The minimal duct thickness is defined by regardless of what code jurisdiction which the undertaking is found in. Down below are two code references linked to the required thickness and product type for grease ducts. Commercial kitchens deliver considerable amounts of heat, steam, grease, and smoke. Commercial kitchen extraction systems https://greasetightextractductwor57890.ampblogs.com/the-2-minute-rule-for-grease-tight-extract-ductwork-73696076