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.
Fast, Reliable Duct Sealing Across Syosset
Duct sealing in Syosset typically runs $850 – $2,400 depending on how much of your ductwork is accessible and how badly the original seams have failed. Most jobs in Syosset take one day, and we schedule within the week. If your 1950s split-level or colonial still moves air through original galvanized steel ducts, the leaks are costing you real money every month, and the fix is usually more straightforward than homeowners expect. Call (516) 559-4917 and we’ll give you a written price before any work starts.

We’re Hollis Air Duct Hempstead, and we work in Syosset constantly. Our crews know the housing stock here: mid-century split-levels off South Oyster Bay Road, colonials near the Syosset LIRR station, ranches along Jericho Turnpike. Those homes share a common problem, and it’s rarely just dirt. It’s air escaping through seams that were never sealed in the first place.
Why Hollis Air Duct Hempstead Is Syosset’s Preferred Duct Sealing Company
Every job we do in Syosset gets a written price before we start. That’s not a sales tactic. It’s how Roy Castellanos runs every Hollis Air Duct location, including the one serving Syosset, and it means the number we quote is the number on the invoice. No discoveries that double the bill once the hatch is open.
Our technicians are background-checked and uniformed. You’ll know who’s walking into your home on Jackson Avenue or Cold Spring Road before they arrive. And every duct sealing job in Syosset is covered by our 365-Day Done Right Promise: if a sealed seam fails within a year, we come back and make it right at no charge. That includes a free second visit. We put that in writing on every job.
The Duct Sealing work we do here uses professional-grade equipment: Rotobrush rotary brush systems, Nikro negative-air machines, and filtration from Honeywell and Aprilaire. Not hardware-store gear. The same tools commercial crews use, run by techs who explain what they’re doing in plain terms before they do it.
Styles & brands we work with




HVAC Duct Sealing in Syosset
HVAC Duct Sealing in Syosset means finding every joint, seam, and connection in your ductwork where conditioned air is escaping and closing it with mastic sealant and metal tape rated for ductwork. For most Syosset homes, this runs $850 – $1,600 for accessible runs in basements and crawlspaces. If ducts run through finished ceilings or require drywall access, expect $1,600 – $2,400. The work typically takes one full day.
What Sealing Actually Does
Sealing stops the air you paid to heat or cool from ending up in your attic, your crawlspace, or inside wall cavities. In Syosset’s older homes, that leakage is often 20 – 30% of total airflow. Sealed ducts mean the second floor actually reaches the temperature on the thermostat, and your HVAC system doesn’t run as long to get there.
When Sealing Is the Right Call
If you’ve had your ducts cleaned and the house still has hot and cold spots, or the AC runs constantly in August, your problem isn’t dirt. It’s air loss. We see this constantly in Syosset colonials where the original returns were under the windows and the metal has corroded at the seams.
Duct Repair in Syosset
Duct Repair in Syosset is what happens when sealing alone won’t fix the problem: crushed returns, disconnected branches, or corroded sections that have split open. Typical duct repair jobs in Syosset run $350 – $900 for a crushed or disconnected branch, and $900 – $2,400 when multiple sections need replacement. We give you the written price for the whole repair before we touch anything.
Common Repairs in Mid-Century Homes
The original galvanized steel in Syosset homes has been sitting in Long Island’s humid air for five or six decades. Seams corrode, tape turns brittle and falls off, and flexible branches added during past HVAC retrofits get crushed under additions or in tight crawlspaces. We find these on nearly every older home we open up.
When Repair Beats Replacement
You don’t need new ductwork because one branch is crushed. In most Syosset homes, the original steel trunk lines are still structurally sound. We repair the damaged sections, seal the joints, and restore proper airflow for a fraction of what a full replacement costs.
Trusted Brands We Service in Syosset
We work on duct systems connected to all major equipment brands and we stock common sealing materials locally so Syosset jobs don’t wait on parts. Our techs use filtration products from Honeywell and Aprilaire on sealing jobs where air quality is part of the equation, and Abatement Technologies negative-air machines on larger projects. If your system uses Guardsman filtration, we’re familiar with it too. The point is this: what we bring to your Syosset home is commercial-grade equipment, not whatever was on sale at the home center.

Common Duct Sealing Problems We See in Syosset Homes
- Corroded galvanized seams that split open. Long Island’s humid summers do real damage to 50-year-old metal. When the seam goes, so does your conditioned air, straight into the attic.
- Crushed or disconnected flexible branches. Past HVAC retrofits and additions in Syosset homes often left flex duct pinched in tight crawlspaces or disconnected at the boot. That’s the sound of money leaking into your foundation.
- Condensation on uninsulated metal ducts under window registers. Syosset’s older homes placed registers under windows for heating efficiency. With modern AC, cold air pools there and condensation forms on the metal, causing rust and musty odors that come back even after cleaning, unless the ducts are sealed and insulated.
- Multiple generations of duct tape failing at once. The original cloth tape dries out and lets go after a few decades. Homeowners patch it with new tape, which also fails. Proper sealing with mastic and metal tape stops the cycle for good.
See the difference
Before
After
Before
After
Before
AfterWhat We Find When We Open Up Syosset Ductwork
In Syosset, many mid-century split-levels and colonials use original galvanized steel ducts that were never sealed at the joints. Over decades, Long Island’s sandy soil and humid air have corroded seams and crushed returns, making duct sealing the only way to stop 50+ years of conditioned air loss. We see it on almost every job: brittle tape flaking off, gaps at the connections, and dust from the attic pulled into the airstream at every seam.
On Muttontown Road, we sealed a 1960s colonial’s original supply ducts after a camera inspection showed crumbling duct tape at every seam and a crushed return under an addition. Our techs used Rotobrush agitation tools and HEPA filtration to clear decades of debris, then sealed all accessible joints with mastic and metal tape, boosting airflow to the second floor by over 40 percent. That’s not a case study from a training manual. It’s what we find in Syosset homes on a regular basis.
Here’s the local truth about Syosset homes: the original floor registers were placed under windows for heating efficiency back when these houses were built. That made sense in 1960. But with central AC, cold air pools at floor level and condensation forms on the metal ducts. That’s the musty smell you notice every time the AC kicks on in July. Cleaning helps. Sealing and insulating the ducts is what actually stops the moisture problem.
Pricing for Duct Sealing in Syosset, NY
Here’s what duct sealing actually costs in Syosset, in real numbers:
| Service | Typical Syosset Range |
|---|---|
| HVAC Duct Sealing (accessible ducts) | $850 – $1,600 |
| HVAC Duct Sealing (finished ceilings/drywall access) | $1,600 – $2,400 |
| Duct Repair (single crushed/disconnected branch) | $350 – $900 |
| Duct Repair (multiple sections) | $900 – $2,400 |
What changes the price most is access. Ducts in an open basement or crawlspace are straightforward to reach. Ducts running through a finished ceiling mean cutting drywall access points, which adds labor. We’ll give you one written flat price before work starts. Call (516) 559-4917 for a free estimate, and the number we quote is the number you pay.
We Also Serve Cities Near Syosset
Our crews cover Syosset and the surrounding communities, including Duct Sealing in Syosset and nearby Plainview, Hicksville, Westbury, and Levittown. If you’re just over the town line and dealing with the same mid-century duct problems, the territory is familiar and the pricing is the same. Call us and we’ll confirm scheduling for your area.
Serving Syosset, NY - Our Local Coverage Area
We’re based in the Syosset 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 Syosset
If the ducts are clean but the airflow is still weak, or you have hot and cold spots between floors, you need sealing, not another cleaning. The test is simple: after a cleaning, if the second floor still doesn’t cool properly in August, your original ducts are leaking air. That’s the condition we find in most Syosset split-levels and colonials, and sealing is the fix. Call (516) 559-4917 and we’ll inspect and give you a straight answer with a written quote.
Yes, and this is one of the most common reasons Syosset homeowners call us. The original registers in these homes sit under windows, where cold AC air pools and creates condensation on uninsulated metal ducts. That moisture breeds mold and rust, and that’s the smell. Sealing the joints stops air leakage, and insulating the ducts stops the condensation at the source. Cleaning alone won’t, because the moisture keeps coming back. Call us and we’ll explain what your specific setup needs.
We inspect the accessible ductwork, show you what we find, and give you a written flat price for the whole job. Then our techs seal every accessible joint and seam with mastic and metal tape rated for ductwork, repair any crushed or disconnected branches, and finish by testing airflow at the registers to confirm the improvement. The typical Syosset split-level takes one full day. Call (516) 559-4917 for a free estimate on your specific home.
As of now, PSEG Long Island offers limited rebate programs for certain energy efficiency improvements, and duct sealing is occasionally eligible when tied to a larger home performance project. We recommend calling PSEG Long Island directly with your account number to check current eligibility for Syosset addresses. We don’t administer rebates, but we’ll give you a written invoice that’s ready for any program documentation you need.
Properly applied mastic and metal tape on clean metal typically lasts 15 – 20 years in Long Island’s climate, and that’s the service life we stand behind with our 365-Day Done Right Promise. If a sealed seam fails within a year, we come back and make it right at no charge, including a free second visit. After that, the seal is designed to outlast the ductwork around it. Call (516) 559-4917 to schedule an inspection.
Written by Roy Castellanos, Owner at Hollis Air Duct Hempstead, serving Syosset with duct sealing and repair backed by the 365-Day Done Right Promise.