What to know
- Typical duct systems lose about 20–30% of conditioned air to leaks, holes, and bad connections (ENERGY STAR) — you pay to heat the crawlspace.
- Aeroseal works from the inside: an aerosolized sealant travels to every leak and bonds across gaps up to 5/8 inch, including joints no hand could reach.
- Measured results: the process records leakage before and after, so you see exactly what was fixed — numbers, not vibes.
- Aeroseal warrants the seal for 10 years, with third-party durability testing beyond that.
- Benefits: stronger airflow to starved rooms, more even temperatures, lower bills, and better air quality (no more pulling crawlspace air into the return side).
Why do leaky ducts cost so much here?
Puget Sound homes commonly run ductwork through vented crawlspaces and attics — unconditioned spaces that are damp, cold in winter, and hot in summer. Every gap at a joint or seam leaks supply air out and, on the return side, sucks crawlspace air (and whatever's in it) into the system. Symptoms: rooms that never get comfortable, weak airflow at far registers, dusty air, and bills that outrun the thermostat setting.
How does Aeroseal seal ducts from the inside?
The process seals the system from within:
- Registers are temporarily blocked and the duct system is pressurized.
- A measured baseline documents exactly how much the system leaks — the same idea as a duct-blaster test.
- Aerosolized, non-toxic sealant particles are injected into the airstream; escaping air carries them straight to each leak, where they accumulate and bond across the gap — up to 5/8 inch wide.
- The computer tracks leakage dropping in real time, and you get a certificate showing before/after numbers. Aeroseal warrants the seal for 10 years.
When is duct sealing the right first move?
If some rooms are always too hot or cold, if airflow is weak, or if you're about to invest in a new heat pump or furnace, sealing the delivery system first means the new equipment's output actually reaches the rooms. It's often the highest-ROI comfort fix in homes with crawlspace or attic ductwork, and it pairs naturally with duct cleaning — clean first, seal second, as one project.
Who should skip it?
Honest exclusions: homes whose ducts run entirely inside conditioned space have little to gain; crushed, disconnected, or undersized duct runs need repair or replacement, not sealant; and gaps wider than 5/8 inch get fixed by hand first. The pre-test tells the truth either way — if your leakage number is already tight, we'll say so.
Ready for the next step?
Talk to a licensed Eco pro — honest guidance and upfront pricing before any work begins.
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Common questions
Is Aeroseal safe to breathe?
The sealant is non-toxic, UL-tested, and has been used in homes, hospitals, and schools; the home is ventilated during the process and the material sets quickly. We'll walk you through the product data before scheduling.
How long does Aeroseal last?
Aeroseal warrants the seal for 10 years, and the company cites third-party lab testing showing the bonds holding well beyond that — this is a seal-once solution, not a maintenance item.
Aeroseal or duct cleaning first?
Cleaning first, sealing second is the ideal order: clean surfaces take the seal best, and you don't seal years of dust inside. We can perform them as one project.
How big a leak can it seal?
Gaps up to 5/8 inch wide, of any length, per Aeroseal's specs. Larger accessible holes get repaired by hand first — which also speeds up the sealing process.