What to know
What it changes
- Rooms at the end of long runs that have never quite kept up, where leakage was the reason.
- Unfiltered air being drawn in on the return side from a crawl space, attic or garage.
- A system running longer than it should because a share of its output never arrives.
- Dust reappearing quickly at registers, where it is entering through return leaks rather than coming from the ducts.
What it does not change
It does not clean the ductwork. If the system is carrying years of accumulation, sealing it traps that in place rather than removing it, which is why the order of work matters and why it should be assessed together.
It does not fix mechanical failures. A crushed run, a disconnected boot, or ductwork too far gone to seal needs a different answer, and sealing over the top of that is money spent on the wrong problem.
And it is not an efficiency upgrade for a system that is already sound. Sealing a tight duct system changes very little, because there was little to close.
How to tell whether you are a candidate
- Look at accessible joints in an attic, crawl space or basement for tape curling away or visible gaps.
- Compare airflow at a register near the furnace with one at the far end of the house.
- Notice whether an unconditioned space feels warmer or cooler than it ought to.
- Note whether particular rooms struggle in both summer and winter, which points at distribution rather than capacity.
The honest version
Sealing helps houses that are losing air. It does very little for houses that are not, and it is not a substitute for cleaning a system that has accumulated material.
Which of those describes your house is a question about your ductwork, and it takes about half an hour to answer properly.
Where to start
Which of these applies to your system depends on how it was built and what shape it is in now, and that is not something a page can settle.
Our inspection is free. We will show you what we find, and if the answer is that your ductwork is sound and simply needs cleaning, that is what we will tell you.