Air Duct Sealing Cost
Reviewed 2026-07-30
Typical range
$450 – $2,500
National average
$1,200
Air Duct Sealing cost breakdown
| Line item | DIY cost | Professional cost |
|---|---|---|
| Manual mastic sealing of accessible joints | $40 – $80 in mastic and foil tape for basic joints | $450 – $1,200 |
| Aeroseal or equivalent interior duct sealing | Not available as a DIY product | $1,500 – $2,500 |
| Duct insulation wrap added after sealing | $1 – $2/linear foot in materials | $300 – $800 add-on |
| Pre/post duct leakage testing (blower door/duct blaster) | Not possible without calibrated equipment | $150 – $400 |
| Register boot and connection repair | $10 – $30 per boot in materials | $50 – $150 per boot |
What pushes air duct sealing cost up
- Extensive ductwork in unconditioned attics or crawl spaces with more joints
- Whole-home Aeroseal treatment instead of spot sealing
- Ducts that are hard to access, such as buried in finished ceilings
- Combining sealing with insulation upgrades in the same visit
- Older homes with deteriorated flex duct needing partial replacement
- Larger square footage with more branch runs and registers
What brings air duct sealing cost down
- Smaller homes with simpler, shorter duct runs
- Easily accessible ducts in an open basement or attic
- Spot-sealing only the worst leaks identified by a duct blaster test
- Bundling with a home energy audit that identifies priority areas first
- Utility or state rebate programs that subsidize duct sealing
Air Duct Sealing diagnostic and emergency fees
$100 – $300 for a duct leakage test, often credited toward sealing work
Duct sealing is rarely an emergency service; most companies schedule it as planned work, though urgent scheduling for extreme energy bills or comfort issues may add a modest rush fee.
Questions to ask before you approve air duct sealing work
- Will you perform a duct leakage test before and after sealing?
- Do you use mastic sealant or an aerosol-based sealing system?
- What percentage of duct leakage are you targeting to fix?
- Are there utility rebates available for duct sealing in my area?
- Will sealing include insulating exposed ducts in the attic or crawl space?
- How long will the sealing take and will my HVAC be usable during the work?
Air Duct Sealing cost questions
How much energy do leaky ducts waste?
According to ENERGY STAR, typical duct systems lose 20–30% of moved air to leaks, which translates directly into higher heating and cooling bills.
Is Aeroseal worth the extra cost over manual sealing?
Aeroseal reaches interior leaks that are impossible to access manually and typically achieves higher leakage reduction, making it worthwhile for extensive or hidden duct networks.
Will duct sealing lower my energy bill immediately?
Most homeowners notice reduced utility bills and more even room temperatures within the first billing cycle after sealing.
Problems air duct sealing solves
- Why Is My House So Dusty?
- Why Is My House Getting Weak Airflow From the Vents?
- Why Is My House Getting Hot Upstairs?
- Why Is My House Getting High Energy Bills?
Sources for these air duct sealing costs
- ENERGY STAR Duct Sealing guidance
- U.S. Department of Energy, Duct Sealing and Insulation guidance
- ASHRAE Handbook — HVAC Applications