How often should a commercial kitchen extraction hood and duct be deep-cleaned?

Question

I run a small café in JLT and I've realised our kitchen extraction hood has never been properly cleaned — the cleaner just pops the metal filters out, washes them, and puts them back. Reading up, apparently the real problem is the grease that builds up inside the canopy and all the way up the duct to the roof fan, and that it's a genuine fire risk as well as something Civil Defence / hygiene inspectors look at.

So I want to get ahead of it properly:

How often does the whole extraction system — canopy, plenum, duct run, fan — actually need degreasing, not just the filters?
What does a proper deep-clean cover versus the filter-wash we're doing?
Does the frequency depend on how much we fry/grill?

Kitchen downtime costs me money, but a grease fire would cost a lot more. What's the right schedule and scope here?

Kareem F. · Accepted Answer

Short answer: washing the filters is NOT cleaning the system — the fire risk lives in the grease coating the canopy, plenum and the full duct up to the roof fan, and that whole run needs scheduled deep-degreasing (typically quarterly for a normal café, monthly-to-quarterly for heavy frying/grilling), while the filters themselves want washing weekly.

Here's why the filter-wash isn't enough and what a proper clean covers:

The risk: grease vapour rises past the filters, condenses on the cold metal inside the canopy and along the duct, and builds a flammable layer you can't see. A flare-up on the range ignites it, and a duct fire spreads through the building — which is exactly why it's a Civil Defence and hygiene concern, not just cleanliness.

Schedule by cooking load (industry norm): | Cooking type | Full system deep-clean | |---|---| | Light (café, reheating, little frying) | ~ every 6 months | | Moderate (typical café/restaurant) | ~ quarterly | | Heavy (constant frying/grilling, wok) | monthly to quarterly | Filters: wash weekly (or soak in degreaser) regardless.

A proper deep-clean covers: filters, the canopy interior, the plenum behind the filters, the accessible duct run, the extract fan, and a report/sticker with the date (inspectors and insurers ask for it).

Common mistake: assuming shiny filters = clean system. The duct is where the danger is. Get a commercial kitchen-equipment and extraction specialist to degrease the full extraction hood system on a schedule and give you the certificate — it protects the café and your licence. This is a step beyond the home extractor-that-lost-suction problem — here it's fire safety, not airflow. The internationally-referenced NFPA 96 standard sets the frequency by cooking volume — roughly monthly for high-volume or solid-fuel kitchens, quarterly for moderate use and half-yearly for light use — which is the logic most authorities and insurers follow. What frequency are other F&B owners on?

DubaiFix Team · Answer

F&B operator tip: keep the dated cleaning certificate on file — Dubai municipality/food-safety and Civil Defence inspections, and your insurer, will ask for proof the full extraction system (not just filters) has been cleaned on schedule. A missing or overdue duct clean is a classic inspection finding. Build it into your PM calendar alongside the grease-trap and the fridge temperature logs; treating it as a licence/insurance requirement rather than "cleaning" gets it done properly.

Omar K. · Answer

Not F&B but watched a friend's restaurant have a small duct flare-up — the insurance conversation afterward hinged entirely on whether they had proof of scheduled duct cleaning. They'd been doing filters only. It got expensive. So beyond the fire risk itself, the paperwork of a proper scheduled clean is what protects you if anything ever does happen. Cheap insurance for a real risk.

How often should a commercial kitchen extraction hood and duct be deep-cleaned?

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