Duct systems for Type I hoods should be constructed with what gauge steel?

Duct systems for Type I hoods are required to be made from a specific gauge of steel to ensure they can handle the high temperatures and grease-laden vapors typically associated with commercial cooking operations. The correct choice, which indicates that 16-gauge steel should be used, is in alignment with standards set by the North Carolina Mechanical Code and other relevant codes, such as the International Mechanical Code.

Using 16-gauge steel provides the necessary structural integrity and durability required for the ducting system to withstand both the mechanical stresses and the conditions of a commercial kitchen environment. Thicker steel offers better resistance to deformation from heat and ensures that the ducting can maintain its shape and performance over time, ultimately contributing to effective ventilation and safety in cooking operations.

The other gauges listed—12, 18, and 20—either do not meet the code requirements for ducting in such applications or may not provide the same level of robustness needed for the high-temperature and high-grease environments typical of Type I hoods.