TL;DR
A blower door test is the diagnostic that mounts a calibrated fan in an exterior doorway, depressurizes the house to 50 pascals, and measures the airflow needed to hold that pressure, which equals the building's total leakage. Results are reported as CFM50 and converted to air changes per hour, the metric the IECC caps at 3 to 5 ACH50 for new homes depending on climate zone.
What it means
A blower door test is the diagnostic that mounts a calibrated fan in an exterior doorway, depressurizes the house to 50 pascals, and measures the airflow needed to hold that pressure, which equals the building's total leakage. Results are reported as CFM50 and converted to air changes per hour, the metric the IECC caps at 3 to 5 ACH50 for new homes depending on climate zone. Crews pair it with smoke pencils or thermal cameras to walk the depressurized house and physically locate each leak. It is the before-and-after proof for air-sealing work and a required verification on most new construction and weatherization programs.
Where it sits in the glossary
Blower door test is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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