Before a hood, duct or fan is exposed to steam, someone has to decide what is safe to wet, what must stay dry, and what result counts as a pass. That decision is easier to defend when it is written down before the lance leaves the cabinet. The checklist below follows the order a cleaning crew would actually work in, using one piece of equipment at a time.
Start with the parts list, not the cleaning method
Pull the equipment records for the ventilation line you intend to trial: filters, filter racks, hood panels, grease cups, the fan housing, the motor, the belt drive, the wiring entry points, the light fittings inside the canopy, the dampers, and any fire suppression nozzles or fusible links. For each part write down what it is made of, how it is fixed in place, and when it was last serviced. If the records are missing, photograph the assembly from two angles and label the components on the photo; that image becomes part of the trial record.
Anything with an electrical connection, a bearing, a belt, a label that must stay legible, or a seal that has never been opened goes on a separate do-not-wet list. Keep that list where the operator can read it during the trial, and agree in writing which parts may be steam-cleaned and which are wiped only.
Separate the dry removal step from the wet finishing step
Ventilation components usually carry two kinds of soil: loose debris that has fallen out of the airstream, and older grease that has hardened and bonded to the surface. The first type should be removed dry — scraped, brushed or vacuumed — and bagged before any water or steam is used. Only then does the wet step get a chance to work on the bonded layer. Running steam over loose debris mostly moves it into seams, corners and drain points.
For the bonded layer, decide which mode and nozzle you will use for each surface, and set the working distance and the travel speed before you begin. Write both numbers on the method sheet so the next shift repeats them rather than guessing. A short practice pass on a small, low-visibility area tells the operator how the surface responds before it is applied to a visible panel.
Check the room conditions that decide whether the trial can finish
Ventilation work usually happens overhead, at height, above a floor that has to return to service. Before the first pass, check the distance from the nearest socket to the work area and how the cable will be routed without crossing a walkway. Confirm where water will be drawn from and how the machine will be refilled during the job. Confirm where run-off will go, whether it reaches a drain, and whether that drain is connected to a grease interceptor. Check door widths, steps and anything that limits how the machine reaches the area.
Agree with the site who is allowed under the work area, how the area is closed off, and how long the floor and surfaces are expected to stay wet before the space is handed back. Steam leaves surfaces hot and damp; both need time.
Protect the components that have to stay dry
Motor housings, terminal boxes, sensors, light fittings, bearings, belts and any opening that leads into the airstream should be covered or excluded before steam is used. Covering is not a licence to aim at them; the point of the cover is to catch stray mist and condensate, not to absorb a direct jet. Mark covered items on the method sheet so the operator can tick them off during the pass.
Dampers, linkages and fire suppression components are checked after the trial as well as protected before it. A damper blade that was adjusted during cleaning, or a nozzle that was moved to reach a panel behind it, is a finding to record — not a detail to leave to memory.
Define the pass criteria before the first pass
For each surface, decide what acceptable means: the panel returned to bare metal; the coating undamaged and unchanged in colour; no water collected in a seam or channel; the label still readable; the fan starting and running normally after reassembly. Write the criteria next to the surface name, and take a photograph from a fixed angle and fixed height so the before and after images are comparable.
Record one line per component during the trial: component, mode used, distance, travel speed, whether the criteria were met, and who checked it. That single row is what makes a second trial repeatable, and it is what a site manager can sign off without standing over the operator.
Decide what the equipment itself needs during the trial
Ventilation cleaning is thirsty work for a machine. Check the feed-water connection and the water hardness at the site, because scale builds up quietly inside a heater and shows up later as reduced output. Confirm the power supply matches the machine, and note the protection warnings for the model you are using — leakage, short-circuit, high-temperature, high-voltage and water-shortage warnings — and record any warning that triggers rather than resetting it and continuing. A protection that trips repeatedly is a fault report, not an inconvenience.
Talk to a supplier with the site detail, not a part number
The most useful thing to send a supplier is the component list, the two photographs, the soil description, the distance and speed you used, and the criteria you want to meet. That is enough to discuss nozzles, modes, and whether the job is better split across two visits. Our team reviews that kind of brief and can discuss customized steam cleaning equipment for kitchen extraction work, or point you to the right model from the Cleaning Equipment Series. Send the details through the contact page and we will answer with a method, not a catalogue.
Once the trial passes, freeze the settings, print the method sheet, and train the crew against it. The next ventilation line then gets cleaned the same way — with a record that says why each choice was made.
