What it does. Calculate the dollar value of residential duct leakage on any specific job. Inputs: home size, climate zone, system size, energy rate, current leakage. Outputs: annual loss + sealing payback.
Duct Leakage Cost Calculator
Job Inputs
Quick Presets
Annual Loss to Duct Leakage
If You Seal The Ducts
Detailed Overview
The Duct Leakage Cost Calculator is the dollar-translator for HVAC Know It All’s 30% Rule. ENERGY STAR’s “20-30% typical leakage” line is hard to sell on. Annual dollars wasted on a specific job, paired with a payback period on a sealing intervention, is much easier to sell on.
Purpose
Residential techs run into duct leakage on every other comfort call. Almost none of them attach a dollar number to it during the customer conversation. The calculator fixes that by translating the LBNL field-survey data into a per-job, per-year, per-climate-zone cost.
It also gives the contractor a service-revenue angle: a $150-$250 duct integrity audit (60-second visual + smoke pencil + TESP before/after) can be sold as a separate line item, and the calculator shows the customer the savings that justify the audit.
When and Where to Use It
- In-home during a comfort call. Show the customer the calculator on a tablet. The dollar number is the unlock to the upsell conversation.
- Quote preparation. Add the calculated annual loss + payback to a replacement proposal. It justifies the duct sealing line item.
- Internal training. Teach apprentices how the LBNL data translates into customer-facing dollars.
- Service contract pricing. Use the audit-revenue math to scope a $150-$250 line item across a contractor’s typical service-call volume.
Limitations
- The calculator models residential split systems. Light-commercial rooftop units have different runtime profiles and energy intensities.
- Heat pump vs gas furnace heating is averaged into the kWh baseline. For gas-heated homes, the calculator’s dollar number is conservative.
- The 22% LBNL average reflects systems with a mix of duct locations. For a specific home, use the slider to model the range.
Sources
- ENERGY STAR, “Duct Sealing with ENERGY STAR” (2024).
- Sherman & Walker, LBNL-47214 (2002), DeltaQ field surveys.
- Less, Walker, & Hoeschele, OSTI 1503810 (2019), Aerosol duct sealing performance.
- EIA Electric Power Monthly (July 2025), US residential average $0.1747/kWh.
- California Title 24 Part 6, 2025 Energy Code (5% duct leakage limit).