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
AfterProfessional Duct Sealing for Homeowners Across the United States
Duct sealing is the fix most homes need and few ever get. Kestrel Air Duct Cleaning has sealed leaky ductwork for homeowners nationwide since 2004, and we give you a written price before we open a single panel. When ducts leak, the air you pay to heat and cool ends up in the attic or crawl space instead of your living room. The result is uneven rooms, higher bills and a system that works harder than it should. Call (469) 972-3151 and a real person will walk you through the next step.
Our technicians are background-checked and uniformed, and they arrive in the window we promised. We test first, seal with materials rated for HVAC use, and test again so you can see the leakage drop. Every job is covered by our 365-day written promise. If you also need a full tear-out of failed runs, we handle that through our air duct replacement work, and you can start from our home page to see everything we do.
What Our Duct Sealing Service Includes
Leak Testing
We start by measuring how much air your system loses. A pressure test and a visual check of joints, boots and plenums show us where the leaks are and how serious they are, so the repair plan matches the real problem.
Mastic and Tape Sealing
Seams, collars and connections get UL-listed mastic or foil-faced tape. These materials stay flexible and bonded for years, unlike the cloth tape that fails after a few seasons in a hot attic.
Connection Repair
Loose or disconnected sections are re-secured with mechanical fasteners before they are sealed. A joint that moves will crack any sealant, so we fix the fit first and the seal second.
Final Verification
After sealing we test again and walk you through the numbers. You see the before and after, and you sign off only when the work matches what we quoted.
What happens when you call
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A real person answersNo phone trees. You reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Duct Insulation
Sealing and insulation work as a pair. Once the leaks are closed, ducts that run through an unconditioned attic or crawl space still lose heat in winter and gain it in summer through the duct wall. Wrapping them in insulation keeps supply air close to the temperature your system produced. We check the existing wrap, replace sections that are torn, wet or missing, and make sure every seam in the wrap is taped so it does not slip.
Insulation also stops sweating. Cold supply ducts in a hot attic collect condensation, and that moisture soaks the wrap and can lead to mold and rusted metal. Sealing the joint first and insulating second keeps humid attic air out of the duct entirely. If the old wrap is damp or moldy, we tell you plainly and replace it rather than covering it up.
HVAC Duct Sealing
HVAC duct sealing covers the whole air path, not just the visible runs. We look at the supply plenum on top of the furnace or air handler, the return plenum, the boots where branches meet the registers, and the trunk lines in between. The plenum and boots are where we find the biggest leaks, because those joints see the most pressure and the most vibration.
Return-side leaks deserve special attention. A leaky return pulls dusty attic or garage air straight into the system, which hurts air quality and loads the filter faster. Sealing the return side often does more for comfort than homeowners expect. If your coils or blower are also dirty, our HVAC cleaning service can be scheduled with the same visit.
Duct Repair
Not every problem is a small leak. We regularly find crushed flexible duct, sections pulled apart by years of settling, and metal trunks with rusted-out seams. When a run is damaged but still worth saving, we repair it in place with new fasteners, straps and sealant. When it is beyond repair, we say so and quote the replacement separately, so you can compare the options with real numbers.
For heavier damage, our air duct repair team can rebuild or reroute sections. The goal is always the same: a duct system that holds air, supports itself and delivers the right amount to every room.
Air Duct Sealing
Air duct sealing is the part you never see but always feel. We work from the equipment outward, sealing every joint we can reach, and we pay special attention to the places that are easy to miss: the seams along the length of a rectangular trunk, the collars where round branches meet the trunk, and the gaps where a duct passes through a wall or floor. Small gaps add up quickly across a whole system.
We also seal around the register boots where they meet the drywall or ceiling. Air escaping there leaks into the wall cavity and can leave dust streaks on the ceiling. Closing those gaps gives you stronger airflow at the vent and cleaner surfaces around it.
Duct Sealing Services
Our duct sealing services are built around a simple standard: test, seal, test again. You get a written price first, and nothing is added without your approval. We can seal a single problem run or work through the entire system, depending on what the test shows and what you want to spend.
If your home also has a dryer exhaust that needs work, ask about dryer vent installation during the same visit. Bundling jobs saves you a trip and often saves on labor.
Signs You Need Duct Sealing Right Now
- Some rooms are always too hot or too cold. If one bedroom never matches the thermostat, air is likely escaping before it gets there. A leak in the trunk or a disconnected branch is a common cause.
- Your energy bills keep climbing. A system that loses air has to run longer to hit the same temperature. If your usage rose and nothing else changed, leaking ducts are a likely reason.
- Dust keeps coming back. Return leaks pull attic or crawl space air into the home. If surfaces get dusty within days of cleaning, the ducts may be drawing in unfiltered air.
- The system runs almost nonstop. Long run times in mild weather point to lost air. Sealing often shortens cycles and eases wear on the blower and compressor.
- You can hear whistling or rattling at the vents. Air squeezing through a gap makes noise. A whistle near a register or a rattle in the wall usually means a loose joint.
Our Duct Sealing Process – Step by Step
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Leak Test and Inspection: We measure leakage with a pressure test and inspect the plenums, trunks, boots and branches. You see where the air is escaping before we start.
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Preparation: We protect floors and work areas, shut the system down and clear access to the ductwork so we can reach every joint.
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Mechanical Repair: Loose or separated sections are re-fastened and supported first. A joint that moves will not hold a seal.
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Mastic and Tape Sealing: We apply mastic and foil-faced tape to seams, collars, plenums and boots, working the sealant into the gaps instead of just covering them.
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Final Test: We test again, confirm the leakage dropped, and review the results with you before we leave.
How Much Does Duct Sealing Cost?
The price of duct sealing depends on the size of your home, how much of the ductwork we can reach, and how many leaks the test turns up. A small, accessible system costs far less than a large home with ducts buried in a tight attic. We do not use teaser coupons or bait-and-switch tactics. When you call, we give you a clear, written price before we begin, so you know exactly what the invoice will be.
Factors that change the cost include attic or crawl space access, the condition of the existing ducts, and whether insulation work is needed on top of the sealing. We are open about these variables during the estimate. If your ducts are in good shape and sealing will not help, we will tell you honestly. Call (469) 972-3151 for a free estimate tailored to your home.
Duct Sealing Across the United States – Our Service Area
Kestrel Air Duct Cleaning serves homeowners nationwide, and our standards stay the same wherever you live. The climate changes what we find, from humid attics that grow mold on poorly sealed ducts to dry regions where heat cracks old tape, but the method is the same everywhere. We prioritize efficient scheduling so we arrive in the window we promised. Call our team to confirm the next opening near you.
Frequently Asked Questions – Duct Sealing
Duct sealing closes the gaps, cracks and loose joints in your ductwork so the air your system heats or cools actually reaches the rooms. Leaky ducts can waste a large share of conditioned air into attics, crawl spaces and wall cavities. Sealing them is one of the most direct ways to improve comfort and cut energy waste. For ducts that are too damaged to seal, see our air duct repair service.
Common signs include rooms that never reach the set temperature, high energy bills, dust that returns right after cleaning, and a system that runs nearly nonstop. We confirm leaks with a visual inspection and a pressure test, so you see where the air is escaping before any work starts.
We use UL-listed mastic and foil-faced tape rated for HVAC use on joints, seams and boots. We do not use ordinary cloth duct tape, because it dries out and peels within a few seasons. Where the whole run is beyond saving, we will recommend air duct replacement instead and explain why.
Most homes take a half day to a full day, depending on how much ductwork is reachable and how many leaks we find. Tight attics or crawl spaces can add time. We give you a window up front and tell you right away if the job will run longer.
Often yes. Sealing over heavy dust and debris can trap it in the system, and tape and mastic stick better to clean metal. If your ducts are dirty, our HVAC cleaning service pairs well with sealing and can be done on the same visit.
Yes. Every job is backed by our 365-day written promise. If a seal we made fails inside that period, we come back and fix it at no charge. Call (469) 972-3151 and we will explain exactly what the promise covers.
Schedule Your Duct Sealing Service Today
Do not keep paying to heat and cool your attic. At Kestrel Air Duct Cleaning, we provide honest, tested duct sealing backed by a 365-day written promise. Our background-checked technicians have served homeowners since 2004 and will show you the results before you pay. Call (469) 972-3151 today for a free, no-obligation estimate.
Written by Dale Whitmore, Owner at Kestrel Air Duct Cleaning, serving homeowners nationwide since 2004.