Bayesian inference method for in situ thermal conductivity and heat capacity identification: Comparison to ISO standard

International audienc

Role of ventilation on the transmission of viruses in buildings, from a single zone to a multizone approach

\ₑprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/ina.13097In a virus pandemic context, buildings ventilation has been recognized as a solution for preventing transmission of the virus in aerosolized form. The impact of the widespread recommendation of window opening and sealing door on ventilation circuits needs to be considered with a multizone approach. We modeled the airflow distribution in a building where people are isolating in a pandemic context, including one infected person. We analyzed the impact of opening the window and sealing the door in the quarantine room on exposures and probability of infection for occupants of the flat and of adjacent flats. In order to study the sensitivity of the results, we tested three ventilation systems: balanced, exhaust-only, and humidity-based demand-controlled, and several window- and door-opening strategies. When the door of the quarantine room is sealed, we observe that opening the window in the quarantine room always results in increased exposure and probability of infection for at least one other occupant, including in neighbors' apartments. When all internal doors are opened, we observe moderate impacts, with rather an increase of exposure of the occupants of the same apartments and of their probability of infection, and a decrease for the occupants located in other apartments. Based on the analysis on the airflows distribution in this case study, we conclude that sealing the internal door has more influence than opening the window of the quarantine room, whatever the ventilation system. We observe that this widespread recommendation to open the window of a quarantine room and to seal the door is based on the consideration of a single zone model. We illustrate the importance of moving from such a single zone approach to a multizone approach for quantifying ventilation and airing impacts in multizone buildings as residences in order to prevent epidemics of viruses such as SARS-CoV-2. It highlights the need of air leakage databases

Méthode d'analyse du comportement thermo-aéraulique des bâtiments pour la construction de modèles zonaux adaptatifs

Afin de concevoir des systèmes énergétiques (chauffage, rafraîchissement, ventilation) et de prédire leurs performances en terme de confort thermique et de qualité de l'air, l estimation des détails des écoulements et des transferts de chaleur au sein des locaux représente un enjeu important. Les modèles zonaux, qui reposent sur un découpage d une pièce en un petit nombre de sous-volumes permettent d'appréhender l'hétérogénéité des caractéristiques thermo-aérauliques d'un espace avec des temps de calcul modérés. Ils correspondent à un bon compromis entre simplicité des modèles et volumes d'informations utilisables pour contribuer à la qualification des ambiances. Si de nombreux progrès ont été réalisés pour l'automatisation de la construction des modèles zonaux à partir d'un maillage du volume et du choix des modèles à utiliser, ces deux tâches restent encore à la charge de l'utilisateur alors qu'elles requièrent une bonne connaissance de la modélisation et de l expérimentation dans le bâtiment. Il reste un travail important à faire pour minimiser l intervention du modélisateur. Notre recherche consiste à proposer un générateur automatique de modèles zonaux permettant essentiellement d affranchir l utilisateur du choix des modèles des écoulements spécifiques présents dans un local et du partitionnement de ce dernier. L outil de simulation dynamique baptisé O-Zone , est basé sur une nouvelle approche des modèles zonaux. Cette approche repose sur un partitionnement de la pièce adapté aux écoulements particuliers en présence. La méthode choisie pour le partitionnement est celle des arbres octaux ou Octree. C'est une représentation hiérarchique de l'espace qui repose sur la subdivision successive et récursive d'un cube en huit cubes plus petits.In order to design HVAC systems and to predict their performances in term of thermal comfort and indoor air quality, the estimation of airflows details and heat transfers within the buildings zones represents an important stake. Zonal models are based on dividing the considered room into a small number of sub-zones. They can appreciate the heterogeneity of the thermal and aerodynamic characteristics of an air space with moderate computing times. These models represent a good compromise between simplicity of models and quantity of data useful in order to contribute to the qualification of environments. If much progress is made to automate the zonal models construction from an air space partitioning and a choice of the models to be used, these two tasks are still spring of the user whereas they require an important modelling expertise and experimentation in the building. There remains an important work to make in order to minimize the user s intervention. In this research, we propose an automatic generator of zonal models that make it possible to free the user from the choice of the specific flows models present in a room and her partitioning. The dynamic simulation tool called O-Zone is based on an advanced formulation of zonal models. It uses on a new way of sub-dividing the room which allows us to obtain a partitioning based on airflow patterns. The selected method for partitioning is the Octree method. It is a hierarchical representation of the space which is based on the successive and recursive subdivision of a cube in eight smaller cubes.NANTES-BU Sciences (441092104) / SudocNANTES-Ecole Centrale (441092306) / SudocNANTES-BU Technologie (441092105) / SudocSudocFranceF

Creation and application of future typical weather files in the evaluation of indoor overheating in free-floating buildings

International audienc

Thermal behaviour of a building in its environment: Modelling, experimentation, and comparison

International audienc

Proper Generalised Decomposition for heat and moisture multizone modelling

International audienc

Bayesian inference for estimating thermal properties of a historic building wall

International audienc

2D whole-building hygrothermal simulation analysis based on a PGD reduced order model

International audienc

Experimental assessment of thermal inertia in insulated and non-insulated old limestone buildings

International audienc