Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Styles & brands we work with
- Whole-home duct cleaning
- Dryer vent cleaning
- Camera inspection
- Sanitizing & deodorizing
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After
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AfterHow Much Does Duct Repair & Sealing Cost in Sunnyvale?
Duct repair and sealing in Sunnyvale typically runs $350 to $1,200 for most single-family homes, with the average job landing around $600. Small sealing jobs on a few accessible leaks can come in under $400, while restoring a full attic trunk line or replacing crushed flex runs in a two-story home pushes toward the top of that range. If your system was installed before the 1990s, has visible gaps at the joints, or you’ve noticed rooms that never get comfortable, a diagnostic visit is the fastest way to get a real number instead of a guess. Call (866) 593-7291 and we’ll quote you up front.
Key Takeaways
- Most Sunnyvale duct repair and sealing jobs fall between $350 and $1,200.
- Sealing existing joints is cheaper than replacing damaged duct sections.
- Age of the home is the biggest cost driver here. Sunnyvale’s 1950s-1970s ranch stock often has original galvanized ductwork with failing tape and mastic.
- We clean it. If it’s damaged, we repair it, so you’re not calling two different companies.
- Free estimates. No surprise line items after the work starts.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s what the individual pieces of the work actually cost in the Sunnyvale market this year. Most jobs combine two or three of these line items.
| Service | Typical Cost Range | What It Covers |
|---|---|---|
| Sealing accessible leaks (mastic + foil tape) | $350 – $600 | Joints, seams, and small gaps in accessible attic or crawlspace runs |
| Sealing with aerosol / duct blaster method | $700 – $1,400 | Whole-house sealing from inside the duct system, best for leaky older homes |
| Repairing a single duct run | $250 – $500 | Patching a crushed or disconnected flex run, reconnecting a boot to a register |
| Replacing damaged flex duct | $400 – $900 per run | Full replacement of torn or collapsed flex duct with new insulated material |
| Rebuilding a trunk line section | $800 – $2,000 | Rotted or disconnected trunk, often in 1960s Sunnyvale homes |
| Insulating exposed ducts in attic | $500 – $1,200 | Adding insulation to bare ducts that sweat or lose heat in unconditioned space |
| Full duct replacement | $2,500 – $6,000 | System-wide replacement when the ductwork is beyond repair |
| Diagnostic and leakage test | $0 with repair | We check your system, document the leaks, and quote before any work begins |
What pushes a job up or down? The main variable is how accessible the ductwork is. A single-story ranch with an open attic is fast to work in. A two-story home with ductwork buried behind drywall or under a low crawlspace takes longer, and that labor shows up in the price. Second is the material itself. Sealing existing metal ducts is straightforward. Replacing crushed flex duct means ordering new insulated material and rehanging it properly. Third is how many separate problems turned up during the inspection. One leaky joint is cheap. A system with disconnected trunk, torn flex, and bare uninsulated runs is a multi-line-item job.
What Affects Duct Repair & Sealing Pricing in Sunnyvale
Sunnyvale has some specific things going on that change duct pricing compared to other Bay Area cities.
- Home age. A big share of Sunnyvale’s housing was built between 1955 and 1978. Original galvanized ductwork from that era is now 45 to 70 years old. The cloth-backed tape and early mastic used back then dries out and fails, and we see it constantly in neighborhoods like Lakewood Village and Cherry Chase. Repairing and resealing that ductwork is usually cheaper than ripping it out, but it takes more time than sealing new construction.
- Crawlspace and attic conditions. Ductwork in this part of the South Bay sits in unconditioned space. In summer, attic temperatures climb well past 130°F. That heat cycle is hard on flex duct, especially the inner liner, and it’s why we see collapsed runs in Sunnyvale homes more than you’d expect. Duct sealing and repair here should include attention to insulation.
- Metal vs. flex duct. Sealing metal duct is a mastic-and-tape job. Repairing damaged flex duct means replacing the damaged section entirely. Metal is more repairable; flex is more replaceable. Most Sunnyvale homes have a mix of both.
- Access. Ductwork that runs through an open attic is fast to reach. Ductwork buried under flooring, inside soffits, or in a tight crawlspace takes longer. Expect higher labor on any home where the technician has to work on their hands and knees or from a ladder.
- Leak volume. A single leaky joint costs a fraction of sealing an entire system. We test and document before we quote, so you know which situation you’re in.
- Whether a leakage test is included. A proper seal job should come with a before-and-after leakage test, often using a duct blaster. Some companies skip this and just eyeball it. We don’t, and that’s part of what’s reflected in the pricing above.
How to Save on Duct Repair & Sealing
You don’t need to cut corners to keep the cost reasonable. A few things reliably bring the bill down.
- Get it inspected before small leaks become big ones. A $15 foil-tape joint today can save you a fully disconnected trunk line later. Small repairs early are the cheapest duct repair you’ll ever do.
- Seal everywhere, not just where you can see. Skipping the inaccessible runs to save labor sometimes means the system stays leaky enough that you’ll be back in two years. Sealing accessible runs plus testing is the right balance.
- Combine cleaning and repair. If we’re already cleaning the ducts, we’re already in the attic. Adding sealing to an existing visit lowers the total labor cost than having us come back a second time for sealing alone.
- Fix insulation while you’re in the attic. Adding insulation to bare ducts at the same time as sealing costs less than a second visit, and it stops the summer heat loss that pushes your HVAC to work harder.
- Ask for a written quote with line items. You should see each repair priced separately so you can decide what to fix now and what can wait.
Our estimates are always free and always come with the leak locations documented. If you’re unsure whether you need sealing, repair, or a full duct cleaning, call (866) 593-7291 and we’ll sort out which service actually solves your problem.
Why Duct Damage in Sunnyvale Is Often Missed
Most people with leaky or damaged ducts in Sunnyvale don’t know it. The system still runs. The house still cools. The problem hides in the energy bill and the comfort gap between rooms. We regularly see three specific situations in this city.
First, original ductwork from the 1960s and 1970s that has been taped and patched multiple times over the decades. Old cloth-backed tape dries out, peels, and leaves joints wide open. If you’ve had a home inspection in the last few years and it mentioned “loose duct tape” or “ducts not sealed,” this is what they were pointing at.
Second, disconnected boots at floor or ceiling registers. Kids, furniture, or just decades of settling can pull a boot loose from the duct run. The register blows air into the room, but the room next door gets none. We see this a lot in two-story homes in Ponderosa and Birdland.
Third, crushed flex duct in the attic. Flex duct gets crushed by attic workers, by settling insulation, or just by being hung with too much sag. A crushed inner liner cuts airflow to almost nothing. The room stays warm, the HVAC works harder, and nobody knows why until someone gets into the attic and looks.
That’s the diagnosis side. The repair side is where our specialty matters. We use Rotobrush rotary brush systems and Nikro HEPA vacuum units to clean the ductwork before repair, so we’re not sealing debris into the system. Then we repair it with the right materials and test for leakage. Honeywell and Aprilaire air filtration systems go in when the customer wants better indoor air quality alongside the repair. Abatement Technologies equipment comes into play on heavily contaminated systems where remediation-level capability is needed. It’s the same standard required for commercial projects, applied to your house.
If you want the fuller picture of what the repair service includes beyond pricing, our Duct Repair & Sealing in Sunnyvale service covers the process from diagnosis through final test. And when the ductwork is healthy and you’re ready for a full cleaning, that’s our home page’s core service.
Repair vs. Replace: Which Makes Financial Sense?
For most Sunnyvale homes, repairing and sealing existing ductwork costs a fraction of full replacement and buys you 10 to 15 more years of service. Replacement is usually only warranted when the ductwork has physically failed in multiple places, is rusted through, or was poorly installed to begin with.
The rough math: sealing and repairing runs $350 to $1,200 on a typical house. Full duct replacement runs $2,500 to $6,000. You’d need the repair job to fail more than three times over before replacement makes sense, and in homes where repairs hold, we usually don’t need to come back.
The exception is a system where the ductwork is disconnected in two or more places, the flex is crushed across multiple runs, and the trunk itself is rotted. At that point, piecemeal repair adds up to more than a new system, and we’ll tell you that plainly before you spend the money.
FAQs – Duct Repair & Sealing Cost
How much does duct repair cost in Sunnyvale?
Most duct repair jobs in Sunnyvale cost between $350 and $1,200. A single crushed flex run is typically $250 to $500. A trunk line rebuild pushes toward the higher end. Call (866) 593-7291 for an exact quote, which is free.
How much does duct sealing cost in Sunnyvale?
Sealing accessible duct leaks in Sunnyvale runs $350 to $600 for mastic and foil-tape work. Whole-house aerosol sealing with a duct blaster test runs $700 to $1,400. The higher end reflects larger or older systems with more leakage. Call (866) 593-7291 and we’ll tell you which range fits your home.
Is it cheaper to repair or replace ductwork in Sunnyvale?
Repairing is almost always cheaper. Repair and sealing averages about $600 on a Sunnyvale home. Full replacement averages $2,500 to $6,000. The only case where replacement wins is when the ductwork has failed in multiple places, which we’ll tell you honestly during the estimate.
Can you come out today to check my ducts?
Often, yes. Spring and summer are busiest for us, and we schedule Sunnyvale visits as quickly as the calendar allows. Call (866) 593-7291 and we’ll give you the next available window. Estimates are always free.
Why is duct repair more expensive in older Sunnyvale homes?
Older Sunnyvale homes have original ductwork from the 1950s through 1970s that has been patched and re-taped over the years. The work is more involved than sealing new construction, so prices run 20 to 30 percent higher on pre-1980 homes compared to newer builds. The upside is that repairing and resealing that ductwork typically adds significant efficiency once it’s done right.
What We Bring and Why It Affects What You Pay
Pricing reflects the tools, and the tools are what make a repair last. On every duct job, we bring Rotobrush rotary brush systems and Nikro HEPA-rated vacuum units. Those are the same equipment brands commercial contractors use. Consumer-grade shop vacuums and a roll of tape from the hardware store do not clean or seal a system properly. Honeywell and Aprilaire air filtration systems are installed as part of the repair when indoor air quality matters to the customer. Abatement Technologies equipment comes in on contaminated systems where a higher level of capability is warranted. Guardsman filtration pieces go into some of the systems we work on.
This matters for the price because the cost of a real duct repair is the diagnostic test, the correct material, the trained labor, and the final leak test. Whoever you hire, make sure all four are on the invoice. If the quote is substantially lower than the ranges above, something is missing.
Ready to get a real number for your home? Call (866) 593-7291 for a free estimate. We’ll check the ductwork, document the leaks, and give you a written quote before any work begins.
Pricing reflects the Sunnyvale market as of 2026. Duct Cleaning Sunnyvale offers free estimates – call (866) 593-7291.
What Our Customers Say
"Job was done well and the house smells better. There was some dust knocked loose around a couple of the registers that I had to wipe down afterward."
- Claudia Martinez"My wife's allergies had been bad in this house since we moved in. It's been two months since they did the ducts and it's noticeably better. Not a miracle, but real."
- Javier Ramirez"Quoted per system rather than the bait and switch per vent pricing everybody else in town uses. The number I was told on the phone was the number on the invoice."
- Leela Shah