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 Northridge
Duct sealing in Northridge usually costs between $450 and $950 for a typical single-story ranch home, depending on how many leaks we find and how much straightening the attic flex ducts need first. That’s the honest range, and you’ll have it in writing before we touch anything. If you’re feeling weak airflow in the far bedrooms or seeing dust settle back onto furniture within days of cleaning, the problem is rarely the AC unit itself. It’s the ductwork in the attic bleeding conditioned air into spaces nobody lives in. Call (661) 523-0295 and we’ll send a background-checked technician to Northridge to find exactly where the air is going.
Roy Castellanos leads our crews, and he’s seen every failure mode a Northridge attic can produce. From kinked flex ducts in post-1994 rebuilds to mastic peeling off dust-choked sheet metal, the work here is different from coastal neighborhoods. It starts with understanding what the Santa Ana winds and wildfire seasons do to the air moving through your home.
Why Hollis Air Duct Santa Clarita Is Northridge’s Preferred Duct Sealing Company
We answer the phone with a live person, 24 hours a day. When you call about duct sealing in Northridge, you won’t sit through a voicemail tree or wait for a callback that never comes. You’ll describe the problem, we’ll schedule a window, and the technician who shows up is background-checked, uniformed, and driving a truck stocked with the right equipment for your attic.
Our Northridge customers tend to ask the same three things: Will the price change once you’re inside? Will you actually fix the airflow, or just patch the joints? What happens if the repair fails? The answer to each is written into the job before work begins. One flat price per system, agreed in writing. A camera inspection before and after so you can see the condition of your own ducts. And the 365-Day Done Right Promise: if a sealed joint fails within a year, we come back at no charge. That includes a free second visit, not a prorated credit or an argument. Roy Castellanos insists on this standard because most of our Northridge work comes from homeowners who already paid someone else to do it wrong the first time.
We coordinate scheduling from the brand’s Los Angeles office, and crews serve Northridge directly. That means shorter waits and a technician who knows the difference between a Porter Ranch attic and a Chatsworth crawlspace.
Styles & brands we work with
HVAC Duct Sealing in Northridge
HVAC Duct Sealing in Northridge means finding every place conditioned air escapes before it reaches your registers, then closing those leaks with mastic, metal tape, or Aeroseal where appropriate. In Northridge, the job almost always starts with an inspection of the attic flex duct, because that’s where the real losses happen. The hot, dry summers here bake ductwork for months at a time, and the flex duct common in 1950s-to-1980s ranch homes breaks down faster than rigid metal. Sealing leaks only helps if the ducts are still round and open. We straighten collapsed sections first, then seal.
Where Air Escapes in Northridge Attics
The registers in your ceiling aren’t the main leak point. In Northridge, most loss happens at the plenum connections, the takeoff collars where branch ducts meet the trunk line, and along the flex duct itself where the inner liner separates from the insulation jacket. If your system was installed or reworked after the 1994 earthquake, those connections may have been rushed. Undersized returns are common in those rebuilds, which means the system pulls hard enough to suck attic dust and insulation particles through any gap in the return path and straight into the air handler.
What Our Sealing Process Includes
Our Duct Sealing team starts with a camera inspection so you see the condition of the ducts before we recommend anything. We don’t sell sealing to a homeowner whose ducts are collapsed beyond repair; we show them the footage and recommend replacement. If sealing is the right call, we clean the surface first. Mastic won’t bond to a dust-choked duct, and applying it over debris is how you get callbacks. Then we seal every accessible joint, verify the repair with a second camera pass, and leave the attic neater than we found it.
Duct Repair in Northridge
Duct Repair in Northridge is the part of the job that doesn’t show up in most online searches, which is why so many homeowners here have paid for sealing that didn’t solve their problem. A kinked flex duct can’t be sealed back into shape. It has to be straightened or replaced. We’ve seen this so many times in Northridge that we start every quote with a visual check of the attic duct runs before we talk about sealing compound. If your far bedroom barely blows air while the living room freezes, you probably have a collapsed duct, not a dirty filter.
When Sealing Isn’t Enough
Sealing around registers in a Northridge slab-foundation ranch home misses the real loss. The problem is often the long, undersized return ducts that pull insulation and wildfire ash into the air handler. That dust then coats the blower motor, the evaporator coil, and everything downstream. You can seal every joint in the system and still have dusty air because the returns are pulling from the attic instead of the rooms. Repair here means correcting the return path, then sealing it properly.
How We Verify the Fix
After straightening or replacing damaged duct sections, we seal the joints with mastic rated for the temperature swings in a Northridge attic, which can hit 140°F in August. Then we run the system and measure airflow at the registers to confirm the far rooms are getting what the system was designed to deliver. The homeowner sees the before-and-after readings in writing, alongside the final price. That’s the Garrison Standard, and it applies to every duct repair job we do in Northridge.
Trusted Brands We Service in Northridge
We stock parts and sealing materials that match the systems already installed in Northridge homes. That includes filtration products from Aprilaire and Guardsman, which are common on the furnace and air handler upgrades that followed the 1994 rebuilds. When a Northridge homeowner needs a replacement filter housing or a sealing collar for an existing Aprilaire cabinet, we usually have it on the truck. For jobs that require source-removal cleaning before sealing, we use Rotobrush rotary brush systems and Abatement Technologies negative-air machines, the same professional-grade gear used on commercial jobs. No hardware-store tape, no shortcuts. If your Northridge home has one of these systems, we can service it correctly the first visit.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Northridge Homes
- Kinked attic flex ducts left sealed but still collapsed. A previous contractor sealed the joints around a kink but never straightened the duct. The system stays starved for air, and the homeowner pays twice. We check for flow before we seal anything.
- Mastic applied over dust-choked flex duct that peels away within a season. Duct sealing works only if the surface is clean. Northridge attics collect a fine film of Santa Susana Pass dust and wildfire ash. We clean first, then seal.
- Sealing registers on a slab-foundation ranch home while the real loss is in the returns. Northridge homes built between 1950 and 1980 often have long, undersized returns that pull attic air into the system. Sealing the supply side alone does nothing for the dust blowing out of the vents.
- Post-1994 rebuild shortcuts: hastily installed flex duct runs with undersized collars and loose takeoffs. Many Northridge systems were reinstalled fast after the earthquake. Connections get loose, inner liners tear, and airflow drops. We repair the run, then seal the entire path.
Pricing for Duct Sealing in Northridge, CA
A typical whole-system duct sealing job in Northridge runs between $450 and $950. That covers cleaning the surface, sealing accessible joints with mastic or metal tape, and verifying the repair with a camera inspection. If we find kinked or collapsed flex ducts, the repair work is quoted separately, usually $150 to $300 per damaged run depending on length and access. Long runs in single-story ranch homes with low-pitch attics take longer and cost more than short runs with easy walk-in access. You’ll see every number in writing before we start. No per-vent pricing games, no coupon that turns into a bigger invoice once the technician is on your driveway. Call (661) 523-0295 for a free estimate, and Roy Castellanos will make sure the price on paper is the price you pay.
We Also Serve Cities Near Northridge
Our crews cover Duct Sealing in Northridge and the surrounding San Fernando Valley communities, including Reseda, Porter Ranch, Chatsworth, and Granada Hills. If you live in one of these areas, the same written pricing and 365-Day Done Right Promise applies. Call (661) 523-0295 and we’ll schedule a window that works for you.
Serving Northridge, CA - Our Local Coverage Area
We’re based in the Northridge 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 Northridge
Wildfire ash settles into ducts and coats the surface where mastic needs to bond, so sealing without cleaning first produces a repair that peels off within a season. In Northridge, every sealing job starts with source-removal cleaning, not just a quick wipe. We use negative-air machines that pull ash and dust out of the system while the rotary brush scrubs the inner walls, then we seal the joints once the surface is actually clean. If your Northridge home sits near the Santa Susana Pass, the ash load is heavier and cleaning takes longer; we quote that honestly up front. Call (661) 523-0295 for a price that reflects the condition of your ducts, not a generic number.
Many HVAC systems in Northridge were reinstalled quickly after the 1994 earthquake, often with undersized returns, long flex duct runs, and takeoffs that were never secured properly. Those rushed connections have been working loose for decades, and they leak. An older system that was originally installed with care may have issues from age, but the rebuild-era systems leak at the joints because they were never right to begin with. Our Duct Sealing process checks for both: loose connections from the rebuild era and age-related liner failure in flex ducts, then seals what’s worth sealing and says so plainly when replacement is the better call.
Sealing a kinked flex duct improves nothing because the kink itself blocks airflow regardless of how tight the joints are. In Northridge, where post-earthquake rebuilds left many long flex runs with sharp bends above the air handler, we straighten the duct first and then seal the run. If the inner liner has torn, the duct needs replacement. A homeowner near Reseda Boulevard off the Northridge Fashion Center once showed us a flex duct so badly kinked that the blower motor was laboring against 60% of its designed airflow. We straightened the run, sealed the joints with mastic, and verified the repair with a camera inspection so the far bedroom finally delivered air. If your Northridge home has a collapsed flex duct, call (661) 523-0295 and we’ll tell you honestly which fix it needs.
In Northridge, we recommend inspecting ductwork every two to three years after a sealing job, because the hot summers and Santa Ana winds stress joints and flex duct liners faster than in coastal neighborhoods. But a properly sealed and straightened system should hold for five years or more before needing attention again. The biggest factor is whether the attic stays clean and the ducts stay round. If you add filtration equipment from Aprilaire or Guardsman, you reduce the dust load on the system and extend the life of the seals. Call (661) 523-0295 for an inspection and we’ll give you a realistic interval based on what your attic actually shows us.
No, because the dust entering a Northridge home from the foothills often comes through the return side, not the supply side. Slab-foundation ranch homes with long, undersized returns pull attic air, insulation particles, and wildfire ash directly into the air handler. Sealing just the supply ducts leaves that path wide open, and you’ll still see dust settling on furniture within days. A correct Duct Sealing job in Northridge addresses both the supply and return paths, especially the return runs that pass through the dusty attic space. Call (661) 523-0295 and we’ll show you where your dust is actually entering the system.
Written by Roy Castellanos, Owner at Hollis Air Duct Santa Clarita, serving Northridge homeowners with written pricing and the 365-Day Done Right Promise.