CostGuideHQ

Air Duct Sealing Cost: $500–$6,000 (Average $2,250) in 2026

Author: CostGuideHQ Editorial·✓ Fact-checked·Updated July 2026·7 min read·5 sources·US national averages, USD
Quick answerQuick answer: Whole-home air duct sealing costs $500 to $6,000, averaging around $2,250. Aeroseal (aerosol) sealing runs cheaper than manual mastic-and-tape work — about $1,300 versus $2,250 on average. Home size, sealing method, and duct accessibility drive the final price.
  • Whole-home duct sealing costs $500 to $6,000, averaging about $2,250 nationally (Angi).
  • Aeroseal (aerosol) sealing averages $1,300 for a whole system, versus $2,250 for manual mastic-and-tape sealing (Angi).
  • Expect roughly $0.50 to $2 per square foot depending on the source and method (Angi, HomeGuide).
  • Sealing just one leaky section, rather than the whole system, typically runs $200 to $1,000, averaging $600 (Fixr).

How much does air duct sealing cost?

National average
$2,250
total project
Typical range
$500–$6,000
Most projects
Whole project
$500–$6,000
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Cost by material / type

TypeLowHigh
1,000 sq ft home, whole system$500$2,000
1,500 sq ft home, whole system$750$3,000
2,000 sq ft home, whole system$1,000$4,000
2,500 sq ft home, whole system$1,250$5,000
3,000 sq ft home, whole system$1,500$6,000
aerosol (Aeroseal) sealing, whole system$1,300$6,900
manual sealing (mastic + tape), single leak/section$200$1,000
Estimate your cost
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Rough estimate only — get local quotes for exact pricing.

What affects the cost?

  • Sealing method — manual mastic-and-tape sealing of a whole system averages $2,250 versus $1,300 for aerosol (Aeroseal) sealing, since aerosol reaches hidden leaks from the inside with less labor (Angi); HomeGuide puts whole-system Aeroseal at $1,500-$6,900
  • Home size and total duct run — cost scales with square footage, from about $500-$2,000 for a 1,000 sq ft home up to $1,500-$6,000 for a 3,000 sq ft home (Angi, HomeGuide)
  • Duct accessibility and layout — ducts buried behind walls, under floors, or in cramped attics cost more to reach and seal than exposed runs, and a complex layout with lots of turns raises labor time (Angi, HomeGuide)
  • Extent and location of leaks — budget roughly $50 per accessible supply vent that needs sealing, or $50-$100+ per leak hidden behind walls, under floors, or in the attic; more leaks drive up the total (Angi)
  • Condition of the ductwork — sections that need repair before they can be sealed add cost; fixing a leaky section and applying sealant averages $600 (range $200-$1,000) at Fixr, with leak-specific repairs at $350-$650, while Forbes Home puts average leak repair at $500 within a $175-$2,000 repair range
  • Pressure testing and inspection — confirming the seal worked typically adds $200-$450 for a post-sealing pressure test (around $300 average) and roughly $150-$500 for a duct/HVAC inspection (Angi, HomeGuide)
  • Labor rate — labor makes up about 90% of a typical manual duct-sealing job's cost, with materials accounting for only about 10% (Angi)

How much does air duct sealing cost?

Whole-home air duct sealing costs $500 to $6,000, averaging around $2,250 (Angi). Angi’s typical range runs $500 to $4,000, and HomeGuide’s independently researched figure spans $1,000 to $6,000 for a full project — both sources agree on a $6,000 ceiling for larger or more complex jobs. Priced per square foot, Angi cites $0.50 to $1.50, averaging about $1, while HomeGuide runs slightly higher at $1 to $2 per square foot. Home size is the biggest driver: a 1,000 sq ft home typically runs $500 to $2,000, a 2,000 sq ft home $1,000 to $4,000, and a 3,000 sq ft home $1,500 to $6,000, based on combined Angi and HomeGuide home-size pricing (Angi, HomeGuide). The sealing method you choose moves the number too, which is covered next.

Manual mastic-and-tape sealing vs. Aeroseal: which costs more?

Manual sealing costs more than Aeroseal on average — $2,250 versus $1,300 for a whole system (Angi). Manual sealing means a technician physically coats duct joints and elbows with mastic sealant and wraps seams and insulation joints in foil tape, working section by section on every accessible run. Richard Trethewey, This Old House plumbing and heating expert, explains why ordinary duct tape doesn’t cut it here: “That’s just cloth-backed utility tape. It’s gonna fall off in a year anyway.” Aeroseal (also called aerosol or inside-out sealing) instead pressurizes the whole duct system and injects an aerosolized sealant that collects at leak points from the inside, reaching gaps behind walls and under floors that manual work can’t touch. HomeGuide’s whole-home Aeroseal figure runs higher, $1,500 to $6,900, reflecting bigger or more complex systems, and This Old House cites the same $0.50 to $1.50 per square foot of ductwork for this method, sourced from Angi’s contractor data. Aeroseal has a limit, though: it generally can’t patch large holes over about 5/8 inch or reconnect fully disconnected sections, which still need manual repair. Choosing Aeroseal over manual work can save around $1,000 on a typical job (Angi).

What if only one section is leaking?

Sealing a single leaky section costs far less than resealing an entire system — Fixr puts the average at $600, with a typical range of $200 to $1,000, and leak-specific repairs at $350 to $650. Loose duct sections and joints, fixed with mastic sealant or aluminum tape rather than a full aerosol pass, run $100 to $500 (Fixr, Forbes Home). Forbes Home separately reports leak repairs averaging $500, within a broader ductwork repair range of $175 to $2,000. These figures cover patching or resealing one problem area a technician can already pinpoint, not testing and sealing an entire duct system, so don’t expect them to scale up proportionally to the whole-home numbers above — a home with several scattered leaks, or ducts that are hard to access, will cost closer to the whole-system range.

What affects the cost, and how can you lower it?

A handful of factors explain most of the spread between a $500 job and a $6,000 one:

  • Sealing method. Manual mastic-and-tape work averages $2,250 for a whole system; Aeroseal averages $1,300 (Angi). If your leaks are small and scattered rather than a few large holes, aerosol sealing is usually the cheaper option.
  • Home size and duct run. More square footage means more ductwork to seal, which is why cost scales from around $500–$2,000 for a 1,000 sq ft home to $1,500–$6,000 for a 3,000 sq ft home (Angi, HomeGuide).
  • Duct accessibility. Ducts behind walls, under floors, or in cramped attics take longer to reach and seal than exposed runs (Angi, HomeGuide).
  • Number and location of leaks. Budget around $50 per accessible supply vent that needs sealing, or $50 to $100+ per leak hidden behind walls, under floors, or in the attic — more leaks add up fast (Angi).
  • Condition of the ductwork. Damaged sections may need repair before they can be sealed at all, which is where the narrower $200–$1,000 single-section figures above come in (Fixr, Forbes Home).
  • Pressure testing and inspection. A post-sealing pressure test typically adds $200 to $450, averaging around $300, and a duct inspection runs about $150 to $500 — ask upfront whether either is included (Angi, HomeGuide).

To save money: get a duct inspection first so you’re not paying to seal sections that don’t need it, ask whether aerosol sealing fits your situation before defaulting to manual work, and confirm pressure testing is included in the quote rather than billed as a surprise add-on. Prices vary by region, duct layout, and contractor, so treat the figures above as a planning budget and get two or three local quotes before committing.

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Frequently asked questions

How much does air duct sealing cost on average?
Whole-home duct sealing averages about $2,250, with a typical range of $500 to $6,000 (Angi). Angi's normal range tops out at $4,000, while HomeGuide's independent estimate spans $1,000 to $6,000 for a full project — the $6,000 ceiling is consistent across both sources.
Is Aeroseal cheaper than manual duct sealing?
Yes. Aeroseal (aerosol) sealing averages $1,300 for a whole system, compared to $2,250 for manual mastic-and-tape sealing — choosing aerosol over manual can save around $1,000 (Angi). HomeGuide's whole-home Aeroseal figure runs higher, $1,500 to $6,900, reflecting larger or more complex systems.
How much does duct sealing cost per square foot?
Angi puts it at $0.50 to $1.50 per square foot, averaging around $1. HomeGuide cites a slightly higher $1 to $2 per square foot. This Old House gives the same $0.50 to $1.50 per square foot specifically for Aeroseal's inside-out method, sourced from Angi's contractor data.
How much does it cost to seal just one leaky section instead of the whole system?
Much less. Fixr puts repairing and sealing a single leaky section at an average of $600, ranging $200 to $1,000, with leak-specific repairs at $350 to $650. Forbes Home reports leak repairs averaging $500 within a broader $175 to $2,000 ductwork repair range.
Does the price include testing for leaks?
Usually not — it's a separate line item. A post-sealing pressure test typically costs $200 to $450, averaging around $300, and a duct or HVAC inspection runs about $150 to $500 (Angi, HomeGuide).
How much energy can duct sealing actually save?
It can be substantial on a leaky system. This Old House documented a project where sealing cut duct leakage by 94%; the tested system had been losing 307 CFM of conditioned air, nearly 20% of its total output, equivalent to a hole of about 58 square inches.
Does home size change the price much?
Yes. For a 1,000 sq ft home, expect $500 to $2,000; for a 2,000 sq ft home, $1,000 to $4,000; and for a 3,000 sq ft home, $1,500 to $6,000, based on combined Angi and HomeGuide home-size pricing tables.

Sources

Figures synthesized and cross-checked across these sources (retrieved 2026-07-28):

  • Angi — Professional air duct sealing costs $500 to $4,000, with an average around $2,250. Low end $375, high end $6,000. Average cost per square foot around $1, range $0.50 to $1.50. By home size: 1,000 sq ft $500-$1,500; 1,500 sq ft $750-$2,250; 2,000 sq ft $1,000-$3,000; 2,500 sq ft $1,250-$3,750; 3,000 sq ft $1,500-$4,500. Sealing method: manual $2,250, aerosol $1,300. Ductwork repair averages $660, range $200-$2,100. About $50 per accessible supply vent that needs sealing, or $50 to $100+ per leak behind walls, under floors, or in the attic. Pressure test $200-$450, average $300. Inspection around $150 average. Labor accounts for about 90% of the average $2,000 duct sealing total, materials about 10%. Choosing aerosol over manual sealing can save around $1,000.
  • HomeGuide — Air duct sealing costs $1 to $2 per square foot or $1,000 to $6,000 total. By home size: 1,000 sq ft $1,000-$2,000; 1,500 sq ft $1,500-$3,000; 2,000 sq ft $2,000-$4,000; 2,500 sq ft $2,500-$5,000; 3,000 sq ft $3,000-$6,000. Aeroseal duct sealing costs $1,500 to $6,900 on average. Duct/HVAC inspection $150-$500. Pressure test $200-$450. Ductwork replacement $25-$55 per linear foot or $1,400-$5,600 total. Duct insulation $1-$13 per square foot.
  • This Old House — Inside-out (aerosol) duct sealing technology typically costs between $0.50 and $1.50 per square foot of ductwork (cost data sourced from contractor estimates used by Angi). In a demonstrated project, sealing reduced duct leakage by 94%; one tested system was found to be losing 307 CFM of conditioned air, nearly 20% of the system's total output, equivalent to a hole of about 58 square inches.
  • Fixr — The national average for ductwork repair is $200 to $1,000, with most homeowners paying $600 to repair a leaky section and apply a sealant to prevent future leaks. Low end $100, high end $6,000. By problem type: loose sections $100-$500 (fixed with mastic sealant or aluminum tape), leak repair $350-$650, hole repair $150-$350.
  • Forbes Home — Repairing ductwork costs $175 to $2,000; repairing leaks averages $500. Repair costs run $5 to $20 per linear foot including materials and labor. Loose ductwork repair, fixed with sealants or aluminum tape, costs $100 to $500.

national_average_usd and the headline range are anchored on Angi's dedicated duct-sealing page, the most complete whole-system estimate available (average $2,250; normal range $500-$4,000; low end $375; high end $6,000). HomeGuide's independent duct-sealing page corroborates the $6,000 ceiling and cites a similar per-square-foot rate ($1-$2, vs. Angi's average $1, range $0.50-$1.50), though its home-size-tier totals run roughly double Angi's at every size (for example, a 2,000 sq ft home: $1,000-$3,000 per Angi vs. $2,000-$4,000 per HomeGuide). The by_type home-size rows use Angi's low end and HomeGuide's high end at each size to represent that full realistic spread, which is why range_high_usd is set at HomeGuide/Angi's shared $6,000 ceiling rather than Angi's $4,000 'normal range' top alone. Method matters for price: Angi reports manual (mastic + foil tape) sealing averaging $2,250 for a whole system versus $1,300 for aerosol/Aeroseal, while HomeGuide puts whole-system Aeroseal at $1,500-$6,900 and This Old House cites $0.50-$1.50 per square foot of ductwork for aerosol/inside-out sealing (that figure is sourced from the same Angi contractor-estimate data, per This Old House's own citation). Fixr and Forbes Home publish figures for a narrower scope — patching or sealing a single leaky section rather than resealing an entire duct system — and are cited separately rather than folded into the whole-system headline range: Fixr's ductwork-repair page puts 'repair a leaky section and apply a sealant' at an average of $600 (range $200-$1,000), with leak-specific repairs at $350-$650; Forbes Home's duct-repair figures show leak repairs averaging $500 within a broader $175-$2,000 repair range. Pressure testing and inspection are commonly quoted as separate add-ons across sources, not included in the base sealing price. Figures generally reflect single-family homes; commercial duct systems are priced separately and are not covered here.