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.
Trusted Duct Sealing for Alpharetta Homeowners
Leaky ducts are the quiet thief in your HVAC system, and in Alpharetta they work overtime. Georgia humidity forces air conditioners to run long cycles from May through September, and every crack, gap, and disconnected joint in your ductwork lets conditioned air escape into the attic or crawl space before it ever reaches your living room. Most Alpharetta homes we test lose between 15% and 30% of conditioned air to duct leakage. That’s not a maintenance footnote. It’s real money leaving the house every month, and it’s why we’ve been sealing ducts in this area since 2004. Roy Castellanos and the Hollis Air Duct Alpharetta team handle Alpharetta Duct Sealing jobs with written pricing, professional-grade materials, and a 365-Day Done Right Promise on every job. Call (762) 769-7145 for a free estimate.
We’re part of the Garrison Partners family, which means we operate under The Garrison Standard. That’s not a slogan. It’s a written set of expectations: show up inside the quoted window, put the price in writing before any work starts, complete the job by the book, and leave your home clean enough that you’d never know we were there except for the difference in your utility bill.
Key Takeaways
- What duct sealing does: closes leaks, gaps, and disconnected joints in your ductwork so conditioned air reaches the rooms you paid to heat and cool.
- What it costs in Alpharetta: most whole-home duct sealing jobs run $1,850 to $3,800 depending on home size, duct accessibility, and number of leaks found.
- Why it matters here: Alpharetta’s hot, humid summers push HVAC systems hard, and leaky ducts force them to work even harder.
- Our guarantee: every job carries the 365-Day Done Right Promise in writing. If it fails within a year, we return at no charge.
- What you’ll pay before we start: a written price, agreed to upfront, that does not move at the door.
Styles & brands we work with
What Duct Sealing Fixes in Your Alpharetta Home
Duct sealing stops conditioned air from escaping through gaps, cracks, and failed connections in your ductwork. The fix is usually straightforward: identify the leaks, clean the surfaces, apply a UL-rated mastic sealant or foil-backed tape, and verify the seal. What’s not straightforward is finding the leaks in the first place. That’s why we use a negative-air method and pressure testing on most Alpharetta jobs. We depressurize the duct system and measure how much air is leaving through places it shouldn’t. The test tells us the severity of the leakage. Then we find and seal it. No guesswork, no sealing ducts that don’t need it, no charging you for work that doesn’t improve your system.
Roy and the crew have sealed ducts in homes across Alpharetta and nearby communities, from Roswell Duct Sealing projects to neighborhoods around Windward Parkway and the older homes near downtown. The homes change. The problem rarely does: ducts installed decades ago, taped at the seams with materials that dried out and failed, or flex duct pulled too tight around bends and split open. If your HVAC system runs constantly in July and your upstairs rooms still feel warm, duct leakage is the first thing we check.
Duct Insulation
Duct Insulation is the material wrapped around your ductwork that keeps the air inside at the right temperature as it travels from your HVAC unit to each room. In Alpharetta, where attic temperatures routinely hit 130°F in summer, uninsulated or under-insulated ducts lose cooling capacity fast. The air leaving your coil might be 55°F, but by the time it travels through a hot attic in bare or thin-walled duct, it can gain heat and arrive at the register closer to 65°F. That means your system runs longer to hit the thermostat setting, and your energy bill climbs. Hollis Air Duct Alpharetta inspects existing insulation during every duct sealing job and replaces or adds insulation where the current material is compressed, torn, water-damaged, or simply too thin for local conditions. Insulation replacement typically adds $250 to $800 to a sealing job, depending on how much duct runs through unconditioned space.
What Failing Insulation Looks Like
Most homeowners never see their ductwork, so insulation failure goes unnoticed until symptoms show up elsewhere. Telltale signs include rooms that feel warmer than others, higher-than-expected cooling bills, and condensation forming on ceiling registers. Water staining around vents is a specific red flag: it usually means warm attic air is condensing on cold ducts where insulation has separated at a seam or fallen away entirely.
How Insulation and Sealing Work Together
Sealing stops the leaks, but insulation stops the heat transfer through the duct walls. One without the other leaves a big gap in performance. A sealed but uninsulated duct still loses significant cooling in a hot Alpharetta attic. We address both because that’s what actually lowers your energy use and evens out room temperatures.
HVAC Duct Sealing
HVAC Duct Sealing is the process of closing air leaks throughout the duct system that distributes heated and cooled air through your home. It’s different from cleaning, which removes debris from inside the ducts. Sealing is about the seams, joints, and connections. When the supply side leaks, you pay to condition air that never reaches your rooms. When the return side leaks, the system pulls unfiltered attic or crawl space air into your home, which is a comfort issue and an air quality issue. Hollis Air Duct Alpharetta provides HVAC duct sealing as a standalone service and as part of larger duct repair or replacement jobs. Whole-home sealing in Alpharetta typically runs $1,850 to $2,950, with higher totals when extensive duct replacement is also needed. Every job starts with the written price and the same 365-Day Done Right Promise.
Supply vs. Return Leaks
Supply leaks push conditioned air out. Return leaks pull dirty air in. The symptoms are different: supply leaks show up as warm rooms and long run times. Return leaks show up as dusty homes, musty smells when the system kicks on, and humidity that stays high even with the AC running. We test both sides of the system because fixing only one leaves the other problem untouched.
The Materials That Actually Hold Up
We use mastic sealant, not hardware-store duct tape, because mastic is what the trade uses to stay sealed. Duct tape fails in hot attics. It dries, cracks, and peels within a few years. Mastic goes on as a paste and cures into a flexible, durable seal that tolerates the temperature swings inside an Alpharetta attic. For larger gaps and disconnected joints, we use foil-backed tape in combination with mastic, mechanical fasteners, and re-hanging brackets where needed.
Duct Repair
Duct Repair addresses physical damage to your ductwork: crushed sections, disconnected joints, holes and tears in flexible duct, and hangers that have failed and left duct sagging or lying on the attic floor. Repairs are often part of a duct sealing job, because you cannot seal a duct that’s structurally broken. The leak has to be closed, not just covered over. Hollis Air Duct Alpharetta handles duct repair across Alpharetta and Duluth Duct Sealing jobs, and our technicians carry the materials needed for most common fixes on the truck: flex duct replacement sections, sheet metal fittings, collars, hangers, mastic, and tape. Minor repairs add $150 to $500 to a sealing job. Sections that need full replacement push that higher, and we quote every dollar in writing before work starts. You’ll know before we begin what needs to be repaired, what needs to be replaced, and what it costs.
When Repair Beats Replacement
Not every damaged duct is a lost cause. A crushed flex duct run can sometimes be re-supported and re-rounded. A separated joint can be reconnected and sealed. We recommend replacement when the duct material itself has failed: tears longer than a few inches, inner liner damage that exposes insulation to airflow, or water damage that’s left the material soft and mold-prone. The goal is a duct system that stays sealed, not one that looks fine from the floor and leaks from the attic.
Water Damage in Ductwork
Alpharetta’s summer thunderstorms and high humidity create conditions for condensation inside uninsulated or poorly sealed ducts. When that water pools, it soaks insulation, drips through ceilings, and can support mold growth inside the duct liner. We check for water staining and moisture issues on every repair visit. If we find water-damaged ductwork, we show you exactly what we found before we touch anything.
Air Duct Sealing
Air Duct Sealing is what most homeowners mean when they call about fixing leaky ducts: closing the gaps, cracks, and failed joints in the duct system so conditioned air stays in the ducts until it reaches the register. The term covers the same work as duct sealing, but it’s worth saying clearly: air duct sealing addresses the entire duct pathway, both supply and return, from the plenum at the HVAC unit to the last register. Hollis Air Duct Alpharetta performs air duct sealing on homes of all sizes in Alpharetta, and every job starts the same way: a pressure test to measure leakage, a visual inspection to find the worst offenders, and a written quote that covers the full scope of work. Most Alpharetta homes fall between $1,850 and $3,200 for complete air duct sealing, with final cost driven by the number of accessible leaks and how much of the ductwork runs through unconditioned attic or crawl space.
Testing Before and After
We don’t seal ducts blind. We measure. Before work begins, we run a pressure test to quantify leakage. After the job is done, we test again. The difference between those two numbers is what you’re paying for. Most homes see leakage drop by 50% or more. We walk you through both numbers so you know what was fixed and what the improvement actually was.
What the Negative-Air Method Does
When we seal ductwork, we often pair the work with a negative-air setup that keeps dust and debris from circulating through the house while we work. The machine pulls air from the ductwork through a HEPA filter, trapping particles before they reach your living space. It’s the same approach commercial duct crews use, and it means your home isn’t dustier when we leave than when we arrived. Our equipment includes negative-air machines from Nikro and filtration products from Honeywell and Aprilaire.
Duct Sealing Services
Duct Sealing Services cover the full range of work needed to make your duct system hold air the way it’s supposed to: leak testing, mastic sealing, joint and seam repair, access panel installation, register-to-boot sealing, and insulation replacement where sealing alone won’t solve the heat-transfer problem. Hollis Air Duct Alpharetta provides these services to homeowners throughout Alpharetta and our Duct Sealing in Cumming. A typical service call for targeted duct sealing, where a handful of known leaks are addressed, runs $450 to $850. A full-system seal with pressure testing, multiple access points, and insulation work on a two-story Alpharetta home most often lands between $2,200 and $3,800. You’ll get a written, itemized price before we begin, and that number is what you’ll pay.
What’s Included in the Written Price
Our written quotes include the labor, materials, testing, and cleanup. No separate trip charges, no fuel surcharges, no extras for mastic or tape. If we find something during the job that wasn’t in the quote, we stop and talk to you first. The price only changes if the scope changes, and only with your signature on an updated work order.
Register and Boot Sealing
One of the most common leaks we find in Alpharetta homes is at the register boot, where the duct connects to the floor or wall opening in each room. Air escapes around the boot into the wall cavity or floor joist, never making it into the room. Sealing each boot is methodical work, but it’s where a lot of comfort is recovered. We include boot sealing in every full-system job we quote.
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.
Brands We Service
Our technicians work on duct systems serving every major HVAC brand installed in Alpharetta homes. That includes systems built around Honeywell filtration, where we regularly see OEM media cabinets and replacement media needs. The Honeywell equipment we encounter is built for simple filter swaps, but the sealing around the cabinet often fails long before the equipment does. We check and seal those connection points as part of our standard process.
We also carry and work with products from Aprilaire, particularly their media air cleaners and whole-home filtration setups. Aprilaire units are common in higher-end Alpharetta homes, and we’re familiar with their cabinet designs and how they integrate with existing ductwork. When we find leaks where the filter cabinet meets the plenum, we fix them with the same mastic and foil-backed tape methods we use throughout the rest of the system. Whether you have Honeywell, Aprilaire, or any other brand of HVAC and filtration equipment, we can seal and repair the ducts connected to it.
See the difference
Before
After
Before
After
Before
AfterSigns You Need a Pro Right Now
- Rooms that never reach the thermostat setting. Some rooms stay warm in summer or cold in winter no matter how you adjust the vents. When certain areas of the house can’t hold temperature while others are fine, the problem is rarely the HVAC unit. It’s usually ductwork delivering air inconsistently. Leaks in the specific branch runs serving those rooms explain the imbalance.
- Your energy bill climbed with no change in usage. Rates rise, but a sudden jump that holds across multiple billing cycles points to efficiency loss. Duct leaks develop gradually, and the system compensates by running longer. The utility bill is where that extra runtime shows up.
- Dust appears on surfaces days after cleaning. Return-side leaks pull unfiltered air from the attic or crawl space and push it into your living spaces. That air carries insulation fibers, dust, and whatever else is in the unconditioned parts of your home. No amount of surface cleaning fixes the source when the source is leaky return ductwork.
- You hear whistling or hissing when the system runs. Air moving through a properly sealed duct system is quiet. Whistles and hisses mean air is being forced through a gap or crack. The noise tells you where at least one leak is, but there are usually more in places you can’t hear.
- Your upstairs is always warmer in summer. Hot air rises, and Alpharetta attics bake. Ducts serving second-floor rooms run through that heat, and leaks compound the problem. If your upstairs registers blow weak warm air in July while the downstairs feels fine, call a pro before the AC works itself to death.
Our Process, Step by Step
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Visual inspection and leak testing. We walk the attic and crawl space, looking at every accessible duct run, joint, and connection. We note damaged hangers, crushed sections, disconnected boots, and failing tape. Then we run a pressure test to quantify total leakage. You get the numbers, not just a guy in a truck saying you need work.
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Written scope and price. Based on what we find, Roy or a senior technician prepares a written work order with every repair itemized. The price is a fixed number, not an estimate with room to grow. You review it, ask questions, and sign only when you’re ready. Nothing proceeds without your approval.
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Surface preparation and sealing. We clean and prep surfaces where mastic will be applied. Then we seal: joints, seams, boots, takeoffs, and plenum connections. Where access panels are needed to reach ductwork inside walls or soffits, we cut clean openings and seal them properly after.
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Verification and insulation checks. After sealing, we re-run the pressure test and compare to the baseline. The difference tells us and you what was accomplished. We also inspect insulation and add or replace material where the sealing exposed thin spots or gaps.
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Cleanup and walkthrough. We remove all debris, tape, and waste from the work areas. We vacuum where we worked. Then we walk you through what was sealed, what the test numbers show, and what to expect in terms of runtime and comfort. The job isn’t done until you’ve seen the work and had your questions answered.
How Much Does Duct Sealing Cost in Alpharetta?
A typical whole-home duct sealing job in Alpharetta runs between $1,850 and $3,800. Smaller targeted repairs, where a specific leak or two is addressed in a single visit, cost $450 to $850. Homes with fully accessible ductwork in a walkable attic tend to land at the lower end. Homes where ducts run through tight crawl spaces or inside finished ceilings require more access work and push toward the higher end. Two-story homes almost always cost more than ranches because there is simply more ductwork to reach and seal.
What affects the price: how many leaks we find, how much of the system is accessible, whether we need to cut and install access panels, and whether insulation needs to be added or replaced after sealing. We don’t price per vent, and we don’t quote a teaser number and grow it at the door. The written price covers the whole job. To avoid overpaying, get the leakage test numbers in writing, ask exactly what materials will be used, and make sure the quote includes the post-work verification test. All of that is standard in every Hollis Air Duct Alpharetta quote. Call (762) 769-7145 and we’ll walk your ducts, run the test, and put a fixed number in your hand.
Our Service Area Near Alpharetta
Hollis Air Duct Alpharetta serves homeowners across north Fulton and the surrounding area. In addition to Alpharetta, we work regularly in Roswell, Milton, Johns Creek, Dunwoody, Duluth, Norcross, Cumming, and Suwanee. We also take jobs in Canton and the neighborhoods around Druid Hills and Fair Oaks. Whether you’re in a Windward subdivision home or an older house near downtown Roswell, you’ll get the same written pricing and the same 365-Day Done Right Promise. We’re also the team to call for Duct Sealing in Cumming and Duct Sealing in Suwanee. If you’re not sure whether we cover your neighborhood, call and ask. A live person answers.
Serving Alpharetta, GA - Our Local Coverage Area
We’re based in the Alpharetta area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions About Duct Sealing in Alpharetta
Duct sealing is the process of closing air leaks in the ductwork that carries heated and cooled air from your HVAC system to the rooms of your home. We use mastic sealant and foil-backed tape to close gaps, seams, and disconnected joints. The process starts with a pressure test to find and measure the leaks, and ends with a second test to verify how much leakage was eliminated.
Most Alpharetta homes take four to seven hours for a complete sealing job. Smaller targeted repairs can be done in two hours or less. Larger homes or those requiring significant access work may take longer, and we’ll tell you upfront in the written quote what the time expectation is.
Whole-home duct sealing in Alpharetta typically costs $1,850 to $3,800 depending on system size, accessibility, and leak severity. Targeted repairs start around $450. Every job gets a written quote before work starts, so the price you sign is the price you pay. Call (762) 769-7145 for a free estimate on your specific system.
Yes. We service duct systems connected to Honeywell and Aprilaire filtration products, and we’re familiar with the cabinet designs and how they integrate with the plenum and trunk lines. We also work on systems from every other major HVAC brand in the Alpharetta market.
We answer the phone day and night, and we’ll schedule your service as quickly as our calendar allows. Duct sealing itself is a scheduled job, not an emergency repair, but if you have a duct failure causing water damage or air loss, call (762) 769-7145 and we’ll get you on the schedule fast.
Every Hollis Air Duct Alpharetta job is covered by the 365-Day Done Right Promise. If the sealing work fails within a year, we return and fix it at no charge, including a free second visit. The guarantee is written, not verbal, and it’s part of every work order we issue.
Clear a path to your attic access and to the indoor HVAC unit. If you have a crawl space, make sure the access door is reachable. Move any stored items away from the furnace closet. That’s it. We handle the rest, and we leave the work areas clean when we’re done.
Schedule Your Duct Sealing Service in Alpharetta Today
You’ve been paying for air that never reaches your rooms. It’s time to stop. Call (762) 769-7145 and talk to a live person from Hollis Air Duct Alpharetta. We’ll schedule a visit, test your ducts, and hand you a written price before any work begins. No pressure, no moving targets, and a full year of coverage under the 365-Day Done Right Promise. Back at home, you’ll find more about how we work and what to expect. Call today.
Written by Roy Castellanos, Owner at Hollis Air Duct Alpharetta, serving Alpharetta since 2004.