Skylights above food courts need a degreasing step that ordinary glass cleaning skips. Grease vapour rises, condenses on the underside of the glass panel, and traps dust into a sticky film that water alone will not lift.
This is a specific problem with a specific fix, and if you clean food court glazing the same way you clean a shopping mall entrance, you will be back on the scaffold in three weeks. The film returns because the source never stops. What you can control is how well each cycle removes it.
Why is grease different from dust?
Dust sits on the surface. Grease bonds to it. In a food court, cooking vapour carries fine oil droplets upward, and those droplets land on the inner face of the skylight. Over a few weeks the oil oxidises and becomes tacky, so every dust particle that touches it sticks. By month two you are not cleaning glass, you are scraping a polymerised film.
The robot matters less than the chemical and dwell time. A skylight cleaning robot with a soft brush and a controlled water flow can do the work, but only if the detergent is formulated for fat, not just for mineral dust.
Which cleaning approach works in 2026?
Use an alkaline degreaser diluted to the supplier spec, let it dwell 60 to 120 seconds, then run the brush and the vacuum return. Two passes. Do not increase brush pressure to compensate for weak chemistry, because you will dull the coating and still leave the film.
| Contaminant | Detergent | Dwell |
|---|---|---|
| Dust / mineral film | Neutral, low foam | 30-60 s |
| Cooking grease | Alkaline degreaser | 60-120 s |
| Mixed grease + dust | Alkaline + surfactant | 90-150 s |
Who should not use a robot here?
If the glass is above a live cooking line with no way to isolate the area, stop. You need to schedule cleaning outside service hours, because a robot that discharges dirty water near open food is a health inspection risk, not just a mess. Also, if the roof pitch is steeper than the machine’s rated limit, a food court is not the place to find out. Lingyun Y3 handles moderate slopes; check the spec before you commit.
What should the cleaning schedule look like?
Monthly for a busy court, six-weekly for a quieter one. The trap is doing it quarterly and then washing with plain water. That just spreads the film. Pair the schedule with a coating inspection every six months, because grease accelerates the breakdown of some hydrophobic coatings.
Document what you used and when. If the film returns early, the log tells you whether the problem is chemistry, dwell time, or the kitchen’s extractor hoods. Fix the hoods and the glass stays clean longer. That is a facilities problem, not a robot problem, and it is worth saying out loud to the building owner. Details on scheduling are on our contact page.
Key Takeaways
- Grease bonds to glass; water alone will not remove the film.
- Use alkaline degreaser with 60-120 seconds dwell time.
- Never clean over a live cooking line during service hours.
- Schedule monthly to six-weekly and log every cycle.
- Fix extractor hoods upstream or the film keeps coming back.