What type of ducting should be used?
Except for a fire suppression system and rated shafts, The ducting must conform to all type I criteria, including cleanouts, a 1/4 inch per foot slope toward the hood on horizontal runs, and maintaining proper clearance to combustibles. We recommend using 16 gauge welded black iron or 18 gauge stainless steel. Type 2 ducting, such as Galvanized ducting or flexible connections are NOT ACCEPTABLE – Do not use them under any circumstance . Inspectors have withheld the certificate of occupancy until inferior ducting is removed and replaced with ducting conforming to our specifications. If you can’t use it in a type I system, you can’t use it on a Qvent system.
