Fast, Reliable Duct Repair & Sealing Across Greenwich
Duct repair and sealing in Greenwich typically costs $280–$750 for most residential jobs, with backcountry estate work running $900–$2,400 depending on system complexity. We’re usually on-site in Greenwich within 24–48 hours, and same-day service is often available for urgent air leaks. Call (833) 754-6107 for a free estimate.
Richard Anderson — owner and lead technician — handles your job personally. We’ve worked in Greenwich for two decades, from the compact colonials along Shore Road in Old Greenwich to the sprawling estates off Round Hill Road in 06831. We know the local housing stock: the coastal humidity that attacks basement air handlers in Riverside, the retrofitted multi-zone systems in backcountry manor homes, the unmarked duct runs that frustrate every generalist HVAC crew who gets called after us. Our Duct Repair & Sealing team brings contractor-grade equipment and the patience to trace systems that have been modified across three generations of owners.
Why Landmark Air Duct Cleaning Service New York Is Greenwich’s Preferred Duct Repair & Sealing Company
Proven results you can verify. 548 customers, 4.9 stars — results you can verify before you book. That review volume matters in a market like Greenwich, where homeowners talk and contractors live or die by reputation.
Richard Anderson is the lead technician on every job. Not a franchise, not a subcontractor network. The person who built the business is the person doing the work, ensuring a level of accountability no franchise model can match. When we seal ductwork in a 06830 colonial or repair flex runs in a 06831 estate, you’re dealing directly with the owner.
Response time that respects your schedule. We route from our New York City base to Greenwich daily, with typical arrival windows of 24–48 hours. Emergency sealing for active air leaks — the kind that spike your energy bill and dump humid attic air into living spaces — often same-day.
Local knowledge that saves hours. We know which Cos Cob basements flood seasonally and what that means for duct corrosion. We know which backcountry homes have original 1960s sheet metal that can’t handle modern static pressure. Two decades of duct work, not generalist HVAC services.
Our Duct Repair & Sealing Services in Greenwich
Duct Sealing
Most Greenwich homes lose 20–30% of conditioned air through leaks before it reaches the vents. In backcountry estates with 3–5 separate air-handling systems, that waste multiplies. We use mastic sealant and metal-backed tape — not the cheap foil tape that fails in Greenwich’s humidity — to close gaps at plenum connections, register boots, and longitudinal seams. For homes near Long Island Sound in 06830, we specify sealants rated for elevated moisture exposure. A typical duct sealing job in Greenwich runs $280–$550 for a single-system home, $750–$1,800 for multi-zone estates.
Flex Duct Repair
Flex duct is the weak link in most retrofit systems. We see it crushed by storage items in Old Greenwich attics, chewed by rodents in Riverside crawl spaces, and simply disconnected in 06831 estate additions where no contractor ever properly supported the runs. Our crew carries replacement flex duct in R6 and R8 insulation values, sized from 4″ to 14″ diameter. We recently sealed and repaired the ductwork on a 1927 manor off Round Hill Road in 06831. The home had four separate systems, and we discovered a flex duct junction in an attic addition that was completely disconnected, dumping conditioned air into the rafters. Our crew used mastic sealant and Rotobrush tools to reconnect and insulate the run, restoring airflow to the master suite. Flex duct repair in Greenwich typically runs $180–$420 per run.
Metal Duct Repair
Original galvanized steel ductwork in Greenwich’s pre-war and mid-century homes corrodes from the inside out, especially where humid return air condenses on cool metal. We patch small sections with matching gauge steel, re-seal joints with high-temperature mastic, and reinforce structural supports that have sagged over decades. For historic carriage-house conversions — common in the 06830 zone near the village center — we repair ductwork routed through original timber framing without compromising the structure. Metal duct repair in Greenwich ranges from $320–$680 for localized work to $900–$1,500 for extensive sectional replacement.
Duct Insulation
Uninsulated or degraded duct insulation in attics and crawl spaces costs Greenwich homeowners hundreds in wasted energy each season. We install formaldehyde-free fiberglass wrap and closed-cell foam insulation where space allows, with vapor barriers oriented correctly for our coastal climate. In basement air handler installations common in Cos Cob and Riverside, we pay special attention to the condensation line — because Greenwich’s coastal humidity penetrates every gap. Duct insulation work in Greenwich typically runs $450–$950 depending on linear footage and access difficulty.
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.
Trusted Brands We Service in Greenwich
We work with Honeywell, Aprilaire, and Guardsman air quality systems — the brands installed in most Greenwich homes with integrated humidification or filtration. Our trucks stock common replacement components for these systems, so we’re not ordering parts and making you wait. For duct sealing and repair, we use professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies — the same tool brands used by industrial and commercial contractors, brought into residential and commercial jobs. When we encounter an Aprilaire media cabinet with a compromised seal, or a Honeywell bypass humidifier with a rotted duct connection, we fix the ductwork and verify the integration. Contractor-grade equipment most residential crews never carry.
Common Duct Repair & Sealing Problems We See in Greenwich Homes
- Unmarked multi-zone ductwork in backcountry estates leads to missed connections and pressure imbalances. In 06831, we regularly find homes with four or five air handlers where the duct connections between additions were never pressure-tested or properly mapped. A generic inspection misses these entirely. We trace every run, mark every junction, and balance the system properly.
- Coastal humidity in riverside neighborhoods destroys standard mastic applications. In Cos Cob and Riverside, basement air handlers sit in chronically damp conditions. Cheap sealants fail within two seasons. We use high-grade, moisture-resistant mastic formulated for marine-adjacent environments.
- Retrofitted duct runs through historic carriage-house walls lack fire dampers and proper insulation. Common in the 06830 village zone, these conversions often violate modern code and bleed conditioned air into unconditioned wall cavities. We seal the penetrations and add proper insulation without damaging original plaster or timber.
- Staff turnover in large households means zero system documentation. We’ve walked into 12,000 sq ft estates where the current property manager has no record of when the ducts were last cleaned, sealed, or even installed. We document everything we find and leave you with a system map you can hand to the next person.
Pricing for Duct Repair & Sealing in Greenwich, CT
Here’s what duct repair and sealing costs in Greenwich’s market:
| Service | Typical Range |
|---|---|
| Duct sealing (single system) | $280 – $550 |
| Duct sealing (multi-zone estate) | $750 – $1,800 |
| Flex duct repair (per run) | $180 – $420 |
| Metal duct repair (localized) | $320 – $680 |
| Metal duct repair (sectional replacement) | $900 – $1,500 |
| Duct insulation | $450 – $950 |
| Backcountry estate full-system assessment + sealing | $900 – $2,400 |
Three factors drive cost in Greenwich: system accessibility (crawl spaces and finished attics add time), the number of air-handling zones (backcountry estates require significantly more labor), and material condition (corroded metal or rodent-damaged flex demands replacement, not just sealing). We provide upfront pricing before any work begins — no open-ended hourly billing. Call (833) 754-6107 for a free estimate.
We Also Serve Cities Near Greenwich
We regularly route to Cos Cob for riverside homes with humidity-damaged basement ductwork, Port Chester for multi-family properties with shared ventilation systems, Rye Brook for split-level homes with accessible attic duct runs, and Rye for coastal colonials with original metal ductwork. From cleaning to repair to sanitizing — one call closes the loop on your air quality.
Serving Greenwich, CT — Our Local Coverage Area
We’re based in the Greenwich 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 — Duct Repair & Sealing in Greenwich
These homes contain 3–5 separate air-handling systems installed across different decades, with duct connections between additions that were never pressure-tested — and homeowners often have no records because staff turnover lost the history. Generic sealing misses the junctions between systems entirely. We map every run, test every connection, and seal with materials rated for the static pressure and humidity conditions each zone actually faces. Call (833) 754-6107 to schedule an assessment — estimates are free.
Greenwich’s southern edge along Long Island Sound creates persistently elevated coastal humidity that penetrates ductwork in homes with crawl spaces or basement air handlers, accelerating mold and mildew colonization inside supply and return plenums. Standard mastic sealants fail prematurely in these conditions. We specify moisture-resistant formulations and verify that vapor barriers are intact on insulated runs. Call (833) 754-6107 if you smell mustiness from your vents — we’ll diagnose the source at no charge.
Yes — we regularly work in converted carriage houses and historic outbuildings throughout 06830, where original timber framing constrains how ductwork can be routed and repaired. We seal penetrations without damaging plaster or structural members, add fire dampers where modern code requires them, and insulate runs that bleed heat into unconditioned wall cavities. These jobs demand patience and hand tools, not force. Call (833) 754-6107 to discuss your specific building.
We use professional-grade sealants and tapes from Abatement Technologies and Nikro, paired with Rotobrush mechanical cleaning and sealing tools when the duct interior requires preparation. For integrated air quality systems, we service and source components for Honeywell, Aprilaire, and Guardsman installations. We don’t substitute generic materials — the sealant that holds in Arizona fails in Greenwich’s humidity. Call (833) 754-6107 to confirm we stock what your system needs.
Yes — we use pressurized smoke testing and thermal imaging to locate leaks without destructive probing, then access through the least invasive route: existing register openings, light fixture cutouts, or strategic ceiling panels that can be restored cleanly. In Greenwich’s high-end finishes, we protect floors and furniture, and we coordinate with your trim carpenter if patching is needed. Most hidden-leak repairs run $450–$1,100 depending on access complexity. Call (833) 754-6107 for an exact quote — estimates are free.
Written by Richard Anderson, Owner at Landmark Air Duct Cleaning Service New York, serving Greenwich since 2005.