A hot-water trial answers one question: will this method clear the soil you actually get, at a pace your crew can hold? If the trial leaves behind only opinions, the purchase decision gets made twice. What follows is the record a buyer should walk out of a trial with, using the mobile active-water machines that PowerDe lists with dry-steam, wet-steam and hot-water modes.
Write down what you are testing before the machine arrives
Put three columns on the sheet: surface, soil, and what "clean" means for that pair. Road film on a painted panel, brake dust in a wheel arch, and grease in an engine bay are three different problems, and a hot-water setting that handles one may be the wrong choice for another. For each row, record the material (painted steel, bare aluminium, plastic trim, rubber seal), how long the deposit has been there, and the pass count you are willing to allow.
Then mark the rows that must not be wetted. Electrical housings, connector blocks, bearings with exposed lips, and insulation are where trials go wrong, and the decision belongs on paper before anyone points a lance at them. The hot water and steam cleaning machine listings describe dry-steam, wet-steam and hot-water modes on the same machine, so your record should show which mode you used on every row, not just that "the machine" did the job.
Record the site conditions that decide whether the trial is repeatable
Log four numbers at the start of each run: the supply distance from the power point to the working position, the water connection type and its distance, the drainage route, and the floor space the unit occupies once handles and hose are routed. Mobile battery-powered units move the power question, but not the water or drainage question. A trial run in a bay with a drain ten metres away and a full-time job on a loading yard with none are two different installations, and both results should say which one they are.
Note the ambient conditions too. Outdoor temperature, wind, and whether the surface was in sun or shade change drying time and therefore change what your crew sees as an acceptable finish. That single line in the log prevents a later argument about whether the second site failed the method or simply had worse conditions.
Measure the cycle, not just the result
Time the whole job from set-up to clean-down: hose out, machine start, pre-rinse if used, hot-water pass, dwell where the soil needed it, drying, and moving the unit between positions. Record refills and any waiting separately. Waiting is where throughput plans die, and it is the number suppliers ask for when sizing a fleet.
Water use deserves its own column: tank capacity read at the start, refills counted, and litres made up. The published tank figures differ across the range, and some parameters on the hot-water models are not published at all, so treat tank capacity as something to read from the unit you are trialling rather than something to assume. The same applies to runtime on battery variants, heater output, and pressures: write what the machine you are holding actually gives, and ask the supplier to state the rest in writing. The PowerDe cleaning equipment pages list mode sets and protection items per model; those are the sheet you should bring back with signatures.
Also confirm you are trialling a machine that has the mode at all. The hand-pushed HMW3 listings describe dry- and wet-steam modes only, while the driving-style PWD and HMW2 listings name hot water as a third mode. If a trial machine has no hot-water setting, the trial tests the wrong method.
Judge the finish with criteria a supervisor can apply
Three checks are enough if they are applied the same way every time: a white cloth drawn across the edge of a panel, a visual check against the reference photograph taken before cleaning, and a re-inspection after the surface has dried. Write the pass as an instruction, not a feeling: "no transfer to cloth on the horizontal surfaces, no residue in the door shut lines." Add the pattern for each soil type, so that next time somebody can tell whether a failure came from the method or from the operator's dwell.
For anything near trim, seals or underbody components, record what changed after the trial: a seal that had begun to weep, a decal edge that lifted, a surface that now drains where it used to hold water. Those observations decide whether the setting needs a wider lance, a shorter dwell, or a different mode on that row.
Trial on the surfaces your site actually has
If the trial is for a parking facility or a forecourt, run it on the layout you have, not an open yard. A parking lot vehicle cleaning equipment trial should include the tight bay, the ramp with its gradient, and the distance crew walk with the lance, because those are what set the pace of a real shift. Fixed installations and mobile units answer different questions; record which one you tested and do not compare their timings as though they were the same setup.
The closing sheet: what to hand the supplier
Send the record, not a summary. The sheet should close out these items in writing:
- Mode used per surface, with dwell times and pass counts that passed your finish criteria
- Measured cycle time, refills, water use, and the gaps spent waiting for the machine to recover
- Power, water connection and drainage actually available at your positions, plus the space the unit occupies in service
- Parameters the listing does not publish for your model: hot-water temperature and pressure, flow, tank capacity, battery runtime and charger output, weight, hose and wand lengths
- Service interval, spares, warranty terms, and the training included with delivery
If the standard configuration does not reach your surfaces or fit your bay, ask about customized steam cleaning equipment at the same time as the quotation, so the trial record and the configuration you buy are the same thing.
