TL;DR
Gas load sizing is the design step of matching pipe diameters throughout a fuel-gas system to the demand each segment must carry, working backward from the calculated total so the farthest appliance still receives its minimum operating pressure. Sizers account for pipe material — black iron versus CSST have different tables — system pressure, and developed length including fittings.
What it means
Gas load sizing is the design step of matching pipe diameters throughout a fuel-gas system to the demand each segment must carry, working backward from the calculated total so the farthest appliance still receives its minimum operating pressure. Sizers account for pipe material — black iron versus CSST have different tables — system pressure, and developed length including fittings. Undersizing reveals itself as appliances that starve when others fire, such as a tankless heater going cold whenever the furnace starts.
Where it sits in the glossary
Gas load sizing 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.