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 Castaic
Leaky ducts in Castaic don’t just waste conditioned air. They pull in whatever’s outside: fine dust off the hills, ash after fire season, and the grit that Santa Ana winds push through every gap in a home’s envelope. We seal ductwork in Castaic homes so the air you pay to heat or cool actually reaches the rooms it’s meant for, instead of bleeding into an attic. Our crew knows the tract-home layouts off The Old Road and the custom hillside builds above Castaic Lake. For a written quote before any work starts, call (661) 523-0295.
Why Hollis Air Duct Santa Clarita Is Castaic’s Preferred Duct Sealing Company
Hollis Air Duct Santa Clarita is part of the Garrison Partners family, and every job runs under The Garrison Code: arrive inside the quoted window, put the price in writing before touching anything, complete the work by the book, and leave the site clean. That matters in Castaic because homeowners here have real reasons to be skeptical. We hear it often: a crew quoted one number, then found “complications” once the van was in the driveway. With us, the price for duct sealing is written down before any work starts, and it does not move at the door.
Our technicians are background-checked and uniformed, so when the truck pulls up on a Castaic street, you know exactly who’s walking into your home. The equipment we run is professional-grade, including Rotobrush rotary brush systems and Abatement Technologies negative-air machines. Not hardware-store gear. Every sealed duct is covered by the 365-Day Done Right Promise, in writing, on every job. If the seal fails within a year, we come back at no charge. That’s not a sales line. That’s the standard, and it’s been the standard since 2004.
Styles & brands we work with




Duct Sealing Services in Castaic
Duct Sealing Services in Castaic means finding and closing the gaps, holes, and disconnected joints in your HVAC ductwork. Duct Sealing is not a cleaning add-on. It’s a repair process: we locate where air is escaping, then seal those points with mastic and metal tape so conditioned air goes where it should. In Castaic homes with long attic runs and multiple systems, unsealed joints are a more expensive problem than most people realize. You’re paying to cool or heat air that’s disappearing into the attic, while outside dust and ash get pulled in to replace it.
Sealing Long Attic Runs
Castaic homes built in the 1990s and 2000s often have flexible ducts stretched across large attic spaces. Those runs develop gaps at connections over time, especially where the original install was rushed. We inspect every accessible joint, then seal with mastic rated for HVAC use. A typical whole-home duct sealing job in Castaic runs $400 – $900, depending on the number of systems and how much of the ductwork is reachable.

Post-Pressure-Test Sealing
After we seal, we can verify the improvement. The difference in airflow at registers is usually noticeable within a day. Rooms that always ran hot in August or cold in January start holding temperature better. That’s the point: not a cleaner duct, a tighter system.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Duct Insulation in Castaic
Duct Insulation in Castaic is the other half of the efficiency problem. Ductwork running through an uninsulated attic in a Castaic summer sits in 130-degree heat. If the insulation around those ducts is thin, torn, or missing, the air inside loses temperature before it ever reaches your living space. We wrap or replace duct insulation where it’s deteriorated, which matters just as much as sealing. Sealed ducts that aren’t insulated still lose energy through heat transfer.
Replacing Deteriorated Duct Wrap
Older fiberglass wrap breaks down over time, especially in hot, dry attic conditions like the ones we see across the 91384 zip code. We remove damaged insulation and replace it with proper R-value material. Insulating exposed duct runs in a typical Castaic single-system home runs $350 – $800, depending on linear footage.
Attic Insulation Coating for Ductwork
Some Castaic homeowners ask about spray-on insulation options. We don’t cut corners with cheap paint-on products. We use the same wrap and sealing materials that commercial crews spec, because the attic is the last place you want to redo in two years.
Trusted Brands We Service in Castaic
We service and seal ductwork across all major HVAC equipment brands found in Castaic homes. Our technicians work with systems from Honeywell, Aprilaire, and Guardsman, among others, and we’re familiar with the duct configurations common in tract-home subdivisions near Castaic Elementary and the custom properties off Ridge Route Road. Because we stock standard mastic, tapes, and insulation materials on the truck, most sealing jobs in Castaic finish same-day without a second trip.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Castaic Homes
- Ash intrusion after wildfire season. Fine ash from the Santa Clarita Valley’s fire zones settles into ductwork through gaps at register boots. Even with windows closed, negative pressure in long flex runs pulls it through every unsealed joint. That ash re-enters the living space every time the fan runs.
- Construction debris in newer tract homes. Builders don’t seal ducts after drywall work. In Castaic homes built in the 1990s and 2000s, we regularly find drywall dust, sawdust, and even fast-food wrappers inside duct runs. Sealing the joints stops the debris from being redistributed by the blower motor.
- Santa Ana wind pressurization. During wind events, external air pushes against the house envelope. If register boots are unsealed at the sheetrock, that outside air, fine dust, and sometimes smoke odor, gets forced into the duct system and distributed through the home.
- Uneven temperatures between floors. Hillside homes above Castaic Lake often have multiple systems with long vertical chase runs. Unsealed joints in those chases bleed conditioned air into wall cavities. The result: upstairs stays hot in summer, downstairs runs cold in winter. Sealing those accessible joints evens out the pressure.
Pricing for Duct Sealing in Castaic, CA
In Castaic, whole-home duct sealing typically runs $400 – $900 for a single system. Homes with two or three separate HVAC systems, which is common in larger properties near Castaic Lake, will land higher because each system is priced separately. Duct insulation replacement in Castaic runs $350 – $800 per system, depending on how many linear feet of ductwork are exposed. We do not quote per-vent pricing. We give you one flat price per system, in writing, before any work starts. If the house has three systems, you’ll see three line items. No ambiguity. Call (661) 523-0295 for a free estimate, and we’ll walk the attic with you before quoting.
We Also Serve Cities Near Castaic
Our crews regularly serve Castaic and the surrounding communities, including Stevenson Ranch, Santa Clarita, Porter Ranch, and Chatsworth. If you’re in one of those areas and need duct sealing, the same written pricing and 365-Day Promise apply. Call (661) 523-0295 and we’ll schedule a visit.
Serving Castaic, CA - Our Local Coverage Area
We’re based in the Castaic 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 Castaic
Wildfire smoke enters homes through attic vents, crawl spaces, and any gap in the building envelope, then gets pulled into ductwork through unsealed joints. In Castaic, where fire season is a recurring reality, we often find a fine layer of ash inside ducts even in homes where windows were never opened. Sealing all accessible joints is the most effective way to prevent smoke particulate from entering the system that circulates your air. Call (661) 523-0295 for a post-fire inspection and quote.
Per-system pricing means each HVAC unit and its connected ductwork is quoted as its own line item. In a large Castaic home with three separate systems, a vague “whole house” estimate can hide what’s actually being done. We walk each system with you, document what needs sealing, and write the price per system. That way you know exactly what one price covers and where your money is going. For an exact breakdown, call (661) 523-0295, estimates are free.
You should receive before-and-after photos of every sealed connection, plus a written description of what was found and what was done. We use a camera inspection before and after the work, and we take photos at each accessible joint we seal. If you can’t see into your attic, the photos are your proof. That documentation is part of every job, not an add-on. Call (661) 523-0295 to schedule a duct sealing inspection with camera documentation included.
Yes, if the dust is coming from inside your ductwork or being pulled through gaps in the system. In Castaic, fine dust from the hills and open space around the community gets pulled into unsealed attic ducts. Sealing the joints stops the intake path. If dust is re-entering from inside the ducts themselves, you may also need a duct cleaning performed before sealing. We’ll diagnose the source during the inspection. Call (661) 523-0295 for a quote.
Newer tract homes often need duct sealing more than older ones, because builders leave joints unsealed and construction debris inside the ducts. In Castaic homes built in the 1990s and 2000s, we regularly see original drywall dust and sawdust inside supply runs. The ductwork is newer, but it was never properly sealed after construction. Sealing those joints is a preventive job that pays off in efficiency and cleaner air. Call (661) 523-0295 and we’ll inspect your system, free estimate included.
At a 1990s tract home near Castaic Lake, we sealed three separate supply runs after our camera inspection found gaps where construction debris and fine ash had accumulated. Our crew used agitation tools and HEPA filtration to source-remove the buildup, then applied mastic and metal tape to all accessible joints, and we documented every sealed connection with before-and-after photos for the homeowner.
If you’re in Castaic and tired of dust returning days after cleaning, uneven room temperatures, or air that smells like the attic, call (661) 523-0295. We’ll inspect your ductwork, give you a written price before any work begins, and stand behind every seal for a full year.
Written by Roy Castellanos, Owner at Hollis Air Duct Santa Clarita, part of the Garrison Partners family serving Castaic since 2004.