Ask a supplier for "steam" and you will get ten different answers. The same word covers a near-dry vapour that barely wets a surface and a hot, wet spray that runs off the floor in seconds. Before any machine is shortlisted, write down which of those two your site can tolerate, because that single answer changes the no-spray list, the drainage work, the drying step and how long the crew stands there. PowerDe's Cleaning Equipment Series lists dry steam, wet steam and hot water as separate modes, which is the cleanest way to compare what is being offered.
Water per pass is the dividing line
Dry steam carries little free water. It heats a surface and loosens bonded grease without forming a film you can wipe off in one pass, so almost everything depends on dwell time and on physically removing the softened residue afterwards. Wet steam carries more free water, so it rinses as it heats, but every pass leaves moisture in seams, joints and underneath components. Hot water, the third mode in the same range, is a different conversation: volume and pressure do the work, and the site must handle the run-off.
The practical consequence is that "which mode" is a property of your floor plan, not of the machine. A bay with a floor drain and an oil-water separator can accept wet passes. An indoor garage, a rented unit or a room with a raised seam cannot, and there a low-water mode is not a preference but a constraint. Record what drainage exists at the exact cleaning point before you discuss any machine specification, because the machine is the last variable in that chain.
The nozzle decides what each mode delivers
A fan nozzle spreads heat over a panel and reduces impact; a pointed nozzle concentrates it on a small area and lifts more residue per second. Change the nozzle and the same mode behaves differently, so when you ask a supplier to describe modes, ask them to describe modes per nozzle, with the spray angle, the material and the extension length stated. Then state your own working distance and travel speed as fixed numbers rather than leaving them to operator judgement, and require the same figures in every quotation so the offers are comparable.
Write the no-spray list before the trial
Both modes push moisture where it is not wanted. Before anyone lifts a lance, have the maintenance lead sign a list of components that must never be sprayed at your site: control cabinets and junction boxes, drive units, sensors and encoders, cable chains and connectors, linear guides that carry an intentional lubricant film, bonded insulation panels, vents and breathers. Then add the mechanical conditions: power isolated and tagged, surface cooled, and the shift window chosen so that water is never directed towards a cabinet or a walkway the next crew will use.
Drying is part of the cleaning task
A wet pass that leaves a joint damp is unfinished work. Decide in advance what "dry" means at your site: how long before a floor is safe to walk on, how long before a housing is re-energised, and which connections are blown or wiped as part of the task rather than left to evaporate. Then measure it. If a low-water mode saves water but leaves the area unusable for an extra part of the shift, the saving is not real, and only your own timing records will show that.
Water supply and hardness follow from the mode
A wet mode consumes more water per hour, so the refill pattern changes: how many stops per shift, the walking distance to the nearest tap, and whether the inlet matches your supply. The product listing for the PowerDe HW02 steam cleaner states a 220 V working voltage, 6 kW heating power, an 80 L SUS304 tank and a tap-water inlet with a 1/2 inch 4-point internal-tooth joint. Read those figures as installation conditions to verify - circuit availability, tank capacity against your shift length, and an adaptor for your tap - and not as a claim that any particular surface can be cleaned.
Hard water then changes the machine over time. Scale inside a heater shifts output and flow, and the cost moves from labour to descaling and replacement parts. Ask for the inlet strainer, the serviceable items with part numbers and lead times, the descaling interval and the hardness limit the supplier expects, and name the person who owns that task in the same controlled document that records the cleaning parameters.
Protections describe stop behaviour, not a feature count
The same product page names protection functions such as leakage, short-circuit, high-temperature, high-voltage and water-shortage response. Judge them by behaviour, not by how many appear in a brochure: what the machine does when one trips, what the operator must record, and where the machine goes for inspection. A protection that trips and is reset repeatedly during a shift has become a production problem, and it is a fault to be logged and submitted for inspection.
Compare both modes on your dirt, once
Choose the dirtiest representative area you own, run the trial with your own staff, and freeze the settings before the first pass: mode, nozzle, gun distance, travel speed, number of passes, dwell time, any detergent dilution. Have the operator sign that sheet. Then measure the same four numbers for each mode - minutes per area, refill stops per shift, walking distance to the water point, and drying time before the area returns to service - and compare against your current method rather than against a claim. Fix the pass criteria in advance, such as a white cloth showing no film, no blistering or discolouration on coatings, and the floor walkable within the agreed window, with one named person signing pass or rework.
What to send instead of asking for a model
Send a surface list, photographs of the soiling, the timing record from the trial, and the facts about power, water and drainage at each point. If a standard configuration does not match, raise customized steam cleaning equipment as the outcome of that site survey rather than as an assumption you began with, and ask PowerDe about the installation conditions through the contact page.
A short checklist before you choose
Before any machine is approved, your file should hold: the drainage answer for each cleaning point; the signed no-spray list; the four measured baseline numbers; a trial sheet with frozen and signed parameters; the supplier's written mode-plus-nozzle description; the inlet adaptor, strainer and descaling plan with a named owner; a serviceable-parts list with part numbers and lead times; and the drying comparison against your present method. Dry steam or wet steam is not a preference to be settled in a meeting. It is settled by what your site can drain, how long it can keep an area out of service, and what your own trial recorded.
