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.
Air Duct Cleaning Company in San Carlos, CA
Air duct repair in San Carlos is often the job a homeowner actually needs, even when they call thinking they need a cleaning. Most homes here were built between the 1940s and 1970s with galvanized sheet-metal trunk-and-branch ductwork running through crawlspaces, and after five or six decades that ductwork has usually separated at the trunk joints, lost its insulation wrap, or collapsed in sections. Cornerstone Duct Cleaning has served San Carlos since 2013, and we repair what others only clean around. Call (877) 824-2920 when your airflow feels weak and you want the ducts fixed, not just vacuumed.
Why San Carlos Homes Are Different
San Carlos is a Peninsula suburb of post-war and mid-century single-story ranch homes. The original furnace ductwork in these houses was typically sheet-metal trunk-and-branch with short runs laid in a crawlspace. That matters for one specific reason: the systems were never designed to move air over long distances. They were built for short, low-static runs, which means any separation at a trunk joint or any collapsed branch immediately shows up as a dead room or a furnace that cycles constantly. Duct cleaning in San Carlos is really about resealing and rebalancing these aging low-static systems rather than clearing long commercial-style runs.
The climate works against these old ducts in a predictable way. Mild Mediterranean weather means forced-air heating runs low and intermittently, especially in the cool, foggy summers and dry autumns. Dust and pollen from the open-space hills settle into the ducts and stay there instead of being constantly pushed through. Homeowners notice it as a fine grit on furniture and a musty smell when the furnace first kicks on. Then there’s the dry-season wildfire smoke concern, which pushes fine particulate into crawlspace duct gaps that have been leaking for years. A routine cleaning visit on a San Carlos ranch often turns into a duct-sealing and reconnect job before the airflow ever improves.
Styles & brands we work with
- Whole-home duct cleaning
- Dryer vent cleaning
- Camera inspection
- Sanitizing & deodorizing
Our Main San Carlos Services
San Carlos homeowners call Cornerstone most often about two things: cleaning the ducts that have been collecting Peninsula dust for decades, and clearing dryer vents that run through tight crawlspaces. Here’s what each involves.
Air Duct Cleaning in San Carlos
We clean the full air pathway in San Carlos ranches using Rotobrush rotary-brush systems rather than suction-only methods that leave debris stuck to duct walls. In crawlspace-trunk homes, that means accessing the trunk line, agitating the walls mechanically, and pulling the loosened dust and pollen out with Nikro HEPA-filtered negative-air equipment. The goal is a duct system that moves air like the original design intended, not just one that looks cleaner at the register. Air Duct Cleaning in San Carlos covers the full process, including what we find in typical 1950s and 1960s sheet-metal systems.

Dryer Vent Cleaning in San Carlos
Dryer vents in San Carlos ranches often run through crawlspaces or out through stucco walls with multiple elbows, and lint builds fast in those bends. We clean the entire vent run from dryer to exterior termination, removing the packed lint that restricts airflow and creates a fire hazard. The dry, warm autumn months are when accumulated lint becomes most dangerous, since it sits bone-dry inside a warm vent. Dryer Vent Cleaning in San Carlos explains the process and what we typically find in older San Carlos laundry setups.

Air Duct Repair in San Carlos
Air duct repair in San Carlos is the service this housing stock calls for most often. The original trunk-and-branch sheet-metal systems in these 1940s through 1970s ranches were solidly built, but six decades of crawlspace moisture, settling foundations, and occasional animal traffic have taken their toll. We regularly find trunk joints that have pulled apart, branch runs that have collapsed under their own weight, and insulation wrap that has fallen away and left bare metal sweating in the marine air. Cleaning alone won’t fix those problems. The airflow never improves until the ducts are physically reconnected and sealed. That’s the work we do, and it’s why we say we repair what others only clean around. For the full scope of this service, see Air Duct Repair.
Ductwork Repair
Signs you need it
Some rooms stay cold or hot no matter how you adjust the registers, or you hear whistling and rattling from the crawlspace when the blower runs.
What it costs in San Carlos
Ductwork repair in San Carlos typically runs $280 – $550 per affected section, depending on whether we’re patching a separated joint or rebuilding a crushed trunk segment.
How we do it
We locate the failed section from the crawlspace, cut out the damaged portion, fabricate a matching replacement from galvanized sheet metal, seal the joints with mastic, and rewrap the insulation.
Air Duct Replacement
Signs you need it
The ducts are original to the house and visibly corroded, the insulation is falling off in sheets, or previous patch jobs have left the system too restricted to balance properly.
What it costs in San Carlos
Full-system air duct replacement in San Carlos runs $2,800 – $6,500 for a typical single-story ranch, with partial replacements starting around $700 – $1,600 per major branch.
How we do it
After confirming the old layout, we remove the failed ductwork, install new galvanized trunk and branch sections with properly sealed connections, and insulate to current peninsula standards before testing the static pressure.
HVAC Duct Installation
Signs you need it
You’re adding a room, converting a garage, or upgrading a furnace and the existing duct layout can’t support the new airflow requirements.
What it costs in San Carlos
HVAC duct installation for an addition or system upgrade in San Carlos runs $1,200 – $3,800 depending on the number of supply and return runs required.
How we do it
We size the new runs to match the blower output using static-pressure calculations, install the ductwork with sealed, insulated joints, and connect everything to the existing trunk or plenum.
What Air Duct Repair Costs in San Carlos
| Item | Typical range in San Carlos |
|---|---|
| Ductwork repair, per section | $280 – $550 |
| Partial duct replacement, per major branch | $700 – $1,600 |
| Full-system air duct replacement, typical ranch | $2,800 – $6,500 |
Can you repair ducts without tearing out walls?
Yes. In most San Carlos ranches the ducts run through crawlspaces, so we access them from below without opening walls or ceilings. We repair or replace sections through the crawlspace access and leave the living space untouched.
How long does a full duct replacement take in San Carlos?
Most full-system replacements in a single-story San Carlos ranch take two to three working days. The work happens entirely in the crawlspace, so you stay in the house and the furnace is usually back online the same day. Call (877) 824-2920 for a specific timeline on your system.
Brands We Service in San Carlos
We work with the filtration and air-handler brands commonly installed in San Carlos homes, including Honeywell and Aprilaire whole-house systems. We keep common replacement filters and Aprilaire media on the truck, which means most filtration service calls in San Carlos are handled in a single visit. See our brands for the full list.
See the difference
Before
After
Before
After
Before
AfterPricing for Air Duct Cleaning Company in San Carlos, CA
| Service | Typical range in San Carlos |
|---|---|
| Air duct cleaning, whole system | $450 – $850 |
| Air duct cleaning, crawlspace-access system | $480 – $900 |
| Air duct cleaning, two-story home | $550 – $950 |
| Air duct cleaning, large custom home | $600 – $1,100 |
| Dryer vent cleaning, single run | $120 – $250 |
| Dryer vent cleaning, long or multi-story run | $175 – $400 |
| Ductwork repair, per section | $280 – $550 |
| Partial duct replacement, per major branch | $700 – $1,600 |
| Full-system air duct replacement, typical ranch | $2,800 – $6,500 |
| HVAC duct installation, addition or upgrade | $1,200 – $3,800 |
What pushes price up in San Carlos is crawlspace height and access. Tight crawlspaces under older ranches mean more labor hours, and any duct section that’s separated or collapsed adds repair work to the cleaning invoice. Cornerstone quotes one flat price per system before work starts, so there’s no surprise add-on when the tech finds a disconnected trunk.
Neighborhoods We Serve in San Carlos
We work throughout ZIP code 92119 and the surrounding San Carlos streets, including the ranch-house blocks east of Jackson Drive, the hillside streets above Mission Trails, the older subdivisions along Navajo Road, and the stucco neighborhoods near Cowles Mountain. Response time across San Carlos is typically one to three business days for a scheduled appointment, depending on the season.
- Mission Trails area
- Jackson Drive corridor
- Navajo Road neighborhoods
- Lake Murray foothills
- Grossmont College area
Service Area – Cities Near San Carlos
Cornerstone Duct Cleaning also works in the communities around San Carlos, including Lake Murray, CA just to the south, La Mesa, CA to the east, El Cajon, CA further out, and Spring Valley, CA to the southeast. If you’re in one of these areas and need contractor-grade duct work, call (877) 824-2920 and we’ll confirm the schedule.
Serving San Carlos, CA – Our Local Coverage Area
We’re based in the San Carlos 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 Air Duct Cleaning Company in San Carlos
Most San Carlos appointments are scheduled within one to three business days. During the spring and fall, when homeowners are thinking about the heating season or post-summer dust, we book out further. Call (877) 824-2920 for current availability in the 92119 area.
No. Duct repair and replacement inside an existing crawlspace or attic doesn’t require a city permit in San Carlos, since it’s considered maintenance of an existing system rather than new construction. If your HOA has rules about contractor access or crawlspace entry, let us know when you call and we’ll work within them.
Yes. Eichler-era homes have a different duct routing, often through the concrete slab or a low attic, but the ventilation principles are the same. We’ve worked on enough of them in San Carlos to know where the access points are and how to avoid damaging the original finishes.
What happens when you call
- 1A real person answersNo phone trees. Talk to a local air duct cleaning pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you. The visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What San Carlos Customers Say
"My wife's allergies had been bad in this house since we moved in. It's been two months since they did the ducts and it's noticeably better. Not a miracle, but real."
- Gilbert Martinez"Quoted per system rather than the bait and switch per vent pricing everybody else in town uses. The number I was told on the phone was the number on the invoice."
- Danika Mosley"Found a disconnected run in the crawlspace while they were in there and told me about it rather than cleaning around it."
- Karen Nguyen