Rationale For Measuring Duct Leakage Flows in Large Commercial Buildings

TitleRationale For Measuring Duct Leakage Flows in Large Commercial Buildings
Publication TypeConference Proceedings
Year of Publication2005
AuthorsWray, Craig P, Richard C Diamond, Max H Sherman
Conference Name26th AIVC International Conference
Paginationpp. 83-88
Conference LocationBrussels, Belgium, 21-23 September 2005
Keywordscommercial, commissioning, diagnostics, ducts, leakage, measurements

Industry-wide methods of assessing duct leakage are based on duct pressurization tests, and focus on "high pressure" ducts. Even though "low pressure" ducts can be a large fraction of the system and tend to be leaky, few guidelines or construction specifications require testing these ducts. We report here on the measured leakage flows from ten large commercial duct systems at operating conditions: three had low leakage (less than 5% of duct inlet flow), and seven had substantial leakage (9 to 26%). By comparing these flows with leakage flows estimated using the industry method, we show that the latter method by itself is not a reliable indicator of whole-system leakage flow, and that leakage flows need to be measured.

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