Buyers comparing steam machines for a restaurant kitchen usually get a specification sheet, not a limitation list. The numbers on the sheet — steam temperature, vapour pressure, tank volume — say what the machine can produce. They do not say what a hood system will allow you to clean on a Tuesday afternoon with two stewards and a service starting at six. The constraints below are the ones that decide whether a steam process works on your hood, and they are worth settling before a machine is quoted.
1. What the hood was built to tolerate
Most commercial hoods, filters and grease containment trays are fabricated from stainless steel or galvanised sheet, and they are assembled with gaskets, rivet lines and pop-riveted stiffeners. Heat does not damage stainless; it damages what holds the stainless together. Gasket material hardens and shrinks, sealant softens, and galvanised coatings change appearance. A buyer should ask the kitchen contractor what the hood liner and filter frames are made of and what the manufacturer says about hot-water washing before assuming that any heat-based method is safe on the whole assembly.
This matters more on older hoods. A hood that has been cleaned chemically for ten years has sealant and gasket material that has already aged. The same process that is fine on new equipment can start a leak at a joint that was never designed for repeated heat exposure.
2. Deposit thickness sets the number of passes
Steam is not a solvent. It softens grease, and the pressure on the wand then moves the softened material. A filter pulled from a line that has run for a week carries a thin, still-tacky film; a filter from a line that has not been degreased for six months carries a dark, hardened layer that has been through the hot-cold cycle many times. The first type responds to a short dwell and one pass. The second type responds to a dwell, a pass, a second dwell, and a mechanical follow-up — and the buyer should expect that in writing rather than as a surprise on site.
Before signing a purchase, ask the supplier to demonstrate on a filter or hood panel with the deposit profile your kitchen actually produces. A machine tested on a clean panel, or on a filter cleaned last night, proves very little.
3. Access to the filters, the plenum and the duct run
A steam wand cleans what it can reach. Baffle filters hang in tracks and must be lifted out and laid flat to be cleaned properly; a filter cleaned in place will look better than it is. Behind the filters sits the plenum, and behind the plenum the duct run — and the duct is almost never worth treating with steam, because the wand cannot be held at a working angle inside a horizontal run and the run-off has nowhere to go.
The practical limit buyers set is this: steam for the filters, the hood's inner face, the baffle tracks and the external surfaces; a separate mechanical or chemical contractor for the duct interior. A supplier who tells you the machine handles the whole extract system is selling you something you will not use.
Where the hood sits above a grill or a fryer bank, the fan intake and the fan housing also need a decision. Electrical assemblies on the fan and on the light fittings are not spray targets, and a cleaning method that cannot name those exclusions is not a method.
4. Water supply, run-off and the grease interceptor
A machine that generates steam from a tank has to be filled, and the water it puts on the hood has to be caught. In a kitchen with a wash point beside the line, filling is a hose connection. In a kitchen where the hood is twenty metres from the nearest tap, filling becomes a bucket-and-carry task, and the crew's willingness to repeat the process falls accordingly.
The run-off is the harder half. Grease-water from a hood clean is not a sink waste; it belongs in the site's waste route through the grease interceptor. That means trays or a containment boundary under the work, a bucket for the collected liquid, and a named person who checks and empties the interceptor. A kitchen with a full interceptor will flood the first time a hood is washed, regardless of the machine used. Ask for the fixed units' inlet arrangement before ordering — the fixed steam cleaning machine on the PowerDe cleaning equipment pages is listed with a tap-water inlet and a tank volume, and the inlet fitting size needs to match the site supply.
5. Downtime and the cleaning window
A hood cannot be cleaned during service. The window is the gap between the last service and the first delivery of the next day, and it is typically two or three hours. Two things consume that window: cooling and drying. The hood and the equipment beneath it must be cool enough for a crew to work under, and the electrical fittings around the hood must be dry before anything is re-energised.
This is where the steam-versus-hose comparison is worth timing rather than arguing about. Steam puts far less free water on the surfaces than a hose wash, so a hood cleaned with steam tends to be back in service sooner; the actual figure depends on the hood size, the room ventilation and the crew. Ask a supplier to run one clean in your kitchen and record the time from start to ready-to-cook. A number taken from your own line is worth more than any figure in a brochure.
6. Power, services and machine size
A machine with a heater in the several-kilowatt class needs a suitable supply. The HW02 unit listed in the Cleaning Equipment Series is specified at 220 V working voltage with a 6 kW heating power, a 160° steam temperature and a 0.8 MPa vapour pressure, with an 80 L SUS304 tank and overall dimensions of 1200 × 800 × 1200 mm including handles. Before ordering, check three things against the kitchen: the available socket and circuit rating on the cleaning circuit, whether the machine's footprint fits through the door and along the route to the hood, and whether the hose and wand reach the highest point of the hood without a ladder in the wash window.
Do not transfer those figures to a different model. PowerDe's cleaning range also includes hand-pushed and driving-style machines with different power sources, tank volumes and modes, and their published parameters differ. Ask for the specification of the exact model number you are being quoted.
7. Operator training and the safety envelope
Steam at the temperatures these machines produce scalds in under a second, and the vapour cloud in a closed kitchen reduces visibility at exactly the moment the operator is aiming a wand. A hood clean needs two people: one on the wand, one on the hose and the room. The buyer should ask what training the supplier provides, how long it takes, and whether the supplier's engineers attend the first clean.
Ask also which protections the machine has and how they are signalled to the operator. A machine that shuts down on a low-water or over-temperature condition has to be reported and reset properly, not restarted repeatedly through the night by a crew under time pressure. The HW02 product page lists leakage, short-circuit, high-temperature, high-voltage, water-shortage and high-voltage-explosion protection; confirm the protection set for the model you are buying, since it is not identical across the range.
8. Compliance records and what the machine cannot replace
Insurers, fire risk assessors and environmental health officers ask for dates and methods, not for a machine brand. Deep grease in an extract system is a fire issue, and a steam clean of the filters and hood face does not reduce the required frequency of a professional duct clean. Build the record to show which parts of the system were cleaned, by whom, with what method, and how often — and keep the duct contractor's certificates in the same file.
A useful acceptance check an operator can run in seconds: no visible free grease on the filter face, no drip from the baffle tracks, filter surfaces not tacky to a gloved finger, and no standing water in the hood's low points. Write those criteria into the schedule rather than relying on "looks clean".
9. What to send a supplier before you ask for a price
Buyers who send photographs and measurements get a usable answer; buyers who send a model number get a quotation. Include the hood type and its dimensions, the filter type and how many are pulled per clean, the distance from the nearest water point, the available power supply on the cleaning circuit, the size of the deposit at the dirtiest point, the length of your cleaning window, and whether the duct interior is in or out of scope. On that information, PowerDe publishes parameters for each machine in the range and customized cleaning equipment can be specified against the site's layout and duty cycle.
Then ask for two things in the reply: the configuration matched to that information, and the cleaning method written as a sequence — dwell, pass, dwell, rinse, dry, re-energise — with the excluded components named. A quotation that arrives with the method attached is usually from a supplier who has done this in a kitchen before yours.
A short list to settle before ordering
- What the hood liner, gaskets and filter frames are made of, and whether the manufacturer permits hot-water washing
- Whether the duct interior is in or out of scope — and if it is out, who cleans it and how often
- Where the machine is filled from, and where the run-off goes, including the interceptor check
- The available supply and circuit, and whether the machine footprint reaches the hood
- The deposit profile on your own filters, demonstrated on your own filters, not on a sample panel
- The start-to-ready-to-cook time measured in your kitchen
- Training, protections, service interval and who to call when the machine stops heating
Steam cleaning does remove kitchen grease, and in a kitchen with a short cleaning window it has real advantages over a hose wash. It does not remove the constraints above. Settle them in the specification stage and the process holds through a busy service; leave them to the first night shift and the machine ends up in a store room.
