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 Merrick
Duct sealing in Merrick means closing the gaps, seams, and pinholes that let conditioned air escape before it reaches your rooms. In a coastal town like Merrick, that work also has to account for salt air, high humidity, and the kind of debris that finds its way into older duct runs. We seal leaks with mastic, wrap exposed runs, and verify the work with before-and-after camera inspection. Call (516) 559-4917 for a written, no-hassle estimate from our Merrick team.

Why Hollis Air Duct Hempstead Is Merrick’s Preferred Duct Sealing Company
We’re part of the Garrison Partners family, and every Hollis location operates under The Garrison Standard: arrive inside the quoted window, price the job in writing before any work starts, do it by the book, and leave the site clean. Merrick homeowners call us because the standard is not a suggestion here. It’s the operating rule on every job, in every duct run, on every crawlspace inspection.
Roy Castellanos leads the crew that covers Merrick. Background-checked, uniformed technicians show up with commercial-grade equipment from Nikro and Abatement Technologies, not hardware-store gear. When a Merrick homeowner asks to see the leak before we seal it, we show them the camera feed. When they ask what it costs, we hand them a written price that does not move at the door. That’s the whole point.
Styles & brands we work with




Duct Insulation in Merrick
Duct insulation matters more in Merrick than it does ten miles north. The South Shore’s humidity means exposed duct runs in crawlspaces, attics, and garages sweat. That condensation soaks insulation, grows mold, and accelerates rust on older galvanized steel. Wrapping ducts with closed-cell insulation after sealing stops warm, moist air from meeting a cold duct surface and dripping onto whatever is below it.
A typical duct insulation job in Merrick runs $900 to $1,800 depending on accessible linear footage and crawlspace height.
When a Merrick Home Needs It
Homes within a mile of the water see condensation on exposed ductwork far sooner than inland properties. If you notice water stains on ceiling tiles below a duct run, rust streaks on the metal, or a musty smell that returns right after cleaning, insulation is likely failing or absent.
What We Do and What We Do Not
We wrap accessible supply and return runs, seal insulation seams with tape rated for high humidity, and confirm coverage with photos. What we don’t do is spray a thin layer of foam over dirty ducts and call it insulated. Dirty ducts get cleaned first. Insulation goes on clean, sealed metal. That sequence is what actually holds up in Merrick’s climate.
HVAC Duct Sealing in Merrick
HVAC duct sealing in Merrick starts with finding where air is actually leaving the system, not just assuming. We use a camera to inspect the full run, then seal accessible seams and pinholes with UL-listed mastic. Mastic is a thick paste that hardens into a durable, flexible seal; it does not peel off the way old tape does when humidity cycles through a Long Island summer.
Full HVAC duct sealing in Merrick typically runs $700 to $1,700. The range depends on how much ductwork is accessible and how many corrosion points need attention.
Coastal Corrosion Points
Salt-laden air eats at galvanized steel from the inside. The first places we find pinholes in Merrick homes are elbows, transitions, and any seam within three feet of the air handler. Sealing only the accessible runs near the equipment while skipping rusted crevices in original 1950s-to-1970s ducts leads to rapid re-contamination. So we seal what we can see, inspect what we cannot, and tell you plainly where the line is.

Sealing Sequence That Actually Works
Remove residue, seal corrosion points, insulate against condensation. Skip step one and the mastic bonds to sand instead of metal. Skip step three and the next nor’easter season undoes the work. This sequence is specific to Merrick because the failure mode is specific to Merrick.
Trusted Brands We Service in Merrick
We work on duct systems connected to equipment from every major manufacturer, and we stock sealing and filtration products from Nikro, Honeywell, and Aprilaire for Merrick jobs. That means less waiting on parts shipped from a distributor when a run needs a replacement filter housing or a sealing job uncovers a component worth upgrading. Our techs know these systems well enough to explain what’s failing in plain terms, then fix it with parts that match what the system was designed to use.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Merrick Homes
- Rusted pinholes near the air handler: Homes built in the 1950s through 1970s still run original galvanized steel ducts. Decades of salt air and condensation create pinholes within a few feet of the blower, where air pressure is highest and leaks cost the most.
- Sand packed into elbows and returns: After nor’easters and storm surges, fine beach sand works its way into return ducts and settles in the elbows. That grit grinds against duct walls, accelerates corrosion, and gives mold something to hold onto.
- Failed duct tape on old seams: Standard cloth duct tape dries, cracks, and falls away after a few seasons of Merrick humidity cycling. We remove it, clean the seam, and replace it with mastic that stays flexible through temperature swings.
- Sweating exposed runs in crawlspaces: Humid South Shore air condenses on uninsulated or under-insulated duct runs. The moisture rots insulation, rusts the metal beneath, and drips into living spaces. Sealing alone does not fix this; the run needs insulation after the seal.
Pricing for Duct Sealing in Merrick, NY
Here’s the honest range for Merrick work. HVAC duct sealing runs $700 to $1,700 for most single-family homes. Duct insulation runs $900 to $1,800 depending on accessible footage and crawlspace clearance. Combined sealing and insulation on a typical split-level or colonial lands between $1,600 and $3,200. What moves the number is access: a standing crawlspace is faster than a 24-inch slither, which means less labor. We write the price before we touch a seam, and that number does not change at the door. Call (516) 559-4917 for a free estimate with no moving target.
We Also Serve Cities Near Merrick
Our Duct Sealing crew covers Merrick and the surrounding South Shore communities of Bellmore, Wantagh, Baldwin, and East Meadow. If you’re unsure whether we cover your street, call and ask. We’ll tell you straight.
Serving Merrick, NY - Our Local Coverage Area
We’re based in the Merrick 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 Merrick
Salt air accelerates galvanized steel corrosion, so seams, elbows, and transitions develop pinhole leaks years sooner in Merrick than in Nassau County towns further from the water. Homes within a mile of the shoreline see the fastest deterioration, and sealing intervals run shorter. If your ducts are original 1950s-to-1970s galvanized, a leak inspection every three to five years is a sensible rhythm here. Call (516) 559-4917 and we’ll inspect what you have before recommending anything.
No. Fogging-only treatments leave salt and sand residues inside the ducts, so corrosion and microbial growth continue under the thin film. Merrick’s problem is physical: salt and moisture have already compromised the metal surface. Sealing the corrosion points and insulating against condensation addresses the source. A fog is a surface treatment. It cannot close a leak. If a company offers fogging as a substitute for sealing, get a second opinion.
Sand acts as an abrasive inside duct runs and holds moisture against metal surfaces, both of which accelerate corrosion in Merrick homes near the water. If sand is left in place, mastic applied over it will bond to grit instead of metal and the seal will fail. That’s why source removal comes first: negative pressure and agitation tools pull the sand out, then we seal clean metal. The sequence matters.
Yes, especially for ranches with exposed duct runs in unconditioned crawlspaces or attached garages. A single-story ranch on the South Shore holds humidity at ground level, and exposed metal runs sweat through the summer. Insulating after sealing prevents condensation from undoing the work and cuts the energy loss that single-story homes are prone to along long horizontal runs. Expect to add $900 to $1,800 for insulation on a typical ranch.
If you can see rust streaks, dark seams, or feel cool air in a crawlspace near the duct run, you likely have leaks worth sealing. If the issue is dust and debris only, a cleaning may be enough. We inspect with a camera and show you what we find before recommending either path. You decide with the evidence in front of you, not on a technician’s say-so. Call (516) 559-4917 to schedule an inspection.
Written by Roy Castellanos, Owner at Hollis Air Duct Hempstead, serving Merrick and the South Shore.