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.
Fast, Reliable Duct Sealing Across Sylmar
Duct sealing in Sylmar typically costs between $450 and $1,450 depending on how much of your ductwork is accessible and how many leaks we find. Most jobs are completed in a single day, and you get a written price before any work starts. Sylmar’s position against the San Gabriel Mountains means your ducts work harder than they should, pulling in dust and leaking conditioned air into attics and crawlspaces. If you also need Sylmar Dryer Vent Cleaning, we handle that too. Call (661) 523-0295 for a straight answer and an honest quote.
Why Hollis Air Duct Santa Clarita Is Sylmar’s Preferred Duct Sealing Company
We’ve sealed ducts in homes along Foothill Boulevard, in the neighborhoods off Hubbard Street, and up in the newer hillside developments near Olive View. Each job starts the same way: a camera inspection of your ductwork, a written price, and a clear explanation of what we found. No pressure, no moving target at the door.
Our technicians are background-checked and uniformed, and they arrive inside the quoted window. The work is covered by our 365-Day Done Right Promise in writing. If a sealed joint fails within a year, we come back and fix it at no charge. That’s the standard, not a talking point.
Sylmar homes present a specific set of problems. We know what original 1960s metal ductwork looks like, we know where the leaks tend to hide, and we know how to work around asbestos-containing duct wrap without disturbing it. That local familiarity changes the quality of the result. Roy Castellanos runs our operation, and he expects every job to meet The Garrison Code: arrive on time, price in writing, complete the work by the book, leave the site clean.
Styles & brands we work with
Duct Repair in Sylmar
Duct Sealing starts with finding out what’s actually wrong, and in Sylmar that often means repairing ducts before or instead of sealing them. Duct repair covers disconnected joints, crushed runs under the house, sagging sections in the attic, and holes punched through by rodents or careless work during remodels. A simple disconnected joint in a crawlspace might run $120 – $250 to reconnect and seal. A crushed return duct that needs replacing can run $350 – $800 depending on length and access.
Disconnected and Crushed Runs
Sylmar’s older homes, many built in the 1950s through the 1970s, often have metal duct runs held together with original mastic that has crumbled to powder. When those joints separate, your system pulls air from wherever it sits: hot attic air in summer, dusty crawlspace air year round. We reconnect the runs and seal every accessible joint with fiberglass mesh and mastic, not tape that peels in two years.
When Repair Isn’t Enough
Sometimes the damage is too extensive. A return plenum that’s collapsed or a supply trunk that’s rusted through from condensation needs replacement, not sealing. We’ll show you the camera footage and explain the difference. The written quote tells you exactly what each option costs before you commit to anything.
Air Duct Sealing in Sylmar
Sylmar homes need air duct sealing because the original construction rarely included it. Air duct sealing means closing every accessible leak in your ductwork so the air your system heats or cools actually reaches your living spaces instead of escaping into the attic or crawlspace. In Sylmar’s mid-century homes, it’s common to find a 15°F temperature difference between supply and return air in unsealed ductwork, a gap that forces your blower motor to run far longer than it should.
Sealing Original Metal Ducts
We seal accessible joints with fiberglass mesh and mastic, the same combination commercial HVAC crews use. It doesn’t crack like old tape, and it holds up to Sylmar’s extreme heat without drying out and failing. Where ducts run through the crawlspace, we work from underneath, sealing every joint we can reach without disturbing the home’s structure.
Negative-Pressure Capture
When we seal ducts in an older Sylmar home, we use a negative-air setup to keep the dust we inevitably stir up from spreading through your house. The work under a 1960s home involves decades of accumulated dust, and the last thing you want is that dust pushed into your living room. We capture it at the source.
Trusted Brands We Service in Sylmar
We work on HVAC systems from all major manufacturers, and when we seal ducts we use professional-grade materials built for the trade. We also provide Sylmar Carrier service for homes with that equipment. Our equipment includes Nikro negative-air machines that keep dust contained during the job, and we spec filtration products from Honeywell and Aprilaire if your system needs better air cleaning once the ducts are sealed. The point is simple: we bring commercial-grade tools to a residential job, and we explain what each one does in plain English before we use it. If you’re in Sylmar and your current HVAC contractor can’t find the source of a leak, call us. We’ll find it.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Sylmar Homes
- Original unsealed metal ducts: Homes built in the 1960s and early 1970s along Glenoaks Boulevard and in the flatlands near Hubbard Street often have ductwork with no sealing at all beyond original mastic that’s now dust. Those gaps leak conditioned air into the attic all summer.
- Santa Ana dust through return ducts: Sylmar’s position against the San Gabriel Mountains means strong wind events push fine mountain dust and wildfire ash into attic returns. Unsealed return ducting pulls that dust straight into your blower motor and evaporator coil, clogging both.
- Crushed crawlspace runs: The soil under many Sylmar homes shifts over decades, and duct runs that were once level can sag or crush. A crushed return duct means your system is starving for air, and a crushed supply run means a room never heats or cools correctly.
- Asbestos-containing duct wrap: Homes built from the 1950s through the 1970s sometimes have duct insulation containing asbestos. Disturbing it is dangerous and illegal to do casually. We know how to identify it, and we’ll tell you if abatement is required before any sealing work can proceed.
Pricing for Duct Sealing in Sylmar, CA
Whole-house duct sealing in Sylmar runs $450 to $1,450 for most homes. The range covers how much ductwork is accessible, how many leaks we find, and whether we need to do repair work before sealing. A single-story home with a crawlspace tends to be more accessible than a hillside home with attic ducting. Here’s what to expect:
- Sealing accessible joints only: $450 – $750
- Sealing plus minor repairs (reconnecting joints, sealing small holes): $700 – $1,100
- Sealing plus replacing a damaged run or return: $1,000 – $1,450
You get a written price before we start, and that price does not move at the door. No per-vent pricing, no surprise line items. Call (661) 523-0295 for a free estimate specific to your home.
We Also Serve Cities Near Sylmar
Our Duct Sealing in Sylmar service area includes the surrounding communities. We regularly seal ducts in San Fernando, Mission Hills, Granada Hills, and Panorama City. Same standard, same written guarantee: a 365-Day Done Right Promise on every job, no exceptions.
Serving Sylmar, CA - Our Local Coverage Area
We’re based in the Sylmar area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Duct Sealing in Sylmar
You need sealing if the ducts are intact but leaky, and you need replacement if the metal is rusted through, crushed, or so badly deteriorated that mastic won’t hold. We’ll run a camera through your ductwork and show you the footage. Most 1960s-era ducts in Sylmar are good candidates for sealing, especially if you’ve already had a cleaning and the airflow is still weak. Call for a camera inspection and a written quote either way.
Sealing will reduce it significantly. The dust entering your registers during a wind event comes through leaks in your return ducting, which pulls attic air directly into the system. Sealing those return runs stops the pathway. You’ll still need regular filter changes and periodic cleaning, because Sylmar gets dust from the San Gabriels that most of Los Angeles doesn’t. But sealing cuts the volume dramatically.
If the asbestos-containing wrap is intact, we can often seal accessible joints without disturbing it. If the wrap is crumbling or has already been damaged by previous work, state law requires licensed abatement before sealing can proceed. We’ll tell you plainly what you’re dealing with and whether you need an abatement contractor first. We don’t touch asbestos-containing material, and we won’t pretend it isn’t there.
Yes. In Sylmar’s summer heat, a system with 25% or 30% duct leakage works that much harder to move the same amount of air. A 15°F differential between supply and return air is common in unsealed ductwork, which means your AC is cooling air that never reaches your rooms. Sealing the ducts fixes that waste directly. Your blower cycles less, and the temperature in your house becomes more consistent.
In most cases, yes. We seal from inside the crawlspace, working under the home rather than through the floor. It’s not easy work, but it’s the right way to do it. We’ll inspect first and tell you if access is too tight or if the soil has shifted enough to make some runs unreachable. Call (661) 523-0295 and we’ll give you an honest assessment.
Call (661) 523-0295 for a free duct sealing estimate in Sylmar. Written price before we start, 365-Day Done Right Promise in writing, background-checked technicians. That’s the whole agreement.
Written by Roy Castellanos, Owner at Hollis Air Duct Santa Clarita, serving Sylmar and the surrounding San Fernando Valley.