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.
Before
After
Before
After
Before
AfterFast, Reliable Duct Sealing Across San Diego
Duct sealing in San Diego typically runs $400 – $1,200 for most homes, with newer tract houses in Otay Ranch or Carmel Valley often landing in the middle of that range. We’re the local Duct Sealing crew that serves San Diego from our metro office, dispatching uniformed technicians to neighborhoods from Ocean Beach to Mira Mesa without the callback loops or vague arrival windows. If you’re finding drywall dust on your registers or rooms that never reach temperature, call (361) 326-5060. We’ll give you a written price before any work starts, and every job carries our 365-Day Done Right Promise.
Why Hollis Air Duct Cleaning Is San Diego’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our San Diego operation runs on The Garrison Standard: arrive inside the quoted window, price in writing, complete the job by the book, leave the site clean. Our technicians are background-checked and uniformed, and our phones are answered by a live person 24 hours a day, 7 days a week. No voicemail. No “we’ll call you back Monday.”
San Diego homeowners know the bait-and-switch routine. A low quote over the phone, then a technician at the door with a clipboard full of add-ons. We don’t do that. The price is written down before we touch your system, and it doesn’t move at the door. Our 365-Day Done Right Promise means if the work fails within a year, we return and make it right at no charge, including a free second visit. That’s not a slogan. It’s in writing on every job.
We know the local housing stock because we work in it daily. The 1940s furnace ducts wrapped in aging insulation in North Park. The salt-corroded boots in Mission Beach. The builder-grade flex runs sagging between joists in Carmel Valley tracts. That local knowledge changes what we look for and how we fix it.
Duct Insulation in San Diego
Duct Insulation in San Diego addresses a problem most homeowners don’t notice until their energy bill climbs or a room stays stubbornly cold: conditioned air leaking through thin or degraded duct walls before it ever reaches the vent. In San Diego’s mild climate, HVAC systems run fewer annual hours than in Phoenix or Las Vegas, which means duct insulation failures often go undetected for years. When we insulate ductwork, we wrap runs in professional-grade material rated for the temperature differential between your attic or crawl space and your living space, sealing the envelope so the air you paid to heat or cool arrives at full force.
A typical duct insulation job in San Diego runs $600 – $1,800 depending on accessible linear footage, whether we’re working in a tight coastal crawl space or a newer inland attic with truss clearance. Homes in Carmel Valley and Mira Mesa with flex duct in vented attics often need re-insulation where the original sleeve has compressed or torn at the hangers.
When Insulation Fails in Coastal Humidity
San Diego’s marine layer keeps attic and crawl-space humidity elevated, especially in May and June. Wet insulation loses its R-value and can harbor microbial growth against the duct wall. We remove saturated material, treat the metal or flex core, and reinstall with a vapor barrier appropriate to the coastal environment.
Insulating After Sealing
Insulation without sealing is a waste. We seal every joint and collar with mastic or foil tape first, then insulate the continuous run. In Otay Ranch homes with long attic trunk lines, this sequence can drop supply-air temperature loss by 8 – 12 degrees at the far registers.
HVAC Duct Sealing in San Diego
HVAC Duct Sealing in San Diego closes the gaps, separations, and porous joints that let conditioned air escape into attics, crawl spaces, and wall cavities. In a typical San Diego home, we measure duct leakage at 20 – 35% of total airflow, which means nearly a third of what your blower produces never reaches the rooms. We seal with mastic compound, foil-backed tape, or mechanical fasteners depending on the duct material and access, then pressure-test to verify the reduction.
Most residential HVAC duct sealing in San Diego costs $400 – $1,200. A compact condo in National City with accessible flex runs might fall at the lower end. A sprawling Carmel Valley home with hard-piped galvanized trunk lines and multiple zones often pushes higher. We quote by the system, not by the vent, and we put the number in writing before we start.
Pressure Testing Before and After
We use a duct blaster or calibrated fan to measure leakage in CFM at 25 Pascals. This gives us a baseline, guides where we focus our sealing effort, and proves the result when we’re done. San Diego homeowners get the before and after numbers in writing.
Sealing Flex Duct vs. Rigid Metal
Flex duct tears at collars and sags between supports. Rigid metal corrodes at the seams, especially in beach-adjacent homes where salt air accelerates rust. Our crew carries the right materials for both. We don’t try to tape a flex tear and call it sealed.
Trusted Brands We Service in San Diego
Our San Diego trucks stock sealing and insulation materials from Honeywell, Aprilaire, and Abatement Technologies, plus professional-grade negative-air and HEPA filtration equipment from Nikro. That means most jobs don’t wait on parts. When we find a failed collar on a flex run in Chula Vista or corroded boots in Coronado, we replace with matching or upgraded components same visit. We also source filtration upgrades for homeowners who want to add a Honeywell media cabinet or Aprilaire whole-house purifier while we’re already in the system. The equipment roster matters because duct sealing is only half the job in many San Diego homes. The other half is making sure what we sealed stays clean and that the air moving through it gets filtered before it reaches your lungs.
Common Duct Sealing Problems We See in San Diego Homes
- Builder-grade flex duct sagging and separating at joints. In newer inland tracts like Otay Ranch and Carmel Valley, the lightweight plastic-core flex installed during construction pulls away from collars as hangers settle. We see this in homes less than five years old. Sealing over a separated joint is pointless; we re-support the run first, then seal.
- Construction debris trapped in supply and return ducts. Drywall dust, wood scraps, and insulation fragments from the build cycle sit undisturbed in San Diego’s mild climate because the HVAC runs fewer hours than in hotter markets. The blower eventually recirculates this debris through the living space. We perform source removal under negative pressure with HEPA filtration before any sealing work.
- Coastal marine-layer humidity driving biological growth inside ductwork. In beach-adjacent neighborhoods like Ocean Beach and Pacific Beach, high humidity plus mild temperatures create ideal conditions for mold and microbial growth on duct liners. Sealing a contaminated duct just traps the odor and spores. We inspect with a camera, treat or replace affected sections, then seal the clean system.
- Salt corrosion on metal components in beach-adjacent homes. Ocean air attacks duct boots, registers, and galvanized trunk lines in Mission Beach and La Jolla. Rust-through creates leaks that tape won’t fix. We replace corroded metal, seal the new connections, and recommend coated or aluminum alternatives where salt exposure is severe.
Pricing for Duct Sealing in San Diego, CA
Most San Diego homeowners pay between $400 and $1,200 for residential duct sealing. A single-zone condo with accessible flex duct in National City typically runs $400 – $650. A larger home in Carmel Valley with hard-piped trunk lines, multiple zones, and attic access challenges can reach $900 – $1,200. Duct insulation adds $600 – $1,800 depending on linear footage and material.
What moves the price: the duct material (flex is faster to seal, rigid metal takes more labor), access conditions (tight coastal crawl spaces vs. open inland attics), whether we need to remove construction debris or treat microbial growth first, and whether insulation replacement is bundled. We quote one flat price per system, agreed in writing before work starts. No per-vent pricing. No add-ons at the door. Call (361) 326-5060 for a free estimate. We’ll inspect your system, show you what we found, and give you a written number you can compare.
We Also Serve Cities Near San Diego
Our San Diego crews make regular runs to Coronado, National City, Chula Vista, and Lemon Grove. Same trucks, same technicians, same written pricing and 365-Day Done Right Promise. If you’re in South Bay or the Silver Strand and your registers are dusting your furniture or a room won’t hold temperature, we cover your area.
Serving San Diego, CA - Our Local Coverage Area
We’re based in the San Diego 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 San Diego
Builder-grade flex duct in newer San Diego tracts often sags, separates at collars, or was never fully cleaned of construction debris before handover. In Otay Ranch and Carmel Valley, we regularly find two-year-old homes with visible gaps at boots and drywall dust still sitting in the returns. The mild climate means your HVAC runs less, so that debris doesn’t get blown out naturally. Call (361) 326-5060 for a camera inspection and written estimate.
Yes. The coastal marine layer keeps relative humidity high much of the year, especially during May and June gloom, which encourages mold and microbial growth on duct liners that sealing alone won’t fix. In Pacific Beach and Ocean Beach, we inspect for biological growth before sealing any duct. Sealing a contaminated system traps moisture and odor inside. Call (361) 326-5060 and we’ll check with a camera first.
We pressurize the system and use a calibrated duct blaster to measure leakage in CFM, then trace the major loss points with smoke pencils or thermal imaging. In San Diego’s newer tract homes, the leaks cluster at collar connections and sag points where flex has pulled away from the support. We mark every location, show you the camera footage, and seal only what needs sealing. Call (361) 326-5060 to schedule a test.
It will if the dust is coming from leaks in the return side pulling attic or crawl-space debris, or from construction debris still inside the duct that the blower pushes out through gaps. In many Carmel Valley homes we’ve worked, the real fix is source removal under negative pressure first, then sealing the joints so the system stops circulating old drywall dust. Call (361) 326-5060 for an inspection and we’ll tell you which problem you have.
Yes. In Ocean Beach, Mission Beach, and La Jolla, we work on 1940s – 1960s galvanized rigid duct and early flex systems. Salt corrosion is common on boots and registers, and some older homes still have asbestos-containing insulation on original furnace ducts that requires special handling before we can seal or clean. Our technicians are trained to identify these conditions and follow proper abatement protocols. Call (361) 326-5060 and we’ll assess what you’re working with.
Ready to Seal Your San Diego Ducts?
We were called to a two-year-old house in Otay Ranch where the homeowner kept finding drywall dust on the registers and a musty smell from the supply and return ducts every time the air handler kicked on. A camera inspection showed the builder’s flexible plastic-core runs sagging between joists, with visible gaps at the collars and boots where construction debris had settled and never been pulled out. We performed source removal under negative pressure with HEPA filtration, then sealed the joints and re-insulated the runs so the system stopped dumping that dust into the living space.
That’s the difference between a crew that seals what they see and a crew that figures out why the problem started. In San Diego, the marine layer, the salt air, and the mix of historic coastal housing and newer inland tracts each create their own failure patterns. We know them because we work here every day.
Call (361) 326-5060 for a free estimate. We’ll arrive inside the quoted window, inspect your system with a camera, and give you a written price before any work starts. Every job is covered by our 365-Day Done Right Promise. If it’s not right, we make it right. No charge. No negotiation.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving San Diego since 2004.