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 Windsor
Duct sealing in Windsor typically costs $800 – $2,400 for a whole-home system, with most single-system homes falling in the $1,200 – $1,800 range. We’re local to the Russian River Valley and can usually schedule within a few business days, with dispatch coordinated from our San Francisco Bay Area office. Call (361) 326-5060 for a written estimate before any work starts.
We’ve been working in Windsor long enough to know the local air signature. Because this town sits directly downwind of the Geysers geothermal field and the Russian River Valley, return-side duct leaks here pull in sulfur-laden particulates and vineyard pollen rather than plain household dust. A duct sealing job in Windsor is really about closing the envelope against that specific outdoor air signature, not just stopping air loss. That’s why we don’t treat this like a generic energy-efficiency service. We treat it like what it is: a barrier repair against a local environment that puts particular stress on HVAC systems.
Our crews know the difference between a 1990s tract home off Mark West Springs Road and a post-war ranch near the Windsor Town Green. The ductwork failures we find in those two houses are rarely the same. We bring that local knowledge to every job, along with written pricing, background-checked technicians, and the 365-Day Done Right Promise that covers every repair we make.
Why Hollis Air Duct Cleaning Is Windsor’s Preferred Duct Sealing Company
We’ve built our reputation in Windsor the same way we’ve built it everywhere else: show up inside the window, price it in writing before we touch anything, and stand behind the work for a full year. The Garrison Standard doesn’t change because the zip code does.
Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday for a scheduling question.
We’re part of the Garrison Partners family, in business since 2004. That track record predates most local competitors in the North Bay. Every job gets the 365-Day Done Right Promise in writing: if the work fails within a year, we come back and make it right at no charge, including a free second visit. The price is written down before any work starts, and it does not move at the door.
We serve Windsor homes from the Foothill Regional Park corridor to the older downtown pockets near the Town Green, and we understand how the local climate, housing stock, and post-fire conditions affect what we find in your ducts.
Duct Sealing Services in Windsor
Duct Sealing Services in Windsor address the specific leak patterns created by our local environment: geothermal particulates, vineyard pollen, and residual ash from regional wildfires that get drawn into return-side gaps and bypass your filter entirely. The job involves locating leaks with camera inspection and pressure testing, then sealing collars, elbows, and seams with mastic and mesh or mechanical fasteners depending on the duct material. For a typical Windsor home with one HVAC system, expect $1,200 – $1,800. Homes with two or three systems, common in the larger tract builds off Shiloh Road and Mark West Springs Road, run $2,000 – $3,600 total.
Return-Side Leak Repair
Return-side leaks are the critical failure point in Windsor. Unfiltered outdoor air gets pulled in through gaps in the return ducting before it ever reaches your filter. We locate these with camera inspection and seal them with mastic and reinforcing mesh, then verify with pressure testing. This stops the Geysers sulfur smell and fine particulates from circulating through your living space.

Supply Register and Boot Sealing
Supply boots often separate from drywall or subfloor over years of thermal cycling, especially in Windsor’s 1980s – 2000s tract homes with flexible ductwork. We resecure the connections and seal with appropriate materials, then check airflow balance room to room. A sealed boot does nothing if the air never reaches the register.

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 Windsor
Duct Insulation in Windsor protects against a specific local problem: coastal fog moisture migrating into attic duct runs, where it condenses on cold metal or soaks fiberglass facing and encourages mold growth at joints. The job involves wrapping or replacing insulation on duct runs, with particular attention to vapor barrier integrity. For a typical single-system home, duct insulation runs $600 – $1,400 depending on attic accessibility and the condition of existing wrapping. Homes with multiple systems or extensive replacement needs can reach $2,000 – $2,800.
Vapor Barrier Assessment
Windsor’s morning fog and winter rains mean moisture control matters as much as thermal control. We inspect existing insulation for saturated or mold-stained facing, then install new wrap with intact vapor barriers where needed. Sealing a damp duct without confirming dryness locks moisture inside the system. We don’t do that.
Attic Run Replacement
In some Windsor homes, particularly the 1990s builds with original fiberglass wrap, the insulation has compressed or degraded to the point that wrapping over it is false economy. We remove and replace, using materials rated for the temperature swings our attic spaces see. The work is documented with before-and-after photos you can review.
Trusted Brands We Service in Windsor
Our equipment roster includes Rotobrush rotary brush systems for mechanical agitation, Nikro negative-air machines for controlled debris extraction, and filtration and sealing products from Abatement Technologies and Guardsman. We stock local parts for common Windsor systems, which means faster turnaround on jobs that need material replacement rather than just sealing. When we find a component that needs swapping, we’re not waiting on a warehouse shipment to Sacramento. The tools we use are the same ones commercial crews deploy in hospitals and schools, explained in plain terms on every job so you know what we’re doing and why.
Common Duct Sealing Problems We See in Windsor Homes
- Failed flex duct collars in 1990s tract homes. The mastic application was thin or the zip tie loosened over twenty years of thermal cycling, letting Geysers-downwind particulates and attic ash bypass the MERV 13 filter on the return side. We remove the old fastening, clean the collar, and reseal with fresh mastic and mesh.
- Rust scale and seam pitting in downtown ranch homes. Post-war metal supply and return ducts in older Windsor pockets have original seams that surface mastic alone won’t hold. Sealing without source-removal and rust treatment traps debris. We assess whether the metal is sound enough to seal or needs section replacement.
- Moisture damage at attic joints from coastal fog intrusion. Unsealed attic penetrations let fog-cooled air condense on duct surfaces, saturating insulation and growing mold at joints. We seal the duct, replace damaged insulation, and verify the attic ventilation isn’t contributing to the problem.
- Disconnected elbows and sagging flex runs from the Glass Fire aftermath. Heat and smoke exposure degraded tape and support straps in some Windsor attics, creating gaps that now pull in unfiltered attic air. We find these with camera inspection, resecure the runs, and seal with materials rated for the temperature range.
Pricing for Duct Sealing in Windsor, CA
A typical duct sealing job in Windsor runs $1,200 – $1,800 for a single-system home, $2,000 – $2,800 for two systems, and $2,400 – $3,600 for three systems. Duct insulation adds $600 – $1,400 per system depending on attic accessibility and the condition of existing wrap. These are whole-system prices, not per-vent teaser rates that balloon once the technician is inside your home.
What moves the number: the number of HVAC systems (many Windsor homes built in the 1990s and 2000s have two or three), attic accessibility, whether we’re sealing existing accessible ductwork or need to open soffits or chase walls, and whether rusted metal sections need replacement before sealing can be effective. We give you one flat price per system, agreed in writing before work starts. No per-vent pricing, no add-ons at the door.
Every estimate is free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Windsor
Our crews work throughout the Russian River Valley and northern Sonoma County, including Duct Sealing calls in Healdsburg, Santa Rosa, Sebastopol, and Guerneville. The same written pricing, same background-checked technicians, same 365-Day Done Right Promise apply in every town we serve.
Serving Windsor, CA - Our Local Coverage Area
We’re based in the Windsor 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 Windsor
Windsor’s position downwind of the Geysers geothermal field means return-side leaks pull in sulfur-laden particulates and fine mineral dust rather than ordinary household dust, creating a distinctive odor and visible black residue on registers. If you notice a sulfur smell when the air handler kicks on or fine dust collecting near return vents, your return ducting likely has gaps that need sealing. Call (361) 326-5060 for a camera inspection and written estimate.
We price per system, not per vent, so a three-system Windsor home typically runs $2,400 – $3,600 for complete duct sealing depending on attic layout and accessibility. Each system gets its own written price before work starts, and the 365-Day Done Right Promise covers each independently. You pay for the work done, not a inflated whole-house rate. Call (361) 326-5060 to walk through your specific setup.
Check for fine black dust on return registers, a faint smoke odor when the air handler starts, or increased allergy symptoms during summer heat when your system runs hardest. These patterns are common in Windsor homes that were operating during the Glass Fire smoke event, especially along the Foothill Regional Park corridor where smoke intrusion was heaviest. We use camera inspection to confirm whether ash has settled in duct runs and whether leaks are pulling it into your living space. Call (361) 326-5060 if you notice these signs.
Yes, but original metal ducts in downtown Windsor’s post-war ranches often have rust scale and seam pitting that surface mastic alone won’t seal permanently. We assess the metal condition first, remove rust and debris where needed, then apply appropriate sealing materials. In some cases, section replacement is more cost-effective than repeated resealing of deteriorated metal. We give you a written recommendation and price before any work begins.
You should receive before-and-after photos from the camera inspection, a written description of what was sealed and with what materials, pressure test results showing leakage reduction, and your copy of the 365-Day Done Right Promise. We document the work because you can’t verify it with a flashlight and a mirror. If a company won’t put the scope and results in writing, that’s information you should weigh carefully. Call (361) 326-5060 and we’ll explain our documentation process before you schedule.
We were called to a three-system 1990s tract home off Foothill Regional Park corridor after the owner noticed fine black dust collecting on the return registers and a faint smoke odor every time the air handler kicked on – a pattern we see in Windsor homes that were running during the 2020 Glass Fire smoke. Using camera inspection and agitation tools under negative pressure, we found flex duct runs in the attic with failed mastic at the collars and two disconnected elbows on the second system, allowing unfiltered attic air and stored ash to bypass the MERV 13 filter. We sealed the collars and elbows with mastic and mesh, verified with a blower-door-assisted pressure test, and the homeowner reported the sulfur-and-smoke smell gone from the supply registers within a day.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Windsor since 2004.




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