The Stakes Are Different in a Commercial Kitchen
Restaurant exhaust cleaning is one of those services where the category name undersells what the job actually involves. This isn't housekeeping. The grease that builds up in a commercial exhaust system is flammable, and in a busy kitchen, the exhaust system runs hot. The combination of fuel source and heat source inside the duct is what makes kitchen fires so fast and so destructive when they start.
The National Fire Protection Association estimates that cooking equipment is involved in a significant portion of restaurant fires annually, and grease accumulation in exhaust systems is a recurring contributing factor. This is why fire codes and insurance carriers both care about whether the exhaust system has been cleaned properly and how recently.
What Proper Restaurant Exhaust Cleaning Covers
A complete restaurant exhaust cleaning works from cooking surface to rooftop. The filters, the hood plenum, the duct interior, the exhaust fan housing and blades, and the grease collection point at the fan all need attention. The duct interior is where contractors cut corners most often — it requires opening access panels and working through potentially long runs in constrained spaces, which takes time.
Grease accumulates particularly in horizontal duct sections, at elbows, and wherever airflow slows. Those are the same spots that are most difficult to reach, which is why cleaning them requires either existing access panels or cutting new ones into the duct.
How Often Your Kitchen Needs It
NFPA 96 sets minimum frequencies based on cooking volume. High-volume operations — a busy burger or fried-food concept, for example — should be cleaned quarterly. Moderate-volume kitchens typically need semi-annual service. The minimum is annual for low-volume operations, but that's a minimum under controlled conditions, not a recommendation for every kitchen.
If your cooking volume changes — you add a fryer, you start doing more volume at night, you change your menu to more grease-intensive cooking — your cleaning schedule should reflect that. The code minimum is a floor, not a ceiling.
What You Get When the Job Is Done
A responsible contractor leaves you with written documentation of the cleaning: what was done, any areas that were difficult to access (noted specifically), the condition of the system, and dated before-and-after photos. That paperwork is not just good practice — it's your protection if a fire inspector shows up or if you ever need to file an insurance claim.