Wet steam sits between dry steam and hot water on most PowerDe cleaning machines: enough moisture to loosen and flush, enough heat to break down grease, and far less water than a pressure washer. The problem for a purchasing team is that a specification sheet cannot tell you whether that mode will actually clean your soil, in your bay, with your power and water supply. A cleaning trial can. A well-run trial answers one question in a way you can defend to finance and to operations: is wet steam the right mode for this job, or is dry steam, hot water, or a conventional wash the better answer?
PowerDe's mobile active-water machines — the PWD02, PWD01 and HMW2 driving-style units — are listed with three modes: dry steam, wet steam and hot water. The fixed and hand-pushed machines add a narrower choice. That means the mode, not just the machine, is the decision you need to justify. Here is how to structure that decision.
1. A trial is only useful if it can fail
Most supplier demonstrations are arranged to succeed: one clean panel, one cooperative surface, ten minutes of the operator's best work. That proves nothing. A useful trial is set up so that a negative result is possible and visible.
In practice that means a side-by-side comparison on the same object. Split one vehicle, one engine bay, one floor section or one machine enclosure into two halves. Treat one half with the wet-steam mode, and treat the other with the method you use today — a cold high-pressure rinse, chemical plus manual scrubbing, or the dry-steam mode of the same machine. Same soil age, same operator skill, same shift. If the wet-steam half is not measurably different from the control half, the mode has not earned its place in your process, and you now know that cheaply.
2. Write the acceptance criteria before the machine arrives
Teams that decide after they have watched a demonstration argue about impressions. Teams that decide beforehand argue about numbers. Set the pass conditions in writing and share them with the supplier before the trial, so both sides measure the same thing:
- What "clean" looks like for your worst realistic soil — not the lightest job on site. Photograph it before you start, at a fixed distance and angle.
- The maximum time per unit of work you will accept, including preparation, moving the machine, refilling and waiting for the boiler to recover.
- Whether a second pass over the same surface counts as a pass or as a failure. On a heavy grease film, one pass versus three changes the labour case completely.
- What residue is acceptable afterwards — standing water in a bay, moisture on electrical housings, run-off into a drain that is not designed for oil-laden water.
Ask the supplier to confirm in writing which mode was used for each pass. On a three-mode machine it is easy, in a live demo, to drift from wet steam into hot water and back again, and then to credit the wrong mode with the result.
3. Match the trial to the machine that would actually run it
A trial in a workshop with a fixed supply is not the same job as cleaning a row of parking bays. Choose the candidate machine first, from your site constraints, and trial that class of unit.
Two questions decide the class:
- Where does the power come from? The battery-equipped versions of the mobile mobile steam cleaning machine range can work away from a socket; the otherwise identical variants listed without a battery need the cable to reach, which in a shared garage or a remote yard changes the routing, the trip length and the labour time.
- How much room do you have? The PWD and HMW2 units are positioned for indoor garages and narrow outdoor parking positions. A walk-behind or fixed machine is a different workflow; a fixed high-pressure steam cleaning machine such as the PowerDe HW02 is a 220 V installation with a 6 kW heater, a 160 °C steam temperature, 0.8 MPa vapour pressure and an 80 L SUS304 tank — capable, but it cleans where its hoses reach.
Run the trial with water quality and inlet pressure close to what you have on site. The machines take a tap-water inlet; if your supply is hard, scale behaviour during the trial is information, not an inconvenience to be hidden.
4. Six things to record while the trial is running
The value of the trial is the record it leaves behind. Without it, the purchase decision is a memory contest. Capture, for both the trial half and the control half:
- Elapsed working time, and separately the elapsed wall-clock time including refills and recovery.
- Number of passes needed to reach the agreed acceptance condition.
- Water used and how often the tank was refilled, plus how much run-off you then had to manage.
- Scrubbing or wiping effort still required after the steam pass — the honest measure of whether the mode is doing the work or the operator is.
- Any chemical that was still needed, and where.
- The failures: surfaces where the soil did not move, areas the nozzle could not reach, damage or moisture where it should not go.
Where the specification you need is not published, ask for it rather than inferring it. For the wet-steam mode specifically, the figures that matter most — delivered steam temperature and pressure for that mode, flow, and on mobile units the battery capacity and runtime between charges — are not all stated on the product pages for the mobile machines. Request them in writing, along with the accessory list for the nozzle set you used, and have the supplier confirm the same figures apply to the variant you would buy, since the same model is listed both with and without a battery.
5. The signals that say wet steam is the right mode
Read the trial against these outcomes. If several hold, wet steam is a genuine fit for the job rather than a feature on a datasheet:
- Grease, oil and food-type films lift in fewer passes than the control method, and with less or no detergent.
- The flushed residue actually leaves the surface, instead of smearing — the usual weakness of dry steam on heavy, thick soil.
- Water run-off stays small enough that your drainage, bunding or bay floor can handle it without additional recovery work.
- Boiler recovery between units does not create dead time that erases the labour saving.
- Your own staff, not the demo operator, can repeat the result the next day.
- Surfaces that must stay electrically or mechanically safe come out within a moisture level you can accept and dry quickly.
If instead the soil only smears, or the operator ends up scrubbing anyway, or the run-off becomes the main job, the trial has told you that the mode is wrong. Switch mode on the same machine — hot water for heavy deposits, dry steam where moisture must be minimised — or reconsider whether a fixed unit with a larger tank suits the workload better than a mobile one.
6. Close the trial with decisions, not conclusions
Take the record back to the supplier with four specific asks:
- Which mode, nozzle and pressure setting produced the acceptable result, and can the machine you would buy repeat it?
- What is missing for your site — tank capacity, hose length, a wand for a recess, a different battery variant, a customised configuration?
- What does the protection package cover in your operating pattern, and what still depends on operator training?
- What the machine needs from you: power routing, water inlet, drainage, storage, and the consumables that will recur.
Then write the answer into a standard method for the job you trialled: mode, nozzle, passes, time, and what to do when the soil is worse than the trial sample. A trial that ends in a method is worth the half-day it takes. One that ends in a positive feeling is not.
If you want the trial run against your own soil rather than a demonstration panel, send photographs of the surfaces, your bay dimensions, and the power and water available at the position to PowerDe. From the PowerDe cleaning equipment range the right model, mode and battery variant can be proposed, and the trial can be set up against the acceptance criteria above.
Figures quoted for the PowerDe HW02 come from its published product page. Steam temperature, pressure, flow and runtime for the wet-steam mode of the mobile machines are not fully published and should be confirmed in writing with the manufacturer before you rely on them.
