2026 Commercial Kitchen Exhaust System Components Practice Test – Complete Preparation Guide

The key idea is that interior kitchen duct cleaning frequency is driven by how much grease the cooking operation generates and the condition of the system, not by a fixed rule of “when you see grease.” NFPA 96 emphasizes maintaining a clean, safe exhaust system through a maintenance plan that adapts to grease load. Baseline practice is to clean on a regular schedule, often around every 6 to 12 months, and to increase that frequency for heavy grease loads. An annual inspection is also recommended to verify cleanliness and system condition. The concern with waiting for visible grease is that hidden accumulations can build up and pose a fire hazard or reduce system performance.

So, the best approach reflects regular maintenance tied to grease load, with more frequent cleaning for heavy grease and periodic inspections, rather than waiting for visible grease or sticking to an overly infrequent interval.