Commercial kitchen extraction by sector
Kitchen Extraction Services for Restaurants
What does extraction in a restaurant kitchen have to deal with?
A restaurant extract system moves heat, steam and grease-laden air off a cooking line that runs near full load for two long service periods a day, most days of the week. The appliance line rarely changes, so the canopy was sized once and stays correct, and grease arrives at a rate that can be measured and forecast. That makes the maintenance schedule genuinely predictable. The cost of it is that when something does fail, it fails mid-service with a full book.
What is different about a restaurant extract system
Every commercial kitchen has the same four parts and the same four failures. What changes is the conditions they work in, and a restaurant sits at the predictable end of that range.
| Part | What that means here |
|---|---|
| The appliance line | Ranges, fryer, chargrill and salamander in a fixed order under one canopy. The heat load was calculated once and neither it nor the canopy has moved since. |
| The grease load | Same menu, same covers, similar hours. Grease accumulates at close to a linear rate, so a reading taken at one clean forecasts the next rather than guesses at it. |
| The duct run | Usually short. A purpose-built unit has a plenum, a riser and a roof fan, with access panels at the direction changes. Short runs foul slower and survey quicker. |
| The demand pattern | Two hard peaks with the extract running through both. The fan turns for more hours than the appliances cook, which is why fan wear beats duct fouling to the first failure. |
The one thing that reliably breaks the pattern is a menu change. Adding a fryer or swapping a flat grill for charcoal raises the grease and particulate load under a canopy sized for something else, and the extract does not announce it. It shows up months later as a kitchen that holds smoke at the pass.
When can the work be done without stopping service?
More of it than most operators assume. The gap between lunch and dinner is long enough for a filter change, a fan service, a belt, a canopy light or an interlock fault. It is not long enough for a full duct clean, and anyone who says otherwise is planning to clean the part they can reach.
A full clean of canopy, plenum, duct and fan needs the kitchen cold and the line clear: overnight after the last cover, or a closed day where the restaurant has one. Repairs are different. An emergency callout goes when the kitchen is down, because a kitchen that cannot extract usually cannot cook.
Where a restaurant stands with the EHO and the insurer
Food hygiene law requires suitable and sufficient ventilation in food premises, and an environmental health officer will look at the canopy and filters and ask what record exists of the last clean. The responsible person for the premises also has to account for a grease-laden extract system in the fire risk assessment required by the Regulatory Reform (Fire Safety) Order 2005. Neither names a cleaning specification. TR19 Grease fills that gap.
Most commercial insurers treat TR19-compliant kitchen extract cleaning as a condition of cover or a key factor in assessing fire claims. Failing to keep your extract system TR19-compliant, or lacking documentation, can jeopardise your right to indemnity and give your insurer grounds to dispute or reduce a claim.
In practice: a measured reading before and after each clean, photographs, and a written note of anything that could not be reached. BESA publishes baseline intervals of 3, 6 and 12 months by daily cooking hours, subject to a competent person conducting a cleanliness risk assessment. A predictable grease load is why a restaurant can hold to a schedule rather than react to one.
What tends to go wrong here
- Baffle filters left in too long. Loaded filters choke airflow across the whole system: the symptom shows at the canopy, the cause sits in the wash-up rota, and the fan gets blamed for both.
- A grease gutter that has overflowed. Once the tray fills, grease runs back down the canopy face onto the line, which is a food safety problem before it is a fire one.
- Fan bearings and drive belts. Bearings wear on a schedule, and the noise that starts weeks before the failure is the warning.
- Make-up air upset by a refit. Sealing a dining room or fitting a new front door changes where replacement air comes from. The extract volume did not change; the building's willingness to supply it did.
- A grease narrowed riser. Invisible without access panels, and it presents as extraction that has quietly got weaker over two years rather than as a fault on a date.