Microbial Volatile Organic Compounds in full scale studs cavities

Full-scale stud cavities were constructed in a climate-controlled chamber to investigate the capacity of wall cavities under experimental conditions to contain mold products, emanating from studs with 10% of their surfaces covered with mold, from penetrating the indoor space. The project investigated the transport of microbical volatile organic compounds (MVOCs), which can be byproducts of mold growth, through the building envelope, and assesses whether the concentration of MVOCs was related to six experimental parameters stated below. The tests were initially designed primarily to study the movement of fungal spores. Later, additional information was collected to investigate the movement of MVOCs. Full size wall assemblies of residential wood frame buildings were constructed, and subjected to air infiltration rates typical of houses in the Quebec region, Canada. A stainless steel sampling chamber, simulating the indoor space, was constructed to encase the inner face of the central stud cavity of the specimens, and to provide controlled depressurization for the air infiltration. The parameters that may influence spores and MVOCs movement selected for the investigation were the air leakage characteristics (air leakage path and rate) and wall configurations (insulation, vapour barrier and sheathing material). The analysis of VOCs was performed using gas chromatography/ mass spectrometry (GC/MS) to identify the volatile species in the stud space, the interior of the sampling chamber and the ambient laboratory air. The results were analyzed using multiple regression analysis to determine the transport through the building envelope.