1,721,066 research outputs found
Dynamic performance assessment of a residential building-integrated cogeneration system under different boundary conditions. Part II: Environmental and economic analyses
No full textThis work examines the performance of a residential building-integrated micro-cogeneration system during the winter by means of a whole building simulation software. The cogeneration unit was coupled with a multi-family house composed of three floors, compliant with the transmittance values of both walls and windows suggested by the Italian Law; a stratified combined tank for both heating purposes and domestic hot water production was also used for storing heat. Simulations were performed considering the transient nature of the building and occupant driven loads as well as the part-load characteristics of the cogeneration unit.
This system was described in detail and analyzed from an energy point of view in the companion paper. In this paper the simulation results were evaluated in terms of both carbon dioxide equivalent emissions and operating costs; detailed analyses were performed in order to estimate the influence of the most significant boundary conditions on both environmental and economic performance of the proposed system: in particular, three volumes of the hot water storage, four climatic zones corresponding to four Italian cities, two electric demand profiles, as well as two control strategies micro-cogeneration unit were considered. The assessment of environmental impact was performed by using the standard emission factors approach, neglecting the effects of local pollutants. The operating costs due to both natural gas and electric energy consumption were evaluated in detail, whereas both the capital and maintenance costs were neglected; the revenue from selling the electric energy surplus was also taken into account.
The performance of the proposed system was also compared with those of a conventional system composed of a natural gas-fired boiler (for thermal energy production) and a power plant mix connected to the national central grid (for electricity production) in order to assess its suitability in comparison to the systems based on separate energy production from both environmental and economic point of views.
The analyses were carried out with respect to the Italian scenario, by considering the most meaningful indexes suggested in current literature
Dynamic performance assessment of a residential building-integrated cogeneration system under different boundary conditions. Part I: energy analysis
No full textThis work examines the energy performance of a residential building-integrated micro-cogeneration system during the winter season by means of a whole building simulation software; a 6.0 kWel natural gas-fuelled internal combustion engine-based cogeneration unit was coupled with a multi-family house composed of three floors, compliant with the thermal transmittances of both walls and windows equated to the threshold values suggested by the Italian Law.
The main purpose of the paper is to compare the proposed system with a conventional system composed of a natural gas-fired boiler (for thermal energy production) and a power plant mix connected to the Italian central grid (for electric energy production) in order to assess the potential energy saving under various operating scenarios. The simulations were performed by considering the multi-family house located into four different Italian cities (Palermo, Napoli, Roma and Milano) representative of different climatic regions of Italy in order to estimate the influence of climatic conditions; a parametric analysis was also performed with the aim to evaluate the sensitivity of the energy flows when varying the volume of the combined storage tank; taking into consideration that the economic viability of the cogeneration unit strongly depends also on the value of the co-produced electricity, the system performance was also evaluated by considering two different electric demand profiles (with and without the electric consumption associated to the overnight charging of an electric vehicle); the operation of the microcogeneration device was estimated under both electric and thermal load-following control strategies.
The analyses showed that, in comparison to the conventional system, the proposed system allows for a relevant reduction of primary energy consumption under thermal load-following logic; significant effects of climatic conditions, tank volume, as well as electric demand profile on the simulation results were highlighted.
In the companion paper (Part II: Environmental and economic analyses) the performance of the proposed system was analyzed and compared with those of the reference system from both environmental and economic point of views
Daylighting design in a low energy building
No full text"An efficient use of the energy that we can get for free from the nature, represents the first. manner to achieve energy saving and to reduce our dependence from fossil fuels. In this. context, daylight plays a fundamental role for both energy saving and improvement of the. quality of life. On this track different tools are today available for researchers, designers. and professionals to carry out the assessment of daylight influence at the early stage of. design process both considering software simulation and\/or other facilities such as real or. artificial sky thus using physical simulation with scale-models. This paper deals with. results of trials performed at the early stage of a design process referred to a low energy. building located in south Italy where the abovementioned tools have been applied for. natural light evaluation. To this aim a scale model has been investigated under an. artificial sky of a mirror-box type and results compared with those obtained by computer. simulation software Ecotect to determine the interior distribution of illuminance in terms. of Daylight Factor. Later, simulation software has been used to evaluate the effect of of. photovoltaic modules with different optical transparency (and number of PV modules. integrated) integrated in large fenestration system, in terms of Daylight Autonomy, theoretical electrical energy deliverable and artificial lighting energy demand.
Energy performance assessment of three MCHP systems integrated in a multi-family house in the south of Italy
No full textA dynamic performance assessment for a number of micro-cogeneration systems, namely two different natural gas-fuelled internal combustion engines and a natural gas-fuelled reciprocating external combustion Stirling engine. These cogeneration units were integrated with an Italian multi-family house compliant with the transmittance values of both walls and windows suggested by the Italian Law. The operation of the residential building-integrated micro-cogeneration systems during the winter season was investigated by means of a whole building simulation software, considering the transient nature of building and occupant driven loads as well as the part-load characteristics of the cogeneration devices. Detailed models, developed within Annex 42 of the International Energy Agency (IEA) and calibrated on the basis of experimental results, were used for carefully predicting the performance of the cogeneration devices. The simulated performance of the proposed system were compared with those of a reference system composed of a natural gas-fired boiler (for thermal energy production) and the central grid (for electricity production) in order to assess the suitability of the cogeneration device-based system in comparison to the system based on separate energy production. The comparison was performed from energy point of view. The energy analysis was carried by determining the primary energy saving
Review of 3D Printing in Architecture: applications, limitations and future developments
No full textAdditive manufacturing has seen a growing interest in the construction industry in the last few years. Along with the possibility of using plastics, cement, clay, mixtures, and so many other materials, the opportunities offered by such technologies mainly rely on the free-shaping of complex geometries and the high customizability of the products. Nowadays, the aim of integrating additive manufacturing processes in the construction stages is to reduce waste materials and reduce the overall environmental impact. This review summarizes the current state-of-art of additive manufacturing, mainly 3D printing, applied to architecture, in current research activities, and actual built projects. The aim is to delineate a comprehensive scenario of its possible applications and current limitations, finally suggesting the opportunities for future investigations
A Review of Gas Engine Driven Heat Pumps for Residential Applications
No full textGas engine driven heat pumps can play an important role in energy saving, environment protection and cost reduction in both cooling and heating residential applications.. In this paper, studies conducted on gas engine driven heat pumps are reviewed and presented to the best of the authors’ knowledge. In particular, all models with rated heating capacity lower than 100 kW today commercially available and their main characteristics are listed; besides, the experimental performance of the units measured by way of field tests or lab tests are discussed in detail. Taking into account the need to accurately predict the operating characteristics and optimum design of gas engine driven heat pumps, the main features of the simulation models available in literature are reported and the results of comparison between theoretical and experimental values are highlighted
Experimental analysis of a micro-trigeneration system composed of a micro-cogenerator coupled with an electric chiller
No full textMicro-trigeneration is one of the most promising technologies allowing the simultaneous production of electricity, heat and cooling on a small-scale basis, with a potential contribution to significant primary energy saving and greenhouse gas emission reduction if compared with the conventional separate energy production.
The on-site performance of a micro-trigeneration plant serving the Built Environment Control Laboratory of Second University of Naples (south of Italy) during summer were measured and analyzed; the system was composed of a 6.0 kW natural gas-fueled reciprocating internal combustion engine-based micro-cogeneration unit feeding a 7.5 kW electric air-cooled water chiller.
The experimental data were compared with the performance of conventional systems based on separate energy production in order to assess the feasibility of the proposed system; the comparison was performed according to the Italian scenario by estimating the potential savings in terms of primary energy consumption, operating costs and carbon dioxide equivalent emissions
Innovative harvesting systems to improve indoor visual comfort
No full textIn this study, we will focus upon the building envelope as a multi-functional component that intersects energy consumption, human comfort, and aesthetics. Given their significant impact, building skins have been extensively studied in recent years to enhance their efficiency and performance in terms of energy usage, comfort, and structural integrity (Schumacher, 2016). Architects must consider numerous factors when designing building envelopes, including environmental issues, appearance, occupant comfort, and view quality, recognizing that the building’s envelope is a critical component in improving sustainability (Khelil, 2018). Consequently, responsive architecture can be achieved by imparting intelligence to the building system through the building’s skin, which responds to environmental stimuli. Designers are exploring the potential of making building skin elements move in response to natural or human stimuli (Gan, 2020). The objective of this paper is to analyse, starting from a biomimicry+ origami mimicking approach, the design concept and application of a harvesting system for building envelopes. This kind of system can adjust to changing environmental conditions in real-time, regulating the internal climate of a space, and exhibit movement and dynamism inspired by natural adaptation strategies to optimize the visual comfort of buildings in hot and arid regions by leveraging this approach. In the paper is presented the utilization of a dual methodology that employs parametric design as an alternative platform for architects to enhance, verify, and make well-informed decisions during the early stages of the design process. This approach will offer unique opportunities for investigating various design options and strategies to achieve environmental performance, including improving indoor visual comfort. The building’s exterior is designed parametrically, utilizing the Grasshopper Visual Programming Language in Rhino 3D Modeller and, based on the results obtained, the proposed harvesting system has demonstrated significant effects on visual comfort
Auditory and visual impact of split systems on the façade of historical buildings
No full textIn the last decades, the demand for air conditioning and cooling systems for buildings continues to increase, despite the awareness campaigns and the Green Policies adopted by European Countries. The adoption of such policies is dictated by climate change, and by the will to reduce GHG emissions and increase the use of energy from renewable sources. Among all the different air conditioning systems, the split systems represent most Room Air Conditioners (RAC) units installed in Europe. Their integration with the buildings of historical centres is not successful due to the sound emissions of external units and their visual impact on buildings' facades. The acoustic and the visual impact are evaluated separately, by comparing the results of outdoor noise prediction models with noise limits levels at receivers or using local regulations. A virtual reality environment has been prepared to carry out a laboratory experiment to understand better how Air Conditioning (AC) split units affect the residents' overall perceptions. This paper investigates the combined (auditory and visual) impacts of installing external units of split systems on historical buildings' facades. By combining different Visual Aspects and Noise Levels, the noise annoyance and other perceptual attributes of the environment have been studied. Main conclusions suggest that visual elements more integrated on the façade of the historical building can help reduce the auditory and the visual impact of these elements. Moreover, well-integrated and pleasant elements led to a lower auditory perception of the loudness and noise annoyance than less integrated elements
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