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 Wilmington
Duct sealing in Wilmington typically runs $350 – $850 for a full supply-and-return sealing job on a single-family home, and most jobs are completed in one visit. We schedule Wilmington homeowners inside a 2-hour arrival window, and the price is written down before any work starts. If you’re losing airflow at the registers or a musty smell won’t leave the hallways of a 1950s bungalow off Avalon Blvd, call (562) 548-7365 and we’ll explain exactly what’s involved, what it costs, and whether sealing is even the right fix for your home.
We work in Wilmington every week. Our crews know the difference between a 1920s Craftsman near Banning Park and a 1960s tract home off L Street: different duct layouts, different crawl spaces, different failure points. That local knowledge changes how we price the job, what we inspect first, and whether the problem is really a leak or something else wearing a leak’s clothes.
Why Hollis Air Duct Long Beach Is Wilmington’s Preferred Duct Sealing Company
Hollis Air Duct Long Beach has been at this since 2004 as part of the Garrison Partners family, and Wilmington homeowners keep calling because we write down the price before we touch the ductwork, then stand behind the work for a full year. The 365-Day Done Right Promise isn’t a slogan. If a seal fails, we come back at no charge and make it right. A free second visit is included, not negotiated. That matters in a trade where too many companies get the van on the driveway and suddenly find “additional work.” We don’t operate that way.
Our technicians are background-checked, uniformed, and they arrive inside the quoted window. When you call, a live person answers, 24/7. No voicemail loops, no “we’ll call you back Monday.” Wilmington residents dealing with a return duct pulling in harbor dust at 7 a.m. on a Saturday should be able to talk to someone who can help that day.
Roy Castellanos leads Hollis Air Duct Long Beach under The Garrison Standard: arrive inside the window, price in writing, complete the job by the book, leave the site clean. We’ve applied that same standard to thousands of local systems, including the aging galvanized runs common in Wilmington’s older housing stock.
Styles & brands we work with
HVAC Duct Sealing in Wilmington
HVAC Duct Sealing in Wilmington is a different job than it is ten miles inland, because the air moving through those ducts carries harbor soot, diesel particulates, and marine-layer humidity that leaves a greasy film on every surface it touches. In a city where a meaningful number of homes sit within a mile of the Port of Los Angeles, the Alameda Corridor rail line, or the truck routes on Avalon Blvd, duct leaks don’t just waste conditioned air. They actively pull grit and moisture into the system from crawl spaces and wall cavities. That’s the first thing we check when a homeowner reports weak airflow or a persistent musty odor.
Here’s what the job actually involves. We camera-inspect the accessible supply and return runs to find where the separation is and what’s being pulled in. Then we remove the contamination before sealing, because mastic or tape applied over a greasy soot film will peel off in sheets within a season. Only after the surfaces are clean do we seal accessible joints with duct mastic and UL 181 foil tape. A full sealing job on a typical Wilmington single-story home runs $350 – $850 depending on how many accessible runs exist and how deteriorated the original connections are.
Supply and return leaks
Supply-side leaks push conditioned air into the crawl space or attic before it ever reaches your living room, which means you pay to heat or cool the space under your house. Return-side leaks pull unfiltered air, dust, and humidity directly into the blower. In Wilmington, return leaks are the bigger problem near Avalon Blvd and the rail corridor, because that unfiltered air carries diesel soot.
Trunk-to-branch joint separation
On older galvanized duct systems in 1950s and 1960s homes, the joints between the main trunk and the branch runs have usually lost their original sealant decades ago. What’s left is a gap that flexes every time the blower cycles. We see this constantly in the tract homes between Wilmington Boulevard and L Street. It’s the single most common source of both dust and humidity-related odor.
Duct Repair in Wilmington
Duct Repair in Wilmington usually means one of three things: reconnecting separated joints, replacing crushed or corroded duct sections, or patching holes that rodents and time have opened in flex runs. In older Wilmington homes with original metal ductwork, the repair is often structural, not just cosmetic. A disconnected return run under a 1940s bungalow near Banning Park can pull in so much crawl space dust that you’ll find a gray film on the return grille within a month.
We inspect before we quote. A camera inspection tells us where the separation is, whether the duct material is still worth repairing, and whether sealing alone will solve the problem or the section needs replacement. Repair pricing in Wilmington generally runs $150 – $450 per damaged section, depending on access and the extent of the corrosion. If the damage is isolated to one or two joints, you’ll be on the lower end. If the original ductwork has multiple failures, a full sealing pass starts to make more sense than piecemeal patching.
Harbor corrosion on metal ductwork
Salt air near the Port of Los Angeles works on unprotected galvanized steel faster than most people expect. Sections of duct in vented crawl spaces show surface rust, loosened joints, and pitting. That’s not a cosmetic issue: pinholes in rusted ductwork leak air constantly, and the rough surface holds soot and moisture more tightly than clean metal.
Crushed flex runs in tight crawl spaces
Homes built in the 1950s and 1960s often have crawl spaces too tight for modern flex duct to survive long-term. Kinked or flattened runs starve rooms of airflow, and the homeowner usually notices that one bedroom never gets warm enough or cool enough. Replacing a crushed flex run is straightforward, but it has to be sized and routed correctly or the replacement fails the same way.
Trusted Brands We Service in Wilmington
We stock parts and sealants for the duct systems Wilmington homes actually have, from original galvanized metal to modern flex. Our Duct Sealing team works with professional-grade materials, including Nikro negative-air machines for source removal and filtration products from Honeywell and Aprilaire for the systems that need it. We specify Abatement Technologies equipment on jobs where harbor particulate counts are high and standard filtration won’t keep up. Because we keep these materials on the truck, most repairs and sealing work don’t wait on a parts order. We arrive with what we need.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Wilmington Homes
- Diesel soot film from Avalon Blvd and the Alameda Corridor. Homes within a mile of major truck routes accumulate a gray, oily residue in return ducts that you won’t see in Torrance or Long Beach. Sealing over that film without removing it first means the mastic peels off in sheets within a season.
- Marine-layer humidity in vented crawl spaces. Wilmington’s coastal fog raises ambient moisture in crawl spaces most mornings. Uninsulated metal ducts sweat, and any open joint becomes a moisture intake point that feeds musty odors throughout the house.
- Deferred maintenance on rental and multi-generational properties. A large share of Wilmington’s housing stock is rental or multi-generational, which often means ductwork hasn’t been touched since the original install. Failures compound: one separated joint becomes three, then the system starts pulling from every gap.
- Ineffective prior seals on uninsulated ductwork. We regularly find cheap foil tape that has lifted completely off uninsulated ducts, because condensation and salt air attack the adhesive. The homeowner paid for a seal and got maybe six months. Properly applied mastic and UL 181 tape on clean, dry metal lasts decades.
Pricing for Duct Sealing in Wilmington, CA
A typical whole-system duct sealing job on a Wilmington single-family home runs $350 – $850. Smaller jobs where only a few accessible joints need work land at the lower end; homes with multiple separated connections, harbor contamination requiring extra source removal, or tight crawl space access land higher. Duct repair runs $150 – $450 per damaged section. We give you a written price before the work begins, and that number does not move at the door. Call (562) 548-7365 for a free estimate. We’ll tell you what we’re going to do, what it will cost, and how long it will take, in plain language.
We Also Serve Cities Near Wilmington
Beyond Wilmington, our crews work regularly in Lakewood, Carson, San Pedro, and Long Beach. The housing stock changes from one city to the next, and we adjust accordingly: what holds up in a Wilmington crawl space near the harbor needs a different approach in a San Pedro hillside property. Wherever you are, you get the same written pricing and the same 365-day guarantee.
Serving Wilmington, CA - Our Local Coverage Area
We’re based in the Wilmington 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 Wilmington
Sealant fails in Wilmington because it’s being applied over a dirty surface, not because the sealant is weak. The marine layer keeps crawl space air humid, and the harbor puts a greasy soot film on everything inside a duct system. Mastic or tape applied over that film debonds when the system cycles and the metal flexes. The fix is source removal first: get the surface clean and dry, then seal. If a prior company fogged or sealed over visible grit, that’s the root cause. Call (562) 548-7365 and we’ll camera-inspect the failed seal and show you exactly what’s underneath.
No, not in most Wilmington homes. Fogging an antimicrobial into a duct system that still has soot, dust, or existing microbial growth on the insulation doesn’t solve the problem; the fog lands on the surface film and never reaches the material underneath. In fact, adding moisture to an already-contaminated fiberglass duct can drive spores deeper into the insulation and make the smell worse. If a company leads with a fogging upsell instead of source removal and sealing, you’re paying for the wrong procedure. The correct sequence is removal, then sealing if leaks are present, then new filtration if the system calls for it.
You can seal accessible joints in an unfinished basement or crawl space, but if the ducts are contaminated with diesel soot from Avalon Blvd traffic, sealing without removing the source first locks the contamination in place and doesn’t stop the air from pulling dust through whatever gaps remain. Duct sealing requires knowing where the leaks actually are; most leaks are hidden in wall cavities or under insulation, which means a camera inspection is the only way to find them all. For anything beyond a loose visible joint, we’d recommend a professional pass. Improper sealing on a system with high static pressure can also push the air through new, worse gaps.
A musty smell that gets worse when the blower cycles and fades when the system is off is usually coming from the ductwork itself, especially if the return runs through a vented crawl space or the smell concentrates at specific registers. In Wilmington’s older bungalows, separated return ducts pull humid, musty crawl space air directly into the air handler, and that air distributes through the entire home. We track this down by camera-inspecting the duct runs, checking for moisture at the joints, and measuring where the airflow is dropping. Once we find the leak, we can tell you definitely whether duct sealing will solve it. Call (562) 548-7365 to schedule an inspection.
Torrance sits farther from the Port of Los Angeles and the rail corridor, so the air moving through its ductwork carries less diesel soot and salt air. Wilmington homes, especially those within a mile of Avalon Blvd or the Alameda Corridor, accumulate a heavy, greasy film that adheres to the duct walls and clogs joints more quickly. Even loose connections pull in more contamination because the surrounding air is dirtier. That’s why Wilmington systems often need sealing after cleaning: the source of the grit is external, so the system needs to be sealed against it, not just wiped clean for a season.
Written by Roy Castellanos, Owner at Hollis Air Duct Long Beach, serving Wilmington since 2004.
If you live in Wilmington and your ducts are leaking, call (562) 548-7365. We’ll give you a written price before any work starts, and we stand behind every seal for a full year.