Whole-home duct cleaning
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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.
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AfterHow Much Does Duct Repair & Sealing Cost in San Jose?
Duct repair and sealing in San Jose typically runs between $350 and $1,200 for most homes, with the average job landing around $650. That covers everything from patching a single disconnected duct run to sealing every accessible joint and seam in a typical 2,000-square-foot house. Larger homes with extensive leakage, hard-to-reach ductwork in crawlspaces or attics, or damaged sections that need full replacement can push the total to $2,500 or more.
At Kestrel Air Duct San Jose, you’ll get a written price before any work begins. No door-step revisions. No “we found something else” surprises. The number we quote is the number you pay, and it’s backed by our 365-Day Done Right Promise in writing.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s what homeowners in San Jose are paying in 2026, based on the work being done and the access conditions in the typical Bay Area home:
| Service | Typical San Jose Price Range | What’s Included |
|---|---|---|
| Minor duct sealing (1-3 accessible joints) | $150 – $350 | Mastic sealant or foil tape applied to visible leaks; includes inspection |
| Standard whole-home duct sealing | $450 – $900 | Sealing all accessible supply and return joints, boots, and plenum connections |
| Duct repair (disconnected or crushed section) | $250 – $600 per section | Reconnecting separated ducts, replacing crushed flex runs, resealing |
| Duct replacement (per 10-foot flex run) | $180 – $320 per run | New R-6 or R-8 flex duct, hanging straps, and sealed connections |
| Plenum repair or resealing | $300 – $700 | Sealing the main supply or return plenum at the furnace connection |
| Attic or crawlspace access premium | $100 – $250 added | Extra time and protection for tight, hot, or low-clearance access |
| Full duct system sealing + repair (older homes) | $1,200 – $2,500 | Combination job: multiple leaks, damaged runs, and complete resealing |
These ranges reflect 2026 pricing across San Jose neighborhoods, from Willow Glen to Berryessa to Almaden Valley. What moves the number? Four things, mostly: how many leaks you have, where the ducts live, how bad the damage is, and whether the system was installed well in the first place.
Homes built before 1990 in San Jose commonly have sheet-metal ducts with taped seams that dried out and failed years ago. Homes built in the 2000s and 2010s often have flex duct in attics that gets kinked, crushed by stored boxes, or gnawed by rodents. Both scenarios leak conditioned air into spaces where it does nothing except raise your PG&E bill.
What Affects Duct Repair & Sealing Pricing in San Jose
No two duct systems are identical, even in homes on the same street. Here’s what changes the final number:
- Access to the ductwork. Ducts in a standing attic or open crawlspace cost less to reach than ducts in a 2-foot crawlspace with a dirt floor. In San Jose’s older Eichler-style and ranch homes, we often work in tight, low-clearance attics that add labor time. Expect access charges of $100 to $250 on those jobs.
- Number of leaks found. A single visible gap at a register boot is a quick fix. A system with 8 to 12 failed seams throughout the attic is a half-day or full-day job. We test and inspect, then show you where the air is actually escaping before quoting a number.
- Type of ductwork. Sheet metal ducts from the 1960s through 1980s can usually be repaired and resealed. Aged flex duct that’s brittle, torn, or compressed flat usually needs replacement rather than repair, since sealing damaged flex is a temporary patch at best.
- Extent of damage. A separated joint costs less than a section crushed by a roof leak or a return duct that rodents have torn open. If insulation on the ducts has been soaked by condensation or a plumbing leak, that section must be replaced for the repair to hold.
- Age of the system. Ducts older than 30 years often have multiple failure points. Repairing one leak on a 35-year-old system is like patching one tire on a car that needs four. We’ll tell you honestly if repair is worth it or if replacement is the smarter money.
- Permit requirements. Most duct sealing and repair work in San Jose does not require a permit if it’s repair-in-kind. But if sections are being replaced and the job involves modifying the duct layout, the city of San Jose may require a mechanical permit. That adds $150 to $400 to the job, depending on scope. We handle this for you and include it in the written quote up front.
Signs You Need Duct Repair or Sealing
Before we talk about how to save money, let’s cover what actually sends you looking for this service. Duct problems rarely announce themselves loudly. They show up as slow, persistent symptoms:
- Rooms that never get comfortable. A bedroom that’s always 5 degrees warmer than the rest of the house usually means a disconnected or kinked supply duct, not a weak AC unit.
- Dust that comes back fast. Gaps in return ducts pull air from attics and crawlspaces, and that air carries dust, insulation fibers, and allergens straight into your living space.
- Higher PG&E bills with no change in usage. Leaking ducts can lose 20% to 30% of conditioned air before it ever reaches the vents. That’s money leaving your house through holes you can’t see.
- Musty or hot smells when the system runs. Air from a crawlspace or attic has a distinct smell. If you notice it when the heat or AC kicks on, you’re pulling air from somewhere you shouldn’t be.
- Noisy air movement. Whistling or hissing at registers, or a furnace that sounds like it’s working harder than it should, often points to a pressure imbalance caused by leaks.
If any of these sound familiar, our Duct Repair & Sealing in San Jose service page walks through what a typical inspection covers and how we approach the work. And if you’re also dealing with years of accumulated dust in the system, take a look at our home page to see the full range of air duct and dryer vent services we offer.
How to Save on Duct Repair & Sealing
Everyone wants a fair number. Here’s how to get one without cutting corners on the work itself:
- Fix problems early. A single separated joint caught now costs $150 to $350 to fix. That same leak left alone for a year can pull enough moisture into the ducts to damage surrounding insulation, doubling or tripling the repair cost.
- Ask for a written quote with a leak-by-leak breakdown. You should know exactly what you’re paying for. We hand you the written price before a single vent is touched, and the Kingswell Guarantee stands behind it. If the price isn’t written, don’t agree to the work.
- Bundle duct sealing with deferred maintenance. If you’re already having your air ducts cleaned, it makes sense to seal obvious leaks while the system is opened up. You’ll pay one trip charge instead of two and only have to take time off work once.
- Don’t wait until peak heating or cooling season. San Jose HVAC companies get slammed in July and December. Scheduling duct repair in spring or fall means more availability and sometimes more flexible scheduling, though our pricing stays the same year-round.
- Get a free estimate and compare apples to apples. Call Kestrel Air Duct San Jose at (669) 220-7869 and we’ll inspect, diagnose, and hand you a written price. Compare it with any other quote, but compare line by line: access, number of leaks, materials, and warranty. A cheap bid that skips sealing half the leaks costs more in the long run.
Repair vs. Replacement: Which Makes Sense in San Jose?
This is the question behind the pricing question, and the honest answer is: it depends on system age and condition.
If your ducts are less than 20 years old and the leaks are at joints, boots, and the plenum, sealing is usually the right call at $450 to $900 for a standard whole-home job. The ducts themselves are still sound, and mastic sealant applied correctly lasts 15 to 20 years.
If your flex duct is compressed flat, torn in multiple places, soaked with moisture, or over 25 years old, replacement starts making more sense. Yes, it costs more up front, typically $1,200 to $2,500 for a full replacement. But sealing a duct system that’s near the end of its service life is like putting new tires on a car with a failing transmission. You’ll pay twice.
Dale Whitmore, who leads Kestrel Air Duct San Jose, puts it this way: “We’d rather tell you the repair isn’t worth it and show you why, than take your money for a seal job that fails in two years. The 365-Day Done Right Promise means we’re the ones who come back if it doesn’t hold, so we have every incentive to do it right the first time.”
That’s the difference between a company that profits from repeat visits and one that profits from doing the job correctly once. We’re the second kind.
What Equipment We Use and Why It Matters
The tools change the outcome. A technician who shows up with a box-store shop vac and a roll of duct tape from the hardware store is not doing the same job as a company running professional-grade equipment.
At Kestrel Air Duct San Jose, our technicians are background-checked, uniformed, and trained on equipment built for this specific work:
- Rotobrush rotary brush systems dislodge debris at the duct wall before sealing. That matters because mastic and tape don’t bond well to dusty or greasy metal. A clean surface is a sealing surface.
- Nikro negative-pressure units pull loosened contaminants out of the system during cleaning, so the process doesn’t push dust back into your living space.
- Abatement Technologies HEPA filtration captures fine particles during the work. If you have allergies, asthma, or a baby in the house, this is the difference between a duct job that helps and one that kicks up a dust storm.
None of this is flashy. It’s the difference between sealing a duct that stays sealed and one that fails in six months because the surface wasn’t prepared properly.
Why Kestrel’s Pricing Is Different
Kestrel Air Duct San Jose is part of the Kingswell family of companies, founded in 2004. The name comes from the kestrel, a small falcon that hangs almost perfectly still in the air by reading the currents around it. That’s the model: steady, precise, and watching the details while everything else moves.
Every job we do operates under the Kingswell Guarantee, and it’s not a handshake. It’s a written standard applied to every visit since 2004:
- A written price before work begins. Never a verbal estimate that changes at the door. The number in your hands is the number you pay.
- A defined arrival window. We show up when we say we will. Not “sometime between 8 and 5.” A real window, kept.
- A clean job site. We leave your home the way we found it, with the ductwork sealed and the floor swept.
- The 365-Day Done Right Promise in writing. If the work fails within the guarantee period, we return and make it right at no charge. That’s a written commitment, not a courtesy. If the duct repair fails, the second visit is free. Not discounted. Free.
There’s also The Kingswell Way, a values code that governs every visit: say the price, show up in the window we gave, leave the place cleaner, put the guarantee in writing, come back if it fails. That’s the whole code. We don’t need a longer one.
Calls are answered by a live human being, 24/7. Dale Whitmore and his San Jose team don’t route you to a voicemail queue or an automated phone tree. You dial, someone answers, and you’re talking to a person who can help. That’s rarer than it should be in this industry, and it’s a promise we make without exception.
FAQs – Duct Repair & Sealing Cost
How much does duct sealing cost in San Jose?
Whole-home duct sealing in San Jose typically costs $450 to $900 for a standard 2,000-square-foot home, while minor sealing of one to three visible leaks runs $150 to $350. The final number depends on access, the number of leaks, and whether any duct sections need replacement. Call (669) 220-7869 for a written quote on your exact system; estimates are free.
Is it cheaper to repair or replace ducts?
For ducts under 20 years old with localized leaks, repair and sealing at $450 to $900 is almost always cheaper than replacement at $1,200 to $2,500. But if your flex duct is torn in multiple places, water-damaged, or over 25 years old, replacement is the cheaper long-term option because repeated repairs will eventually add up to more than a full replacement. We’ll show you the numbers for both paths and let you decide without pressure.
How much does a disconnected duct cost to fix?
Reconnecting and resealing a single disconnected duct run in San Jose typically costs $250 to $600, including the inspection, reconnection, sealant, and a check of the surrounding sections. If the disconnected section is damaged or crushed, plan on $180 to $320 per replacement run of flex duct. Call (669) 220-7869 and we’ll give you a written price before any work starts.
Does duct sealing actually save money on energy bills?
Yes. The U.S. Department of Energy estimates that duct leaks waste 20% to 30% of the air your HVAC system produces, and sealing those leaks in a San Jose home can reduce heating and cooling costs by $100 to $300 per year depending on system size, usage, and PG&E rates. The savings compound over time, especially in summer when air conditioning runs hard in the San Jose heat. For an exact picture of your system, schedule a free inspection at (669) 220-7869.
How long does duct sealing last?
Properly applied mastic sealant on clean duct surfaces lasts 15 to 20 years, which is why surface preparation matters so much. Foil tape typically fails within 3 to 7 years because the adhesive dries out and separates from the metal. That’s why we use professional-grade mastic and clean the surface with professional equipment before sealing. The 365-Day Done Right Promise covers the work in writing, so if a seal fails within the guarantee period, the return visit is free.
Pricing reflects the San Jose market as of 2026. Kestrel Air Duct San Jose offers free estimates – call (669) 220-7869.
Written by Dale Whitmore, Owner at Kestrel Air Duct San Jose, serving San Jose since 2004 under the Kingswell Guarantee.
What Our Customers Say
"Our dryer was taking two cycles to dry a load. They cleaned the vent and pulled out a frightening amount of lint. Dries in one cycle now and honestly I feel better about the fire risk."
- Marcus Lee"My wife's allergies were awful every morning. Had the ducts done and it's made a real difference. Tech was on time and wore booties in the house without me asking."
- Rob Pendergast"Bought an older home and the previous owners had pets everywhere. After Kestrel did the ducts the stale smell was just gone. On time, quick, and they showed me the filter they pulled."
- Preston Ngata