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 Lowell
Duct sealing in Lowell typically costs $450 – $1,200 for a single-family or triple-decker unit, with most jobs completed in one visit after a written quote. We dispatch crews from our Boston office and serve Lowell neighborhoods including the Acre, Lower Highlands, and Belvidere regularly. If your registers blow cold air when the neighbor’s heat kicks on, or your utility bills spike every winter, your ductwork is likely leaking pressure through gaps, illegal cross-taps, or failed seams. Call (361) 326-5060 for a free estimate with a written price before any work starts.
Why Hollis Air Duct Cleaning Is Lowell’s Preferred Duct Sealing Company
We’ve worked Lowell’s dense housing stock long enough to know the difference between a standard seal job and one that needs city coordination. Our technicians carry background checks, wear uniforms, and arrive inside the quoted window. The Garrison Standard means we price in writing before touching your system, leave the site clean, and back every repair with our 365-Day Done Right Promise: if the seal fails within a year, we return and make it right at no charge, including a free second visit.
Lowell homeowners aren’t shopping for the lowest teaser coupon. They’re shopping for a crew that won’t disappear after the invoice is paid. Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops. No callback queues.
HVAC Duct Sealing in Lowell
HVAC Duct Sealing in Lowell means closing pressure leaks in supply and return ductwork so heated or cooled air reaches the rooms it’s supposed to serve, not your basement, attic, or the apartment next door. In a city where triple-deckers and mill conversions dominate, sealing often reveals deeper problems: shared flues, cross-connected returns, and galvanized ducts with pinhole corrosion that foil tape cannot fix. A typical HVAC duct sealing job in Lowell runs $450 – $950 for a single unit in a triple-decker or modest single-family, and $800 – $1,200 for larger mill-converted apartments with complex runs. We use mastic and mesh on irregular seams, not hardware-store tape that peels in humid summers.
Pressure Testing Before Sealing
We run a duct blaster or calibrated fan test to measure leakage in CFM25 before opening a tube of sealant. This gives us a baseline and proves the result after. In Lowell’s older housing, we regularly see 30 – 50% leakage, meaning nearly half the air your furnace moves never reaches a register.
Mastic vs. Tape on Old Metal
Standard foil tape fails on the irregular, corroded seams of original galvanized ducts common in Lowell’s 1880 – 1920 housing. We brush on water-based mastic reinforced with fiberglass mesh, which bridges gaps up to 1/4 inch and flexes with thermal expansion through New England’s freeze-thaw cycles.
Duct Repair in Lowell
Duct Repair in Lowell addresses physical damage: crushed flex runs, disconnected boots, rusted-out sections, and breaches from decades of amateur modifications. Repair runs $300 – $750 for localized fixes and $700 – $1,500 for extensive rebuilds in mill buildings where entire trunk lines need replacement. Cold, snowy winters and humid summers mean Lowell systems run hard year-round; seasonal condensation in uninsulated attic and basement ducts breeds mold and accelerates metal fatigue. We don’t seal over damage. We repair or replace the damaged section, then seal the system as a whole.
Cross-Connection Remediation
When our camera inspection finds an illegal tap between units, we stop and document. Sealing without fixing the cross-connection traps pressure, blows seals open, and can backdraft combustion gases. We coordinate with Lowell’s inspectional services to bring the system into code before completing the seal.
Dryer Vent Stack Rebuilds
Shared dryer vent stacks in triple-deckers create lint pathways that bypass duct sealing if the entire run isn’t addressed. We clean from the source using Rotobrush agitation under negative pressure, then seal joints with fire-rated mastic rated for the 400°F peak temperatures these stacks see.
Trusted Brands We Service in Lowell
We stock parts and filtration products from Aprilaire, Abatement Technologies, and Guardsman for fast turnaround on Lowell jobs. Our equipment roster includes Rotobrush rotary brush systems and Nikro negative-air machines, the same tools commercial crews use in hospitals and schools. When your mill-converted apartment needs a custom boot or a rare fitting for original sheet-metal ductwork, we source it without the multi-week delays that send other crews back to Google. Every technician carries common fittings on the van, and our Boston office maintains a parts pipeline for the oddball requests that Lowell’s historic housing generates.
Common Duct Sealing Problems We See in Lowell Homes
- Illegal cross-taps between triple-decker units. In the Acre and Lower Highlands, ducts illegally tapped across units create pressure imbalances that standard sealing cannot fix. We coordinate with Lowell’s inspectional services to disconnect and reroute before sealing.
- Pinhole leaks in galvanized returns. Original ducts in mill-worker housing have irregular seams and corrosion that foil tape cannot bridge. Mastic and mesh are required for a lasting seal.
- Lint-choked shared dryer stacks. Triple-decker dryer vents shared through a single stack accumulate decades of lint that creates fire risk and bypasses sealing attempts. The entire run must be cleaned and sealed from source to termination.
- Condensation damage from uninsulated basement and attic runs. Lowell’s humid summers and freezing winters produce seasonal moisture in unconditioned spaces, degrading tape adhesives and rusting metal seams from the inside out.
Pricing for Duct Sealing in Lowell, MA
A typical duct sealing job in Lowell runs $450 – $950 for a standard single unit in a triple-decker or modest home, and $800 – $1,200 for larger mill-converted apartments with extended duct runs or code-coordination requirements. Duct repair, when needed before sealing, adds $300 – $750 for localized fixes. What moves the price: the linear footage of ductwork, accessibility (crawl spaces and sealed chases take longer), whether cross-connection remediation requires city inspection, and the condition of existing metal. We give one flat price per system, agreed in writing before work starts. No per-vent pricing. No invoice that balloons once the van is in your drive. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Lowell
Our crews regularly work Duct Sealing in Lowell and travel to neighboring communities including Andover, Lawrence, Wilmington, and Pinehurst. Dispatch and scheduling are coordinated from our Boston office, with local crews serving each metro area.
Serving Lowell, MA - Our Local Coverage Area
We’re based in the Lowell 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 Lowell
Yes, but we must address the shared flue first. We inspect with a camera, document any cross-connections, and coordinate with Lowell’s inspectional services to separate or properly damper the systems before sealing. Sealing without this step traps pressure and can create dangerous backdraft conditions. Call (361) 326-5060 to schedule an inspection.
Lowell’s mill conversions and triple-deckers have original or poorly retrofitted sheet-metal ducts with irregular seams, galvanized returns, and decades of accumulated coal dust and debris that suburban flex-duct systems don’t face. Sealing here is as much about remediation and code coordination as it is about applying mastic. Call (361) 326-5060 for an estimate tailored to your building.
The Acre’s dense triple-decker housing regularly contains illegally tapped ducts sharing a single furnace flue between units. Our techs find cross-connected supply and return lines that require disconnection and city inspection before sealing can proceed safely. We were called to a 1905 triple-decker on Market Street where the second-floor tenants complained of cold air blowing from their registers whenever the first-floor furnace kicked on. Our tech ran a camera inspection and found a shared flue with a broken damper and an illegal cross-tap in the basement. We used Rotobrush agitation tools under negative pressure to clear decades of lint and coal dust, then sealed the breached supply and return ducts with mastic and mesh, and the tenants finally got independent temperature control.
We coordinate access with all affected units and schedule during agreed windows. The stack is cleaned and sealed as a single system; partial work on one unit leaves lint pathways that defeat the purpose. We document before-and-after photos for each unit’s records. Call (361) 326-5060 to arrange multi-unit coordination.
Yes. Our Duct Sealing work follows NADCA assessment and cleaning protocols, adapted for Lowell’s historic housing where asbestos wrap, lead paint, and fragile original metal require additional containment and handling procedures. Every job gets a written scope, written price, and our 365-Day Done Right Promise backed in writing.
Ready to stop heating your basement and start heating your living room? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free estimate on duct sealing in Lowell. We’ll give you a written price before any work starts, show up in uniform inside the quoted window, and back the repair with our 365-Day Done Right Promise. If it’s not done right, we make it right. No negotiation needed.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Lowell and the greater Boston metro.