Ducts are the part of a kitchen extraction system that most cleaning programmes handle worst. Hoods are visible, filters are reachable, fans are inspectable, and each of those items has an obvious owner. Duct work sits above ceilings and behind walls, runs through other people's premises, collects deposits at bends nobody can see, and is booked whenever a shutdown window happens to appear. That is the difference between a kitchen whose hood looks maintained and a kitchen whose duct record cannot be followed.
A repeatable method is a written sequence in which the duct run is defined before anybody quotes, the deposits are defined before anybody cleans, and each stage closes on a defined result. This page sets out how a kitchen operator or facilities manager can build that process, stage by stage, and how to keep it stable once the first cycle is finished.
A repeatable method is a written sequence in which the duct run is defined before anybody quotes, the deposits are defined before anybody cleans, and each stage closes on a defined result. This page sets out how a kitchen operator or facilities manager can build that process, stage by stage, and how to keep it stable once the first cycle is finished.
Write the exhaust route down as a numbered list of duct elements
Repeatability starts with a definition that does not depend on memory. Walk the extraction system and produce one list that names every element in the exhaust airflow path: hood faces, grease filters, plenums, the first duct section, horizontal runs, risers, offsets, fire and smoke dampers, the fan housing, and the terminal discharge. Give each element a number and record the access that exists for it, because an element without access cannot be cleaned, inspected or verified.
For a kitchen exhaust duct grease cleaning route, the path from hood face to terminal discharge is one continuous run, and quoting it piecemeal is how sections go missed. Two columns then settle most of the arguments later. The first records how an element is opened: an existing hatch, a panel that needs tools, a cut that must be made and resealed, or no opening at all. The second records what sits above the ceiling or behind the wall that has to be protected before work starts. When a route is written as a numbered list, a buyer can ask for one price covering the whole path, and the same list becomes the order of work on the day.
State what the inside of the duct must look like when work ends
Most cleaning disputes come from the absence of an end state. Write it in plain words per zone: which surfaces must be free of soft, loose and baked residue, which surfaces may retain staining, and which surfaces are only partly reachable and will be reported rather than cleaned. Where the stated end state cannot be met without heavy grease removal equipment, say so on the same line, so the enquiry carries the requirement instead of a hope.
Then write the two conditions that close a zone. First, nothing loose remains anywhere in that section, including the parts nobody can reach. Second, each element that has an opening is either cleaned to the stated end state or carries a written exception naming the reason, the alternative that was tried and the next action. A programme that only records dates cannot show this; a programme that records conditions can.
Set the cleaning company's method against the access you actually have
For the accessible sections of a commercial kitchen steam cleaning routine, a lance-fed hot, grease-softening medium with recovered wash water is a common answer: a single operator works along the opening, deposits are released and pulled back into a collection tray, and the section can be re-inspected the same day. The same unit often serves the hood face, the filter racks and the fan housing, which shortens the working window.
Where the duct interior is beyond the reach of the lance, the working method changes: a robot, a brush machine, a manual wipe-down from an access panel, or a hand-off to a duct contractor. Choose one of those working methods per element while writing the route, not on the day. Record it against the element number so that a repeat visit starts from the same plan.
Whatever the tool, ask whoever performs the work for two page-sets: the protective and electrical arrangements on the machine, and the figures for the individual unit assigned to that location. The published pages list the electrical supply, the heater output, the delivery temperature, the vapour pressure, the tank volume and the steel grade, the floor space it occupies and the water feed; the numbers belong to the individual unit, and a catalogue figure is not a purchase specification.
Name a trigger, not a calendar date, for each zone
Fixed dates drift, because kitchens do not run at a constant load. A repeatable method assigns each zone a condition that brings work forward. Common triggers are a filter differential that no longer returns after cleaning, visible deposit at an opening, a measured deposit at a witness point, a change in cooking hours, a new appliance added to the line, or a repeat of the same complaint from the same area.
Pair each trigger with an interval ceiling so that nothing waits forever, and let the interval fall when the cooking load rises. A kitchen running long weekend service will need shorter intervals on the sections serving the grill line than on the sections serving the boiling range, and that difference belongs in the written plan rather than in a conversation.
Put the sequence, not the crew, on paper
One page should carry the order of work and a named owner for each stage: who isolates the fan and confirms it cannot restart, who protects the cooking line and the floor beneath the work, who opens the panels, who performs the cleaning, who inspects, who reseals the openings, and who signs the section closed. The names change; the sequence does not.
Add the pre-start checks that make the sequence safe to run: power isolated and proved, the discharge path clear, protection in place below the work, the wash-water route agreed for the day, and a written stop condition for anyone on site - a damper that will not reset, a duct support that has failed, a seal that cannot be renewed.
| Stage in the written procedure | Closing condition for the stage |
|---|---|
| Numbered route agreed with access recorded for every element | No element is left without an access note or a written reason |
| End state per zone written before the enquiry goes out | Every zone has words an inspector can apply without asking |
| Method chosen per element and recorded against its number | No element carries the words "to be decided on site" |
| Trigger plus interval ceiling set for each zone | Each zone has both a condition and a maximum wait |
| Isolation, protection and wash-water route confirmed | Written sign-off before the first panel opens |
| Cleaning performed against the numbered route | Every element marked done, excepted or deferred with a reason |
| Inspection of every opened element by someone other than the operator | Pass or exception recorded per element, not per visit |
| Openings resealed and the system returned to service | Sealing and damper positions checked and recorded |
| Next trigger reviewed and the plan version updated | Changed intervals and methods written into the current version |
Let the closure pack prove the process, not the visit
A repeatable method produces comparable evidence every cycle. Ask the companies on site for one pack per visit: the numbered route with each element marked, photographs of the openings before and after, the exceptions with their reasons, the items the operator could not reach, the seal and damper checks, and the signatures for cleaning and inspection. Nothing in that pack is a marketing artefact; it is the input to the next cycle.
Then compare cycles. Three visits in a row in which the same sections return as exceptions say something about the access, or about the working method chosen for those sections. Two visits with the same trigger firing say something about the interval. A process that produces comparable packs makes those patterns visible; a pile of certificates does not.
Decide in advance what stays outside the method
Write the exclusions once, in the same document as the method. Interior duct surfaces with no opening remain outside the cleaning scope and are reported, not cleaned. Structural faults, failed supports, damaged dampers, leaking joints and any work needing trades beyond cleaning and sealing are handed to another contract. Electrical repairs to the fan motor, control wiring and fire-system components are outside a cleaning procedure entirely.
Also state plainly what this work cannot achieve. It removes fuel, so it changes a fire load; it is not a substitute for the fire risk assessment, the statutory inspection of the system, or any independent certification the premises require. Keeping that sentence in the procedure prevents the cleaning record from being read as something it is not.
Build one bounded trial before the process becomes site standard
Choose the worst section you can reach, run the whole written sequence on it, and treat the trial as a test of the procedure rather than of the vendor. Record what slowed the work, which opening was inadequate, which consumable ran out, how long the section took, and what the inspection found at the closing condition. If the trial cannot be run to the written steps, the steps are wrong - not the kitchen.
Running a trial along a restaurant kitchen grease cleaning section is worth running even when the rest of the work will be contracted out, because it produces the vocabulary the buyer needs in the enquiry: named elements, named access, named end states, and named closing conditions.
Control the plan the way a drawing is controlled
Give the plan a version number and a review date; a plan covering central kitchen hood degreasing is a controlled document, not a note in a folder. Change it when an appliance is added to the line, when a ceiling is reconfigured and new access appears, when a section is replaced, or when two cycles show the same exception. Delete superseded wording instead of keeping several versions in circulation, and keep the numbered route as the spine that each new version edits.
Where the kitchen is one of several on an estate, add a small comparison table across the sites - same columns, different kitchens - and let the differences drive the next round of questions for the supplier. Where the system is ageing, carry an item on reachability and spare access panels. Where a central kitchen degreasing routine covers several production lines, one shared numbered route per line keeps the comparison honest.
Questions to settle with whoever performs the work
Ask whether the quoted price covers every element on the numbered route or only the elements with existing openings, and how a deferred element is priced and reported. Ask how a section is declared clean, by whom, and what record is handed over for it. Ask what happens when the work releases more deposit than expected and a downstream section turns into a new exception part-way through the visit.
Ask who protects the cooking line and who removes the recovered waste, and whether the wash-water route is decided by the site or by the contractor. Ask for the figures for the exact unit assigned to your site, and for the protective and electrical arrangements listed for that unit. Finally ask what the contractor will not do, and whether that list is written into the order.
Common gaps in duct cleaning programmes
Several gaps appear in almost every kitchen review of this kind. The route is described in words rather than numbers, so different visits clean different things. The end state is missing, so the buyer accepts whatever is reported. Access is assumed rather than recorded, so an expensive day ends with the worst section untouched. The inspection is performed by the person who did the cleaning. Exceptions are noted in prose instead of carrying a next action and an owner.
A final gap is the absence of a comparison between cycles. Without it, an interval can run far too long on one zone and far too short on another, and nobody can see it. Closing these gaps costs nothing beyond the writing, which is why they usually stay open.
Where cleaning equipment suppliers fit into the process
A supplier's role here is to answer the written questions and to work to the written end state. Published pages describe machine types and the arrangements fitted to them; they describe vehicle cleaning and workshop settings, and a kitchen duct run is not something to be read off a catalogue page. The buyer supplies the route, the access list and the end state; the supplier confirms reach, working method and machine choice against that list.
For sites where several production lines or several kitchens share one programme, suppliers that build for a defined duty rather than a standard catalogue item can be asked what changes they would make to the tank capacity, footprint, medium delivery and recovery arrangement for a given duct route. Those answers belong in the enquiry file and in the next version of the plan, where they are still readable at the following cycle.
