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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After
Before
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Before
AfterFast, Reliable Duct Sealing Across Keller
Duct sealing in Keller typically runs $450 – $1,200 for a whole-house seal, depending on how much of the system is accessible and whether we’re repairing crushed flex runs or sealing accessible joints. Most Keller jobs take a half day, and we price them in writing before any mastic goes on. Call (361) 326-5060 for a free estimate.
We’ve worked in Keller since 2004, and our crews know the territory from the Heritage neighborhood off Keller-Smithfield Road to the newer gated communities near Bear Creek Parkway. Dispatch and scheduling are coordinated from our Dallas-Fort Worth office, but the technicians who arrive at your door live and work in this market. They understand what a 104-degree August afternoon does to flex duct in an unconditioned Keller attic, and they know which subdivisions built out during the 10 SEER era still carry the original undersized ductwork that high-efficiency upgrades leave struggling. That local knowledge changes what we find, how we fix it, and what it costs.
Why Hollis Air Duct Cleaning Is Keller’s Preferred Duct Sealing Company
Hollis Air Duct Cleaning operates under The Garrison Standard, which means written prices, written guarantees, and no moving targets. Our Duct Sealing in Keller crews arrive inside the quoted window, in uniform, with background-checked credentials you can verify before they step through your door. Every job carries our 365-Day Done Right Promise: if the seal fails or the repair doesn’t hold, we come back and make it right at no charge, including a free second visit.
We don’t compete on teaser coupons. We compete on discipline: price it before we touch it, do it by the book, leave the site clean. Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops. No callback queues. No waiting until Monday to schedule.
Our equipment roster includes Rotobrush rotary brush systems, Nikro negative-air machines, and sealing products from Guardsman and Abatement Technologies, the same professional-grade tools commercial crews use. We explain what each does and why it matters for your specific system, not in jargon, but in plain terms you can use to make a decision.
Duct Insulation in Keller
Duct Insulation in Keller addresses a problem most homeowners don’t discover until their upstairs bedroom won’t hold temperature in July: flex duct running through 140-degree attic spaces loses so much conditioned air that the system never catches up. In Keller’s humid subtropical climate, uninsulated or poorly insulated ductwork sweats in the attic, dripping condensation onto ceiling drywall and breeding mold inside the fiberglass liner. We insulate accessible runs with closed-cell foam or foil-faced fiberglass wrap, depending on the clearance and the condition of the existing duct.
A typical duct insulation job in Keller runs $300 – $800 for partial attic work, or $1,100 – $2,400 for a full replacement of degraded insulation across the entire system. Homes in the Heritage area and other late-1990s subdivisions often need both: the original insulation has compressed to half its R-value, and the vapor barrier has torn where installers dragged it across truss nails.
When Insulation Beats Sealing Alone
Sometimes the duct is sealed tight but still bleeding energy. In Keller’s unconditioned attics, R-4 or R-6 flex duct with a compromised vapor barrier acts like a radiator in reverse, warming your 55-degree supply air to 75 degrees before it reaches the register. We check surface temperature with infrared thermometers during our inspection. If the delta is more than 10 degrees, insulation is the priority, not another layer of mastic.
Condensation Control in Humid Attics
Keller’s humidity averages 65% through the cooling season. Cold supply air plus hot humid attic air equals sweating metal. We see water stains on ceiling drywall in homes near Keller-Smithfield Road and Bear Creek Parkway every summer. Proper insulation with an intact vapor barrier stops the sweating. Sealing alone won’t.
HVAC Duct Sealing in Keller
HVAC Duct Sealing in Keller is often the missing step after a duct cleaning, especially in homes that upgraded their outdoor condenser to a 16 SEER or higher unit while leaving the original 14-inch flex duct in place. The new air handler pushes more static pressure than the old system. Seams that held for 20 years under gentle airflow blow open within a season. We find supply boots separated from trunks, takeoff collars leaking at the ring, and longitudinal seams on the flex duct itself hissing conditioned air into the attic. Our crew cleans the metal to NADCA standards, then seals with Guardsman mastic and mechanical fasteners where the joint geometry allows.
Whole-house HVAC duct sealing in Keller typically costs $450 – $1,200. A partial seal of accessible supply trunks might run $350 – $600. If we discover crushed or kinked flex runs that need rerouting or replacement, we’ll show you the camera footage and price the additional work before proceeding.
The 10 SEER Upgrade Problem
Because Keller’s late-1980s to 2000s subdivisions upgraded many original 10 SEER condensers to high-efficiency units while keeping the undersized original flex duct, we routinely find the new air handler overpowering 14-inch runs and pressurizing leaky seams. Sealing the existing duct is what actually delivers the efficiency the homeowner paid for. This is a pre-upgrade-remnant problem specific to Keller’s build-out era, not the newer luxury builds nearby.
Camera Verification Before and After
We run a duct camera through the system before we seal and again after the mastic cures. You see the gaps. You see the seal. No guesswork, no trust-me claims. The footage stays on file if you ever need warranty service under the 365-Day Done Right Promise.
Trusted Brands We Service in Keller
Our Keller crews carry professional-grade equipment from Rotobrush, Nikro, and Guardsman, plus filtration and sealing products from Abatement Technologies. We stock common mastic compounds, mechanical fasteners, and flex duct diameters for the 14-inch and 16-inch runs typical in Keller’s 1990s and 2000s housing stock. That local inventory means we don’t leave to chase parts mid-job. A seal that starts Monday morning finishes Monday afternoon. We also source Honeywell and Aprilaire filtration upgrades when a sealing job reveals the system needs better downstream protection against the dust load Keller’s long cooling season pushes through the ducts.
Common Duct Sealing Problems We See in Keller Homes
- Undersized flex duct overpowered by modern air handlers. Original 14-inch runs from the 10 SEER era can’t handle the static pressure of a modern high-efficiency unit. Seams blow open and the sealing fails within a season unless the run is properly sized or the takeoff is reinforced. We measure static pressure during our inspection and flag runs that need upsizing, not just resealing.
- Failed sealant on dirty galvanized metal. In Keller’s humid subtropical attic conditions, builder-grade foil-tape and mastic applied over dirty galvanized metal won’t bond. The sealant peels off within a year unless the surface is cleaned to NADCA standards first. Our negative-air source removal prep step exists for this reason.
- Kinked or crushed flex runs taped instead of rerouted. We find flex duct pinched against trusses in attics across the Heritage neighborhood and near Keller-Smithfield Road. Some crews tape the kink and move on. Airflow stays choked. The blower motor pulls higher amps than it should. We reroute or replace the run and seal the new connection properly.
- Disconnected takeoff boots dumping air into the attic. The vibration of a higher-RPM modern air handler shakes loose the collar connections that held fine for decades. We find supply boots hanging open by an inch or more, blowing 55-degree air directly into 140-degree attic space. Camera inspection catches this. Sealing without looking misses it entirely.
Pricing for Duct Sealing in Keller, TX
Whole-house duct sealing in Keller runs $450 – $1,200. Partial sealing of accessible supply trunks: $350 – $600. Duct insulation for attic runs: $300 – $800 partial, $1,100 – $2,400 full system. What moves the number? Accessibility (crawl space versus walk-in attic), linear feet of duct, whether we need to reroute crushed runs, and whether the job follows a cleaning that prepped the metal properly.
We don’t quote per-vent or per-linear-foot teaser prices that balloon once the technician is inside. We inspect, we price in writing, and that number doesn’t move at the door. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Keller
Our Duct Sealing crews also work in Haslet, North Richland Hills, Roanoke, and Southlake. The same 365-Day Done Right Promise, the same written pricing, the same background-checked uniformed technicians. Dispatch is coordinated from our Dallas-Fort Worth office for the full metro area.
Serving Keller, TX - Our Local Coverage Area
We’re based in the Keller 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 Keller
Cleaning removes the debris; sealing fixes the leaks that let it back in. In Keller’s 10 SEER-era subdivisions, we often find that high-efficiency AC upgrades have pressurized original seams that held for 20 years but won’t survive the new static pressure. A clean duct with open seams recontaminates within a season. Call (361) 326-5060 and we’ll camera-inspect to show you what’s open.
We pressurize the system and use theatrical smoke to trace leaks, plus a duct camera for visual confirmation of separated boots and crushed runs. Most Keller homes have enough attic access through scuttles or pull-down stairs that we can inspect the entire distribution system without cutting drywall. The camera footage is yours to keep.
Often yes. In Keller’s humid subtropical climate, uninsulated flex duct in a 140-degree attic loses 10 – 20 degrees of cooling before the air reaches your register. Sealing stops air loss; insulation stops thermal loss. We check both with infrared thermometers during our inspection and price each separately so you choose what fits your budget.
A proper seal with Guardsman mastic on clean metal should last 10 – 15 years. But in Keller, if you’ve upgraded to a high-efficiency AC without resizing the duct, new leaks can appear within a season. We recommend inspection every 3 – 5 years, or immediately after any HVAC equipment change. The 365-Day Done Right Promise covers our work for a full year if anything fails.
Yes, and it’s often critical. Newer units move more air at higher static pressure, which overwhelms undersized original ductwork. Sealing without addressing sizing can actually increase pressure and blow new leaks. We measure static pressure and flag runs that need upsizing before we seal. Call (361) 326-5060 for an inspection that accounts for your specific equipment match.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Keller since 2004.