TL;DR
A vacuum decay test is the verification step after refrigerant system evacuation in which the technician isolates the vacuum pump, watches the micron gauge, and judges tightness and dryness by how far the reading rises over a timed hold. Pulled to 500 microns or below, a system that drifts up and plateaus still holds moisture boiling off; one that climbs steadily toward atmosphere has a leak.
What it means
A vacuum decay test is the verification step after refrigerant system evacuation in which the technician isolates the vacuum pump, watches the micron gauge, and judges tightness and dryness by how far the reading rises over a timed hold. Pulled to 500 microns or below, a system that drifts up and plateaus still holds moisture boiling off; one that climbs steadily toward atmosphere has a leak. The standing pass benchmark in quality install practice is staying under roughly 1000 microns for ten minutes, and charging a system that fails the hold seals acid-forming moisture inside the refrigerant circuit.
Where it sits in the glossary
Vacuum decay 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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