Water use in a commercial kitchen is usually measured at the wrong point. The meter, the utility invoice and the water team all report the building total, which includes toilets, cooling towers, dish machine inlets and the hose left running in the yard. None of those lines tell a kitchen manager what one wash-down of the cook line, or one degrease of the pipe exteriors above the ranges, actually costs. To price the cleaning of pipe runs, canopies, hoods and the walls around them, you have to measure the task, not the building, and you have to measure it before you change the method, or there is nothing to compare the change against.
What the task actually is, and why it is the one to measure first
In this article, pipe exteriors means the extract ducting, the hood canopy, the grease filter housing, the risers and the horizontal runs above the cooking line — everything on the kitchen side of the extract system that collects a film of grease from cooking vapour and has to be wiped, scraped or washed rather than taken apart. It is a cleaning task, not an extract-system service task. The deeper internal duct clean that a contractor carries out on a scheduled frequency is a separate job with its own access requirements, and it should stay out of the water figures you collect for daily and weekly cleaning.
This task is worth measuring because it is the kitchen task most likely to be done with a hose and a bucket, and it is the one where the water choice shows up somewhere else: water that goes over a hood canopy ends up on the floor, in the drain, and in the wash water that a grease interceptor then has to hold. It is also a task where a wet, cold rinse does little to a polymerised grease film, so crews answer the poor result with more passes, which means more water each time.
Step 1: Break the task into measured units
Do not measure "clean the kitchen". Split the pipe work into units you can time and repeat:
- a metre of horizontal duct or the outside of a canopy, at a stated height and reach
- one grease filter housing and its frame
- one riser, top to bottom
- the wall and tile shield behind the line, which is usually washed with the pipes
A figure per metre, per housing and per riser can be compared across shifts and across weeks. A figure for "the kitchen" cannot, because no two weeks look the same.
Step 2: Measure the current method before changing anything
Pick one unit of work and record four things about it.
- Volume per fill. A bucket has a working volume — fill it level, pour it into a graduated container once and write the number down. For a hose, meter it: a handheld meter on the supply line, or a flow-cup on the lance if the fitting allows it. If neither is available, time how long a known volume takes to leave the nozzle at the working pressure and use that to convert minutes into litres.
- Fills or minutes per unit of work. Count them for one pipe run on one normal day, not the best day.
- Passes. How many times the crew goes over the same metre to get the film off. This is the hidden multiplier on every water figure in the kitchen.
- Labour minutes. Water that costs little can still be the expensive option if it needs two people and forty minutes.
Multiply volume per fill by fills, then divide by the metres cleaned. That gives you litres per metre for the current method, and it is the only honest baseline you will have.
Step 3: Look at where the water goes, not only how much of it you use
Two kitchens can use the same volume on the same task and get very different results, because one of them controls where the water runs. Note these points while you are measuring:
- Run-off from a canopy lands on the cook line, the floor and the floor drain. The more water you apply overhead, the more floor you then have to clean — a second task that inherits the first task's water.
- Greasy run-off belongs in the site's waste route through the grease interceptor. Record who checks the interceptor and when it was last emptied; a full interceptor turns a routine wash-down into a flood and a hygiene failure.
- Where the water is plumbed in matters. A fixed unit at a wash point near the line keeps crews from dragging hoses across an aisle and re-wetting floors that were meant to be dry.
Step 4: Compare methods on the same unit of work
Once the baseline is recorded, run one unit of work with the alternative method and take the same four readings. The comparison that matters for pipe exteriors is not volume alone but the number of passes needed to move a baked-on film.
A cold rinse with detergent lifts fresh oil. It does little to a varnished layer that has been baked onto ducting and canopy panels repeatedly. For that deposit, central kitchen degreasing with hot water and high-temperature steam works by softening the film before pressure moves it, which is why the pass count usually falls even when the operator is not trying to save water. A dry and wet steam cleaner such as the PowerDe HW02 gives the crew two modes for one job: the drier mode puts heat into the deposit with comparatively little water carried onto the surface, and the wetter mode finishes as a rinse once the film has released. The HW02 is plumbed to a tap supply, holds an 80 L SUS304 tank and works on 220 V, with 6 kW of heating power, a stated steam temperature of 160° and a vapour pressure of 0.8 MPa.
For a kitchen that wants the low-water case stated in the site's own terms, the customer-facing description of low-water steam cleaning equipment on the PowerDe site is the place to check what the equipment is claimed to do, and the Fixed Steam Cleaning Machine PowerDe HW02 product page is where the published parameters live. When you build the comparison, treat those parameters as the machine's specification and your own measured pass count as the number that decides water use.
Step 5: Put the figures into a decision, with the trade-offs named
Write the result as a small table per unit of work: litres per metre, passes per metre, labour minutes, and whether the surface is dry in time for the next service. Then read it honestly.
- A method that saves 30 litres but adds two passes and fifteen minutes is not a water saving; it is a labour cost that looks green on paper.
- A method that uses less water on the pipes but leaves the floor wetter has moved the cost, not removed it.
- A method that shortens the return-to-service window has value in a kitchen that cannot close the line, and that value should be counted against the equipment.
Also record what the machine itself needs. Scale collects inside a heater where the supply is hard, and output falls long before the machine fails, so a descaling routine and an owner for it belong in the same document as the water figures. On any fixed unit, the water inlet fitting, the tank volume and the working voltage decide whether it can be used where your line actually is.
Step 6: Set the standard the crew can check in seconds
Operators will not hold a measuring cup during service, so the acceptance check has to be visual and fast: no visible grease film on the canopy panel or the duct surface within reach, no residue at the filter frame, no streaking on the riser, floor dry within a metre of the line, and no detergent smell on a surface that touches food. Fix a frequency for each unit — daily for the surfaces in front of the line, weekly for the housing and frame, periodic for the higher runs — and put a named owner and a realistic duration against each one, because a schedule with no owner is not followed on a busy Friday.
Safety sits inside the method, not beside it. Working overhead means goggles and gloves, hot vapour near the face means controlling distance and dwell, and any steam work near lighting, motors or electrical enclosures means those parts are wiped around rather than sprayed. Confirm the equipment's own limits with the supplier before anyone points a wand near an electrical fitting.
Step 7: Review on a date, using the sheets
Re-measure after a set number of weeks with the same units of work and the same crew if possible. If a task keeps slipping, the frequency or duration in the plan is wrong. If a surface still needs heavy scrubbing after the scheduled method, that is a finding about the method, not about the crew, and the fix belongs in the document.
Where the run of ducting is long, the reach is awkward, or several operators share one kitchen, the water figures from a template will not describe your site. PowerDe cleaning equipment covers fixed and mobile machines for different layouts, and customized steam cleaning equipment can be specified against your pipe runs and duty cycle. Send your litres-per-metre figure, your pass count and photographs of the worst deposit to the contact page, and ask for a method and configuration matched to the kitchen rather than a catalogue page.
