A restaurant kitchen gets its range hood cleaned on a schedule, but it gets signed off on a standard. The difference between the two is what a facility is prepared to write down and defend: what counts as clean on the canopy face, on the filters, on the fan housing and inside the duct, who checks it, with what, and what happens when the answer is no. Those criteria have to be written before the work is ordered, because after the work is done the only evidence left is a receipt and a shinier-looking surface.
Where the acceptance boundary sits before anything else is decided
The hood is not one surface. It is a canopy with an outer face, an inner face, a grease trough and its drain, filters and their seats, the plenum and fan housing behind them, a transition into ductwork, risers and, on most sites, a terminal out of doors. Each of those has its own owner, its own access, and its own definition of failure, and they are cleaned by different trades under different contracts.
Write the boundary as a line on a drawing, not as a phrase. The line says which assemblies the facility accepts on, where the cleaning contractor's scope ends, and where a separate duct or fan cleaning scope begins. A criterion that crosses that line without naming the owner cannot be enforced: nobody signs for the far side of it, and when grease is found there, the two contracts each point at the other.
Put a named accountable person against each side of the line before the first inspection. In practice that is the kitchen manager for the canopy and filters, a facilities or engineering lead for the fan, plenum and riser, and one contract manager who is responsible for the whole hood being signed off as a unit. If all three names are the same person, write that too, because it decides how quickly a defect gets routed.
What the surface and deposit list is for
Acceptance criteria are only testable if the surfaces they name exist on a list. Walk the hood with the kitchen closed and write one row per assembly: the outer canopy face and its corners, the front valance and any decorative trim, the underside and the filter rails, each filter type and its seat, the grease trough and drain plug, the plenum walls behind the filters, the fan housing and wheel where reachable, the access panel and its fasteners, the duct entry, and the visible internal surface of any riser reachable from an access door.
Give each row three columns. The first names the deposit as staff actually describe it, not in contractor vocabulary: a soft oily film, a set sticky varnish, a hard baked crust at the filter edges, loose grit bound into that crust, drip marks below a joint, a dark haze on a painted face. The second records the material and its condition, because a criterion applied to damaged material is a false pass. The third records access: what has to be removed to see the surface at all, and how far a hand or an inspection mirror reaches.
That third column decides more of the plan than any other, because it sets what can honestly be inspected. A criterion written for a surface nobody can reach after the panels go back is decoration. Where access needs a ladder, a roof access, or the removal of a panel held by more than a few fasteners, write who provides access, who replaces the panel, and what the kitchen loses while it is off.
Condition has to be recorded before the method is discussed
Before any cleaning method is proposed for the hood, the condition of every listed surface has to be recorded, because cleaning is what turns a latent defect into a visible claim. On the painted and coated faces, look for lifting, blistering and crazed paint, existing corrosion at edges and fastener holes, and any coating that has gone soft where solvent has been used before. On stainless faces, look for scratches, pitting, heat discolouration, and weld seams or laminate edges that have opened. On filters, look for warped frames, torn mesh, clogged pleats, and tabs that no longer seat. On seals, gaskets and draft dampers, look for perished and split material.
Photograph every one of those before the work, from an angle rather than square on, so relief and texture show. A record made after cleaning cannot distinguish deposit from damage, and a contractor who is blamed for existing corrosion will produce their own quotation, not an apology. Condition defects are a repair item; they are not a cleaning defect, and they should be written on a separate list with a separate owner and date.
The same rule protects the equipment around the hood. Lighting, fire detection heads, sprinkler heads and covers, electrical enclosures, control panels, gas pipework and valves sit within reach of hood cleaning work. Record their condition, shield them, and write in the standard that they are not to be washed, degreased or walked on.
State the criteria as pass, fail and defect
A criterion that only says "clean" cannot be argued about, which is exactly why it fails. Write one row per surface with four parts: the pass condition, the fail condition, the defect that triggers that fail, and the route the defect takes. Pass is what may remain after cleaning, and it should be written in terms an inspector can confirm with a fingertip, a mirror, a torch and a photograph, not with a laboratory result.
Pass on an accessible canopy face, for example: the surface is uniform in appearance, no loose or soft residue transfers to a white cloth drawn across it, no grit is felt under the fingertip, and the deposit at corners and joints matches the deposit on the open face. Fail: a sticky or hard film that does not transfer and does not move, a crust along a filter edge, drip marks that were not there at the last inspection, or a film at a joint that the open face does not show.
Filters need their own criteria, because they fail in two different ways. A filter is failed by residue that will not release and by deformation; a warped frame or a torn mesh fails even when it looks cleaner than the day it was fitted. Write whether filters are accepted on visual condition or on a measured state such as mass or pressure drop across the bank, and record which of the two the contract actually uses. A visual-only criterion quietly permits a filter that has been washed thin.
Inside the plenum and the duct, write the criterion for what the inspector can see from an access opening, and be explicit that unseen lengths are covered by the contractor's own inspection record rather than by the facility's signature. Where a length cannot be seen and cannot be reached, write that as an exclusion, name the method used instead, and record the trade that exclusion accepts, such as relying on a camera survey instead of hands-on inspection.
Inspection method has to match what is actually being claimed
Different claims need different evidence, and a facility that asks for one kind while claiming another ends up with paperwork and a dirty hood. A visual check answers "is there visible deposit here". A wipe test answers "is there transferable residue here". A torch and mirror check answers "what is happening at the joint, in the corner and behind the rail". A camera survey answers "what is in a length nobody can reach". A performance check answers "is the hood still moving air after this work".
Write the method against each row of the surface list, and state what the inspector carries: torch, mirror, white cloth, camera, the two photographs from the last cycle. State who inspects, and keep that person separate from the person doing the cleaning. Where the contractor both cleans and signs, add one check by the facility on the same day, on a named subset of rows, and let that check be enough to reject the job.
Photographs are the cheapest durable evidence on a hood, because the alternative is an argument about a surface nobody can now see. Require the same framed view at every cycle, from the same side, before and after, and require that the before set is taken before any chemical is applied. A before photograph taken after degreaser has been sprayed records a partially dissolved deposit, not the starting state the job was priced against.
How a heat-and-dwell method changes what you check
Some facilities clean accessible hood surfaces with a heated, low-moisture method rather than a spray of detergent and a bucket, and that changes two things in an acceptance sheet: what the operator is relying on, and what has to be inspected afterwards.
On the method side, heat with dwell is what loosens a set fatty film, while the volume of liquid is what carries a thick crust off an open face. Those are two different jobs, not a strong setting and a weak one. Low-moisture work suits a warm surface, a vertical face, and places where you want the dwell held on the film without liquid running down a frame or into a joint. Higher-moisture work suits thick crust on open flat faces where volume is what lifts the deposit, and where the run-off can be routed and collected. Decide which one each row gets and write it in the standard, so nobody chooses a mode standing at the machine.
On the inspection side, a heated method leaves a surface that can look finished while still carrying a thin film. Require the wipe test and the fingertip check on a method like that, not just a visual pass, and require a dry finish as a closing step rather than assuming the surface dried on its own.
Where such equipment is being specified for kitchen work, the pages for Fixed Steam Cleaning Machine PowerDe HW02 publish switching between dry and wet steam, a tap-water inlet connection and a protection list on a fixed floor-standing unit, and they describe that machine around vehicle exterior work at fuelling and parking sites, interior work and engine compartments. Those published rows belong to that one machine; they are not a rating for hood duty and they do not transfer to another model.
So a hood specification asks for rows rather than quoting values: the working voltage and what supply the site provides at the point of work, the heating power, the steam temperature as the page writes it, the vapour pressure where the lance meets the surface, the tank volume and the water use per hour as separate items, the inlet fitting against the site tap, the footprint and the travel route to the hood, and the protective features named for that unit rather than counted. Two cautions to keep in the file: the temperature at the generator is not the temperature at the nozzle, and a tank volume is not a working time.
Frequency, ownership and the defect route
Acceptance without frequency is a one-off event. Set frequency in two separate ways: a fixed interval per surface group, and a condition trigger that overrides the interval. Filters, canopy faces and troughs are usually driven by use and can be inspected weekly or daily. Plenum, fan and duct work are usually driven by interval and by what the last inspection found, so the interval itself should be a number the facility can change on evidence rather than a clause it is not allowed to touch.
Write a defect route per row, not one for the whole hood. A fail at a filter seat goes to the kitchen manager for the next shift. A fail at a plenum joint goes to the contract manager and stops the next scheduled clean until it is cleared. A fail that turns out to be damage rather than deposit goes onto the repair list with the date it was found, the photograph reference, and who is closing it.
Keep the whole standard to one page per area group, with owner, frequency, method, inspection evidence and defect route on the row. A standard that runs to several pages is not read at the pass, and the pass is where the criteria either work or they do not.
Exclusions written down with what you do instead
Every hood has assemblies that must not be washed, degreased or heated, and a serious acceptance sheet names them with a replacement method beside each, so the exclusion is not read as a gap in the job.
Electrical enclosures, motors and their terminal boxes, control panels, wiring and its insulation are excluded; they are wiped and inspected dry, and any wet cleaning near them is stopped at the enclosure boundary. Fire detection heads, sprinkler heads and their covers are excluded; they are cleaned to their own maintenance regime and never degreased on the hood schedule. Sealed and insulated duct sections are excluded unless access is made and reinstated under the duct scope, with that reinstatement costed rather than assumed. Painted and decorative faces with uncertain coating condition are excluded pending a test patch, and the trade is accepted in writing before the patch. Labels, safety markings and certification plates are excluded from any wash and are only wiped. Assemblies already damaged, perished or corroded are excluded from cleaning until repair is scheduled, because cleaning can complete a failure that was already beginning.
For each exclusion, write the alternative, its trade and its review date. An exclusion with no alternative is how a facility ends up with a clean canopy and an unexamined plenum.
Prove the criteria on one bounded section first
Before the criteria become a site standard, run them on a bounded section: a length of canopy, one filter set, or one access opening and the plenum face behind it. Mark the limits with tape so the record shows what was in and what was out, take the angled photographs as the surfaces stand, and write the criteria and the stop conditions down before any cleaning agent touches the section.
Write the stop conditions as named events, not as judgement: paint lifting or crazing, a label edge starting, a joint opening, liquid reaching an assembly on the exclusion list, a coated surface going dull or hazy, a filter frame distorting. Any one of those ends the trial on that section, and the trial report records the surface, the deposit, the method used and what stopped it.
Then re-inspect the same rows the next day, after a full service. A canopy face that looks clean at the end of the job and shows drip marks by the end of service tells you the criterion missed a deposit at a joint, not that the cleaning was bad. Take the timing from the second run, not the first, because the first run includes finding the access, and keep the work in named blocks, so a slow block can be attacked separately: isolation and shielding, filter removal, the pass itself, the dry finish and recheck, restore and hand back to the kitchen.
Decide the water and run-off question in writing
Hood cleaning moves water and grease into a kitchen, and the acceptance sheet is where that is controlled rather than discovered. Before the first pass, write down the water supply and how it is connected, where each area group discharges to, whether the floor in that area has fall and whether it stands water after washing, what has to be closed to the kitchen while work runs, and how long the area needs to be dry before it reopens.
The same sheet carries the utility questions for the point of work: what supply is available near the hood, how the cable is protected in a wet area, and how far the equipment can travel and reach from one position. For a wheeled or hand-pushed unit that is route and clearance; for a fixed unit it is the working radius of the hose and wand from one anchor point. Both answers come from a tape measure in your building, not from a data sheet.
What to ask a supplier when the criteria are set
Once the criteria exist, the enquiry writes itself, and it asks for rows answered for the exact unit quoted rather than for a range brochure. Ask which method is intended for each of your surface groups; which mode and reach each group needs; how the machine is fed at your site and what your supply has to provide; how run-off is controlled in a kitchen; what protective features that particular unit has, by name; what the consumables and refill limits are inside one shift; and what the trial arrangement is, on your surfaces, with your photographs and your stop conditions.
Where hood duty is not covered by an off-the-shelf configuration, that is an enquiry for customized steam cleaning equipment rather than an assumption about an existing model. Ask the question with your surface list attached; a supplier who can answer it row by row is worth more than one who can quote a price.
For the wider range and its published application wording, the PowerDe cleaning equipment listing is where the recorded scenarios are stated, and it is worth reading before the specification is finalised so that the duty you are buying is described somewhere on a page rather than only in your enquiry.
Sign-off, records and review
Close the cycle with a signature that means something. One page per area group, signed by the named inspector, dated, with the photograph references for that cycle and the defect list attached. Record the interval actually used, the deposit found, the method used, and what failed. Where a criterion was waived, record who waived it and until when.
Then set a review date and the events that force an earlier one: a change of cooking load or menu, a change of fuel, a new canopy or fan, a change of cleaning contractor, any cycle where a row failed twice, and any inspection that found damage rather than deposit. Criteria written once go stale within a year of a kitchen's life, whatever the paperwork says today.
Signs the criteria are not working
A few checks on the sheet itself. If a row has no pass condition written, it is a description of work, not a criterion. If the only evidence is the contractor's invoice, nothing has been inspected. If there are no dated before photographs, the comparison the whole scheme depends on does not exist. If the exclusion list has no alternatives, the job has gaps nobody priced. If the inspection is signed by the person who cleaned, the standard is advisory. And if nobody on the kitchen team can name three excluded assemblies from memory, the exclusions have not been trained, and the acceptance sheet is a document rather than a control.
