Seal leaks, cut drafts, and lower energy bills. Model heating and cooling savings using inputs. See payback, ROI, and net value over years clearly.
| Home (sq ft) | Leakage reduction | Heating cost | Cooling cost | Project cost | Year-1 saved | Payback |
|---|---|---|---|---|---|---|
| 2,000 | 20% | $1,440 | $432 | $1,800 | $112 | 16.1 yrs |
| 2,800 | 30% | $2,050 | $650 | $2,400 | $307 | 7.8 yrs |
| 1,500 | 15% | $980 | $300 | $950 | $66 | 14.4 yrs |
This calculator estimates savings by applying an air-leakage improvement factor to the portion of your heating and cooling costs driven by infiltration.
(LeakageReduction% × InfiltrationHeatShare%)(LeakageReduction% × InfiltrationCoolShare%)HeatingCost × HeatingSavingsFraction + CoolingCost × CoolingSavingsFractionProjectCost ÷ Year-1 savingsIn many homes, uncontrolled air exchange increases heating fuel use in winter and raises cooling electricity in summer. This calculator treats infiltration as a share of annual heating and cooling costs, then applies your expected leakage reduction. For example, a 20% leakage reduction with a 30% heating infiltration share implies a 6% heating cost reduction. Enter your bill totals, then adjust inputs to bracket best and worst cases for budgeting at home quickly today.
The savings rate is a two-part estimate: how much leakage improves and how much of your load is driven by infiltration. Heating savings fraction equals LeakageReduction × InfiltrationHeatShare, and cooling follows the same structure. If your infiltration share is conservative, results will be conservative; if it is aggressive, results will rise accordingly.
Simple payback divides project cost by first-year savings, providing an intuitive time-to-recover metric. Net present value discounts future savings using your discount rate and escalates energy prices using your escalation rate. A positive NPV suggests the project beats your required return, while IRR summarizes the implied annualized return.
Pull annual totals from utility statements or sum the last 12 months of kWh and heating units. Match prices to the same period, including supply and delivery charges, to avoid understating costs. If you enter delivered heat instead of utility energy, use the efficiency field so the model can translate energy correctly.
Air sealing scope varies by attic bypasses, rim joists, duct leakage, and penetrations, so quotes can differ significantly. Use this tool to compare scenarios: change leakage reduction, infiltration shares, and project cost to see impacts on savings and NPV. As a rule of thumb, many projects pencil out when year‑1 savings reach 10–15% of project cost, though climate and prices matter. When multiple bids exist, the best choice is often the highest savings per dollar invested.
Use an audit estimate or contractor range. Targeted sealing often lands near 10–30%. Whole-home sealing with verified testing can be higher, but treat extreme values cautiously for planning.
Start with 20–40% for heating and 10–25% for cooling. Drafty homes, older construction, and windy sites trend higher, while newer or well-sealed homes trend lower.
No. The outputs focus on utility cost savings and investment metrics. Comfort improvements, reduced drafts, and better humidity control can be meaningful, but they are not priced here.
It shows how savings accumulate over time relative to the upfront project cost. The line crossing zero indicates the approximate year you break even under the selected escalation assumptions.
Escalation increases future energy savings as prices rise. Discount rate reduces future savings to present value, reflecting your required return or opportunity cost. Both affect NPV significantly.
Yes, if you have reliable annual heating and cooling costs. Use the same structure, but ensure the infiltration shares reflect the building type and usage patterns for better results.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.