Innovative integrated solutions for the reduction of the energy demand and for the development of the renewable resources in residential buildings

One of the primary European Union’s “Europe 2020” energy strategies is the reduction of the total energy consumption by means of energy efficiency improvements. In the European Union (EU) the building sector is responsible of about the 40% of the total final energy consumption and of the 36% of the Europe global CO2 emissions. During the last decade the European Commission released the first legislative instrument aimed to improve the energy performance of buildings: the “Energy Performance of Building Directive (EPBD) was introduced in 2002 and updated in 2010. The first edition of the document focused the analysis on new buildings, in order to promote the diffusion of energy efficient buildings, characterized by very low energy demand, possibly almost zero energy buildings. The recast of the document introduces the important topic of the existing building stock. It presents and discusses the recommendations that the European Commission released so far and focused on the possibilities of increasing the energy efficiency of buildings according to feasible retrofit strategies. The renovation of the existing building stock and the improvement of the energy performance are expected to have a key role in the increasing of European energy efficiency as well, considering that the 75% of the future stock has already been built. This thesis aims to investigate the possibilities of energy saving existing in the residential building sector. Some case studies will be presented with integrated HVAC systems based on different sources (multi-energy systems) combined to operate in the most suitable conditions to achieve higher efficiency performance as a whole. This type of system will be referred as IMES (Integrated Multi-Energy Systems). IMES performance will be evaluated according to new and retrofitted buildings, in order to investigate different plant configurations performances and to determine the extension of their applicability domain. The first chapter provides an overview of the European building stock, in order to comprehend the magnitude of the issue. The composition and the age of the existent buildings are analyzed as well as the actual energy consumption according to the final uses. Based on the described situation, the requirements introduced by the EPBD are analyzed according to new and existent buildings. The second chapter presents an analysis carried out to assess the effectiveness, in terms of reduction of primary energy demand, of the retrofit of the building envelope and of the HVAC system in a single dwelling house. The analysis has been realized by the means of dynamic simulations carried out by means of the commercial transient code TRNSYS. A model of the building and of the thermal system has been implemented according to the situation before the retrofit, and several redevelopment actions have been evaluated in order to achieve the maximum energy saving. The third chapter presents an activity which aimed to esteem the performance analysis of an IMES conceived to serve a multi-residential building. The main purposes are: to identify the configuration of the system that maximize the contribution of the renewable energy resources, i.e. solar energy and the renewable share due to the use of an heat pump; to set the mathematical model of the thermal storage by the means of experimental measurements, in order to better replicate the behaviors of real storages; to investigate the possibility of extending the applicability domain of the IMES to traditional buildings, equipped with non-insulated envelopes and radiators as emissions devices. The fourth chapter presents an analysis on the energy saving possibilities according to the retrofit of the European building stock. The work has considered the composition of the dwellings around Europe, identifying a general classification of the existent buildings. The analysis has been conducted on the basis of four case studies which have been subjected to an energy performance analysis, according to the status before and after a major renovation of the building envelope and of the HVAC system. The energy performance has been evaluated by means of dynamic simulations carried out with the commercial software TRNSYS. The work aims to evaluate the possible energy savings due to the renovation of the buildings into low energy buildings; to achieve this goal 20 simulation have been carried out on the buildings models, and 80 simulations have been necessary to conclude the analysis on the performance of the HVAC system. Four cities have been considered in the study to assess the effects of the redevelopment in different European climate conditions: Budapest, Venice, Athens and Helsink

Hypothesis for a more efficient and sustainable development of a district heating in Padova, integrating renewable energies and existing generation plant

The present paper shows the background analysis to develop the optimization strategy of a neighborhood heating network sited in Padua, including it in a wider project of district renovation. The case study accounts several different end users: scholastic and offices buildings, a social housing residence and residential buildings. The analysis starts from a systematic assessment of the buildings, evaluating the need of refurbishment of the envelope and of the distribution system. Further analysis focuses on the optimization of the existing heat generation system, integrating three condensing boilers, with an air to water heat pump and a ground source heat pump, which work more efficiently during base-load periods. The management of the district heating network have been investigated using the dynamic simulation tool TRNSYS, the control strategy of the delivery temperature has been tested based on the outside temperature and verifying to satisfy comfort conditions inside the buildings. A sustainable solution is the recovery and drainage of rainwater, that can be reused for the toilets' flushing. Therefore, the project solution identified aims at a more rational use of energy sources, which is the simplest and cheapest way to proceed on the decarbonization path that is a mid-term target for the Padua administration

A European Database of Building Energy Profiles to Support the Design of Ground Source Heat Pumps

[EN] The design of ground source heat pumps is a fundamental step to ensure the high energy efficiency of heat pump systems throughout their operating years. To enhance the diffusion of ground source heat pump systems, two different tools are developed in the H2020 research project named, Cheap GSHPs: A design tool and a decision support system. In both cases, the energy demand of the buildings may not be calculated by the user. The main input data, to evaluate the size of the borehole heat exchangers, is the building energy demand. This paper presents a methodology to correlate energy demand, building typologies, and climatic conditions for different types of residential buildings. Rather than envelope properties, three insulation levels have been considered in different climatic conditions to set up a database of energy profiles. Analyzing European climatic test reference years, 23 locations have been considered. For each location, the overall energy and the mean hourly monthly energy profiles for heating and cooling have been calculated. Pre-calculated profiles are needed to size generation systems and, in particular, ground source heat pumps. For this reason, correlations based on the degree days for heating and cooling demand have been found in order to generalize the results for different buildings. These correlations depend on the Koppen-Geiger climate scale.This work received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 657982.Carnieletto, L.; Badenes Badenes, B.; Belliardi, M.; Bernardi, A.; Graci, S.; Emmi, G.; Urchueguía Schölzel, JF.... (2019). A European Database of Building Energy Profiles to Support the Design of Ground Source Heat Pumps. Energies. 12(13):1-23. https://doi.org/10.3390/en12132496S1231213De Carli, M., Tonon, M., Zarrella, A., & Zecchin, R. (2010). A computational capacity resistance model (CaRM) for vertical ground-coupled heat exchangers. Renewable Energy, 35(7), 1537-1550. doi:10.1016/j.renene.2009.11.034Grossi, I., Dongellini, M., Piazzi, A., & Morini, G. L. (2018). Dynamic modelling and energy performance analysis of an innovative dual-source heat pump system. Applied Thermal Engineering, 142, 745-759. doi:10.1016/j.applthermaleng.2018.07.022Engineering Reference Manual. In EnergyPlus V8.5https://energyplus.net/Sandberg, N. H., Bergsdal, H., & Brattebø, H. (2011). Historical energy analysis of the Norwegian dwelling stock. Building Research & Information, 39(1), 1-15. doi:10.1080/09613218.2010.528186Application of Energy Performance Indicators for Residential Building Stocks Experiences of the EPISCOPE Projecthttp://episcope.eu/fileadmin/episcope/public/docs/reports/EPISCOPE_Indicators_ConceptAndExperiences.pdfGustafsson, M., Dipasquale, C., Poppi, S., Bellini, A., Fedrizzi, R., Bales, C., … Holmberg, S. (2017). Economic and environmental analysis of energy renovation packages for European office buildings. Energy and Buildings, 148, 155-165. doi:10.1016/j.enbuild.2017.04.079De Carli, M., Bernardi, A., Cultrera, M., Dalla Santa, G., Di Bella, A., Emmi, G., … Zarrella, A. (2018). A Database for Climatic Conditions around Europe for Promoting GSHP Solutions. Geosciences, 8(2), 71. doi:10.3390/geosciences8020071Cartalis, C., Synodinou, A., Proedrou, M., Tsangrassoulis, A., & Santamouris, M. (2001). Modifications in energy demand in urban areas as a result of climate changes: an assessment for the southeast Mediterranean region. Energy Conversion and Management, 42(14), 1647-1656. doi:10.1016/s0196-8904(00)00156-4Kottek, M., Grieser, J., Beck, C., Rudolf, B., & Rubel, F. (2006). World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift, 15(3), 259-263. doi:10.1127/0941-2948/2006/0130Herrera, M., Natarajan, S., Coley, D. A., Kershaw, T., Ramallo-González, A. P., Eames, M., … Wood, M. (2017). A review of current and future weather data for building simulation. Building Services Engineering Research and Technology, 38(5), 602-627. doi:10.1177/0143624417705937Peel, M. C., Finlayson, B. L., & McMahon, T. A. (2007). Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences, 11(5), 1633-1644. doi:10.5194/hess-11-1633-2007D’Amico, A., Ciulla, G., Panno, D., & Ferrari, S. (2019). Building energy demand assessment through heating degree days: The importance of a climatic dataset. Applied Energy, 242, 1285-1306. doi:10.1016/j.apenergy.2019.03.167Al-Hadhrami, L. M. (2013). Comprehensive review of cooling and heating degree days characteristics over Kingdom of Saudi Arabia. Renewable and Sustainable Energy Reviews, 27, 305-314. doi:10.1016/j.rser.2013.04.034Degree Days.net-Custom Degree Day Datahttp://www.degreedays.netAnnunziata, E., Frey, M., & Rizzi, F. (2013). Towards nearly zero-energy buildings: The state-of-art of national regulations in Europe. Energy, 57, 125-133. doi:10.1016/j.energy.2012.11.049Principle for Nearly Zero-Energy Buildings, Ecofys Germany GmbHhttp://bpie.eu/documents/BPIE/publications/LR_nZEB%20study.pdfAhern, C., Griffiths, P., & O’Flaherty, M. (2013). State of the Irish housing stock—Modelling the heat losses of Ireland’s existing detached rural housing stock & estimating the benefit of thermal retrofit measures on this stock. Energy Policy, 55, 139-151. doi:10.1016/j.enpol.2012.11.039Kaklauskas, A., Zavadskas, E. K., Raslanas, S., Ginevicius, R., Komka, A., & Malinauskas, P. (2006). Selection of low-e windows in retrofit of public buildings by applying multiple criteria method COPRAS: A Lithuanian case. Energy and Buildings, 38(5), 454-462. doi:10.1016/j.enbuild.2005.08.005Zavadskas, E., Raslanas, S., & Kaklauskas, A. (2008). The selection of effective retrofit scenarios for panel houses in urban neighborhoods based on expected energy savings and increase in market value: The Vilnius case. Energy and Buildings, 40(4), 573-587. doi:10.1016/j.enbuild.2007.04.015Aerts, D., Minnen, J., Glorieux, I., Wouters, I., & Descamps, F. (2014). A method for the identification and modelling of realistic domestic occupancy sequences for building energy demand simulations and peer comparison. Building and Environment, 75, 67-78. doi:10.1016/j.buildenv.2014.01.021Yang, Z., & Becerik-Gerber, B. (2014). The coupled effects of personalized occupancy profile based HVAC schedules and room reassignment on building energy use. Energy and Buildings, 78, 113-122. doi:10.1016/j.enbuild.2014.04.002Richardson, I., Thomson, M., & Infield, D. (2008). A high-resolution domestic building occupancy model for energy demand simulations. Energy and Buildings, 40(8), 1560-1566. doi:10.1016/j.enbuild.2008.02.006Villi, G., Peretti, C., Graci, S., & De Carli, M. (2013). Building leakage analysis and infiltration modelling for an Italian multi-family building. Journal of Building Performance Simulation, 6(2), 98-118. doi:10.1080/19401493.2012.69998

two software tools for facilitating the choice of ground source heat pumps by stakeholders and designers

For promoting the diffusion of GSHP and making the technology more accessible to the general public, in the H2020 research project "CHeap and Efficient APplication of reliable Ground Source Heat exchangers and PumpS" (acronym Cheap-GSHPs) a tool for sizing these systems has been developed, as well as a Decision Support System (DSS) able to assist the user in the preliminary design of the most suitable configuration. For all these tools a common platform has been carried out considering climatic conditions, energy demand of buildings, ground thermal properties, heat pump solutions repository, as well as renewable energy database to use in synergy with the GSHPs. Since the aims of the tools are different, there are different approaches. The design tool is mainly addressed to designers. The calculation may be done in two ways: with a simplified method based on the ASHRAE approach and with a detailed calculation based on the numerical tool CaRM (Capacity-Resistance method). The DSS final aim is to support decision-making, by providing the stakeholders at all the level with a series of scenario. The Cheap-GSHPs project has developed a DSS tool aimed at accelerating the decision-making process of designers and building owners as well as increasing market share of the Cheap-GSHPs technologies. Hence the DSS generates different possible solutions based on a defined general problem, identifying the optimal solution. Both tools are presented in the paper, showing the potentialities provided by both software

Innovative integrated solutions for the reduction of the energy demand and for the development of the renewable resources in residential buildings

One of the primary European Union’s “Europe 2020” energy strategies is the reduction of the total energy consumption by means of energy efficiency improvements. In the European Union (EU) the building sector is responsible of about the 40% of the total final energy consumption and of the 36% of the Europe global CO2 emissions. During the last decade the European Commission released the first legislative instrument aimed to improve the energy performance of buildings: the “Energy Performance of Building Directive (EPBD) was introduced in 2002 and updated in 2010. The first edition of the document focused the analysis on new buildings, in order to promote the diffusion of energy efficient buildings, characterized by very low energy demand, possibly almost zero energy buildings. The recast of the document introduces the important topic of the existing building stock. It presents and discusses the recommendations that the European Commission released so far and focused on the possibilities of increasing the energy efficiency of buildings according to feasible retrofit strategies. The renovation of the existing building stock and the improvement of the energy performance are expected to have a key role in the increasing of European energy efficiency as well, considering that the 75% of the future stock has already been built. This thesis aims to investigate the possibilities of energy saving existing in the residential building sector. Some case studies will be presented with integrated HVAC systems based on different sources (multi-energy systems) combined to operate in the most suitable conditions to achieve higher efficiency performance as a whole. This type of system will be referred as IMES (Integrated Multi-Energy Systems). IMES performance will be evaluated according to new and retrofitted buildings, in order to investigate different plant configurations performances and to determine the extension of their applicability domain. The first chapter provides an overview of the European building stock, in order to comprehend the magnitude of the issue. The composition and the age of the existent buildings are analyzed as well as the actual energy consumption according to the final uses. Based on the described situation, the requirements introduced by the EPBD are analyzed according to new and existent buildings. The second chapter presents an analysis carried out to assess the effectiveness, in terms of reduction of primary energy demand, of the retrofit of the building envelope and of the HVAC system in a single dwelling house. The analysis has been realized by the means of dynamic simulations carried out by means of the commercial transient code TRNSYS. A model of the building and of the thermal system has been implemented according to the situation before the retrofit, and several redevelopment actions have been evaluated in order to achieve the maximum energy saving. The third chapter presents an activity which aimed to esteem the performance analysis of an IMES conceived to serve a multi-residential building. The main purposes are: to identify the configuration of the system that maximize the contribution of the renewable energy resources, i.e. solar energy and the renewable share due to the use of an heat pump; to set the mathematical model of the thermal storage by the means of experimental measurements, in order to better replicate the behaviors of real storages; to investigate the possibility of extending the applicability domain of the IMES to traditional buildings, equipped with non-insulated envelopes and radiators as emissions devices. The fourth chapter presents an analysis on the energy saving possibilities according to the retrofit of the European building stock. The work has considered the composition of the dwellings around Europe, identifying a general classification of the existent buildings. The analysis has been conducted on the basis of four case studies which have been subjected to an energy performance analysis, according to the status before and after a major renovation of the building envelope and of the HVAC system. The energy performance has been evaluated by means of dynamic simulations carried out with the commercial software TRNSYS. The work aims to evaluate the possible energy savings due to the renovation of the buildings into low energy buildings; to achieve this goal 20 simulation have been carried out on the buildings models, and 80 simulations have been necessary to conclude the analysis on the performance of the HVAC system. Four cities have been considered in the study to assess the effects of the redevelopment in different European climate conditions: Budapest, Venice, Athens and HelsinkiUno dei principali obiettivi del programma energetico europeo "Europe 2020" é la riduzione dei consumi finali di energia per mezzo di interventi mirati ad incrementale l'efficienza energetica. Nell'Unione Europea (EU) il settore edilizio é responsabile di circa il 40% dei consumi finali di energia e del 36% delle emissioni di CO2. Nel corso dell'ultimo decennio la Commissione Europea ha emanato il primo strumento legislativo mirato ad incrementale l'efficienza energetica del settore edilizio: la "Direttiva sull'Efficienza Energetica negli Edifici" (EPDB) é stata introdotta nel 2002 e successivamente aggiornata nel 2010. La prima edizione del documento focalizzava l'attenzione sugli edifici di nuova costruzione, con l'obiettivo di promuovere la diffusione di edifici energeticamente efficienti; la revisione introduce l'importante tema del parco edilizio esistente, mettendo in luce le possibilità connesse all'incremento dell'efficienza energetica degli edifici esistenti, per mezzo di strategie di retrofit mirate. Il rinnovamento del parco edilizio esistente e l'incremento delle prestazioni energetiche ricopriranno un ruolo determinante a livello europeo verso l'incremento complessivo dell'efficienza energetica. La presente tesi si propone di investigare quali possibilità di risparmio energetico risiedono nel settore residenziale. Sono presentati alcuni casi studio in cui i sistemi di climatizzazione HVAC sono stati analizzati per verificarne le capacità di soddisfare i fabbisogni energetici attraverso l'impiego di differenti sistemi di generazione (sistemi multi energia) combinati per operare ciascuno nelle condizioni di lavoro più favorevoli (sistemi integrati). La tipologia di impianti descritta viene definita IMES dall'acronimo inglese di sistemi integrati multi - energia. . Le prestazioni dei sistemi IMES sono state analizzate in relazione all'installazione presso edifici di nuova costruzione ed edifici ristrutturati, in modo da valutare le prestazioni di diverse configurazioni impiantistiche e di determinare il campo di applicabilità di tali sistemi Il primo capitolo fornisce una panoramica dello stato e della composizione del parco edilizio Europeo, al fine di comprendere l'entità del tema trattato. Sono presentati, inoltre, i dati riguardanti i consumi energetici relativi al settore edilizio che sono stati analizzati e discussi in relazione alle disposizioni introdotte dalla CE tramite l'EPBD e al suo aggiornamento. Il secondo capitolo presenta un'analisi condotta per verificare l'efficacia in termini di risparmio di energia primaria di un sistema IMES abbinato a un'abitazione monofamiliare. L'analisi si é servita di simulazioni dinamiche operate con il software commerciale TRNSYS, per mezzo delle quali sono stati creati un modello dell'involucro edilizio e un modello dell'impianto che sono stati quindi integrati per valutare le prestazioni energetiche complessive. Sono state valutate le condizioni pre e post rinnovamento dell'edificio e sono state, inoltre, considerate diverse configurazioni impiantistiche in modo da determinare quella capace di generare il massimo risparmio in termini di energia primaria. Il terzo capitolo riguarda l'analisi delle prestazioni dei sistemi IMES applicati ad un complesso residenziale di trenta unità abitative. Lo scopo principale é quello di valutare le prestazioni del sistema e di massimizzare il contributo di energia delle fonti rinnovabili, ovvero del sistema solare termico integrato e della quota di energia rinnovabile associabile al funzionamento dei sistemi dotati di pompa di calore. Si e' voluto inoltre migliorare la compatibilità' tra i sistema reale e la simulazione dinamica mediante una serie di test di laboratorio e di successive calibrazioni del modello matematico degli accumuli termici. Infine l'analisi e' stata estesa ad applicazioni del sistema IMES in edifici non ristrutturati, caratterizzati da involucri dalle basse performance energetiche e equipaggiati con sistemi di emissione del calore ad alta temperatura, quali i tradizionali radiatori. Il quarto capitolo estende l'analisi dei sistemi integrati in una valutazione ad ampio spettro compiuta sulla possibilità di risparmio energetico connesse al rinnovamento del parco residenziale Europeo. L'analisi ha valutato la composizione e la distribuzione delle tipologie edilizie sul territorio europeo, individuando quattro casi studio, edifici tipo, sui quali compiere le successive valutazioni. Le prestazioni energetiche dei casi studio sono state valutate in relazione al loro stato precedente e successivo ad una completa ristrutturazione dell'involucro edilizio e degli impianti tecnici. L'analisi é stata nuovamente operata per mezzo di una serie di simulazioni dinamiche in ambiente TRNSYS, mirate a valutare il possibile risparmio energetico legato alla riqualificazione dei casi studio in edifici a basso consumo energetico (LEB, Low Energy building). Allo scopo di garantire allo studio una prospettiva di carattere europeo,l'analisi é stata ripetuta e rimodulata per diversi climi: sono stati individuati quattro siti, caratterizzati da condizioni climatiche molto diverse tra loro, rispettivamente Budapest, Venezia, Atene e Helsink

Renovation as a means to improve the enrgy efficiency in buildings. Initial phase resume of a detailed analysis on the renovation of the European residential building stock into LEB. Strategies, feasibility and energy saving potential.

The renovation of the existing building stock and the improvement of the energy performances are expected to have a key role in the increasing of European energy efficiency. With this work authors want to face the issue of the actual European building stock. The analysis will be conducted on the basis of four case studies: a single dwelling house, a linear terraced house, and two multifamily buildings, respectively with low and high housing density. The work aims to evaluate the possible energy savings due to the renovation of the buildings into low energy buildings. This paper presents the result of the first stage of the work

Simulazioni dinamiche per l\u2019ottimizzazione di un sistema integrato per il riscaldamento e la generazione di acqua calda sanitaria al servizio di un complesso residenziale multifamiliare

Il presente lavoro si propone di effettuare l\u2019analisi delle prestazioni energetiche di un sistema di climatizzazione integrato al servizio di un complesso multifamiliare, costituito da due palazzine accostate, per un totale di 30 abitazioni. L\u2019impianto \ue8 costituito da una caldaia a condensazione modulare (220kW) impiegata sia per il riscaldamento sia per la generazione di ACS, e da una pompa di calore aria-acqua (130kW) impiegata come integrazione per il riscaldamento. Al servizio sia del sistema di riscaldamento che della preparazione dell\u2019ACS \ue8 presente un sistema solare costituito da 18 collettori sottovuoto , esposti a sud ovest ed installati sul tetto con un inclinazione di 45\ub0C. Il sistema prevede, inoltre, tre accumuli termici: uno dei quali dedicato al riscaldamento e due, in parallelo, dedicati alla preparazione dell\u2019ACS. Lo scopo della presente analisi consiste nel determinare la migliore configurazione dell\u2019impianto e del sistema di regolazione al fine di massimizzare l\u2019impiego della fonte energetica solare, aumentare il coefficiente di carico della pompa di calore e di modulare il generatore a condensazione per realizzare le migliori prestazioni possibili ai carichi parziali. Infine, le prestazioni energetiche del sistema integrato descritto sono state confrontate con soluzioni impiantistiche differenti, basate sull\u2019impiego del solo generatore di calore a condensazione o della sola pompa di calore abbinati al sistema solare. Le analisi numeriche sono state condotte per mezzo del software commerciale TRNSYS

Dynamic Simulations for the Optimum Management of an Integrated System for Air Conditioning and DHW Generation in Multifamily Buildings

The paper describes the analysis made on an integrated system for heating and DHW generation, which serves thirty families, accommodated into two blocks of apartments. The system consisting of a gas modulating condensing boiler (220 kW) used for heating and DHW, and of a heat pump (130 kW) used as integration to the boiler. A thermal solar system with evacuated tube is also considered (thirty collectors, south-west orientation and 45\ub0 slope); the energy produced is used both for heating and for DHW generation. Three storage tanks are installed: one of them is designed to integrate the thermal sources for heating, the other two work in parallel for the DHW production. The plant described is complex and each circuit (boiler, heat pump, solar field) needs to be managed according to all the other systems in an integrated way. The aim of the analysis is to figure out the optimum design for the control and the regulation system, in order to maximize the exploitation of the solar energy, to increase the load factor of the heat pump and to manage the boiler operation for achieving the highest efficiency at partial loads. The buildings and the plant have been modeled in details, to ensure a good correspondence to the real case. Dynamic simulations have been run first to analyze the management of the solar system, and subsequently to evaluate the overall efficiency of the plant, as it has been managed with different set of controls and different priorities among devices. Numerical analyses have been carried out via the commercial code TRNSY

Ottimizzazione di sistemi per la generazione di acqua calda sanitaria. Confronto tra la normativa e la pratica progettuale

Il presente lavoro ha come obiettivo l\u2019ottimizzazione della progettazione di sistemi per la preparazione di acqua calda sanitaria (ACS) in ambito residenziale. Sulla base di quanto indicato dalle correnti normative nazionale ed Europea e delle soluzioni comunemente adottate nella pratica progettuale sono state confrontate le prestazioni di differenti tipologie d\u2019impianto. Sistemi ad accumulo (a miscela e a doppio serpentino) sono stati confrontati a sistemi per la generazione istantanea di ACS. Sono state valutate diverse taglie d\u2019impianto, partendo da sistemi al servizio di abitazioni monofamiliari e bifamiliari, fino a complessi residenziali plurifamiliari. In funzione del fabbisogno complessivo e del carico di punta \ue8 stata individuata la tipologia di impianto pi\uf9 indicata e ne \ue8 stato effettuato il dimensionamento secondo la norma, ovvero il calcolo del volume ottimale del serbatoio di accumulo e della potenza di progetto dell\u2019impianto. Per ogni soluzione \ue8 stata valutata la prestazione da un punto di vista energetico per mezzo del codice di analisi dinamica TRNSYS. Opportuni profili di carico per l\u2019ACS, assunti dalla pratica, dalla letteratura e adattati alle utenze considerate, sono stati applicati ai casi in esame per un periodo di prova tale da garantire il funzionamento a regime del sistema. Attraverso la simulazione dinamica sono state verificate per ogni tipologia di utenza le indicazioni per il dimensionamento degli impianti fornite dalla normativa. Il risultato in alcuni casi ha confermato le indicazioni della norma in altri ha evidenziato una tendenza al sottodimensionamento dell\u2019impianto. L\u2019analisi, infine, ha permesso di determinare la migliore soluzione tra quelle analizzate, sia nel soddisfare le richieste da parte dell\u2019utenza sia nel garantire le minori perdite di energia, rispettando i criteri di igiene e sicurezza che devono essere garantiti quando si lavora con accumuli e reti di ACS