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 Los Angeles?
Duct repair and sealing in Los Angeles typically costs between $350 and $1,100 for most homes, with the average job landing around $650. Minor sealing work on a few accessible joints starts at $175 – $300, while a full-system repair with Aeroseal or mastic treatment across a 2,000-square-foot house can reach $1,800 – $2,500. The price depends on how much of your ductwork is accessible, how many leaks we find, and whether sections need replacement rather than sealing.
Those numbers come from what we see on job sites across Los Angeles every week, from homes in West Adams built in the 1920s to newer construction in Porter Ranch. If you’ve noticed uneven room temperatures, a spike in your LADWP bill, or dust settling on furniture two days after you wipe it down, your ducts are likely losing conditioned air. Call (213) 733-0665 for a free estimate with a written price before any work begins.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s what you can expect to pay in the Los Angeles market right now. These are real numbers from our service area, not national averages skewed by cheaper labor markets.
| Service | Typical Cost Range | Notes |
|---|---|---|
| Inspection & diagnostics (with camera) | $95 – $195 | Often waived when you proceed with repair |
| Sealing 2 – 4 accessible joints with mastic | $175 – $325 | Attic or crawl space access required |
| Sealing 8 – 15 joints (typical single-system home) | $350 – $700 | Most common job we do |
| Full-system Aeroseal treatment | $1,200 – $2,500 | Pressurized sealant reaches leaks behind walls |
| Replacing a 10 – 15 ft section of flex duct | $250 – $475 per section | Includes new duct, connections, and sealing |
| Replacing a supply register or return grille | $40 – $90 each | Materials and labor included |
| Re-insulating exposed ductwork | $1.50 – $3.50 per linear foot | R-6 or R-8 wrap depending on code |
| Whole-house duct repair (2,000 – 2,500 sq ft home) | $900 – $2,500 | Multiple leaks, several sections replaced |
What drives the number up or down? Accessibility is the biggest one. If your ducts run through a crawl space with 18 inches of clearance, labor hours climb. If they’re in an open attic with plywood decking, the same repair might take half the time. The age of your system matters too. Homes in neighborhoods like Hancock Park or Mid-Wilshire built before 1950 often have hard-pipe ducts with asbestos-wrapped insulation that requires special handling, which adds cost. Newer flex duct is simpler to repair and usually cheaper.
The number of leaks also moves the price significantly. A single pinhole at a plenum connection might be a $200 fix. A system where every joint has separated over decades of thermal expansion could need eight hours of work. We price everything upfront in writing, so you’ll know the number before we touch a single vent.
What Affects Duct Repair & Sealing Pricing in Los Angeles
Five factors move the needle most in this city. Here’s what we’re looking at when we walk through your home:
- Access to the ductwork. Los Angeles homes run the spectrum: some have walkable attics, some have flat roofs with zero attic space and ducts buried in soffits. If we need to open drywall to reach a leak, the repair cost includes patching and that adds $150 – $400 per access point.
- Age and type of the duct system. Homes built before 1970 in areas like Jefferson Park or Leimert Park often have rigid metal ducts with failing taped joints. The tape dries out, loses its adhesive, and gaps form. Metal ducts are actually great candidates for sealing because the material holds mastic well. Flex duct from the 1980s and 1990s in the San Fernando Valley tends to tear at the connection collars and often needs full section replacement.
- Leak severity and count. One separated joint at the air handler is a quick fix. Twenty loose connections across a sprawling ranch house in Encino is a full day’s work. We measure this with pressure diagnostics rather than guessing, which is why our estimates hold up once the work starts.
- Seasonal demand. Los Angeles doesn’t have the extreme seasons of Phoenix or Minneapolis, but prices firm up between June and September when AC systems are running constantly and homeowners notice their upstairs bedrooms won’t cool below 78. Booking in spring or fall won’t change your price from us, but it can mean a faster appointment.
- Repair method. Hand-applied mastic at $175 – $325 for small jobs is the most cost-effective approach. Aeroseal runs $1,200 – $2,500 because it requires specialized equipment and seals leaks you can’t physically reach. We’ll tell you when the cheaper option will work, and we won’t push the expensive one when it won’t make a meaningful difference.
How to Save on Duct Repair & Sealing
Nobody wants to overpay. Here are practical ways to keep the bill down without cutting corners on the work itself.
Fix all leaks in one visit. A single service call in Los Angeles includes travel time and setup. If you spread repairs across three visits, you’re paying that overhead three times. Bundle everything into one appointment and the per-repair cost drops.
Have your ducts cleaned first, then sealed. Sealing over debris doesn’t hold. Mastic needs a clean surface to bond. If you’re already scheduling an air duct cleaning, ask about adding sealing to the same visit. Kestrel Air Duct Los Angeles does both, and doing them together means one trip charge, one setup, one afternoon.
Check what’s actually failing. Sometimes a “duct problem” turns out to be a dirty blower wheel or a clogged return. A $150 inspection can save you from a $1,000 repair that wouldn’t have fixed the root cause anyway. We won’t sell you a repair you don’t need. The Kingswell Way values code says: 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 means honest diagnostics.
Don’t wait until peak summer. Los Angeles HVAC companies get swamped in July and August. Prices at some shops reflect that demand. Ours stay consistent year-round, but booking in spring gets you a faster slot and more time to spot problems before the first 90-degree week. Call (213) 733-0665 and a live person will answer, any time of day. Estimates are free.
Is Duct Sealing Actually Worth the Money?
For most Los Angeles homes, yes. We’ve measured return on this hundreds of times. Here’s the math.
The typical single-family home in Los Angeles loses 20 – 30% of conditioned air through duct leaks. That means every dollar you spend heating or cooling, a quarter of it goes into the attic or crawl space. On an average LADWP bill of $180 – $250 a month during summer and winter peak months, sealing your ducts typically cuts $30 – $60 off each of those monthly bills. A $600 sealing job pays for itself in one to two seasons, then keeps saving for a decade or more. Duct sealing is one of the few home improvements with a faster payback than window replacement or attic insulation.
Beyond the money, sealing fixes real comfort problems. The upstairs bedroom that’s always 10 degrees hotter in summer usually has a duct run that’s leaking into the attic. The living room that never heats up in “winter” (yes, Los Angeles has one) often has a return leak pulling cold air from the crawl space. Sealing doesn’t just save energy; it evens out the temperature from room to room. We see this consistently in two-story homes in Sherman Oaks and Studio City where homeowners have been living with hot upstairs bedrooms for years.
There’s also an indoor-air-quality angle. Duct leaks on the return side pull air from whatever environment those ducts run through. Attic dust, crawl space mold spores, insulation fibers. When the return side is sealed, your system draws air from the rooms it’s supposed to instead of from the spaces between your walls. That’s why the technicians who handle sealing for us are the same ones trained on Duct Repair & Sealing in Los Angeles: the work overlaps, and doing both correctly requires understanding airflow, pressure, and filtration together.
Repair vs. Replace: How to Know Which You Need
This is the question behind almost every call we get. The honest answer depends on three things: the age of your ducts, the extent of the damage, and the material they’re made from.
Repair makes sense when: leaks are limited to visible joints, the ducts are metal or newer flex in decent shape, and the system is under 15 years old. A $400 sealing job can add 10 years of life to a sound system.
Replacement makes sense when: flex duct has torn along its length, insulation is crumbling or soaked from a roof leak, or you have hard-pipe ducts that have rusted through in multiple spots. Replacing the full duct system in a 2,000-square-foot Los Angeles home runs $3,500 – $7,500. That’s a big number, and we will not recommend it unless repair genuinely won’t hold. When we do recommend replacement, the price is in writing before any demolition starts.
The frustrating truth: many contractors jump to replacement because it’s a bigger ticket. That’s not how we operate. Dale Whitmore built this business on giving homeowners the straight answer, and the Kingswell Guarantee backs it: a written price before work begins, a defined arrival window, a clean job site, and a free return visit if the work fails within the guarantee period. That applies whether the job is $200 or $2,000.
How Duct Sealing Works (In Plain English)
If you’re going to pay for this, you should know exactly what’s happening. We use two methods, and we’ll recommend one based on your home’s specifics.
Mastic application. Mastic is a thick, pasty sealant that goes on with a brush or trowel. It never hardens completely, so it flexes with the duct as it expands and contracts through temperature swings. We apply it to every visible joint, seam, and connection, including where ducts meet the plenum at the air handler. It’s the workhorse method for accessible ductwork in attics and crawl spaces. For loose or separated sections, we first re-secure them with screws and UL-listed aluminum tape, then mastic over the top.
Aeroseal (pressurized sealing). Aeroseal uses a machine that pressurizes your duct system and injects a fine sealant mist. The mist finds its own way to every leak, including ones inside walls where no human hand can reach. It builds up at the edges of leaks until they’re sealed, typically closing off 90 – 95% of leakage in a single visit. It costs more, but for homes where leakage is concentrated in inaccessible areas, it’s the only effective option without cutting into drywall. Los Angeles homes with flat roofs and no attic fall into this category frequently; ducts run through the roof framing, and Aeroseal reaches what mastic can’t.
The equipment we use matters, and it’s not something you’ll find at a box store. Our rotational brush agitation systems from Rotobrush dislodge debris at the duct wall. Nikro negative-pressure units pull contaminants out of the system during cleaning. Abatement Technologies HEPA filtration keeps loosened particles from re-entering your living space. When we seal, we seal clean ducts, because mastic over dust is a waste of your money.
The 365-Day Done Right Promise, Explained
You’ve probably seen “satisfaction guaranteed” from a dozen companies. Here’s what ours means in concrete terms, because vague promises don’t help anyone.
Every job we do includes a written 365-Day Done Right Promise. If the sealing fails within one year, if the repaired duct separates, if you find a leak we told you we fixed, you call us. We come back and make it right at no charge. No negotiation, no “that’s not covered.” The promise is printed on every invoice, and you keep that document. A free second visit if the repair fails is not a courtesy; it’s a contract obligation we write down before the work starts.
The Kingswell Way governs how this actually plays out on site. Our technicians are background-checked and uniformed. They show up in the arrival window we gave you, not a four-hour span. They put down drop protection. They clean up after themselves, and they leave evidence of the work: pressure readings before and after, photos of the repairs, and a written record of what was sealed and where. If something goes wrong within that year, the same standards apply to the return visit. That’s what the 365-Day Done Right Promise means in practice, and it’s been in force since the business was founded in 2004.
What Duct Repair & Sealing in Los Angeles Should NOT Cost
Knowing what’s reasonable helps you spot a bad deal before you sign anything. Here are numbers that should raise an eyebrow.
- Sealing a single visible joint for more than $250. Access is usually simple, materials cost under $20, and the job takes under an hour.
- A “free estimate” followed by an upsell. Reputable companies, including us, give free estimates. The estimate should stand on its own; if the technician arrives and suddenly finds four other urgent problems that double the price, get a second opinion.
- Aeroseal quoted under $800. The equipment and certification cost thousands. Any price dramatically below market means either the operator isn’t certified or they’re planning to switch you to something cheaper once you’ve committed.
- Any quote for replacement ductwork without first pressure-testing your existing system. You can’t know if replacement is necessary without measuring leakage. If they quote replacement before testing, they’re guessing, and guesses favor the contractor’s wallet.
If you have a quote in hand and want a sanity check, call (213) 733-0665. We’ll walk through it with you honestly, even if that means telling you the other company’s price is fair. The Kingswell Way applies to conversations, not just job sites.
Duct Sealing and Los Angeles Code
Los Angeles has specific energy efficiency requirements that affect duct work, and it’s worth understanding where you stand. California’s Title 24 energy code mandates that new duct systems and major alterations meet specific leakage limits. For many retrofits, the code requires that duct sealing be verified by a pressure test. What does that mean for you if you’re repairing existing ducts rather than building new?
Existing homes don’t need to meet current Title 24 unless you’re doing a permitted remodel, but the standards are informative. If your system leaks less than 6% on a pressure test, you’re in good shape. Most unsealed homes in Los Angeles test at 20 – 40% leakage. Sealing toward that 6% target is an attainable goal, and it’s the number we use internally to verify our work. If your system tests at 12% after we’re done, that’s an improvement but not done right. The 365-Day Done Right Promise backs the standard we set: we test before and after, and if the after number isn’t where it should be, the job isn’t finished.
If you’re planning a remodel that passes through LADBS with plans and permits, duct sealing and pressure testing will likely appear in your project requirements. We can handle the sealing work, but our two services are air duct cleaning and dryer vent cleaning plus the repair and sealing that goes with them. For full HVAC system design or permits, you’ll need a licensed HVAC contractor. We’ll tell you that straight rather than pretending to be something we’re not.
Frequently Asked Questions About Duct Repair & Sealing Costs in Los Angeles
How much does duct sealing cost for a typical Los Angeles home?
Most single-family homes in Los Angeles run between $350 and $1,100 for duct sealing, with smaller jobs on accessible joints starting around $175 – $300 and full-system Aeroseal treatments reaching $1,200 – $2,500. The average job we complete sits near $650. Your specific number depends on leak count and accessibility. Call (213) 733-0665 for a free estimate with exact pricing in writing before work begins.
Does duct sealing actually reduce energy bills in Los Angeles?
Yes. Homes in Los Angeles typically lose 20 – 30% of conditioned air through duct leaks. Sealing those leaks usually cuts $30 – $60 off monthly peak-season utility bills, meaning a $600 sealing job pays for itself in one to two years. The savings continue for the life of the sealed ductwork. We can measure the leakage before and after so you see the difference in real numbers.
Is it cheaper to repair or replace my ducts?
Repair and sealing at $350 – $1,100 is almost always cheaper than full replacement at $3,500 – $7,500. Repair is the right call when leaks are at visible joints and the duct material is in decent shape. Replacement only makes sense when the duct itself has failed: torn flex duct along its length, rusted-through metal, or insulation that’s waterlogged from a roof leak. We recommend repair unless replacement is genuinely necessary, and we’ll show you the pressure-test evidence either way.
How long does duct sealing take?
Standard mastic sealing on a typical home takes 3 – 6 hours, often done in a single visit. Aeroseal treatment takes 4 – 8 hours including setup and pressure testing. Both are usually completed within one business day. We schedule a defined arrival window and show up in it. Call (213) 733-0665 to check current scheduling for your neighborhood.
Can you come today for duct repair in Los Angeles?
In many cases, yes. Our call center has a live person available 24/7, and we hold same-day slots for repair emergencies like a duct that’s fully separated and blowing attic air into your home. During peak summer months, same-day availability may be limited. Call (213) 733-0665 and we’ll tell you honestly when we can get there.
What is Aeroseal and is it worth the higher cost?
Aeroseal pressurizes your duct system and injects a sealant mist that finds and closes leaks even in inaccessible areas inside walls. It typically seals 90 – 95% of leakage and costs $1,200 – $2,500 in Los Angeles. It’s worth the price when your home has significant leakage in ducts you can’t reach, like in flat-roof Los Angeles homes without attics. If your leaks are all in accessible locations, traditional mastic sealing at $350 – $1,100 achieves similar results for less money. We’ll test your system and recommend whichever method fits, not whichever costs more.
Key Takeaways on Duct Repair & Sealing Cost in Los Angeles
- Expect to pay $350 – $1,100 for duct repair and sealing in Los Angeles, with small sealing jobs starting at $175 and full-system Aeroseal at $1,200 – $2,500.
- A $600 sealing job often pays for itself in 1 – 2 years through lower LADWP bills from reduced air leakage.
- Repair beats replacement on cost in most cases: $350 – $1,100 to repair and seal versus $3,500 – $7,500 to replace.
- You need a pressure test before and after to verify the work actually reduced leakage. We include this on every job.
- Every Kestrel job includes a written 365-Day Done Right Promise. If the repair fails within the year, we return and fix it at no charge.
- Estimates are free and binding. The written price is in your hands before any work starts, and that number doesn’t change at the door. Call (213) 733-0665.
Ready for an Honest Number?
We price duct repair and sealing with a pressure test, a visual inspection, and a walkthrough of your specific findings. Then we put the number in writing and leave it with you, no obligation. That’s the Kingswell Guarantee, and it’s been the standard on every job since 2004. If you’re tired of companies that guess, upsell, or change the price when they arrive, you’ll notice the difference in the first phone call. Call (213) 733-0665 now and ask for a duct sealing estimate. A live person answers, day or night, and the estimate is free.
Written by Dale Whitmore, Owner at Kestrel Air Duct Los Angeles, serving Los Angeles since 2004.
Pricing reflects the Los Angeles market as of 2026. Kestrel Air Duct Los Angeles offers free estimates – call (213) 733-0665.
What Our Customers Say
"Set up an appointment for the whole house plus the dryer line. They called the morning of to confirm, showed up in the window, and showed me pictures of the gunk they pulled out. Worth it."
- Terrence Boyd"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"Air smells cleaner and the work was good. One tech tracked a little dirt in near the back door, but he noticed it himself and wiped it up before leaving. Would use again."
- Olivia S.