Ductwork is built to SMACNA construction standards, and a mechanical subcontractor that does not read the duct pressure class and construction requirements on a package is pricing the wrong fabrication.
What SMACNA standards set
The SMACNA duct construction standards govern how sheet metal ductwork is fabricated and installed, setting the pressure and seal classes, the gauges and reinforcement, and the hangers and supports. A mechanical package references the SMACNA standards and the Division 23 specifications to set the duct pressure class, the construction, and the leakage testing the sub must meet. The pressure class and the construction decide the fabrication cost.
Why duct scope is easy to misprice
The duct pressure class, the seal class, the construction requirements, and any leakage testing sit in the Division 23 specifications, not the title. A sub that assumes a low pressure system can miss a higher pressure class, a tighter seal, or a leakage test that changes the fabrication and the cost.
How an AI bid agent reads duct construction
An AI bid agent reads each mechanical package, identifies the SMACNA and Division 23 duct provisions, and surfaces the pressure class, the construction, and the leakage testing that drive the fabrication. The mechanical sub prices the actual ductwork.
You can see how the agent reads a mechanical package in our AI bid agent demo for MEP subcontractors. It pulls the SMACNA duct pressure class and construction requirements so the fabrication is priced correctly.