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 Longwood
Duct sealing in Longwood typically runs $450 – $1,200 for a whole-home system, and most jobs are completed in a single day. If your AC smells musty every spring or your upstairs rooms never cool properly, the problem is often leaks and deteriorated insulation in the ductwork itself, not the unit on your pad.
We’ve worked in Longwood since 2004, and our crews know the difference between a 1978 ranch near the historic district and a 1995 build in Sabal Point. We also offer Longwood Dryer Vent Cleaning for local homeowners. The duct problems are different. The fixes are different. Our dispatch team coordinates scheduling from our South Florida office, and we route crews to Longwood with the right materials already on the truck. Call (361) 326-5060 for a free estimate with a written price before any work starts.
Why Hollis Air Duct Cleaning Is Longwood’s Preferred Duct Sealing Company
Longwood homeowners call us because we’ve seen what the humidity here does to ducts over decades, and we put the fix in writing. Our Duct Sealing team arrives in uniform, background-checked, and on time. The Garrison Standard means we quote the full price before touching anything, and our 365-Day Done Right Promise covers every repair for a full year. If it fails, we come back at no charge, including a free second visit.
We serve Longwood homes from the older neighborhoods near the historic district out to the subdivisions along State Road 434. Our technicians carry mastic sealant, foil tape rated for Florida attics, and replacement insulation wrap on every truck. No callbacks for parts. No “we’ll come back next week.” The price you approve is the price on the invoice.
HVAC Duct Sealing in Longwood
HVAC Duct Sealing in Longwood is the process of closing gaps, disconnected joints, and deteriorated seams in your home’s duct system so conditioned air reaches your rooms instead of leaking into the attic. In Longwood’s climate, where the AC runs 10 – 11 months a year, even small leaks force your system to work harder, raise your electric bill, and pull humid attic air into the airflow. A typical whole-home duct sealing job in Longwood runs $450 – $1,200 depending on accessibility, duct material, and how many runs need attention.
We seal with mastic compound and mechanical fasteners, not duct tape. Duct tape fails in Florida attic heat. Mastic remains flexible and airtight for years. We pressure-test after sealing to verify the system holds static pressure.
Sealing Older Flex Duct Systems
Many Longwood homes built in the 1970s and 1980s use flexible duct runs with fiberglass insulation wraps. After forty-plus years of condensation, that insulation sags, tears, and becomes a mold reservoir. We remove the deteriorated wrap, seal the underlying duct at every joint and puncture, then re-insulate with code-compliant materials rated for our humidity.
Metal Trunk Sealing for Subdivision Homes
Homes in Sabal Point and the Springs often have rigid metal trunk lines with flex takeoffs. The seams in these trunks and the collars where flex connects are common leak points. We seal trunk seams with mastic and replace deteriorated flex collars so your system delivers full airflow to every register.
Duct Repair in Longwood
Duct Repair in Longwood addresses physical damage that sealing alone won’t fix: crushed flex runs from contractors crawling through attics, disconnected returns pulling air from the attic instead of your rooms, and sections of ductwork that have collapsed or rotted through. Repair costs in Longwood typically range from $200 – $600 for isolated fixes to $800 – $1,500 when multiple runs need replacement. We always inspect with a camera before quoting so you know exactly what needs repair versus what needs sealing.
Our field crews carry replacement flex duct, metal fittings, and insulation on every truck. Most repairs are completed same-day once you approve the written price.
Disconnected Return Lines
A disconnected return is common in Longwood’s older ranch homes. The return duct pulls from the attic instead of your living space, bringing in dust, pollen, and attic heat. We find the disconnect, rejoin the run with mechanical fasteners and mastic, and verify airflow at the grille.
Crushed or Collapsed Flex Runs
Storage in the attic, rodent activity, or decades of compression can crush flex duct flat. No air moves through a flat duct. We replace the damaged section with properly sized new flex, support it to prevent future sagging, and seal both ends.
Trusted Brands We Service in Longwood
Our trucks stock parts and materials from Rotobrush, Nikro, and Guardsman so we can complete most Longwood jobs without a parts run. Rotobrush rotary systems let us clean and inspect before sealing so we know exactly where the leaks are. Nikro negative-air machines maintain containment during repair work. Guardsman filtration products help protect your system after we’ve sealed it. We don’t show up to diagnose and leave you waiting. We carry what Longwood homes need.
Common Duct Sealing Problems We See in Longwood Homes
- Moldy fiberglass insulation on original 1970s ductwork. In Longwood’s historic district and nearby neighborhoods, the original flex duct runs are wrapped in fiberglass that has absorbed years of condensation. The insulation itself grows mold and releases musty odors every spring. Sealing the duct without addressing the insulation wrap is a temporary fix at best.
- Sagging flex runs trapping debris and leaking air. The 1980s ranch homes near Longwood’s downtown often have flex duct that has sagged between supports over decades. The low spots collect dust and organic matter from the oak canopy overhead, while the sagging stretches create gaps at the joints.
- Seam leaks in rigid metal trunks. Newer subdivisions like Sabal Point and the Springs used metal trunk lines, but the longitudinal seams and takeoff collars were often sealed with tape that has dried and failed. Humid attic air enters through these gaps, raising indoor humidity and promoting mold despite the ducts looking intact from below.
- Poorly sealed takeoffs in constant-AC homes. Because Longwood homes run cooling nearly year-round, any leak at a takeoff collar operates 10 – 11 months a year. The cumulative energy loss and humidity infiltration is far greater here than in climates where ducts rest through a real winter.
Pricing for Duct Sealing in Longwood, FL
Whole-home duct sealing in Longwood typically costs $450 – $1,200. Isolated repairs run $200 – $600. Several factors move the price: how many duct runs need attention, whether we can access the attic or if we need to work through a crawlspace, and whether deteriorated insulation wrap requires replacement in addition to sealing.
We do not quote per-vent teaser prices that balloon once we’re inside. We inspect with a camera, show you what we found, and write down one flat price for the complete job before any work begins. That price does not move at the door. Every sealing job includes post-work pressure testing to verify results. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Longwood
Our crews work throughout Seminole County and neighboring areas, including Duct Sealing in Longwood proper plus Lake Mary, Altamonte Springs, Casselberry, and Winter Springs. The duct conditions we see in Longwood, especially the humidity-driven mold issues in older homes, are common across these nearby communities as well.
Serving Longwood, FL - Our Local Coverage Area
We’re based in the Longwood 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 Longwood
The musty odor usually comes from mold growing on deteriorated fiberglass insulation wrapped around your original ductwork, not from the duct interior alone. Longwood’s year-round humidity keeps that insulation damp, and mold colonies release spores when the first strong airflow of spring disturbs them. We remove the contaminated insulation, seal the underlying ducts, and re-wrap with mold-resistant materials. Call (361) 326-5060 if you’re smelling this every spring.
If rooms stay hot despite good airflow at the register, or if your electric bill climbs every summer without explanation, you likely have leaks that cleaning won’t fix. Cleaning removes debris; sealing stops conditioned air from escaping into the attic. We camera-inspect first and show you exactly where the leaks are before quoting either service.
Yes. Homes from the 1990s and early 2000s often have rigid metal trunk lines with flex takeoffs, and the tape or mastic used at factory seams frequently fails after 25 – 30 years of Florida heat and humidity. The ducts may look fine from the outside while leaking significantly at seams and collars. We pressure-test to find leaks you can’t see.
We access the duct system through attic or crawlspace openings, identify leaks with camera inspection and pressure testing, then seal joints and seams with mastic compound and mechanical fasteners. Most Longwood homes are completed in four to six hours. Larger homes or those requiring insulation wrap replacement may take a full day. You’ll get a written price before we start and a pressure-test result after we finish.
Yes, by preventing your system from pulling unfiltered attic air, pollen, and mold spores through duct leaks. In Longwood’s climate, where oak and pine pollen are heavy and humidity keeps mold active, a sealed duct system delivers only filtered, conditioned air to your rooms. Sealing also reduces the moisture load that promotes mold growth inside the ducts themselves.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Longwood since 2004.