Physically Based Modelling of the Material and Gaseous Contaminant Interactions in Buildings: Models, Experimental Data and Future Developments
INTRODUCTION Interactions between gaseous contaminants and materials in buildings involve a variety of phenomena, including volatile organic compound (VOC) emissions from new or newly applied covering materials, deposition of reactive species (ozone and sulphur dioxide, as well as some nitrogen oxides) from the room air to the material surfaces, and what is commonly called the reversible sink effect of the walls and furnishings (or adsorption/desorption processes; but this term proves to be confusing and somewhat inappropriate, as will be shown later on). These phenomena have been extensively studied since the mid 1980s. First, the source/sink behaviour of building materials has been characterized from environmental chamber studies. Most of them lead to the proposal of empirical or semi-empirical models obtained by fitting an appropriate mathematical expression to a set of experimental data, usually concentration at the air exhaust of the chamber as a function of time (Dunn and Tichenor, 1988; Chang and Guo, 1992; Colombo and De Bortoli, 1992; Haghighat and Zhang, 1999). Although such experiments are still relevant today, especially for standardization on material emissions, researches have now also clearly been directed toward the development of physically based models to be implemented in indoor air quality simulation tools.