Dynamic Analysis of Moisture Transport Through Walls and Associated Cooling Loads in the Hot/Humid Climate of Florianopolis, Brazil

摘要

We describe the use of a dynamic model of combinedheat and mass transfer to analyze the effects oncooling loads of transient moisture storage andtransport through walls with porous buildingmaterials, under varying boundary conditions.The materials studied were brick, lime mortar andautoclaved cellular concrete. The physical propertiesof these materials, such as mass transportcoefficients, thermal conductivity and specific heat,were taken to be functions of moisture content.The simulation results were compared to thoseobtained by pure conduction heat transfer withoutmoisture effects. Also analyzed were the influence oncooling loads of high moisture content due to rainsoaking of materials. and the influence of solarradiation on sunny and cloudy days. The weatherused was a hot/humid summer period inFlorian6polis (South Brazil).It is shown that neglecting moisture migration orassuming that the physical properties of wallmaterials do not depend on moisture content canresult in large errors in sensible and latent heattransfer.