TL;DR
ACCA Manual D is the industry-standard procedure for sizing residential ductwork so each room receives the airflow calculated in the Manual J load study. It converts room-by-room CFM targets into trunk and branch duct diameters based on friction rate, fitting losses, and available blower static pressure.
What it means
ACCA Manual D is the industry-standard procedure for sizing residential ductwork so each room receives the airflow calculated in the Manual J load study. It converts room-by-room CFM targets into trunk and branch duct diameters based on friction rate, fitting losses, and available blower static pressure. Ducts sized by rule of thumb instead often whistle, starve far rooms, or overload the blower. A proper heat pump or furnace proposal should state that the duct design follows this method, and many code offices require the report with the permit.
Where it sits in the glossary
ACCA Manual D 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
License: CC-BY-4.0 — quote freely with attribution to ProFix Editorial Team / ProFix Directory.