Measuring the hygroscopic properties of porous media in transient regime. From the material level to the whole building HAM simulation of a coated room.

Moisture level inside buildings is a key factor influencing the durability of construction, indoor air quality, thermal comfort and energy performance. Numerical simulation can be used to predict the hygric inertia of a room, but reliable material data are needed as inputs for the model. Although the advancement of numerical models for whole building HAM (Heat Air and Moisture) transfer, a general need for more experimental data able to quantify the hygroscopic performance of porous building material remains. Recent benchmark data for validating 1-D HAM simulation models proposed in international projects are based on numerical and analytical data, while well-documented and accurate data are scarce. In IEA Annex 41 new numerical models have been implemented and used to simulate the HAM interaction between indoor air and hygroscopic materials during transient changes in indoor humidity due to internal moisture gains. Some experimental data obtained in dynamic humidity regime are presented in this study. The goal is to validate models that represent the moisture buffering of hygroscopic materials in contact with indoor air. In order to fit the experimental data with numerical simulation and to determine the most influencing hygroscopic material properties in HAM modeling, a sensitivity analysis on the numerical fitting of measured properties relevant for indoor moisture buffering, such as the water vapour permeability and the sorption isotherm was carried out. Material data have been monitored using a climate chamber device especially designed for this purpose. In Italian buildings, especially dwellings, walls are very often plastered with gypsum plaster for levelling purposes. The gypsum plaster is generally covered with waterborne wall paint for decoration which represents a barrier for the water absorption or desorption. In order to assess the hygric performance of a room in real conditions, the influence of the water transfer properties of the painted gypsum on the whole building HAM dynamic simulation is assessed considering both an uncoated and a coated room using a waterborne paint

The influence of coatings on the environmental hygric inertia of plastered rooms

In Italian buildings, especially dwellings, walls are very often plastered with gypsum plaster for levelling purposes. The gypsum plaster is generally covered with waterborne wall paint for decoration which represents a barrier for the water absorption or desorption. To know the hygric performance of a room in such real conditions, the water transfer properties of the Painted gypsum must be known. Wall paints can be roughly divided into waterborne and solvent borne paints. Waterborne wall paints are increasingly being used for their low odour and fast environmental friendly drying. The newer waterborne paints are based on aqueous dispersions of synthetic vinyl-type binders, such as polyvinylacetate or polyvinylpropionate (co-)polymers, and acrylic polymers. Moreover, paints containing volatile organic components have recently been prohibited by the European Commission for professional indoor use. The pressure to reduce volatile organic components and the industrial trend towards friendlier products with low toxicity of the product formulation led to the current expansion of waterborne types of coating. In building physics literature, knowledge is lacking about the moisture transfer properties of waterborne wall paints. Also the behavior of painted substrates has not been examined sufficiently. The role of the paint constituents in the moisture transfer properties is unclear. This lack of knowledge is partly caused by the lack of simple measuring techniques. Also the moisture behavior of the gypsum plays an important role in controlling the relative humidity, as the experimental activity in the paper for measuring its hygroscopic properties (Moisture Buffer Value) highlights. Painting gypsum is not done to prevent deterioration of the substrate as usually done for wood; gypsum is mainly painted for decorative reasons: this can also be a means to control the moisture transfer properties of the gypsum. Anyway, aim of the present study is not the numerical modelling or measuring of waterborne paints, but their influence once applied to the gypsum substrate, of which the hygroscopic properties where calculated when coated and uncoated. The numerical simulation using an whole building HAM-transfer model is then used to simulate the hygroscopic performance of a room in different condition

CFD vs. lumped model applied to HAM: a comparison between HAM-Tools and Comsol.

CFD models have several advantages in comparison with zonal-models, due to the more accurate calculation of the airflow distribution within the built environment. Nevertheless, in currently available CFD software the simulation of mass transfer cannot be directly extended from the fluid region to the solid region. In the whole building moisture transport studies, the mass coupling between the indoor environment and the wall system is usually achieved by third party programming. The Annex 41 research project of the International Energy Agency (IEA) was carried out to explore the complex physics governing the whole building heat, air and moisture (HAM) transfer, by developing several models to couple 3-D CFD simulations with hygrothermal models of walls. The objective of this study is to develop a coupled CFD model able to simulate the HAM transport in a single environment (i.e. a simple test room), influenced by the room factors. A numerical method was utilized to model the indoor environment and the moisture transport process in the simple room and inside the wall system as influenced by the moisture loads and ventilation conditions. The comparison between the CFD and a lumped model allows us to demonstrate how a simplified model can be reliable in predicting the RH variation inside a room, also taking into account the indoor material buffering effect

District Information Modeling and Energy Management

In recent years the European Commission enhanced strategies to promote ICTs for energy efficiency in buildings and cities. Within the Smart City context, energy-related information coming from different data-sources, either hardware or software needs to be integrated into a common smart digital archive for the city. We propose DIMMER, a distributed software infrastructure for district information modelling and energy management. It correlates energy-related information from different data-sources with user behaviour patterns and feedbacks. Hence, different actors playing in this scenario can access relevant information for providing new services and developing more efficient policies to enhance energy optimization in cities. This will provide support for strategic planning of the city and will foster the competition in the marketplace

AUGMENTED REALITY AND GAMIFICATION APPROACH WITHIN THE DIMMER PROJECT

Innovative learning methods as well as research projects dissemination can be achieved by digital technology. AR (Augmented Reality) can play a key role in the education field in order to transmit knowledge to young generations. AR is used to develop a playing cards game for children based on energy saving topics within the DIMMER (District Information Modelling and Management for Energy Reduction) European Project, where energy consumption awareness is one of its main aims. The DIMMER system enables the integration of BIM (Building Information Modelling), distribution network models, real-time data from sensors and user feedback through QR Codes and web portals. The energy performance of buildings is analysed from their actual utilization and especially from users’ feedback. Despite pervasive sensors implementation is a necessary tool to monitor buildings, the more effective way to reach real energy saving is to pursue user awareness and promote good practices in energy using. In fact, energy information sharing has been intended as the main focus in the DIMMER game, since children can adopt good habits that will be reflected on adults behaviour. The game conception has been reached by the collaboration between Politecnico di Torino and Primo Liceo Artistico Statale, as well as the staging of a theatrical show about these issues. In this way a connection between University and High School has been established about current research topics and the uses of new technologies for pedagogical purposes. AR is investigated in order to promote an interactive game for children in which the differences between good and bad practices in terms of sustainability and energy efficiency are discussed. It indeed turns out to be an effective means of communication with immediate impact on children learning. Cards are characterized by markers which are linked to 3D models through a specific software that enables their visualization on personal devices in AR. In the game, natural elements that are capable to generate energy (sun, fire, earth, water and wind) define the seed of every card. Attractive and colourful figures are used to represent renewable energy sources and their applications, while dark images represent the most polluting solutions. The DIMMER game purpose is not to pick up the higher number of cards, but saving energy through positive figures, avoiding those that involve pollution generation. This kind of approach establishes an interaction between children and the energy problem by encouraging active learning through the game and raising their awareness. Children are stimulated by AR multimedia elements that make learning more interesting and entertaining

The energy efficiency management at urban scale by means of integrated modelling

Innovative technologies such as ICTs are recognized as being a key player against climate change and the use of sensors and actuators can efficiently control the whole energy chain in the Smart Thermal Grids at district level. On the other side, advances on 3D modelling, visualization and interaction technologies enable user profiling and represent part of the holistic approach which aims at integrating renewable energy solutions in the existing building stock. To unlock the potentiality of these technologies, the case study selected for this research focuses on interoperability between Building Information Models (BIM), GIS (Geographic Information System) models and Energy Analysis Models (EAM) for designing Renewable Energy Strategies (RES) among the demonstrator. The objectives aims at making a whole series of data concerning the energy efficiency and reduction at district level usable for various stakeholders, by creating a District Information Model (DIM). The described system also integrates BIM and district level 3D models with real-time data from sensors to analyse and correlate buildings utilization and provide real-time energy-related behaviours. An important role is played by the energy simulation through the EAM for matching measured and simulated data and to assess the energy performance of buildings starting from a BIM model or shared data. With this purpose interoperability tests are carried out between the BIM models and quasi-steady energy analysis tools in order to optimize the calculation of the energy demand according to the Italian technical specification UNI TS 11300. Information about the roofs slope and their orientation from the GIS model are used to predict the use of renewable energy – solar thermal and PV – within the selected buildings (both public and private) of the demonstrator in Turin, Italy. The expected results are a consistent reduction in both energy consume and CO2 emissions by enabling a more efficient energy distribution policies, according to the real characteristics of district buildings as well as a more efficient utilization and maintenance of the energy distribution network, based on social behaviour and users attitudes and demand. In the future the project will allow open access with personal devices and A/R visualization of energy-related information to client applications for energy and cost-analysis, tariff planning and evaluation, failure identification and maintenance, energy information sharing in order to increase the user’s awareness in the field of energy consumption

La centralità della Rappresentazione con il BIM

La transizione digitale del settore delle costruzioni è un’esigenza per tutte le figure professionali coinvolte durante l’intero ciclo di vita dell’edificio. In questo contesto il tema della rappresentazione rafforza la centralità del proprio ruolo in relazione ai diversi ambiti coinvolti, grazie all’interoperabilità dei dati. Il disegno è da sempre considerato la forma di sintesi e di comunicazione visiva che si occupa di condividere gli elementi utili alla conoscenza e/o alla realizzazione di oggetti complessi, grazie ai metodi della rappresentazione. Il Building Information Modelling (BIM) è la metodologia che consente ai diversi professionisti di fornire informazioni grafiche e alfanumeriche di diverso tipo in maniera integrata tra loro. In questo senso la modellazione parametrica, oltre che permettere la rappresentazione tridimensionale dell’elemento complesso, assolvendo al dovere del disegno, dà vita ad un ambiente capace di contenere tutte le informazioni di natura eterogenea derivanti dalle molteplici discipline interessate durante il processo di progettazione, costruzione, gestione e manutenzione di un’opera. L’ambiente BIM deve essere inteso non solo come strumento di rappresentazione e visualizzazione, ma piuttosto come una banca dati le cui informazioni possono essere condivise e utilizzate agevolmente in diversi ambiti seguendo un flusso metodologico interoperabile. Quanto affermato è stato approfondito e analizzato su diversi casi studio reali, con l’obiettivo di definire il migliore processo di interoperabilità in funzione delle finalità richieste al modello. Verrà descritta la metodologia messa a punto nel corso degli anni sulle attività svolte relativamente: 1) al BIM per il patrimonio architettonico con il progetto di ricerca Building Heritage Information Modelling and Management (BHIMM-PRIN) relativo alla modellazione di edifici storici, con un approfondimento del tema della gestione delle nuvole di punti; 2) al Facility Management (FM) applicato ai casi studio della Nuova Sede per Uffici di Reale Mutua e alla Torre per la Sede Unica della Regione Piemonte, per la realizzazione di modelli as-built strutturati per il collegamento ad un software di Computer Aided FM (CAFM) rispettivamente sulle attività di gestione dell’edificio e sulle attività di manutenzione impiantistica; 3) all’analisi energetica nell’ambito del Progetto di Digitalizzazione del Patrimonio Pubblico della Città di Torino e a livello distrettuale con il progetto District Information Modelling and Management for Energy Reduction (DIMMER-FP7); 4) all’InfraBIM per la sperimentazione della metodologia BIM per la progettazione, costruzione e manutenzione dell’ingegneria infrastrutturale. La metodologia adottata nei diversi lavori prevede sempre tre fasi successive: rilievo e ricerca documentale; modellazione digitale con interpretazione critica dei dati da inserire nel modello con il livello di dettaglio e di sviluppo (LoD) volta per volta più adatto; utilizzo dei dati del modello grazie all’interoperabilità e alla interrogazione del data base del modello stesso. Attraverso i vari casi studio si sono raggiunti risultati diversi in relazione alle specifiche finalità dei vari progetti: la modellazione architettonica/strutturale/impiantistica di oggetti complessi (edifici e infrastrutture), la gestione degli spazi, il risparmio energetico e le attività di gestione e manutenzione. Il processo BIM ad oggi non ha ancora raggiunto un grado di interoperabilità che permetta di condividere i dati senza perdita di informazioni determinando di fatto la necessità di replicazione/reinserimento del dato. In questo senso è chiaro quanto sia fondamentale l’attività di ricerca in questo ambito. L’interoperabilità è il valore aggiunto dell’innovazione tecnologica per l’industria delle costruzioni che valorizza la rappresentazione come strumento fondamentale nel processo edilizio per la condivisione dell’informazione tra i vari utenti coinvolti

Valutazione della capacità di accumulo igrico dei materiali superficiali interni attraverso la modellazione HAM

I materiali porosi utilizzati per le finiture interne dell’involucro edilizio influenzano il controllo del microclima interno, smorzando i picchi di umidità dovuti ai carichi endogeni temporanei. Se immersi in un ambiente in cui si verifica una variazione di UR sono in grado di adsorbire o rilasciare umidità sino al raggiungimento di uno stato di equilibrio igroscopico. Il cosiddetto effetto di accumulo d’umidità (moisture buffering effect), definito come la capacità delle finiture interne di moderare l’UR ambientale, migliora la prestazione dell’edificio a livello di comfort termoigrometrico, qualità dell’aria (IAQ), efficienza energetica e durabilità. Il livello di umidità dell’aria è condizionato dai carichi latenti endogeni, dal trasporto di massa attraverso la ventilazione e dallo scambio di vapor d’acqua con l’involucro edilizio. Nel presente caso studio viene ricercato l’effetto dell’applicazione di un materiale igroscopico come finitura interna, quale l’intonaco di gesso, sul microclima ambientale. Attraverso la modellazione HAM (heat, air and moisture transfer) per la simulazione numerica, viene valutata l’influenza della capacità di accumulo igrico del materiale sull’andamento dell’UR ambientale. La ricerca mira ad evidenziare la prestazione del gesso quale strato di accumulo d’umidità (moisture buffering layer) per il controllo del livello igrometrico dell’aria, che consiste nella capacità di smorzare i picchi di umidità causati da carichi endogeni temporanei. Per il caso studio è stata scelta una simple room, conformemente alla norma ISO 13791, e le condizioni al contorno sono state assunte quanto più realistiche possibile, considerando diversi profili di carico latente e tassi di ventilazione. Le condizioni climatiche esterne sono riferite alla località di Torino. L’involucro è composto da una struttura in calcestruzzo aerato con isolamento ad intercapedine di polistirene e finitura ad intonaco di gesso. Al fine di valutare quantitativamente il tasso di assorbimento ed accumulo di umidità del solo strato di intonaco (3 cm) è stato interposto un foglio di alluminio tra il gesso e l’isolante, arrestando la diffusione di vapor d’acqua tra ambiente interno ed esterno. Al fine di valutare l’influenza dei cosiddetti room factors (tassi di ventilazione e di carico latente) sulla variazione di contenuto igrico del materiale sono stati ipotizzati diversi scenari di simulazione, i quali vedono un profilo di produzione di vapor d’acqua in ambiente accoppiato ad una variazione del tasso di ventilazione

Impatto del moisture buffering sul clima interno di uffici ventilati meccanicamente

The aim of this work is to demonstrate the reliability of measured hygroscopic properties of materials in predicting the RH variation inside a room taking into account the material’s buffering effect. An analysis of reliability of the measured hygroscopic properties and their influence on numerical simulation is carried out. The influence of an important room factor as ventilation on the moisture buffer is taken into account for different scenarios