How often should commercial kitchen ducts be cleaned?
TR19 Grease sets kitchen extract cleaning frequency based on daily usage hours. Get the classification right and you have a defensible compliance schedule.
The TR19 frequency table
| Usage hours per day | Cleaning frequency |
|---|---|
| 12 hours or more (heavy) | Every 3 months |
| 6–12 hours (moderate) | Every 6 months |
| Less than 6 hours (light) | Every 12 months |
How to classify your kitchen
Count the hours the extract fan is actually running, not the trading hours. A pub with a 5pm-to-11pm restaurant service runs the extract for ~6 hours and falls into moderate. A 24/7 airport-corridor hotel runs the extract continuously and falls into heavy.
Edge cases
Some kitchens have multiple zones with different extract systems running at different durations. Each system is classified separately. A hotel might have a 24/7 fryer zone (heavy) and an event-kitchen zone running 12 times a year (light) — different cycles for each.
What happens between cleans
The extract runs, grease accumulates. WFT readings at the next clean tell you whether the frequency is right. If readings are well below 200μm at the next visit, you could stretch the cycle. If they are at or above 200μm before the scheduled clean, the kitchen needs reclassifying.
Why this matters
Insurers expect the frequency cycle to match the BESA usage classification. A claim review will check: was the kitchen classified correctly, and was the cycle held to? A misclassification (kitchen actually runs 14 hours, classified as moderate at 8 hours) can void cover.
See our TR19 cleaning service for current scheduling.
