Commercial Systems

• Ductwork for commercial kitchens in accordance with Clause 6.2 of AS1668.1 must have:
• Galvanized steel ductwork of a thickness not less than 1.2 mm or stainless steel not less than 0.9 mm
• Joints which are grease tight
• Fall towards the extraction hood
• Flexible connections which are grease proof and not longer than 300mm
• Ceiling access panels which provide unhindered access to the kitchen exhaust
• A grease proof plug for drainage at the bottom of the vertical shaft
• Clean out access panels large enough to enable cleaning of ducts which are located:
• At the bottom of a shaft along the side of ductwork.
• At every change of direction along the side or top of ductwork.
• Every 3m in straight runs along the side or top of ductwork.

• Kitchen exhaust systems must be:
• Protected with sprinklers when located in a building required to have sprinkler protection, and
• Have sprinklers installed under kitchen hoods and within kitchen exhaust ductwork.