A residential heating system has 16" galvanized duct. The minimum thickness required by code is __________.

A residential heating system has 16" galvanized duct. The minimum thickness required by code is __________.

• A. 24 gauge
• B. 26 gauge
• C. 28 gauge
• D. 30 gauge

Answer: (B)

The question focuses on the minimum sheet metal thickness allowed for galvanized residential ductwork. In HVAC ductwork, thickness is expressed as gauge, where a lower gauge means thicker metal. Codes specify a minimum thickness for typical residential galvanized ducts to ensure the duct maintains its shape, resists dents and punctures, and holds up to handling during installation and service. For a standard residential low‑pressure system, the minimum acceptable thickness is 26 gauge. That choice provides enough rigidity and durability without the extra weight and cost of thicker gauges, while thicker options like 24 gauge aren’t required by code for these applications, and thinner options such as 28 or 30 gauge could be more susceptible to damage and deformation. So, the minimum thickness required by code in this scenario is 26 gauge.

The question focuses on the minimum sheet metal thickness allowed for galvanized residential ductwork. In HVAC ductwork, thickness is expressed as gauge, where a lower gauge means thicker metal. Codes specify a minimum thickness for typical residential galvanized ducts to ensure the duct maintains its shape, resists dents and punctures, and holds up to handling during installation and service.

For a standard residential low‑pressure system, the minimum acceptable thickness is 26 gauge. That choice provides enough rigidity and durability without the extra weight and cost of thicker gauges, while thicker options like 24 gauge aren’t required by code for these applications, and thinner options such as 28 or 30 gauge could be more susceptible to damage and deformation.

So, the minimum thickness required by code in this scenario is 26 gauge.