1,720,965 research outputs found
Energy and Economic Savings Assessment of Energy Refurbishment Actions in Italian Residential Buildings: Comparison between Asset and Tailored Calculation
Full text linkResidential buildings have become one of the leading sectors in the energy refurbishment process towards the clean energy transition. Energy Performance Certificates (EPCs), based on the asset rating calculation method, are often used to quantify the energy performance in standard conditions before and after renovation, but their energy outcomes can significantly differ from the actual energy consumption and savings. More consistent results can be obtained by adopting a “tailored” approach, capable of considering more the actual building operation conditions and users’ behaviour. In this framework, the study evaluates the heating energy needs of Italian representative multi-family houses in all the climatic zones and five retrofitting scenarios with both asset and tailored ratings. Finally, a cost–benefit analysis, based on energy savings and interventions costs, is also carried out to assess the affordability of the refurbishment actions depending on the adopted calculation methods. The analysis of retrofitting scenarios highlighted that asset energy outcomes are generally slightly greater than the tailored ones (differences of around 3–13% on average), but the affordability of the chosen energy efficiency measures is significantly overrated. It could underline the need to adopt the tailored approach for more accurate energy savings assessment and economic evaluation
Energy analysis and refurbishment proposals for public housing in the city of Bari,Italy
Full text linkFrom the perspectives of the energy and the environment, building stock should be considered a useful resource in the struggle against greenhouse gas emissions and scarcity of energy resources. The aim of this work is to provide an example of the application of a methodology to evaluate the energy needs of the building stock of a city and to determine the possible strategies for energy planning. This paper aims to obtain an estimate, on an urban scale, of the energy needs and CO2 emissions of the public residential buildings of Bari. This estimate is achieved by evaluating the critical issues of the built heritage, the most common architectural typologies and the heating systems in the territory of the city of Bari in southern Italy, as well as the possible strategies for upgrading energy efficiency, through the combined use of energy software and geo-referenced systems. Furthermore, several possible interventions are assumed to improve the energy performance of buildings in not only environmental terms but also economic terms through the instrument of cost-benefit analysis. The ultimate goal is to compare the different intervention strategies to determine which demonstrate greater cost effectiveness and feasibility for future energy plannin
Multi-criteria and multiscale assessment of building envelope response-ability to rising heat waves
No full textGlobal warming increases the probability of extreme events and heat waves, intensified by Urban Heat Island phenomenon, triggering severe impacts on both human health and economy. The paper aims at developing a new methodological approach for the assessment of building ability to face rising temperatures, also considering the effects on the surrounding urban areas. It focuses on resilient retrofitting strategies need for building envelope according to three macro-categories: reliability, adaptability and mitigation ability. A set of indicators is defined to achieve a Response Index to cope with heat waves. The method is tested on reference building and its neighborhood. The selected strategies are investigated through an integrated and multilevel analysis with EnergyPlus and ENVI_met, in three different cities with increasing summer temperature. The final comparative analysis is carried out through a multi-criteria analysis according to the identified indicators. The best responsive solutions result the green ones combined with high albedo, but the research highlights also some controversial aspects. The method can be a valid tool to support the decisional process about heat waves mitigation in the roadmap towards a more responsive built environment
Energy and environmental effects of human habits in residential buildings due to covid-19 outbreak scenarios in a dwelling near rome
Full text linkThe COVID-19 pandemic and resulting containment measures have shown that energy consumption in buildings is linked to several factors, such as living habits, occupancy profiles, and heating ventilation and air conditioning (HVAC) systems. This paper addresses the influences of such factors on energy consumption in a residential building, analysing different scenarios (pre-COVID-19, lockdown, post-COVID-19), in terms of discomfort and energy needs, through the new hourly calculation method (UNI EN ISO 52016). Energy and environmental effects were studied in a real case study near Rome by varying occupancy profiles, lighting and appliance schedules, and HVAC systems. Results show that, during the heating period, the lockdown scenario led to the lowest hours of discomfort (−29% on average), but the highest in the cooling period (up to +154%, +28% on average). The same scenario led to reasonable reduction of energy needs for heating (−14%), but also highlighted a significant increase (+60%) for the cooling period. This study underlines how the pandemic has influenced the energy and environmental behaviours in buildings. Moreover, the new hourly calculation method points out the importance of analysing HVAC systems, in terms of hours of discomfort, which could provide results that are more reliable
Studio di un sistema innovativo di retrofit per la riqualificazione energetica del patrimonio edilizio residenziale pubblico
No full textAttualmente, il settore delle costruzioni ha assunto un ruolo chiave nella lotta ai cambiamenti climatici e nella riduzione delle emissioni di CO2 in atmosfera. L'obsolescenza del patrimonio edilizio esistente ha reso più che mai indispensabili gli interventi di recupero edilizio, necessari a raggiungere livelli ottimali di efficienza energetica e di sostenibilità. In tale ottica si inserisce la proposta di un sistema integrato innovativo, denominato "Kit albero solare", che, ispirandosi al concetto della pergola, funge da sistema di captazione solare, conciliando aspetti di qualità architettonica ed ecocompatibilità. Esso è costituito da esili strutture in acciaio modulari e ripetibili che avvolgono l'edificio come una "pelle", dotandolo di dispositivi solari integrati e buffer spaces abitabili, quali serre, portici e logge, e assicurando l’ombreggiamento, la ventilazione naturale e il recupero delle acque piovane. Si incrementa così la superficie di captazione attiva dell'energia solare, altrimenti estremamente limitata negli edifici esistenti, senza la necessità di effettuare interventi invasivi. Le simulazioni in regime dinamico evidenziano come il Kit Albero Solare incida notevolmente sulla riduzione del fabbisogno energetico dei fabbricati, trasformandoli da consumatori a produttori di energia.
Inoltre, poiché la nuova Direttiva Europea 2012/27/UE punta ad aumentare il tasso di ristrutturazione degli immobili, ponendo nuovi obblighi soprattutto a carico del patrimonio edilizio di proprietà pubblica, la proposta trova un ideale ambito di applicazione nei contesti periferici di edilizia residenziale pubblica e risulta, pertanto, di forte interesse per la sua innovatività e per la rispondenza alle politiche ambientali nazionali e internazionali
Towards the objective of Net ZEB: Detailed energy analysis and cost assessment for new office buildings in Italy
No full textRecently, the built environment has become one of the leading sectors in the challenge of decarbonization and energy consumption reduction. Because of the specific use and the complexity of the typological, architectural, and technical characteristics, non-residential buildings represent a challenge to overcome the nearly Zero Energy Building standard and to achieve the objective of Zero or Net Zero Energy Buildings. It is desirable that the energy produced in situ from renewable sources totally covers the energy demand (ZEB); alternatively, the amount of energy self-produced and dispatched into the grid must be greater than (or equal to) the energy withdrawn from the grid (Net ZEB). At the same time, it is necessary not to neglect the economic aspects. The aim of this work is to propose an integrated energy-economic analysis to demonstrate the actual feasibility of new Net ZEB offices in different Italian climate zones. Thus, the energy analysis of a reference building, based on consolidated and cost-effective envelope and HVAC systems, has been carried out through dynamic simulations. The photovoltaic field located on the roof provides the energy needed for lighting, appliances, and HVAC. The obtained results are the energy demand and the energy production from renewable sources for the case study in each Italian climate zone. Moreover, the paper discusses the complexity of the annual energy balance, considering contributions such as grid integrations, self-consumption, energy stored and losses. Finally, the cost assessment of the proposed building has been carried out and compared to the state-of-art, pointing out the economic feasibility of the Net ZEB
Pathway to Zero-Emission Buildings: Energy and Economic Comparison of Different Demand Coverage by RES for a New Office Building
Full text linkIn recent years, energy efficiency and the decarbonization of the building sector have become key goals in Europe. However, substantial efforts are still needed to support the increase in on-site energy generation from renewable energy sources (RES) and to phase-out the use of fossil fuels. Moreover, this challenge must be backed by financial mechanisms provided by Member States. In this context, the aim of this work is to investigate different RES generation layouts for a reference office building in Italy and to determine whether it can achieve the goal of a net zero energy building (net ZEB) or a positive energy building (PEB). Different layouts are analyzed from both energy and economic perspectives through dynamic energy simulation, considering different financial schemes, such as “net metering” (SSP) and “premium tariff” (RID). The results show that the energy performance improves due to the size and the characteristics of the PV system. However, the avoided operating costs due to RID increase linearly, while the economic benefits provided by the SSP scheme encourage an appropriate design of the renewable energy system, avoiding oversizing for economic profitability
Mitigation and Adaptation Strategies for Different Urban Fabrics to Face Increasingly Hot Summer Days Due to Climate Change
Full text linkAs global warming and heat waves are becoming more frequent and severe, cities, with their different morphological districts, must be at the forefront of environmental challenges. Notably, many Mediterranean towns maintain the original medieval urban fabric and the regular one. The research focuses on the development of a methodology with the application of high-resolution 3D modelling software ENVI-met V5.1 to analyze the microclimatic effects of mitigation and adaptation strategies derived from the study of medieval and regular urban fabric. The aim is to address contemporary challenges such as heat waves and urban heat island (UHI) effects in modern cities. By studying outdoor energy behavior in a southern Italian city (Bari), the research proposes scenarios for urban settlements in the face of climate change. This approach provides recommendations for creating more climate-resilient urban environments both in the historic and modern city. The use of trees with large crowns and tall shrubs and the inclusion of fountain jets are strategies to achieve sky view factor and air temperatures in the modern city similar to those in the historical fabric. Increasing albedo values and the use of green roofs prove to be further strategies for improving outdoor climatic conditions
Transformation process and induced comfort in the Ottoman houses
No full textThe old town of Algiers, known as the Casbah, is the product and the place of social relations, but also of
cultural models impregnated with history and intrinsic immaterial qualities. It is the manifestation of a
superposition of several strata in a complex and original system; it is the trace of successive occupations, the
collective memory which preserves and transmits the adopted or rehabilitated cultures to its ways of life. In
other words, it is a living whole that has withstood the wear and tear of time.
Algeria has a rich heritage, not only as a historical value and identity, but also for the different solutions used to
meet the environmental requirements and more precisely the needs of comfort.
The Casbah of Algiers is an eminent example of a traditional human habitat, representative of the deeply
Mediterranean culture, synthesis of numerous stratifications. It composed of the most interesting houses,
which have retained their authenticity and integrity, such as the aesthetic characteristics, the materials used
and the architectural elements, retaining their original aspects and expressing values that gave it a place in
World Heritage in 1992.
They have an old architecture that remains impressive and represents aspects of traditional vernacular
architecture, illustrated as an example of a perfect harmony in the built environment with the natural
environment, allowing a quality of comfort, ensuring a healthy and comfortable indoor environment.
During the colonial and postcolonial periods, it is clear that the houses of the Casbah of Algiers had a process of
transformation/modification that is still undergoing, due to the will of the inhabitants to rise to the standards
of modernity. These same transformations have certainly manifested themselves according to the needs, but
often at the expense of the environment. They are the result of the overlap and juxtaposition of architectural
models (local and colonial ones): each way of life reflects a historical period and a population that is constantly
changing.
This paper focuses mainly on the nature of transformations endured by the residential building of the old
Ottoman Algiers until now and analyses their impact on thermo-hygrometric comfort and indoor microclimate.
Our reflection is linked to concepts with multidisciplinary dimensions that flicker between history, architecture,
town planning, geography, socio-cultural, hydraulics and environment. In fact, the environmental issue is
becoming more and more dominant in the new orientations and concerns related to the improvement of
comfort conditions.
Therefore, the applied methodology is based on two approaches: a historical one, aiming to identify the
architectural changes into old Ottoman houses, transforming the space and the openings (patio or chebâk
roofing “it is a house with a courtyard that is either covered with a fence called chebâk, or discovered called
patio”, close off openings, ventilation, new openings, kitchens and bathrooms renovation, heating plant
system, etc.), and an environmental one in order to measure the effect of these transformations on the
thermo-hygrometric comfort. These practices have generated sometimes small or even enormous disorders,
which have brought changes also in the indoor comfort.
Archives consultation, field investigations, modeling and numerical simulations will be essential tools, which
will allow us to achieve the expected results. A detailed corpus, considering the least transformed houses to
the most transformed ones, will be presented, accompanied by an accurate evaluation of the parameters
influencing the thermo-hygrometric comfort
- …
