Duct leakage test or blower door test: what are you paying to learn?

Questions covered in this guide

Name the question before the test

A proposal that says air leakage test needs a little more detail. ENERGY STAR's new-home guidance distinguishes a blower door test, which measures whole-house air leakage, from a duct blaster test, which measures duct leakage. These answer different questions. The guidance describes a certification program; it does not establish a testing requirement for every existing-home HVAC replacement.

Describe the problem in ordinary language

Write down what you notice: a room that stays uncomfortable, a draft, a noisy return or a change in utility use. Add when it occurs and which equipment is running. Ask the contractor which observation the proposed test will investigate. Keep symptoms separate from conclusions. A high bill alone does not identify a leaking duct, and a room complaint should not automatically become authorization to replace every duct.

Request a useful result record

Before buying the test, ask what report you will receive and who will explain it. Request the test method, measurement units, conditions and an explanation of any comparison standard used. If work is recommended, ask which finding supports that specific repair. For a before-and-after comparison, have the provider explain whether the measurements are comparable and what changed between them. A number without a method or units is difficult to use when reviewing another proposal.

Price the investigation and repair separately

Keep the diagnostic visit, recommended work and any follow-up measurement on separate lines. Ask whether the quoted repair price includes verifying the result or only completing the installation tasks. The HVAC calculator leaves unresolved duct work visible; it cannot infer leakage from home size or a comfort description. Use the findings to define the scope first, then carry the supplied repair or replacement prices into your project budget.

Putting it into practice

The test-purchase checklist connects a symptom to a proposed measurement and then to a specific repair. Method, units and comparable follow-up records are requested without imposing a universal pass threshold.

Sources and supported claims

ENERGY STAR describes a blower door test as measuring whole-house air leakage.
Source ↗ · national · Checked 2026-10-12

ENERGY STAR distinguishes a duct blaster test that measures air duct leakage within its new-home certification guidance.
Source ↗ · national · Checked 2026-10-12