Statistical Analysis of Microbial Volatile Organic Compounds in an Experimental Project: Identification and Transport Analysis

Abstract

This paper is based on an experimental project that investigated the capacity of wood frame stud walls to restrain the movement of mould products from the stud cavity into an investigative chamber, representing the indoor environment. While the programme of the research includes the investigation of spores and microbial volatile organic compounds (MVOCs), this paper reports only the analysis of MVOCs. Twenty full-scale wall specimens were constructed, incorporating six experimental factors (air leakage path patterns, mould presence, insulation, vapour barrier, sheathing material, and ambient humidity conditions). For each specimen, four VOC samples were taken simultaneously from the sampling chamber and from the stud cavity through the external sheathing, and one sample was taken from the background laboratory air for comparison. Multiple regression analysis was applied to identify the MVOCs, and subsequently to evaluate the effect of construction factors on the movement of these MVOCs through the envelope. Box—Cox transformation was applied prior to the regression analysis to normalise the data. Five VOCs were identified as related to the presence of mould in the stud cavity, at 5% level of significance. The transport of these MVOCs from the sampling chamber to the cavity was confirmed. However, no significant effect of the parameters related to wall configurations was detected.