An optoelectronic sensor for the monitoring of mould growth in concealed spaces

The growth of mould in the indoor environment is an important contributor to the development and exacerbation of atopic disease, and potentially poses other health risks. Moreover, the detection and elimination of mould have resulted in massive remedial expenditures, often without clear engineering knowledge of the nature of the moisture events that led to the damage, especially for residential light wood-frame construction. Relatively little research has considered such failure of the building enclosure as a starting point for developing practical, evidence-based construction practices to improve building performance. One research limitation concerns the use of invasive or destructive testing as the sole means to monitor mould growth in concealed assemblies, such as wall cavities, making it difficult or impossible to conduct time-course experiments to assess the performance of different materials and designs. The present paper concerns the development and testing of a new optoelectronic sensor capable of non-invasive monitoring of mould growth in concealed spaces in real-time by measuring changes in light reflectance from the sensor’s active element, a membrane impregnated with mould spores. It builds upon an earlier concept in which mould-impregnated cellophane coupons were attached to building surfaces, then removed and examined periodically for growth by microscopy. The new device incorporates computer-controlled measurement of mould growth, in response to the environmental conditions and, thus, functions as a remote sensor. Although primarily intended for research use, the device has the potential to be used as a post-remediation monitoring device to provide early-warning of any re-occurrence of mould growth.