Commercial exhaust hoods sit at the awkward end of kitchen cleaning: heavy baked-on grease, restricted access, sensitive electrical components, and a schedule that rarely allows the kitchen to go offline. Before buying a machine for this job, a buyer needs a shortlist of facts about their own site, not a brochure. The questions below are the ones worth answering before you request a quotation.
Start with a surface list, not a machine catalogue
Write down every part of the hood you expect to clean: filters and baffles, the interior canopy, the outer panels, the grease cups or collection trays, and the accessible section of duct nearest the hood. For each item, note the material and finish, how the part is removed, and whether it can be reached from below or requires access from the roof or a ladder. A machine is then matched to that list. If most of the work is removable filters, a sink or tank station plus a hand-held wand may matter more than a large on-board tank. If the canopy interior is the recurring job, hose reach, lance type, and where the machine can be parked become the deciding factors. When a supplier publishes applications such as range hood cleaning, check that the listed application actually matches the surfaces on your list before treating the model as fit for the job.
Match the mode to the soil, not to the marketing label
Kitchen grease behaves differently depending on whether it is fresh, emulsified, or polymerised. Fresh splatter responds to heat and a short dwell time. Polymerised coating on a canopy interior needs the heat held on the surface long enough to soften it before the residue is wiped or scraped off, and that is where operator technique changes results more than any specification line. When comparing modes, ask which ones the machine offers and how the operator switches between them; a machine that locks into one mode forces the crew to work around it instead of with it. Ask the supplier to describe, in plain words, what each mode is meant to do to a greased metal surface, and treat any answer that only repeats the mode name as unhelpful.
Confirm the utilities at the hood, not somewhere in the building
Most kitchen cleaning failures trace back to site services rather than to the machine, which is why a commercial steam cleaning machine that looks adequate on a specification sheet can still fail on installation. Walk the hood area with a tape measure and answer four questions. Is there a protected socket on a circuit that can reach the hood without a cable crossing a walkway or a service door? Where will the machine be refilled, and is that point at the same level as the kitchen or up another floor? Where does the run-off go, and is there a drain or interceptor that can accept grease-laden water, or will everything have to be captured in trays? Can the machine physically pass the doors, corners, and steps between storage and the hood? A fixed machine is sized by its footprint plus hose swing and the operator's standing room, so measure the parking spot before believing the dimension on a product page.
Write the no-spray list before the first trial
Hoods are full of components that must not be hit with a steam lance: lights and their wiring, fan motors and cable glands, control panels and thermostats, junction boxes, bearing housings, insulation seams, open duct penetrations, and any fire damper or suppression hardware. Have the maintenance lead sign that list, and keep a copy with the cleaning instruction. This single page protects the equipment, the crew, and your claim position. It also settles arguments on the night of the job, when nobody wants to decide what is safe to spray.
Run one trial on your own worst hood
Ask the supplier to prove the machine on your soil, not on a clean demonstration panel. Choose your dirtiest hood, use your own staff, and record what happens: time per surface, number of passes, how much water was used, how many refills were needed, and how long the hood had to stay out of service before it was dry enough to reopen. Freeze the settings that worked, including lance-to-surface distance and travel speed, so the next crew repeats the method instead of rediscovering it. Judge the result against your own baseline, not against a supplier's promotional figures. A fixed PowerDe HW02 steam cleaner, for example, publishes 220 V working voltage, 6 kW heating power, an 80 L SUS304 tank, and a 1/2-inch four-point internal-tooth tap-water inlet; those figures tell you whether the machine suits your services, and your trial tells you whether it suits your grease.
Check what the machine needs to stay working
A steam machine in a kitchen runs on hard water and runs hot, which means scale and wear parts are the real operating cost. Ask which items are consumables, how they are replaced, whether spares are stocked, and what the lead time is. Ask who at your site is responsible for descaling and for checking inlet fittings and nozzles, and put that person's name in the maintenance plan. Machines that publish protection functions, such as leakage, short-circuit, high-temperature, high-voltage, water-shortage, and high-voltage-explosion protection, should be treated as alarms to investigate: when one trips, record the cause rather than resetting it repeatedly, because repeated resetting hides a developing fault and produces cleaning results that look like operator error.
Ask the same questions about the vendor behind the machine. A hood job is usually done out of hours, so spares that arrive late stop the kitchen the following day. Ask whether the supplier can send a technician to your site to run the trial with your own crew, and what happens if a part fails mid-service. For operators running several kitchens, ask whether the same configuration can be repeated at each site and what changes when layouts differ. If the supplier can also arrange hardware testing and an integrated engineering team, that is a useful sign that a non-standard requirement can be evaluated rather than simply refused.
Decide what "clean" means before the job starts
Write the pass criteria in the same document as the method: bare metal visible on treated surfaces, no residue in grease trays, filters refitted correctly, no standing water in the canopy, lights and controls confirmed working, floor dry and slip-safe. Add a one-line record for each hood, with date, operator, and any exception raised. That record is what an inspector, an insurer, or a franchise auditor asks for, and it is also the file you use at review time to see whether the method is holding.
When the catalogue does not fit your kitchen
Multi-site operators, hoods with unusual geometry, or kitchens with no usable drain and no convenient power should not force a standard model into an unsuited layout. Send the supplier three things instead: a site survey of power, water, drainage, and access; the surface list from the first section; and the time log from the trial. That is enough to request customised cleaning equipment rather than accepting the nearest catalogue item, and it also supports a conversation about custom configurations if your requirements sit outside the published range. Where the answer is genuinely a question about a specific hood, layout, and shift pattern, the fastest route is to send those details and ask for a configuration at contact PowerDe.
