The box above the hatch, not the whole villa ducts
Central / ducted cleaning here means the fan coil or air handler: filters, coil face, blower, pan and trap, through the ceiling hatch. The long duct runs are AC duct cleaning. Mixing the two on one WhatsApp thread is how a studio FCU gets billed as a villa duct day.
District-cooling flats still have an FCU in the demise. We clean that box. We do not enter the building plant room or add refrigerant to a water coil.
Gypsum lids
A sealed decorative lid is extra labour if you want a legal opening. A 2-metre Marina loop with a real hatch is a short FCU job. Arabian Ranches with two bathroom boxes and roof flex is not.