A transient-based technique to locate depleted appliance trap seals within the building drainage system

The building drainage and ventilation system has gained increased attention in recent years over growing concerns regarding its role in the spread of airborne contamination. Depleted appliance trap seals were shown to have been a causal factor in the rapid spread of the SARS virus in Hong Kong in 2003. The fast identification of open trap seals is, therefore, crucial in safeguarding public health. This paper presents a novel technique to identify the location of depleted appliance trap seals through time analysis of the system response to a low-amplitude pressure wave. Experimental analysis of this transientbased approach has been shown to confirm this methodology, while the findings from an extensive field study of an occupied building confirm the practicality and effectiveness of this proposed technique. The paper also confirms the considerations required to determine the number and location of suitable measurement stations. © BHR Group 2008.