By Pacific Heating & Cooling | NATE-Certified Service Technicians | Updated April 2026
If some rooms in your home never seem to reach the temperature on your thermostat while others feel just right, leaky ductwork is often the reason. Air duct sealing closes the gaps and loose connections in your duct system so the air your system produces actually reaches your rooms, instead of leaking into your attic or crawl space. Based on our service records, standalone air duct sealing typically runs about $1,995 in Western Washington. Here is what the service includes, what our technicians commonly find, whether it is worth it for your home, and the best time to schedule it.
What does air duct sealing actually include?
Air duct sealing is a process that finds and closes the leaks throughout your duct system. Our technicians run a duct leakage test first, seal the connections and gaps from the inside, then test again to confirm the improvement. Most homes are sealed in a single visit, and you get before and after readings so you can see the change for yourself.
The process seals your ducts from the inside out, which reaches leaks in places you could never get to by hand, like inside walls, attics, and crawl spaces. That matters in Western Washington, where many older homes route ductwork through unconditioned crawl spaces that lose air the moment the system turns on.
Because we test before and after, this is not guesswork. You will see what we are seeing and know what it means. Our NATE-certified, background-checked technicians walk you through the readings and give you clear pricing before any work begins, so there are no surprises. You can read more about our air duct sealing service and how the process works.
What a duct sealing visit includes
- Duct leakage test. We measure how much air your system is losing before we start.
- Whole-system sealing. We seal accessible joints, seams, and connections from the inside.
- Confirmation test. We test again and give you the before and after readings.
- Clear, upfront pricing. You know the cost before we begin any work.
Many Western Washington homes also qualify for a Puget Sound Energy rebate, which we can check as part of the test.
What we commonly find, and what it means for your system
Duct sealing solves one specific problem: air escaping before it reaches your rooms. During the visit, some things are handled as part of the service, and some point to a separate conversation. We keep those clearly separated so you always know what is included and what is not.
Handled as part of the service
The leakage test, the sealing of reachable connections and gaps, and the before and after readings are all part of the standard duct sealing service. For most homes, this closes the leaks that were quietly wasting your heated and cooled air. The result is more even temperatures and less air lost to your attic or crawl space.
What turns into a separate repair conversation
Sealing works on ducts that are basically sound. If a technician finds a duct run that is disconnected, crushed, or badly deteriorated, that section usually needs to be repaired or replaced, which is priced separately. In some older homes, we also find ductwork that needs replacement rather than sealing. And if your ducts are full of dust and debris, that is a job for professional duct cleaning, a different service that solves a different problem.
Example From a Recent Service Visit
A homeowner in Auburn had an older system and rooms that never warmed up evenly, no matter where they set the thermostat. When we ran the duct leakage test, we found significant air loss spread across the home’s duct runs.
Solution:
We sealed the system from the inside across all of the runs and tested again to confirm the improvement, so this Auburn homeowner could see the difference on paper and in their comfort.
Homes like this are common across the South Sound. We see duct sealing most often in Tacoma, Puyallup, Kent, Lakewood, and Auburn, where a mix of older housing stock and crawl-space ductwork adds up to real air loss.
Is air duct sealing worth it?
Air duct sealing is usually worth it when you have rooms that are hard to heat or cool, energy bills that seem higher than they should be, or a duct system with visible leaks. It is most valuable when paired with a new system, so your new equipment is not pushing expensive air through leaky ducts. Homes with tight, newer ductwork may see less benefit.
A few signs point to leaky ducts more than others. Rooms that stay too warm or too cold no matter the thermostat setting, rising energy bills with no clear cause, rooms that feel stuffy or dusty, and ductwork you can see running through an unfinished attic or crawl space are all common signals. None of these guarantees a leak, but together they are worth a test. The good news is we can pinpoint the loss with the leakage test, and from there we walk you through your options.
That pairing shows up clearly in our own records. Based on 47 duct sealing jobs we completed across Western Washington between June 2025 and April 2026, 29 were done as part of a new system installation. Sealing the ducts at the same time protects the investment in the new system and helps it perform the way it was designed to. If you are already planning a new system installation, it is worth asking about sealing at the same time. In most cases, we also recommend a duct cleaning before sealing, so the system is clear before we close it up. For non-club members, a cleaning typically runs around $750. It is a separate service, and we will always tell you upfront whether your home needs it first.
Here is what the numbers look like in our service area:
| Duct sealing scenario | Typical cost in Western Washington |
|---|---|
| Standalone duct sealing (most homes) | About $1,995 |
| Larger homes or more duct runs | $2,245 to $2,445 |
| Sealing done with a new system install | Bundled into the project |
We build value before we talk price, and we back the work. Our repairs and installations are covered by a 100% Money-Back Guarantee, and our No Worry, No Breakdown Guarantee stands behind the systems we service. When the cost is a factor in a larger project, we also offer flexible financing options so you can plan the investment on your terms.
When should you schedule air duct sealing?
The best time to seal your ducts is when you are replacing your heating or cooling system, so your new equipment starts out working with
The labeled access panel our technicians work through to clean and seal the duct system from the inside
a tight, efficient duct system. If you are not replacing equipment, spring and fall are ideal, before the heaviest heating and cooling seasons arrive. Rebate timing can matter too, so it is worth asking early.
Western Washington’s marine climate means your system works across long shoulder seasons, heating in the cool, damp months and cooling through the summer stretch. Sealed ducts help in both directions. Scheduling in spring or early fall also means you are ahead of peak demand, when booking windows fill up fast.
If your home qualifies for a Puget Sound Energy rebate, that can shape the timing as well, since qualification depends on a duct leakage test we perform before sealing. Whenever you book, you get the same experience: a 2-hour arrival window, upfront pricing, and technicians who handle the details for you. Members of our Peace of Mind Club membership get priority scheduling, which helps during the busiest weeks. You can also pair sealing with whole-home air filtration if indoor air quality is on your list.
Pacific Heating & Cooling has served Western Washington families since 1984, with more than 6,000 Google reviews and a 4.9 average rating. If you are weighing whether duct sealing is right for your home, call us at (253) 248-6260 and we will walk you through it. Clear answers so you can make a confident decision. No Surprises. Just Solutions.
FAQ: Common questions for Air ducts
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ased on our service records, standalone air duct sealing typically runs about $1,995 in Western Washington. Larger homes or homes with more duct runs can reach $2,245 to $2,445. When sealing is done as part of a new system installation, it is bundled into the project. We give you a clear price before any work begins.
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Standard cloth duct tape is one of the worst choices for ducts because it dries out and peels within a year or two. You can seal a few visible, reachable joints with mastic or foil tape, but most duct leaks are inside walls, attics, or crawl spaces where you cannot reach them. A professional process seals the whole system from the inside and confirms the result with a before and after test.
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Duct cleaning removes dust and debris from inside your ducts. Duct sealing closes the leaks and loose connections that let air escape before it reaches your rooms. They solve different problems, and many homeowners do both. If your main issue is uneven temperatures or high bills, sealing is usually the bigger fix.
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It often does, because sealed ducts stop wasting the air your system already paid to heat or cool. The savings depend on how leaky your ducts were to start. Homes with major leaks tend to see the biggest change in comfort and efficiency. You also get before and after test readings so you can see the improvement.
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Puget Sound Energy has offered rebates that can reduce the cost of duct sealing for qualifying homes. Qualification usually depends on a duct leakage test that measures how much your system leaks before sealing. We can run that test and let you know if your home qualifies. Rebate programs change, so we confirm current details before you commit.
Still not sure if your system is ready for the season?
Tell us what your system is doing and we’ll help you figure out the right next step. Pacific Heating & Cooling has been diagnosing heating and cooling problems across Tacoma and the South Sound since 1984. NATE-certified technicians, 2-hour arrival windows, and upfront pricing before any work begins.
