A sourcing email for a mobile steam unit usually contains two numbers: the floor space the buyer can spare, and the amount of soil the team has to remove each shift. Those two numbers point at different machines, which is why the same model can look oversized in one plant and underpowered in the next. This article walks through how to compare the footprint and the working capacity of the PowerDe HMW2 steam cleaner supplied with its battery, using the published specification sheet line by line instead of assumptions.
Three separate measurements decide the floor question
The HMW2 with battery occupies 1275 mm in length, 570 mm in width and 1185 mm in height. Each of those figures answers a different layout question, and buyers routinely read them as one "size" number, which is where comparison errors start.
The 570 mm width is the tightest constraint in most existing buildings. Aisle clearance, lift doors, equipment bays and the gap between machine tables are usually sized in the 600 to 800 mm range, so a unit that is 570 mm across passes through most of them without a layout change. Before any other figure is discussed, have the team measure the narrowest point on the route the machine will actually travel, from the charging corner to the cleaning area, and compare it against that width rather than against the length.
The 1275 mm length behaves differently, because it only matters when the machine turns. Walk the route with a tape measure at the corners, not along the straight runs. A corridor that accepts a 570 mm width can still reject a 1275 mm machine if the turning radius at a corner is restricted by a column, a cabinet or a parked pallet rack. This is the single most common reason a mobile unit is returned after delivery, and it costs nothing to check in advance.
The 1185 mm height clears standard doorways, but it matters when the machine has to be loaded into a van or parked under low shelving. If a cleaning contractor is buying the unit for multi-site work, confirm the interior height of the vehicle and any mezzanine storage before the order is placed. Door frames and equipment tops are fixed; a machine that will not fit beside the operator is not a machine that will be used.
Capacity is a duty-cycle question, not a tank number
The published specification lists a 60 L clean-water tank, refilled from the tap through a 4-point internal-thread inlet. For many buyers that single figure reads as the machine's capacity limit, but the useful question is how many minutes of continuous gun work one fill covers between two refills, and that number depends on soil load and nozzle work rather than on the tank alone.
A practical test that avoids guesswork: take the heaviest typical cleaning task of the shift, run the machine with the operator's normal pace and technique, and record the elapsed time until the low-water indication appears. Repeat it three times and average the result. That measured figure tells the team how many refills a shift needs and how much of an operator's time is spent walking to a water point instead of cleaning. If the interval is short relative to the shift, the correct answer is a refill point closer to the work area, not necessarily a larger machine.
The 60 L figure should be read next to the supply arrangement, not on its own. The tank is a reservoir; tap-water supply and refill access determine the real throughput of the day. A site that has a hose bib within a few metres of the cleaning zone can run a 60 L tank continuously. A site where the nearest water point is two floors away will lose more time to refilling than the tank size would ever suggest.
What the battery variant changes in the comparison
The with-battery configuration runs the working circuit at 48 V mobile battery power. For the buyer, the consequence is that the machine is not tied to the location of a mains outlet, so the footprint comparison stops being only a question of floor area and becomes a question of where the charging point sits. The published sheet lists the battery as customer supplied, so a purchasing team should budget for the battery and charger as a line item of their own choice and confirm the voltage match with the supplier before the machine is commissioned.
That point changes the evaluation order. With a mains-powered unit, layout freedom is limited by cable reach and outlet placement. With a battery-powered unit, layout freedom is limited by charge duration and where a charger can be installed safely. Neither answer is better in the abstract; one is better for a specific building. Ask the supplier to state the expected run time per charge and the recharge time, and put those two figures next to the shift pattern of the team before deciding which variant to trial.
The heating element on this platform is rated 4.5 KW, using PTC semiconductor heating, and the machine offers hot-water, dry-steam and wet-steam modes. For a capacity comparison, the mode selection matters more than the wattage number: dry steam draws far less water per minute than the hot-water mode, so the same 60 L tank covers a much longer period in steam mode than in hot-water mode. Teams comparing two machines should state which mode they intend to work in when they quote tank size, tank interval and element power, otherwise the numbers are not comparable at all.
Reading the comparison against a fixed unit
Buyers often weigh a mobile steam unit against a fixed one, and on paper the fixed machine looks stronger: the fixed PowerDe steam cleaning machine in the same product family is listed at 1200 mm by 800 mm by 1200 mm, with an 80 L tank in SUS304, a 6 KW element, steam at around 160 °C and a vapour pressure of 0.8 MPa, on a 220 V supply. It carries a vacuum function as well, which the HMW2 sheet does not list.
That comparison is only fair if the work stays in one place. A fixed unit with a wider footprint and a bigger tank wins where a bay is dedicated to cleaning and the operator walks to the machine. A mobile unit wins where the operator brings the machine to several machines, several vehicles or several bays in one shift, because the travel time of the operator, not the capacity of the tank, is what the shift is actually paying for. Total cost per cleaned part includes operator walking time, and that is the line most quotations leave out.
The third option in the range, the walk-behind platform at 2500 mm by 900 mm by 1050 mm with an 80 L tank and a vacuum function, shows what the buyer trades for extra capacity: length. That footprint needs aisle width and turning room a HMW2 does not. If the narrowest point on the route is under 900 mm, that comparison ends there, and the decision becomes a question of tank interval instead of machine size. The PowerDe cleaning equipment range covers these footprint classes side by side, which lets a buyer shortlist on measurements before discussing price.
Checks that belong on the request for quotation
Protection functions are easy to skim past and expensive to miss. The HMW2 sheet lists leakage protection, short-circuit protection, high-temperature protection, high-voltage protection, water-shortage protection and high-voltage explosion protection. For a purchasing team, that list maps directly onto the questions to ask during commissioning: who signs off the electrical installation the machine is connected to, where the machine will be charged, and what the water-shortage indication does to the element if an operator leaves the gun running on an empty tank.
Put four items on the request for quotation and the comparison stops being vague: the aisle and turning measurements of the actual route, the soil type and area cleaned per shift, the distance from the work area to the nearest water point and power point, and the battery and charger arrangement the site intends to supply. Send those four items to two or three shortlisted models, mobile and fixed, and read the answers against the measurements you already took rather than against a datasheet headline.
A machine chosen on printed dimensions alone is usually the machine that sits unused in a corner. A machine chosen against a measured route, a measured soil load and a measured refill interval is the one the team keeps using. If the footprint and capacity figures above do not match the site conditions your team has measured, the supplier's engineering team can review those measurements with you before a trial unit is agreed.
