TL;DR
A makeup air louver is a fixed or motorized vent installed through a wall or door to admit replacement air into a room where appliances exhaust or burn it, such as a mechanical room, laundry, or commercial kitchen. Sizing follows the fuel-gas code's free-area rules — for combustion air, commonly one square inch per 1,000 Btu/h of appliance input when drawing from indoors.
What it means
A makeup air louver is a fixed or motorized vent installed through a wall or door to admit replacement air into a room where appliances exhaust or burn it, such as a mechanical room, laundry, or commercial kitchen. Sizing follows the fuel-gas code's free-area rules — for combustion air, commonly one square inch per 1,000 Btu/h of appliance input when drawing from indoors. Inspectors look for it whenever a gas appliance sits in a tight enclosure.
Where it sits in the glossary
Makeup air louver 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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