. Some studies that considered the exploitation of renewable energy sources, but not as a whole sub-stitute for fossil sources, have also been included. In particular, the analysis investigated the layouts of the systems by considering the type and the size of the components, the control methods applied (by distinguishing rule-based control methods and predictive control methods), and the main performance indices used to calculate energy, exergy, environmental and economic performance. Most of the analysed studies demonstrated that the hybrid systems could be very advantageous if the switch or the integration of the two generators is well managed. Nevertheless, the energy and economic performances are very different for each system studied. They are highly influenced by the control strategies implemented and by the objective functions adopted. Furthermore, climate can influence performance while affecting the Coefficient Of Performance of the heat pump and the availability of energy sources. Regarding economic issues, the systems' performances vary according to specific Country tariff structures. The review reported a promising research activity also pursued by manufacturers of components and equipment. Nevertheless, the paper highlights new possible research and development directions
Energy performances and life cycle assessment of an Italian wind farm
No full textRenewable energy sources are often presented as clean. A more correct definition is that they are cleaner than ones based on fossil fuel conversion. When the energy consumption and the environmental impacts related to the plant's life-cycle are considered, a more comprehensive assessment of these technologies can be carried out. This paper aims to evaluate the energy and the environmental performances of the electricity production of a wind farm. The impacts related to all the phases of the wind farm construction and operation have been compared to the environmental benefits due to the green electricity generation during its useful life. In other terms, the goal is to trace the ecoprofile of the production of 1 kWh of electricity.A life cycle assessment (LCA) has been performed based on data related to an Italian wind farm: production and deliver of energy and raw materials, components manufacturing, transports, installation, maintenance, disassembly and disposal have been analysed. The attention focused to those life cycle steps generally neglected or not adequately investigated as installation, civil works and maintenance. The results can be assumed as representative of the Italian context and they can represent a further incentive to the diffusion of wind farms. In fact, the environmental performances of the wind farm have been compared to other power energy generation systems. The results showed a great environmental convenience of the inquired technology
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