# Duct leakage testing: ask for a measurement, not a generic savings claim

Canonical: https://www.savpwr.com/knowledge/duct-leakage-test
Market: United States
Author: SAVPWR Editorial (VDX Logic LLC)
Published: 2026-11-09
Sources checked: 2026-11-09

## What should a duct-leakage proposal tell me?

Ask what test is performed, which leakage it measures, the units and test pressure, and how the result will be verified after repairs. A population-level leakage statistic is not a measurement of your house.

## Clarify the quantity being measured

Total duct leakage and leakage to outside the conditioned envelope are different quantities. Test conditions and reporting units matter. Keep the original report rather than reducing it to an unexplained percentage on a sales page. [1][2]

## Connect leakage with distribution

A complete assessment should consider damaged runs, supply and return balance, insulation and airflow after repairs. Sealing alone cannot fix every comfort problem. Ask whether access limits prevent inspection and how unresolved sections are documented. [2]

## Require before-and-after evidence

Write down the repair scope, target, test method and completion evidence. Where combustion appliances are present, ask how relevant combustion safety is addressed. Do not assume an average leakage figure means an equal percentage reduction in the entire utility bill. [2]

## Decision exercise

If one bidder quotes a leakage percentage and another quotes CFM at a stated pressure, do not rank them until the quantities and denominator are clear. Ask both to provide the same before/after test format and describe which ducts are outside the conditioned space.

Numbers are illustrative assumptions, not forecasts.

## Preparation checklist

- Request test type, units, pressure and denominator.
- Include airflow and return-balance checks.
- Do not turn average leakage into guaranteed savings.

## Does a high utility bill prove that ducts leak?

No. Duct performance is one possible contributor; bills alone do not measure duct leakage.

## Sources

[1] ENERGY STAR — Duct Sealing: https://www.energystar.gov/saveathome/heating-cooling/duct-sealing
[2] ENERGY STAR — Professional Duct Improvement: https://www.energystar.gov/saveathome/heating-cooling/duct-sealing/professional-duct-contractor

AI-assisted preparation; no licensed professional review is claimed. Editorial policy: https://www.savpwr.com/editorial