# Air Duct Cleaning Gilbert AZ | Comfort Pros AZ and CA > Duct cleaning, mastic sealing and attic duct insulation in Gilbert and Greater Phoenix. Fix the dust and the uneven rooms at the same time. Flat-rate pricing. URL: https://www.comfortprosaz.com/duct-cleaning-sealing/ ![Technician applying mastic to a duct joint in an attic](/images/misc/candid-photo-of-a-technician-in-a-hot-attic-applyi.webp) Same-Day Service # Duct Cleaning and Sealing That Stops Cold Air Leaking Into a 140-Degree Attic Last updated: August 25, 2026 Duct cleaning, sealing and attic insulation that cuts the cooling load before you upsize equipment. Licensed AZ & CA Flat-rate pricing 17 years in business Get Your TrueQuote [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) (480) 435-2334 [tel:+14804352334 →](tel:+14804352334) From $ 400 varies by system size, duct run length and insulation scope 4.9 Rating 115+ Google reviews Same-Day Service Across AZ and CA service areas Licensed & Insured AZ ROC 364742 | CA C-20 #1040927 Flat-Rate Pricing Quoted before work begins Sound familiar? ## What Brings People to Us for Duct Services The situations behind most of these calls, and what we actually do about each one. ### One room that never gets cold The thermostat says the system is running, the living room is fine, and the back bedroom sits four degrees warmer all summer. Adding a bigger unit does not fix it, because the air is not reaching that room. We measure static pressure and inspect the attic runs, then repair the crushed flex, disconnected boots and leaking plenum joints that are actually starving the register. ### Cooling you paid for, dumped into the attic Leaky duct joints in a 140-degree attic throw away conditioned air before it reaches a single room, and the system runs longer to make up for it every hour of an eight-month season. Mastic sealing at joints, boots and plenum connections, with static pressure measured before and after so the improvement is a number rather than a claim. ### Dust settling back an hour after you clean Fine desert dust and wildfire ash get pulled in through return leaks and unsealed boots, then redistributed through the house every cycle. Wiping surfaces does nothing about the source. We clean the trunks, branches, registers and blower compartment, and seal the return side so the system stops drawing attic and crawlspace air in the first place. ### Being quoted a bigger system instead A house that cannot hold temperature gets a replacement quote with more tonnage on it. The leaks and the missing attic insulation carry straight over to the new equipment. Sealing and insulating change the load calculation, and sometimes the equipment size you need. In a lot of homes this is the work that should happen before a replacement quote, not after. ## The Cooling You Already Paid For A duct system running through a Southwest attic is operating in an environment that reaches 140 degrees on a July afternoon. Every foot of uninsulated or poorly insulated duct in that space is a heat exchanger working against you, and every unsealed joint is conditioned air being delivered to your attic instead of your bedroom. Add a leaky return, which pulls that 140-degree attic air, and the dust in it, straight into the system, and you have a house that is simultaneously expensive to cool, unevenly cooled, and dustier than it should be. All three symptoms, one underlying cause. This is frequently the work that should happen before a replacement quote rather than after. Sealing and insulating changes the Manual J result. We have run homes where the improved duct system needed a smaller air conditioner than the original, which means the duct work partly paid for itself in reduced equipment cost. ## Three Different Problems, Three Different Jobs People call about duct cleaning. What they usually have is one of these: **A dust problem.** Almost always a leaky return pulling attic air past your filter. Cleaning the ducts makes them clean for a few weeks. Sealing the return fixes it permanently. **An uneven-rooms problem.** Usually a disconnected or crushed flex run in the attic, an undersized branch, or a return path issue. All are diagnosable with static pressure readings and a physical inspection, and none are solved by cleaning. **A running-cost problem.** Uninsulated attic runs and distributed leakage. The fix is mastic and insulation, and it is measurable. We look at the system first and tell you which one you have. Occasionally the answer is genuine duct cleaning, and we do that too. ## What Proper Sealing Involves - **Mastic, not tape.** Duct tape adhesive degrades under attic temperature cycling and lets go within a couple of seasons. Mastic stays flexible and bonded. - **Boots and plenum connections.** The largest leaks are usually at the connections, not along the duct body. - **Physical repairs first.** A crushed or disconnected flex run gets repaired or replaced. No amount of sealant fixes a duct that has come off its boot. - **Static pressure before and after.** The measurement that proves the work did something. You get both numbers. - **Aerosol sealing where appropriate.** Aeroseal-style interior sealing reaches distributed small leaks a technician physically cannot get to. Frequently the right answer is both methods. ## Insulation: The Cheapest Capacity Available Attic duct runs at R-4.2 or bare metal are common in older Mesa and Tempe housing. Bringing them to R-8 produces an immediate, measurable difference in delivered air temperature at the register. The attic envelope itself compounds it. Reducing the attic temperature the ducts sit in reduces the conductive loss along their whole length. Attic insulation is one of the highest-return improvements available in a Southwest home for exactly that reason, and we handle it alongside the duct work rather than sending you to another contractor. ## Cost Guide | Work | Typical range | What drives it | | --- | --- | --- | | Full duct cleaning | $400 - $900 | System size, register count, access | | Mastic sealing | $900 - $2,400 | Number of connections, attic accessibility | | Flex duct repair or replacement | Quoted per run | Length, routing, whether the boot survived | | Attic duct insulation to R-8 | $800 - $2,000 | Linear footage of attic runs | | Attic envelope insulation | Quoted after inspection | Existing depth, coverage gaps, square footage | | Title 24 duct testing (CA) | Included with changeout | Compliance requirement, documented | ## When to Call Us About This - The house is dustier than it should be, and filters do not seem to help - Some rooms never reach the thermostat setpoint - Cooling bills have climbed without a rate change or equipment problem - You are about to replace the system and want the load calculation to be honest - Your air conditioner freezes up repeatedly, which often traces to restricted airflow - You are in California and a changeout has triggered Title 24 duct testing If your system is genuinely failing rather than underperforming, start with AC repair [/ac-repair/ →](/ac-repair/) . If the ducts turn out to be the constraint on a replacement, AC installation [/ac-installation/ →](/ac-installation/) sequenced after this work produces a smaller, cheaper, better-matched system. For the deeper explanation, attic insulation and duct sealing [/guide/attic-insulation-and-duct-sealing/ →](/guide/attic-insulation-and-duct-sealing/) and why is my house so dusty [/guide/why-is-my-house-so-dusty/ →](/guide/why-is-my-house-so-dusty/) cover the diagnostics in more depth. Transparent Pricing ## How Much Does Duct Services Cost? In a lot of homes this is the work that should happen before a replacement quote, not after. Sealing and insulating changes the load calculation, and occasionally the equipment size you need. ### Duct cleaning Full system clean with source removal $400 - $900 - Supply and return trunks and branches - Register and boot cleaning - Blower compartment and coil access cleaned - Honest assessment of whether cleaning is the actual fix Get exact pricing [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) Most chosen ### Duct sealing Mastic sealing with static pressure verification $900 - $2,400 - Mastic applied at joints, boots and plenum connections - Disconnected and crushed runs repaired - Static pressure measured before and after - Title 24 duct testing handled on California jobs Get exact pricing [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) ### Seal, insulate and repair Full attic duct improvement package $2,400 - $4,500 - Attic duct runs insulated to Southwest R-value targets - Attic insulation top-up where the envelope needs it - Damaged flex duct replaced rather than patched - Airflow rebalanced at the registers afterward Get exact pricing [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) ### Financing available GreenSky, Wisetack and Goodleap, so you can pick the lender that fits your credit profile. Where your equipment qualifies for a utility rebate, it stacks with financing. Compare options [/financing/ →](/financing/) Why Choose Us ## Why Choose Us for Duct Services? ### We tell you when cleaning is not the fix Plenty of dusty houses do not need duct cleaning, they need a leaky return sealed. Cleaning ducts that are pulling attic air just resets the clock. ### Static pressure before and after Numbers, not claims. You see what the system was doing before the work and what it does afterward. ### Mastic, not tape Duct tape fails in an attic. Mastic stays flexible, adheres through thermal cycling, and is what actually holds a seal at 140 degrees. ### Insulation targeted at the real loss Uninsulated ducts running through a 140-degree attic lose a meaningful share of the cooling you already paid for. That is the cheapest capacity available. ### Sequenced before replacement Sealing and insulating changes the Manual J result. In several homes it has reduced the equipment size the replacement needed. ### Title 24 testing in California Duct leakage testing and sealing on a changeout is a compliance requirement, and we handle the documentation as part of the job. Step by Step ## How Our Duct Services Works 1 ### Measure and inspect Static pressure across the system, then a physical look at the attic runs. Disconnected boots and crushed flex are more common than people expect. 2 ### Tell you which problem you have Dust from a leaky return, uneven rooms from a duct sizing issue, or high bills from uninsulated attic runs. These are three different jobs. 3 ### Do the work Source-removal cleaning, mastic sealing at every joint and boot, and insulation brought up to a sensible Southwest R-value. 4 ### Verify the result Static pressure measured again and airflow checked at the registers. You see the before and after numbers, not a claim. ## Still deciding on Duct Services? Flat-rate pricing quoted before we start, parts and labor warranty on the finished work, and an honest answer if you do not need it yet. Get Your TrueQuote [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) (480) 435-2334 [tel:+14804352334 →](tel:+14804352334) Our Work ## Recent Duct Services Jobs Click any photo to enlarge. ## How Comfort Pros AZ and CA Compares | What matters | Typical provider | Comfort Pros | | --- | --- | --- | | Diagnosis | Cleaning sold on sight | Static pressure and physical inspection first | | Sealing material | Foil tape | Mastic at joints, boots and plenums | | Verification | Visual, before-and-after photos | Static pressure measured both ways | | Insulation scope | Not offered | Attic duct runs and envelope insulation | | Sequencing advice | Sold independently of equipment | Recommended before a replacement quote where relevant | | Title 24 documentation (CA) | Subcontracted or skipped | Handled as part of the job | Reviews ## What Customers Say About Our Duct Services **4.9** from 115+ Google reviews > Two bedrooms were always warmer than the rest of the house. Turned out one flex run had come off its boot in the attic. They found it in twenty minutes. M Marcus T. Mesa, AZ > They told me my ducts did not need cleaning, which is not what I expected to hear from a duct cleaning company. Sealed the return instead and the dust problem went away. R Rachel M. Gilbert, AZ > Sealed and insulated the attic runs before we replaced the AC. The load calc came back smaller than the original system, which saved us real money on the equipment. P Priya N. Scottsdale, AZ Got Questions? ## Duct Services FAQs ### Do I actually need my ducts cleaned? Often, no, and we would rather say that than sell it. Duct cleaning is genuinely worthwhile after construction or renovation work, after a rodent problem, where there is visible biological growth, or where the system has run for years without adequate filtration. What it does not fix is a dusty house caused by a leaky return, and that is the far more common cause in this market. A return duct with unsealed joints pulls attic air, and attic dust, directly into your living space, bypassing your filter entirely because the air enters downstream of it. Cleaning the ducts in that situation makes them clean for a few weeks. Sealing the return fixes it. We look at the system and tell you which problem you have. ### How much cooling am I losing through the attic? In a Southwest home with uninsulated or poorly insulated ducts running through an attic that reaches 140 degrees in July, the loss is meaningful, commonly in the range of a fifth to a third of the cooling capacity leaving the air handler. Some of that is conductive loss through the duct wall and some is leakage. Both are recoverable with sealing and insulation, and both represent capacity you have already paid for at the meter. It is the cheapest cooling available in this climate. ### Why mastic instead of duct tape? Because duct tape fails in an attic, reliably and fairly quickly. The adhesive degrades under sustained high temperature and thermal cycling, the backing separates, and within a couple of seasons the joint is open again. Mastic is a thick brushed-on sealant that stays flexible, bonds to the duct material, and survives the temperature swings an attic imposes. Where a mechanical connection is needed we use foil-backed tape rated for the application plus mastic over it, not tape alone. ### What does duct work cost? A full system cleaning with source removal runs $400 to $900 depending on system size and register count. Mastic sealing with static pressure verification lands between $900 and $2,400, driven by how many joints, boots and plenum connections need attention and how accessible the attic is. A full package of sealing, insulating attic runs and topping up attic insulation runs $2,400 to $4,500. We quote flat-rate after the inspection. ### Should I do this before or after replacing my AC? Before, in most cases, and this is one of the more genuinely useful things we tell people. Sealing and insulating the duct system reduces the cooling load your equipment has to meet, which changes the Manual J result. We have run homes where the sealed and insulated version of the house needed a smaller system than the original, meaning the duct work partly paid for itself in reduced equipment cost. Doing it in the other order means paying for capacity to compensate for losses you were about to fix. ### Why are some rooms always warmer than others? Four common causes, and they need different fixes. A disconnected or crushed flex duct run in the attic, which is far more common than homeowners expect and is a repair rather than a redesign. A branch run that is too small or too long for the distance it serves, which is a sizing problem. A return path problem, where air can get into a room but not easily out of it. Or an oversized system that short-cycles and shuts off before air has physically reached the far rooms. Static pressure readings plus a physical attic inspection usually identify which one within an hour. ### What R-value should attic ducts have here? Southwest attic conditions justify more than the code minimum. R-8 flex duct insulation is a sensible target for attic runs, and where existing runs are R-4.2 or bare metal, upgrading them produces an immediate and measurable improvement. The attic envelope itself matters too: bringing attic insulation up to an appropriate depth reduces the temperature the ducts are sitting in, which compounds the benefit. ### Is Aeroseal-style sealing better than mastic? They solve slightly different problems. Aerosol-based sealing is applied from inside the duct system and is excellent at sealing small leaks distributed throughout a system, including places a technician physically cannot reach. Mastic is applied from outside and is better for larger gaps, boot connections and plenum joints. On many homes the right answer uses both. We assess accessibility and leak distribution and recommend accordingly rather than defaulting to whichever we happen to sell. ### Do you handle attic insulation as well as duct insulation? Yes. Attic insulation is one of the highest-return improvements available in a Southwest home, because it reduces both the heat entering the living space and the temperature the ducts operate in. We assess existing depth and coverage, identify gaps and compression, and quote a top-up or a full replacement as appropriate. ### Will duct sealing help with dust? If your dust problem is caused by return leakage, dramatically. A leaky return draws unfiltered attic air into the system continuously while it runs, and every particle in that air ends up circulating through your house. Sealing the return means all incoming air passes through your filter, which is what filtration was designed to do. This is the single most common real fix for a house that seems to generate dust faster than it should. ### How long does the work take? A duct cleaning is typically half a day. Mastic sealing runs half a day to a full day depending on accessibility and the number of connections. A full seal, insulate and repair package usually runs one to two days. Attic work in summer is scheduled for mornings where possible, for obvious reasons. ### Is duct testing required in California? On a system changeout, commonly yes. Title 24 Part 6 requires duct leakage testing and sealing as part of a compliant installation, with documentation. It is not an optional add-on, and a replacement quote that omits it is incomplete. We include it in the quote from the beginning. ### Still have a question? Call the team in your state and talk to someone who actually works on these systems. (480) 435-2334 (AZ) [tel:+14804352334 →](tel:+14804352334) (818) 690-7951 (CA) [tel:+18186907951 →](tel:+18186907951) Guides ## Read Before You Decide Plain-language answers to the questions homeowners ask us about Duct Services. scenario ### Attic Insulation and Duct Sealing: Cutting the Load Before You Upsize the AC A 140-degree attic makes uninsulated ducts lose a large share of your cooling. R-value targets, how sealing changes the Manual J, and when this defers a replacement. Read guide [Attic Insulation and Duct Sealing: Cutting the Load Before You Upsize the AC →](/guide/attic-insulation-and-duct-sealing/) concern ### Why Is My House So Dusty? Leaky Returns and Attic Duct Loss How leaky returns pull attic dust into your living space, why desert attics make it worse, and whether cleaning or sealing is the fix that actually lasts. Read guide [Why Is My House So Dusty? Leaky Returns and Attic Duct Loss →](/guide/why-is-my-house-so-dusty/) ## Related Services ### Indoor Air Quality Whole-home air purification, UV-C, media filtration and smart thermostat setup. View details [Indoor Air Quality →](/indoor-air-quality/) ### AC Maintenance & Tune-Ups A real multi-point tune-up at $27 per unit, plus the Care N'Comfort membership at $9.99/month. View details [AC Maintenance & Tune-Ups →](/ac-maintenance/) ### AC Installation & Replacement New system installation sized by a real load calculation, priced online, installed without a sales visit. View details [AC Installation & Replacement →](/ac-installation/) ![](/images/hero/cool-comfortable-bedroom-with-air-moving-from-a-ce.webp) Same-day appointments available ## Ready to Book Duct Services? Flat-rate pricing quoted before we start, and an honest answer about whether you actually need this service. Same-day appointments available across Arizona and California. Get Your TrueQuote [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) (480) 435-2334 [tel:+14804352334 →](tel:+14804352334) Flat-rate pricing, no upsells Parts and labor warranty Licensed in AZ and CA California team: (818) 690-7951 [tel:+18186907951 →](tel:+18186907951) · Text us: (818) 489-2826 [sms:+18184892826 →](sms:+18184892826)