Air Duct Replacement in San Jose, CA

When does duct replacement beat another repair?

Ask this first: is the duct material still sound? Flex duct with a torn inner liner is done. Patching the outer jacket hides nothing. Fiberglass ductboard plenums from older San Jose installs get soft at the corners as the binder ages, and the cut edges shed. Galvanized trunk-and-branch in a 1960s attic often outlives everything around it. That metal we usually keep. The branches off it are the problem.

Replacement scope follows the house. Post-1990 attic flex is the easy case. Open the attic, pull every run, re-strap with wide saddles so nothing sags and ponds dust. In-slab perimeter ducting is the hard case. Once winter water gets into a slab duct, you do not replace it in place. The system moves overhead or into a new chase. That is a bigger conversation.

Boots and returns matter more than the runs. Most weak airflow we find traces to an undersized return, not the supply side. We check the filter cabinet too. Wildfire ash and roadside dust load returns hard after a dry summer.

Honest limit: if your coil is fouled and your filter has been the wrong size for years, new duct alone will not fix the odor.