Only testing will tell.

Describes how substantial differences resulted from performing a 'Duct Blaster' test during the framing stage and at completion. Outlines the tests used to pinpoint the problem. The tests included: frame-stage leakage - unit untaped; frame-stage leakage - unit taped; finish-stage leakage - face taped; finish-stage leakage - complete-taped; subtraction method; leakage to outside. The data obtained allowed the quantification of leakage at air handler units, at metal supply boots to outside and at supply registers to inside. In addition, the authors were able to extrapolate the leakage based on duct leakage data collected when a house is completed. The test battery was used to study the differences between measurements of duct leakage using a Duct Blaster and measurements using the blower door subtraction method.