Duct leakage is the main energy waster in homes especially when such ducts are situated outside the home’s thermal boundary in a crawl space, attic, and attached garage. When these zones remain outside the thermal boundary, duct sealing is typically cost-effective.
Ducts in unconditioned space with some noticeable leakage will be qualified for duct sealing:
- Some noticeable leakage: Joints are not closed with an appropriate sealant and there are gaps at most of the seams. Duct insulation shows staining at most field joints.
NOTE: Duct leakage in the thermal boundary or Semi Conditioned Spaces such as basements will not be eligible to be duct sealed.