Plenary Lecture
Heat and Moisture Transfer Mechanisms. Assessment of Hygrothermal Transfer Effects on Energy Performance of Building, Indoor Air Quality and Durability of Building Structure
Professor Rafik Belarbi
Head of Mechanical and Civil Engineering Department
LaSIE: Laboratory of Engineering Science of Environment, UMR 7356 CNRS
University of La Rochelle
France
E-mail: rafik.belarbi@univ-lr.fr
Abstract: The coupled heat and moisture transfer in porous building materials has been widely studied due to its presence in many fundamental and industrial applications. Indeed, buildings are one of the highest energy consumption sectors, contributing to almost 45% of the world energy consumption and responsible for 36.1 billion tons of CO2 emission. High moisture level can cause metal correction, wood decay and structure deterioration. Moreover, moisture transport results in condensation-evaporation processes which accompany energy transfer through building envelopes, and has a significant influence on indoor air humidity and air-conditioning loads, especially latent cooling load. Consequently, studying the coupled heat and moisture transport behavior of porous building materials is essential to improving their performances.
In the present work, a coupled heat, air and moisture transfer model is proposed. This model take into account simultaneously the diffusive, convective and conductive mechanisms on the building elements. Heat transfer is considered in the strongly coupled situation where the mass and heat flux are temperature, vapor pressure and total pressure dependents. The model input parameters are evaluated experimentally through the development of various experimental prototypes in the laboratory. Thereafter, an experimental setup has been established in order to evaluate the hygrothermal process of building walls. The experimental procedure consists to follow the temperature and relative humidity evolutions within the envelope thickness, submitted to controlled and fixed boundary conditions.
A new methodology to predict the overall behavior of buildings, which combines two simulation tools: COMSOL Multiphysics© and TRNSYS. The first software is used for the modeling of heat, air and moisture transfer in multilayer porous walls (HAM model - Heat, Air and Moisture transfer), and the second is used to simulate the hygrothermal behavior of the building (BES model - Building Energy Simulation). The combined software applications dynamically solve the mass and energy conservation equations of the two physical models. Simulation in case studies buildings highlight the effect on heat and moisture transfer on energy performance on building, indoor air quality and durability of building structure.
Brief Biography of the Speaker: Professor, Dr-Ing. Rafik BELARBI, Received his engineer degree in Building Physics from School of engineers of Poitiers (ESIP) and Master of thermal sciences from University of Poitiers, France in 1993. He obtained his PhD Thesis in civil engineering in La Rochelle University, 1998. In 1999, he joined the LEPTAB research staff laboratory and civil engineering department of La Rochelle University as Associate Professor. Actually, he is full Professor.
His Research field covers wide spectrum and several domains. It cover multi physic and multiscale approaches as: building material for energy and environment applications, urban microclimate modeling and durability aspect; comfort and indoor air quality as well as renewable and energy system. His main expertise is in microstructural, thermal, physical and hydric characterization of porous building material and heat and mass transfers with application in Energy Efficiency in Buildings and Indoor Environment and durability of constructions.
Since 1994, he was involved in several National and International projects dealing with Heat and moisture transfer in the building energy conservation. The main projects are: Pascool/Joule and Altener/Sink (passive cooling systems modelling and their impact on the building energy consumption), PDEC/Joule II (Utilisation of Passive Downdraught Evaporative Cooling systems on non-domestics buildings), Joule/Thermie B (Efficient Ventilation Systems for Buildings), Altener/Greencode (Reglementary Frame for Renewable Energy Use in Urban Site Through Vegetation Planting and Strategic Surfacing), Altener/SolVent, (Development of Strategies for Efficient Use of Solar Passive Ventilation in Urban Buildings) and Altener/Cluster (Solar Passive Heating and Cooling), Seventh Framework Programme" Marie Curie (OldMasonryRepair). He is author or co-author of more than 100 papers in international journals or international conferences. Since October 2007, he is the Head of the Civil Engineering Department.