Whole-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 Calabasas
Duct sealing in Calabasas typically runs $1,200 – $2,800 per HVAC system depending on duct length and accessibility, with most hillside homes needing two to three days for full multi-system work. Our Duct Sealing in Calabasas crews coordinate dispatch from our Los Angeles office and carry the specialized chemical baths and agitation tools needed for post-wildfire residue removal. We’re familiar with the long duct runs in Mulwood, the multi-zone systems in The Oaks, and the original flex duct still found in 1970s tract sections off Mulholland Highway. Call (361) 326-5060 for a written estimate before any work starts.
Why Hollis Air Duct Cleaning Is Calabasas’s Preferred Duct Sealing Company
We’ve been serving Calabasas since 2004 as part of the Garrison Partners family, and our reputation here was built on showing up inside the quoted window with background-checked, uniformed technicians who price the job in writing before touching anything. Calabasas homeowners aren’t looking for the lowest teaser quote; they’re looking for the quote that doesn’t change when the van pulls into the driveway.
Our Calabasas customers regularly mention the same thing in follow-up calls: they chose us because we answered the phone live, explained the per-system pricing upfront, and left documentation they could actually use. The 365-Day Done Right Promise covers every seal we apply. If a joint fails or a seal cracks within a year, we return and make it right at no charge, including a free second visit.
Response time to Calabasas neighborhoods like Calabasas Highlands, Bellagio, and Park Moderne is typically next-day or within 48 hours for standard duct sealing. We don’t promise same-day dispatch because this work requires proper inspection, written pricing, and scheduled access. That’s The Garrison Standard: arrive when we said, price it before we touch it, do it by the book.
Duct Sealing Services in Calabasas
Duct Sealing Services in Calabasas address a specific problem most homeowners don’t notice until their energy bills spike or rooms stop heating evenly: conditioned air escaping through gaps, joints, and deteriorated connections before it ever reaches the registers. In Calabasas, this problem is compounded by long duct runs in hillside homes, Santa Ana wind pressure forcing unfiltered air inward, and the Woolsey-era smoke residue that prevents standard sealants from bonding properly. A typical single-system seal runs $1,200 – $1,900; multi-system hillside homes with three zones often range $2,200 – $2,800.
Pre-Seal Inspection and Smoke Residue Removal
We don’t seal over problems. Our techs run camera inspection through the full duct run first, then apply chemical bath treatment and rotary agitation to remove any resinous smoke film. Sealant bonds to clean metal and properly prepared flex liner, not to sticky residue. This step adds half a day but prevents seal failure within months.

Joint Sealing and Mastic Application
We seal metal joints with UL-181 rated mastic, applied by brush to ensure full coverage at every connection. For flex duct sections, we replace deteriorated liner where needed, then seal with proper collars and clamps. Every sealed joint is photographed before and after for your documentation packet.

What happens when you call
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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 Calabasas
Duct Insulation in Calabasas protects sealed ductwork from the extreme attic temperatures that bake hillside homes in summer, when roof cavities can hit 140°F and undo the efficiency gains of sealing alone. Uninsulated or poorly insulated ducts in Calabasas attics lose 20 – 30% of conditioned air to thermal transfer. A typical insulation job runs $800 – $1,500 per system depending on linear footage and R-value needed. We use Guardsman and Aprilaire filtration-rated insulation products specified for the temperature swings in Southern California hillside construction.
Attic Duct Wrap and Thermal Barrier
We wrap sealed metal trunk lines with formaldehyde-free fiberglass insulation, secured with proper vapor barrier to prevent condensation in winter. For flex duct in Calabasas’s hot attics, we verify the existing insulation jacket is intact and add wrap where the original has compressed or torn. The goal is keeping the air you paid to cool actually cool when it reaches the register.
Insulation for Original 1970s Flex Duct
Original flex duct in Calabasas tract homes off Las Virgenes and Mulholland often has degraded insulation jackets that crumble on contact. We don’t just wrap over this; we replace sections where the inner liner is cracked, then insulate the new material properly. Sealing failing flex without addressing the insulation is a half-measure that costs more later.
Trusted Brands We Service in Calabasas
We stock parts and materials from Rotobrush, Abatement Technologies, Aprilaire, and Guardsman for Calabasas jobs, which means no waiting on shipped components when your multi-system home needs same-visit completion. Our Rotobrush rotary systems handle the agitation work inside long Calabasas duct runs. Abatement Technologies HEPA negative-air machines contain particles during smoke residue removal, protecting your home’s interior. Aprilaire and Guardsman filtration products integrate with sealed systems to maintain air quality after we’ve left. We don’t use hardware-store tape or generic sealants on Calabasas hillside homes; the temperature cycling and wind pressure here require materials rated for the application.
Common Duct Sealing Problems We See in Calabasas Homes
- Sealing over deteriorated original flex duct in 1970s-era tract sections. The cracked inner liner looks intact from outside, but sealant bonds to failing material and peels within a season. We replace compromised flex sections before sealing anything.
- Applying sealant before removing Woolsey-era resinous smoke residue. The sticky coating prevents proper adhesion and traps odor behind the seal. Our chemical bath step exists specifically for this Calabasas condition.
- Sealing only the main trunk on a three-system hillside home. Branch runs and registers still leak at every joint during Santa Ana wind events, pulling unfiltered attic air into living spaces. We seal the full distribution network or explain exactly why a partial seal won’t solve your problem.
- Ignoring insulation on long attic runs after sealing. Sealed ducts in 140°F Calabasas attics still bleed cooling through thin metal walls. We quote insulation as part of complete system efficiency, not as an add-on.
Pricing for Duct Sealing in Calabasas, CA
Duct sealing in Calabasas runs $1,200 – $1,900 for a single HVAC system with standard accessibility and duct length under 80 linear feet. Multi-system hillside homes with three zones, long runs, and smoke residue prep typically fall in the $2,200 – $2,800 range. Duct insulation adds $800 – $1,500 per system depending on footage and existing condition. These are whole-system prices, not per-vent teaser rates that balloon once we’re inside. We write the price down before any work starts. It doesn’t move at the door. What affects cost: number of systems, linear footage of ductwork, accessibility (crawl space vs. walk-in attic), presence of smoke residue requiring chemical prep, and whether insulation replacement is needed alongside sealing. Every estimate is free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Calabasas
Our crews work throughout the western San Fernando Valley and Ventura County corridor, including Calabasas neighbors Topanga, Agoura Hills, Oak Park, and Westlake Village. The same per-system pricing, written guarantees, and post-wildfire expertise apply across this service area.
Serving Calabasas, CA - Our Local Coverage Area
We’re based in the Calabasas 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 Calabasas
Calabasas duct sealing often requires pre-treatment with chemical baths and agitation tools to remove Woolsey Fire residue before sealant can bond properly, a step rarely needed in Woodland Hills homes outside the burn zone. Our Calabasas crews also price per system rather than per vent because hillside homes here average 2.7 HVAC systems compared to single-system norms elsewhere. Call (361) 326-5060 for a written estimate that reflects your home’s actual configuration.
Yes, we seal all systems or explain specifically why a particular system doesn’t need service after inspection. We price each system separately in writing so you know the full cost before we start. Multi-system hillside homes in The Oaks and Mulwood are our standard Calabasas job, not an exception. Call (361) 326-5060 to schedule inspection of all three systems.
You receive before-and-after photos of every sealed joint, a written summary of work performed on each system, the final price as quoted, and your 365-Day Done Right Promise in writing. For Calabasas multi-system homes, we also include system balance readings showing airflow improvement at each register. This documentation is your proof the work happened and your protection if something fails within the year. Call (361) 326-5060 to discuss what’s included.
Proper duct sealing reduces unfiltered air intrusion during wind events by closing the leaks that pull attic and exterior air into your system. In Calabasas, we combine sealing with source removal of existing smoke residue and upgraded filtration from Honeywell or Aprilaire to address both the pathway and the existing contamination. Sealing alone won’t remove residue already inside; we quote the full sequence for homes in the Woolsey burn zone. Call (361) 326-5060 for an inspection.
Original flex duct in 1970s Calabasas tracts typically has degraded insulation jackets that crumble when handled, so yes, insulation replacement or addition is usually necessary for full efficiency gains. We inspect the flex condition during our pre-seal camera work and quote insulation separately so you see the line-item choice. Sealing without insulation in a hot Calabasas attic leaves significant thermal loss unaddressed. Call (361) 326-5060 for a complete assessment.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Calabasas since 2004.




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