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 Highland Park
Duct sealing in Highland Park typically costs between $1,850 and $3,400 per system for a full mastic-and-fabric application, and most jobs wrap up in a single day. We work on the older estate homes around Lakeside, Beverly, and Armstrong, where original 1920s and 1930s ductwork leaks air far more than homeowners realize. When you call (361) 309-6223, you’ll get a straight answer about what your system needs, a written price before we touch anything, and a crew that knows how to protect the finishes those older Highland Park homes are built around.
Why Hollis Air Duct Dallas Is Highland Park’s Preferred Duct Sealing Company
Highland Park homes aren’t like the new developments spreading through Richardson or Garland. These are estates with original cast-iron registers, hand-fitted galvanized runs, and plaster walls that predate our grandparents. Our techs have sealed ducts behind silk wallpaper and above hundred-year-old oak floors without leaving a mark, because we treat containment and surface protection as the job itself, not an afterthought. Roy Castellanos runs our crews with one rule baked into every job: leave the home the way you found it, just with better air moving through it.
We answer our phones with a live person, 24 hours a day. When a Highland Park homeowner books with us, they get a background-checked, uniformed technician who arrives inside the quoted window. We don’t send subcontractors and we don’t hand the job to whoever’s closest. Every tech carries the same Rotobrush, Nikro, and Honeywell equipment we’ve used since 2004, and every job comes with our 365-Day Done Right Promise in writing. That means if a sealed joint fails within a year, we return and fix it at no charge. No negotiation, no fine print.
Styles & brands we work with
Duct Repair in Highland Park
Duct Repair in Highland Park almost always means working on ductwork that was never meant to carry modern air loads. The original runs in these 1920s to 1940s homes were often retrofit for central air decades ago, and the connections are nothing like the uniform, machine-made fittings you’ll find in newer construction. We see loose seams, corroded sections, and tap-ins that were patched with tape and paint so many times the original metal is buried under layers of failed repairs. Repair here means cutting out the bad section, fitting new material to the hand-built dimensions, and sealing every joint with mastic and embedded fabric that flexes with the system.
Repairing Original Galvanized Runs
Early galvanized duct in Highland Park homes tends to fail at the seams first. Decades of vibration from undersized or overloaded air handlers wears the mechanical connections loose, and gaps open up even in rooms that feel comfortable. Our techs locate these leaks with camera inspection and pressure testing, then seal over the original metal rather than tearing out walls to replace everything. In most cases, the repair is done from the attic or crawl space, with the living areas untouched.
Fixing Failed Tap-Ins and Plenum Connections
Homes built before 1950 often have 1-inch or 2-inch tap-ins on plenums covered with nothing but duct tape and paint. That’s not a repair; it’s a placeholder. Highland Park humidity degrades tape adhesive within a season, and the leak returns. We remove the old material, rebuild the connection to fit the specific plenum, and apply mastic that cures to a durable, airtight seal. Expect this kind of repair to cost between $450 and $900 per connection, depending on access and the condition of the surrounding metal.
Air Duct Sealing in Highland Park
Air Duct Sealing in Highland Park is a different job on a two-story 1935 estate than it is on a single-story rancher in Rowlett. The runs are longer, the systems are more numerous, and the original ductwork rarely matches any modern spec. We approach sealing per system: each air handler and its connected runs get inspected, sealed, and tested as one unit. That matters when your home has three or four systems and the leaks are spread across a dozen zones. A partial seal fixes nothing, and homeowner after homeowner in Highland Park has learned that the hard way after another crew sealed one zone and left the bypass damper in the attic leaking enough to overwhelm every other improvement.
Mastic and Fabric Sealing for Vintage Ductwork
For original cast-iron or early galvanized ducts, we apply mastic with embedded fabric over every accessible joint, seam, and connection. The fabric gives the seal flexibility, which these older systems need because the metal expands and contracts with Highland Park’s hot summers and cooler winters. A proper mastic seal on a hand-fitted 1930s duct can hold for decades; tape peels off in a year. This is the core of what we do, done right and documented.
Negative Pressure Verification
After sealing, we verify the work. Our crews pull negative pressure on the system and measure leakage against NADCA standards. That’s the difference between a crew that says “we sealed some ducts” and one that can show you the before-and-after numbers. Highland Park homeowners deserve to know the air they’re paying to condition is staying inside the duct, not bleeding into a 90-degree attic. Verification is included in the job, not billed as an add-on surprise.
Trusted Brands We Service in Highland Park
The equipment in Highland Park homes runs from original gravity-style systems retrofitted with modern blowers to fully zoned multi-stage setups. We carry parts and materials compatible with Rotobrush, Nikro, Honeywell, and Aprilaire components, plus the common fittings for older galvanized and cast-iron runs. When a repair requires a specific damper or connection piece, we source it quickly through our Dallas-Fort Worth supply network rather than leaving a system down for days. Highland Park customers get the same professional-grade gear commercial crews use, explained in plain terms before we start.
Common Duct Sealing Problems We See in Highland Park Homes
- Vibration-worn seams on 1930s galvanized runs. The original ducts in these estate homes were often suspended with basic hangers that never anticipated decades of continuous AC use. Seams loosen, air escapes, and rooms at the far end of the run never quite cool down. We seal the seams from inside where accessible, without opening walls.
- Uneven sealing across multiple zoned systems. Large homes with three or four air handlers frequently get a partial seal: one zone fixed, the others ignored, and the bypass damper leaking so badly it defeats the whole effort. We inspect and seal every zone connected to each system, then test the entire system as one unit.
- Original floor registers set into hardwood or marble. Many Highland Park homes have century-old oak around every register. A careless crew will scratch the floor, drip mastic on the finish, or both. Our techs lay protective mats around every vent before starting, and we treat those finishes as irreplaceable, because they are.
- Humidity-driven microbial growth in unsealed return plenums. Hot, humid summers force near-continuous AC use, and unsealed returns pull attic air into the system. That air carries heat, pollen from mature oaks and pecans, and moisture that supports growth inside the ducts. Sealing the return side of the system changes this, and we document the before-and-after moisture difference.
See the difference
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After
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AfterPricing for Duct Sealing in Highland Park, TX
A typical single-system duct sealing job in Highland Park runs $1,850 to $3,400, depending on the number of zones, access difficulty, and whether original cast-iron or galvanized runs require custom fitting. Homes with two systems usually land between $3,000 and $5,600 total, and three-system estates commonly run $4,800 to $8,200. Duct repair work, like rebuilding a failed plenum tap-in, adds $450 to $900 per connection. We price by the system, not by the vent, because per-vent pricing is exactly how the bait-and-switch outfits around Dallas operate. The price we write down before starting is the price you pay. Call (361) 309-6223 for a free estimate; we’ll come out, inspect your systems, and give you a number that holds.
We Also Serve Cities Near Highland Park
Highland Park sits at the center of our service area, and we also run crews to Dallas, Garland, Richardson, and Rowlett. If you’re in one of those cities and need someone who understands vintage ductwork, call the same number. You can also read about how we approach the job on our Duct Sealing page for a broader look at the service.
Serving Highland Park, TX - Our Local Coverage Area
We’re based in the Highland Park 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 Highland Park
Yes, and the age is exactly why. Original cast-iron and early galvanized ducts were often hand-fitted with loose mechanical connections that have never been airtight. Sealing those joints properly can cut duct leakage from 30 to 40 percent down to under 5 percent, which means the rooms at the far ends of those long Highland Park hallways finally get the air they were designed to receive. The original metal often has decades of service left in it; what’s failing is the connections, and those can be rebuilt and sealed without tearing out walls.
We seal per system, one air handler at a time, so you’re never without cooling across the entire house at once. Our crews inspect all zones connected to that system, seal every accessible joint, and verify the result with pressure testing before moving to the next system. This per-system approach also means the price is per system, which keeps the scope clear when you have three or four of them. Call (361) 309-6223 to schedule an inspection; we’ll map out exactly which systems need what before any work begins.
You should expect before-and-after pressure test results, camera inspection images of the sealed joints, a written summary of exactly what was repaired and where, and a copy of our 365-Day Done Right Promise covering the work in writing. We provide all of that as standard. If a crew can’t show you documentation that proves the work was done, you have no way to know it wasn’t just a visual once-over. Our jobs include verification to NADCA standards, and the paperwork leaves with you, not with the tech.
No. We access the ductwork from the attic, crawl space, or basement wherever possible, and we don’t open walls to seal ducts. For the original floor registers set into hardwood or marble, our techs lay protective mats around every vent before starting, and we use drop cloths for any path we walk with tools. Homes with silk wallpaper and antique furnishings get the same containment protocols we’d use on a museum job, because in Highland Park, the interior finishes are often as valuable as the structure itself.
Highland Park’s housing stock skews older and larger, with more original retrofitted ductwork still in service than you’ll find in most of Dallas or University Park. Those original 1920s to 1940s systems leak more air per linear foot, and the hot, humid summers force them to run harder and longer, which accelerates seam wear and pulls more attic air into the system. Add in the mature oaks and pecans dropping pollen every spring, and unsealed ducts become a direct line for allergens into your living spaces. The houses are also bigger, with longer runs, so every percentage point of leakage costs more in conditioned air than it would in a smaller home.
Get a Straight Answer About Duct Sealing in Highland Park
If you own an older home in Highland Park and your AC runs constantly in July while some rooms never cool off, the problem is usually the ductwork, not the equipment. Call (361) 309-6223 and we’ll schedule an inspection, show you exactly where the air is going, and give you a written price for what it actually takes to fix it. No per-vent games, no price that moves at the door. We’ve been doing this since 2004, and Roy Castellanos holds every crew to the same standard: do it right, document it, and stand behind the work for a full year. That’s what you’re paying for, and in Highland Park, it’s the only way this job should be done.
Written by Roy Castellanos, Owner at Hollis Air Duct Dallas, serving Highland Park and the surrounding area with documented, NADCA-verified duct sealing.