Wherever the ductwork leaves the compartment from which it serves (demonstrated in blue) it must keep integrity and insulation fire scores for the same period of time given that the compartment through which it passes. The basement extract ductwork procedure (shown in brown) must be appropriate for clearing fumes and https://greasetightextractductwor13456.blogginaway.com/37710611/grease-tight-extract-ductwork-fundamentals-explained