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Duct Sealing Savings Calculator

Estimate the annual heating and cooling cost savings from sealing leaky ductwork.

Result

Estimated Annual Savings
$270
Estimated Savings Rate
15%

The U.S. Department of Energy estimates that a typical home loses about 20-30% of the air moving through its duct system to leaks, holes, and poor connections, especially in unconditioned spaces like attics and crawlspaces - sealing ducts recovers a meaningful share of that loss as usable heating and cooling.

About the Duct Sealing Savings

This calculator estimates how much sealing leaky HVAC ductwork could save on a home's annual heating and cooling costs, based on your current combined energy bill and a rough assessment of how leaky the ducts currently are. It is meant for homeowners weighing whether a duct sealing job is worth the expense before scheduling a professional inspection.

How It Works

You enter your combined annual heating and cooling cost and choose one of three duct leakage severity levels: minor, moderate, or severe. Each severity level maps to a fixed savings percentage, and the calculator multiplies your annual cost by that percentage to produce a dollar estimate.

Estimated savings = annual heating and cooling cost x savings rate, where the savings rate is 6 percent for minor leakage, 15 percent for moderate leakage, and 27 percent for severe leakage.

Examples

Older Home, Moderate Leakage

A home with $1,800 in combined annual heating and cooling costs and moderate duct leakage would see an estimated $270 in annual savings from sealing, based on the 15 percent rate.

Visible Gaps, Severe Leakage

A home with $2,400 in annual heating and cooling costs and visibly gapped, uninsulated ductwork in the attic, rated as severe leakage, would see an estimated $648 in annual savings at the 27 percent rate.

Advantages

  • Provides a dollar estimate from just a utility bill figure and a visual condition assessment, without requiring a professional blower-door duct test first.
  • Anchors each leakage category to a fixed, consistent percentage so the estimate is repeatable rather than a fresh guess each time.
  • Scales automatically with your actual combined energy cost, so a larger or smaller heating and cooling bill produces a proportionally larger or smaller savings figure.

Common Mistakes

  • Selecting 'severe' leakage without visible evidence like gaps or disconnected runs, which inflates the estimated savings beyond what a sealing job is likely to deliver.
  • Entering only the heating portion or only the cooling portion of the annual bill instead of the combined total, which understates the baseline cost the savings percentage is applied to.
  • Treating the output as a guaranteed savings figure rather than a planning estimate, when actual results depend on how much of the leakage a sealing job successfully addresses.

Edge Cases to Watch For

  • Savings are tied to one of only three severity levels rather than a continuous measurement of actual duct leakage, so two homes both selecting 'moderate' could have meaningfully different real-world leakage and different actual savings from sealing.
  • The percentage is applied to the entire combined heating and cooling cost, so if that figure mixes different fuel types or rate structures, the resulting dollar estimate is an approximation rather than a fuel-specific calculation.
  • The severity levels assume ducts run partly through unconditioned spaces like attics or crawlspaces; ducts routed entirely through conditioned living space would likely see smaller real savings than the selected level implies.

Common Use Cases

  • Homeowners deciding whether to schedule and pay for professional duct sealing.
  • Energy auditors or HVAC contractors framing a rough savings estimate before running diagnostic testing.
  • Buyers or renters evaluating an older home's HVAC system for likely hidden inefficiencies.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Should ducts be sealed with regular duct tape?

No, despite the name, ordinary cloth-backed duct tape dries out and fails within a few years on HVAC ductwork - professional duct sealing uses mastic sealant or foil-backed (FSK) tape rated for the purpose, which holds up much longer under the heat and pressure cycling ducts experience.

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Conclusion

Because the estimate is based on a severity category rather than a measured leakage rate, it works best as an initial screening figure to decide whether further investigation is worthwhile. A professional duct leakage test remains the more precise way to confirm actual savings potential.