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.
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AfterFast, Reliable Duct Sealing Across Altadena
We seal ducts in Altadena homes where the San Gabriel Mountains meet the foothills, and we know this town’s schedule runs on Santa Ana wind advisories, not spring calendars. Our dispatch office in Los Angeles coordinates crews who serve Altadena directly, with same-week availability for most sealing jobs and written prices before any work starts. Call us at (361) 326-5060 for a free estimate, or read on to understand why duct sealing in Altadena is different from anywhere else in the Pasadena Valley.
Why Hollis Air Duct Cleaning Is Altadena’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Duct Sealing crews have worked the specific housing stock that defines Altadena: pre-1940s Craftsman bungalows on raised foundations, Spanish Revival homes with converted gravity furnaces, and post-war ranch houses with decades of piecemeal duct additions. Roy Castellanos leads our operation, and every technician who enters an Altadena home arrives background-checked, uniformed, and operating under The Garrison Standard: arrive inside the quoted window, price in writing, complete the job by the book, leave the site clean.
Our phones are answered by a live person 24 hours a day, seven days a week. No voicemail loops. No callback queues. When you’re calling because last night’s wind advisory pushed smoke smell through your registers, you talk to a human who can schedule.
Every job carries our 365-Day Done Right Promise in writing. If the seal fails or the smoke smell returns within a year, we come back at no charge. That includes a free second visit, not a negotiation.
HVAC Duct Sealing in Altadena
HVAC Duct Sealing in Altadena is typically an event-driven service, scheduled in the days after Santa Ana wind advisories or red flag warnings rather than on a routine maintenance calendar, because ember-laden gusts through the north-facing canyons force fine ash and char particulate into leaky return-side connections before the system is ever run again. The job involves locating every leak point in your supply and return ductwork, then sealing joints, seams, and connections with mastic and mesh reinforcement to create a closed system that moves conditioned air only where it’s designed to go.
A typical HVAC duct sealing job in Altadena runs $450 – $1,200 for a whole-home system, depending on accessibility and the condition of existing ductwork. Homes with original gravity furnace conversions or extensive crawlspace runs fall at the higher end. We write the price down before touching anything, and it does not move at the door.
Sealing After Wildfire Smoke Events
Because the 2020 Bobcat Fire burned to Altadena’s northern foothill edge, we’ve seen a distinct pattern: homeowners north of Altadena Drive call us within 48 hours of a red flag warning, reporting char smell in supply registers even when the HVAC hasn’t run. The smoke is entering through leaky return-side connections and crawlspace chases, then distributing when the blower finally cycles. Sealing these entry points stops the intrusion at its source rather than masking it with filters or deodorizers.
Crawlspace and Raised-Foundation Work
Many Altadena homes sit on raised foundations with accessible crawlspaces, but “accessible” is relative in a 1923 Craftsman. Our techs navigate tight spaces to reach original duct chases, seal trunk-to-branch connections, and replace dry-rotted flex connectors that Altadena’s hot, dry air has degraded faster than coastal climates would allow.
Duct Repair in Altadena
Duct Repair in Altadena often means addressing the cumulative damage of decades on original sheet-metal or early flex duct systems that were never designed for modern forced-air loads. We replace collapsed sections, reconnect separated joints, and rebuild plenum connections that have failed from vibration, age, or rodent intrusion in crawlspaces. A typical duct repair in Altadena runs $280 – $650 for localized fixes, or $800 – $1,800 when we’re rebuilding significant portions of a deteriorated system.
Our field crews carry the tools for this: Rotobrush rotary brush systems for mechanical agitation, Nikro negative-air machines for controlled debris extraction, and the mastic, mesh, and mechanical fasteners to rebuild connections that will hold under pressure.
Gravity Furnace Conversions
The converted gravity furnaces common in Altadena’s pre-1940 housing stock create unique repair challenges. Original sheet-metal trunks are often undersized for modern blowers, leading to pressure imbalances that separate joints. We reinforce these systems where possible and recommend full replacement when the metal fatigue is too advanced.
Exterior Attic Ductwork on North-Side Homes
Homes bordering the Angeles National Forest frequently have duct runs in exterior attics exposed to ember-laden Santa Ana winds. These runs suffer seal degradation that crawlspace-only inspections miss. We check them explicitly, because a sealed crawlspace means little if the attic trunk is pulling wildfire-exposed outdoor air.
Trusted Brands We Service in Altadena
We seal and repair duct systems connected to equipment from every major manufacturer, and we stock sealing materials and replacement components for fast turnaround on Altadena jobs. Our equipment roster includes Rotobrush rotary brush systems and Nikro negative-air machines for source removal before sealing, plus filtration products from Honeywell, Aprilaire, and Guardsman. For sealing itself, we use professional-grade mastic and mesh systems, not hardware-store tape. When we leave an Altadena job, the materials in your ducts are rated for the temperature swings and dry conditions that degrade lesser products.
Common Duct Sealing Problems We See in Altadena Homes
- Dry-rot in flex connectors at trunk-to-branch takeoffs. Altadena’s hot, dry air and seasonal temperature swings crack flex duct and degrade old mastic faster than in coastal climates. We replace these connectors and seal with fresh mastic and mesh during every sealing job.
- Cloth duct tape failures on original gravity furnace conversions. Previous owners often taped gaps with standard cloth duct tape, which dries and falls away within months in Altadena’s climate. We remove it entirely and seal with proper mastic.
- Inaccessible crawlspace chases on raised-foundation Craftsman homes. The long horizontal runs under 1920s bungalows are frequently too collapsed or obstructed to reach. We seal at accessible points, register boots, and plenums, then document what remains unsealed so homeowners understand their system’s limitations.
- Exterior attic ductwork penetrated by ember-laden winds. North-side homes with attic runs exposed to Santa Ana gusts often have seal degradation that standard crawlspace-focused sealing misses. We inspect these runs explicitly on every north Altadena job.
Pricing for Duct Sealing in Altadena, CA
Whole-home duct sealing in Altadena typically runs $450 – $1,200. Localized sealing of accessible trunk and branch connections runs $280 – $550. Full system rebuilds on deteriorated pre-1940s homes with extensive crawlspace work can reach $1,500 – $2,400. What moves the price: accessibility of crawlspace chases, extent of flex connector replacement needed, whether exterior attic runs require attention, and the condition of existing plenum connections.
We do not quote per-vent prices. We do not offer teaser coupons that balloon once the van is in your driveway. We inspect, we write one flat price per system, and that price is agreed before work starts. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Altadena
Our crews work throughout the Pasadena Valley and San Gabriel foothills, including Duct Sealing in Altadena and surrounding communities: Pasadena to the south, San Marino to the southeast, Sierra Madre to the east, and South Pasadena to the southwest. Each job carries the same written price guarantee and 365-Day Done Right Promise, regardless of city.
Serving Altadena, CA - Our Local Coverage Area
We’re based in the Altadena 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 Altadena
Seal ducts in Altadena after every significant Santa Ana wind event or red flag warning that produces visible smoke or ash, and plan a full inspection every 3 – 5 years for routine maintenance. The event-driven schedule matters more than calendar cleaning here. Call (361) 326-5060 after the next advisory and we’ll assess whether your seals held.
Smoke smell enters through leaky return-side connections and crawlspace chases, then sits in the ductwork until the blower distributes it. The system doesn’t need to run during the wind event for contamination to occur. Sealing these entry points with mastic and mesh stops the intrusion at its source rather than treating symptoms with filters or deodorizers.
Yes, sealing helps significantly even on converted gravity systems, though the original sheet-metal trunks and undersized branches create pressure challenges that modern ductwork doesn’t face. We seal accessible joints, replace dry-rotted flex connectors, and document any crawlspace runs that remain inaccessible. The improvement in airflow and reduction in smoke intrusion is measurable even on these older systems.
Yes. Altadena’s hot, dry air and wide seasonal temperature swings accelerate dry-rot in flex duct and cause mastic to crack and separate faster than in coastal or more temperate climates. Seals that might last 10 years elsewhere often need attention in 5 – 7 years here, which is why we use professional-grade materials rated for these conditions.
Yes, we seal ductwork in detached structures, though these systems often have additional exposure to dust, pollen, and temperature extremes on Altadena’s low-density foothill lots. The same written pricing and 365-Day Done Right Promise applies. Call (361) 326-5060 to describe the system and we’ll schedule an inspection.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Altadena and the San Gabriel foothills since 2004.