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 Worcester
Duct sealing in Worcester typically costs $450 – $1,200 for a single-family home, with triple-decker units running $800 – $2,400 depending on whether the full vertical trunk chase needs work. Most jobs are scheduled within a week and completed in a single day. Call (361) 326-5060 for a written estimate before any work starts.
We’ve been crawling through Worcester’s attics and basements since 2004. Our crews know the difference between a Grafton Hill triple-decker with original riveted sheet-metal trunk lines and a 1995 split-level off Tatnuck with foil flex runs that tear if you look at them wrong. Dispatch and scheduling are coordinated from our Boston office, but the technicians who show up at your door live in and around Worcester County. They understand why a Vernon Hill basement smells different from a West Side crawl space, and they price the job in writing before touching a single duct.
Why Hollis Air Duct Cleaning Is Worcester’s Preferred Duct Sealing Company
Worcester homeowners call us back because we show up inside the window, in uniform, with a written price that doesn’t move. That’s The Garrison Standard, and it’s how every Hollis location operates, including ours serving Worcester.
Our 365-Day Done Right Promise covers every duct sealing job in writing. If a seam opens or a seal fails within a year, we return and make it right at no charge, including a free second visit. No negotiation, no runaround.
Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. And when you call (361) 326-5060, a live person answers, 24 hours a day, seven days a week. No voicemail loops, no callback queues, no waiting until Monday.
We carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, the same tools commercial crews use. We explain what we’re doing in plain terms, leave the site clean, and stand behind the work for a full year.
Duct Insulation in Worcester
Duct Insulation in Worcester is often the missing half of a sealing job, especially in triple-deckers where uninsulated exterior wall chases turn your heated air lukewarm before it reaches the second floor. In Worcester’s climate, with January highs averaging 31°F and summer humidity pushing 80%, uninsulated ducts waste energy and breed condensation problems year-round.
A typical duct insulation job in Worcester runs $600 – $1,500 for a single-family home, with triple-decker vertical chases ranging $1,000 – $2,800 depending on access and existing condition. We use closed-cell foam wrap and fiberglass board rated for residential HVAC, installed after sealing is complete so insulation doesn’t trap air leaks inside.
When Insulation Comes Before Sealing
Some Worcester homeowners ask us to insulate first and seal later. We don’t do it that way. Insulating over leaky ducts traps conditioned air inside wall cavities where it condenses against cold plaster. We seal every joint and seam first, test with a duct blaster, then insulate. The order matters in old Worcester housing stock.
Oil Soot and Insulation Compatibility
Basement oil furnaces are still common in Worcester’s older neighborhoods, and they leave an oily film on duct surfaces. We clean and degrease before insulating, or the insulation adhesive fails within a season. Our Nikro negative-air machines pull that residue out so the new insulation bonds properly.
HVAC Duct Sealing in Worcester
HVAC Duct Sealing in Worcester means something different than it does in a suburb full of 2005 builds. Here, we’re often working with riveted sheet-metal trunk lines from the 1920s, patched with decades of tape that’s dried to dust, or with flexible foil runs from the 1990s that have sagged, torn, or pulled loose at the collar.
A standard residential HVAC duct sealing job in Worcester costs $450 – $1,200. Triple-decker vertical trunk chases run $800 – $2,400 because we must access and seal the full shared column, not just one unit’s branch lines. Every price is written down before work begins.
Triple-Decker Trunk Sealing
In Worcester’s triple-deckers, especially the thousands built between 1890 and 1920 in Vernon Hill, Grafton Hill, and Main South, all three units share a single forced-air system ducted through uninsulated exterior walls. Sealing one unit’s branch runs while the shared vertical trunk keeps leaking is pointless. The real work is sealing the full vertical chase that serves every floor, accessed from basement to attic.
Flex Duct Replacement vs. Sealing
West Side and north Worcester homes from the 1980s – 2000s often have flexible foil ducts that tear during agitation or cleaning. Sealant can’t bridge a gaping hole. When we find torn flex, we replace the run with new insulated flex or rigid duct, then seal the connections. We tell you before we cut, and the price is in writing.
Trusted Brands We Service in Worcester
We carry equipment and parts from Rotobrush, Nikro, and Abatement Technologies, brands that commercial HVAC contractors use, not hardware-store specials. For filtration and air-quality components, we stock Honeywell, Aprilaire, and Guardsman products. Our Worcester crews keep common duct diameters, collar sizes, and mastic compounds on the van, so most jobs don’t wait on parts. If your system uses an unusual fitting, our Boston office sources it fast and schedules the return visit without a second trip charge.
Common Duct Sealing Problems We See in Worcester Homes
- Shared trunk leaks in triple-deckers. In Vernon Hill and Main South, we regularly find that a tenant had their branch lines sealed, but the main vertical chase in the exterior wall still leaks at every riveted seam. The fix doesn’t hold because the system is one connected column, not three separate units.
- Oily soot from basement oil furnaces. Worcester’s older neighborhoods still run oil heat, and that fuel leaves a film inside ductwork that standard brushes won’t remove. Sealing over it traps the residue, so we degrease with Nikro negative-air extraction before applying mastic.
- Freeze-thaw black paste in attic ducts. Worcester’s cold winters and humid summers create condensation inside uninsulated attic ducts. When moisture mixes with dust, it forms a sticky black paste that recontaminates a newly sealed system within weeks unless we dry and sanitize first.
- Torn flexible ducts in west-side homes. The 1980s – 2000s housing stock in Worcester’s western and northern neighborhoods used foil flex duct that degrades and tears. Sealant can’t bridge a torn run, so we replace the damaged section and seal the new connections properly.
Pricing for Duct Sealing in Worcester, MA
Here’s what duct sealing costs in Worcester’s market:
| Service | Typical Range |
|---|---|
| Single-family home, standard sealing | $450 – $1,200 |
| Triple-decker, full vertical trunk chase | $800 – $2,400 |
| Duct insulation (single-family) | $600 – $1,500 |
| Duct insulation (triple-decker chase) | $1,000 – $2,800 |
| Flex duct replacement + sealing | $200 – $600 per run |
What moves the price: accessibility (crawl space vs. full basement), extent of existing damage, whether we need to clean before sealing, and whether the job requires drying and sanitizing for oil soot or freeze-thaw residue. We give 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 Also Serve Cities Near Worcester
Our crews travel regularly to Northborough, Spencer, Westborough, and Oxford for duct sealing and insulation work. If you’re in Worcester County and your ducts need attention, we cover your area. Learn more about Duct Sealing in Worcester and surrounding communities, or call to schedule.
Serving Worcester, MA - Our Local Coverage Area
We’re based in the Worcester 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 Worcester
No, and any company that says they can is wasting your money. In Worcester’s triple-deckers, especially the pre-1930 buildings in Grafton Hill and Vernon Hill, the three units share a single vertical trunk chase through uninsulated exterior walls. Sealing only your branch lines while the main trunk keeps leaking at every riveted seam means your conditioned air escapes into the wall cavity before it reaches your registers. We seal the full vertical trunk from basement to attic, then test pressure balance across all three floors. Call (361) 326-5060 to schedule an inspection.
Basement oil furnaces common in older Worcester neighborhoods produce combustion byproducts that settle as an oily film inside ductwork. Standard agitation brushes won’t remove it, and sealing over it traps the residue where it continues to off-gas. We extract that film with Nikro negative-air equipment and degreasing agents before we seal any joint or seam. The smell disappears, and the sealant bonds to clean metal instead of oily residue. Call (361) 326-5060 if you’re noticing that odor.
Worcester’s freeze-thaw cycles push moisture into uninsulated attic ducts; when that moisture mixes with dust, it creates a sticky black paste that’s unique to cold-humid climates with this temperature swing pattern. Drier New England cities don’t see it as severely. If we seal your ducts without drying and sanitizing that paste first, it recontaminates the system within weeks. We always inspect attic runs with a camera, remove the paste with rotary brush and negative-air extraction, dry the duct thoroughly, then seal. Call (361) 326-5060 for an attic duct assessment.
We pressure-test with a duct blaster after sealing. The device measures airflow leakage in cubic feet per minute; we show you the before and after numbers in writing. A proper seal drops leakage by 50% or more. We also photograph accessible joints with a borescope camera so you see the mastic application, not just our word. This documentation comes with every job, backed by our 365-Day Done Right Promise. Call (361) 326-5060 to see how we document our work.
It might, if the flex is already degraded. Foil flex duct from the 1980s – 2000s gets brittle and tears under agitation or even careful handling. We camera-inspect first. If the flex is intact, we seal collars and connections without disturbing the run. If it’s torn or sagging, we replace it with new insulated flex or rigid duct, seal the new connections, and price that replacement in writing before we start. No surprises. Call (361) 326-5060 for an inspection of your flex duct condition.
We were called to a triple-decker off Grafton Hill where the third-floor tenant’s registers were pushing barely any air and the basement oil furnace area smelled like oily soot. Camera inspection showed a crushed flexible run in the uninsulated wall chase and riveted trunk seams leaking at every joint, so we sealed the trunk and branch runs, then dried and sanitized the attic duct that had been forming that sticky black paste from freeze-thaw condensation. The third floor finally got even airflow, and the oily film stopped reappearing within weeks.
Ready to stop losing heated and cooled air into your walls? Call (361) 326-5060 for a free written estimate on duct sealing in Worcester. We’ll inspect your system, explain what we find, and give you one flat price per system before any work begins. Every job is covered by our 365-Day Done Right Promise, backed in writing.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Worcester since 2004.