3,344 research outputs found

    Nearly Zero Energy Building (NZEB)

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    Reducing the impact of climate change is one of the main challenges of today’s society. As such, it is necessary to reduce the high energy consumption that comes with constructing and using buildings. Current energy policies are promoting decarbonization of the built environment using the nearly zero-energy building’s concept. This book presents information on nearly zero-energy buildings, including materials, design, and new approaches

    Cost optimal building renovation with a net zero energy target for the Portuguese single-family building stock built before 1960

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    Cost Optimality and nearly Zero Energy Buildings (nZEB) are two fundamental concepts within the current European Union policy related to the energy performance of buildings and consequently related to climate change mitigation and non-renewable resources con-sumption. While Cost Optimality is mainly focused on costs, nZEB are focused on low energy consumption levels and on site renewables harvesting. If the differences between Cost Optimality and nZEB approaches result in major differences in the selection of the best package of renovation measures, the transition from the Cost Optimal concept to nZEB might result incompatible. In this context, using a virtual building representing the Portuguese residential building stock from the 20th century prior to 1960, this study investigates the most cost-effective packages of renovation measures to achieve a zero energy balance building and compares these packages with those resulting from the calculation of cost-optimal levels. Investigating the trade-offs between a renovation towards zero energy balance and a cost optimal renovation without the use of renewables is relevant to achieve a smooth transition from Cost Optimal levels to nearly Zero Energy Buildings

    On the refurbishment of the public building stock toward the nearly zero-energy target: two Italian case studies

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    The study presents some results of the on-going European Project, RePublic_ZEB, on the refurbishment of the public building stock towards nearly Zero Energy Building (nZEB). The work is focused on the application of the nZEB requirements to two existing public buildings representative of the 1960s in Northern Italy. Many packages of energy efficiency measures that comply with nZEB requirements are identified and evaluated. The aim is to promote energy efficient but also cost-effective solutions for the Italian building stock refurbishment. The results are presented in terms of “package of measures”, energy consumption, global costs, actualized pay-back period and CO2 emission

    NZEB, cost- and comfort-optimal retrofit solutions for an Italian Reference Hotel

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    Building upon the implementation of EBPD recast in the large majority of EU Member States, this paper studied how far cost-optimality is from the Nearly Zero Energy Building (NZEB) performance level for an Italian Reference Hotel (RH) undergoing major renovations. The energy performances of retrofit options for the RH were compared with the Italian NZEB requirements. Simulations results confirmed that the Italian NZEB target is reachable. However, the financial analysis of these retrofit options denounced a worrying gap between financially interesting solutions and NZEB ones. Then, through a novel comfort-optimal approach, the comfort-related consequences of the proposed retrofit options were investigated

    Post occupancy analysis of nZEB implementation via the PH standard

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    Building regulations are currently under development across Europe in advance of the implementation of the nearly Zero Energy Buildings (nZEB) standard at national member state level. However, when revising the national building regulations to improve energy efficiency, few examples exist of the monitored performance of such dwellings, making informed decision-making difficult. This paper reports on the monitored performance of nZEB compliant dwellings which were built to the Passive House (PH) Standard. It finds that the PH bedroom CO2 concentrations are significantly better than in houses built to the current building regulations which use natural ventilation. KEYWORDS: IAQ, CO2, Passive House, nZEB, Cardon Dioxid

    Danish, Estonian and Finnish NZEB requirements comparison with European Commission recommendations for office buildings in Nordic and Oceanic climates

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    Direct comparison of building energy performance levels between countries is usually not possible due to differences in climatic conditions, calculation methods, primary energy (PE) factors and input data. The aim of this paper is to analyse the differences in nearly zero energy office buildings requirements and energy calculation methodology in Denmark, Finland, and Estonia. The study is based on a newly built Estonian office building, designed to meet national NZEB requirements. To account for the climatic differences between the countries a heating-degree-days-based correction factor was applied for building envelope thermal transmittance. NZEB requirements for each country are compared with European Commission (EC) recommended values (EU 2016/1318) using normalization and benchmarking through detailed computer simulations. National NZEB primary energy threshold was needed to be reduced by 7% in Denmark and by 23% in Estonia to meet EC recommendations. At the same time, the flagship reference building, that was better than Estonian NZEB, met both Nordic and Oceanic EC recommendations. Finnish NZEB requirement was not exceeded with any building configuration applied in this study, indicating that Finnish NZEB is considerably less strict compared to Danish and Estonian ones

    Nearly Zero Energy Building (NZEB) using IoT and Smart Grid

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    Current energy policy and climate mitigation goals require distinct reductions of the primary energy demand in the building sector. The existing building stock poses challenge since clear-cut technical and economical retrofit strategies for different types of existing buildings are still not established. The goal of the study is to identify such retrofit strategies to achieve optimal cost levels and to assess costs and benefits of nearly zero energy buildings (nZEB). Firstly building types are defined by covering single-family houses, multi-family houses, office buildings and school buildings. Secondly, a large set of generic energy efficiency measures are described, covering seven strategic fields, namely building envelope measures, heating and hot water supply technologies and fuel choice, ventilation and lighting systems, electricity and district heat mixes. This covers the usage of smart home appliances, eco-friendly building ventilation system. Thirdly, energy performance is calculated based on technical and physical characteristics and using building energy balance software. Fourthly, investment costs and life cycle costs are established based on unitary costs of building elements and building technologies. Cost-effectiveness is determined based on he net present value method which is compared to the annuity method for a couple of cases. The integration of smart grid and IoT(Internet of Things) is a new concept for conserving more

    From nearly zero energy buildings (NZEB) to positive energy buildings (PEB): The next challenge - The most recent European trends with some notes on the energy analysis of a forerunner PEB example

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    Abstract The European energy policies introduced the Nearly Zero Energy Building (NZEB) objective (Directive, 2010/31/EU and 2018/844/UE) to stimulate the energy transition of the construction sector. EU programs, specifically "Horizon 2020", promote the NZEB design and also its evolution, namely the Positive Energy Building (PEB) model. Based on the most recent developments, a critical review of the main actions of the European Union towards the development of the NZEB and PEB design models has been conducted. Some considerations on advanced materials and technologies (PCM, VIP, smart glass, integrated photovoltaic systems) have also been added. Finally, a case study is presented (single-family residential NZEB) to show how a careful and integrated design of the building envelope and systems not only allows to obtain an almost total coverage of the energy consumption by renewable sources, but also to generate an energy surplus that could be shared with urban grids (PEB potential)

    A Portuguese study on building renovation towards a nearly zero energy building (nZEB)

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    The social and environmental urgency of large-scale integrated retrofitting of the European residential building stock is widely acknowledged and supported by all Member States. However, the European building sector is currently still not able to offer an integral solution for deep renovation toward nearly Zero Energy Building (nZEB) for reasonable costs. MORE-CONNECT project aims to tackle this issue by developing cost optimal solutions to renovate buildings towards nZEB. In this project, the optimal solutions include the development of prefabricated, multifunctional renovation elements for the total building envelope (façade and roof) and installation/building services. This paper presents the first stage of the project, namely the analysis and comparison of three scenarios following the current national requirements in Portugal i) 80% reduction of the current primary energy consumption of the building, ii) cost optimal solution (nZEB) and iii) net zero energy (NZEB). The optimization of the building envelope will be the main driver for the three scenarios as well as the inclusion of renewable energy strategies. Overall, results suggest that it is possible to achieve cost-effective solutions for the renovation of Portuguese residential buildings. Moreover, the cost-optimal solution (scenario ii) matches approximately with the 80% reduction of energy scenario (scenario i).MORE-CONNECT is funded by the European Commission within the framework of the Horizon 2020 progra

    Refurbishment of the residential building stock toward the nearly-zero energy target through the application of the building typology

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    Directive 2010/31/EU requires since 2019 the new public buildings and since 2021 all the new buildings to be nearly zero-energy (nZEB). In Italy, as in many geographical contexts, the existing buildings represent the majority of the building stock and equally the largest and most cost-effective energy saving potential. This study presents the energy performance calculations carried out by means of quasi-steady state method for some Italian reference buildings refurbished into nZEB. The results are presented in terms of “packages of measures” and potential energy reductions. The differences among measures depending on building type and climatic conditions are discussed
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