Kitchen ductwork can vary from simple systems through an outside wall to large, complex systems discharging a long way from the extraction canopy. A compliant kitchen duct clean should include the whole system (and all components) so an initial survey to trace the system and the level of contamination before ductwork cleaning is usually recommended.
Kitchen extraction cleaning involves manually removing the grease or carbon from the duct, in most cases by installing access doors into the duct to reach inside to clean the system. All components should be cleaning including the kitchen canopy, filters, fan, and discharge.
Cleaning intervals should be based on the individual usage of the kitchen ductwork. Kitchen exact cleaning should take place when the ductwork reaches an average deposit level of 200μm (micron), gathering this data on each clean allows us to predict the future cleaning frequencies allowing extract cleaning to take place before it becomes a fire hazard.