How Often Should a Commercial Kitchen Extract System Be Cleaned?

One of the areas in a commercial kitchen that is most difficult to keep clean is the extract system which removes the cooking fumes from above the cookers to the outside air. With a little knowledge, much of this maintenance can be carried out as a regular activity by the kitchen staff themselves. This article outlines how frequently components need cleaning as well as some of the hazards to look out for.

One of the areas of a kitchen that becomes contaminated most quickly is the area above the cookers themselves – where the air and fumes are ventilated to the outside through an extract canopy which will contain grease filters to capture oil and grease given off in the cooking process as well as fans to force the air circulation to the outside of the building through an extract duct.

The Grease filters themselves are intended to capture contaminants, and to remain effective will need regular cleaning before they reach the point of becoming saturated. How often the filters need cleaning will depend on the type of establishment, but for a rough idea, here are some recommended cleaning intervals for the different elements in an extract system for both heavy (e.g. high-output fast food restaurants or food factories) and light (e.g. school or workplace kitchens) usage.

Baffle Filter: (wash every 1 to 7 days)

Mesh Filter: (wash every 5 to 7 days)

Electrostatic filter: (Swap out every 3 to 6 months)

Carbon filter: (Replace every 3 to 6 months)

UV Tube: (Wipe down every 1 week to 2 months, and replace after 8000 hours of use)

Grease Drawers: (Clean every 1 to 7 days)

Extract Ductwork: (Clean every 3 to 12 months)

When cleaning grease filters and grease collection drawers yourself, these are often best washed in a commercial dishwasher, so they should be designed, sized and constructed to be robust enough to withstand regular washing in this environment.

Providing that cleaning intervals are not left too long, washing with soap or mild detergent and warm water, followed by a clear water rinse is usually quite adequate for most equipment. When too long a period is left between cleans, grease will become baked-on and require special attention. An enhanced aesthetic appearance will be achieved if the cleaned surface is finally wiped dry.

In reality, deciding upon how often cleaning should take place is relatively subjective and it is ultimately the facility manager who will have to make a judgement call. However, the simplest guide to follow is that if a surface or component looks dirty, then it needs cleaning.

There is no reason why you shouldn’t undertake most of this work yourself, but a little training as well as an understanding of the risks will help ensure that you can do so safely. It is strongly recommended that an in-house, site specific risk assessment of potential risks and hazards should be carried out.

For example, if your system has specialist odour removal systems such as UV, ESP or Carbon Cells, in-house staff members will require some specific training in monitoring, testing and handling of the various components.

It is also important that when handling any components of a canopy, people wear proper, gripping, cut-resistant work-gloves for protection against metal edges, as well as the detergents and cleaning agents used. Even with a well finished filter panel, it is surprisingly easy to cut soft water-soaked skin during the cleaning process. Grease filters by their very nature will have a coating of grease and therefore will be slippery and difficult to handle. Gaining access to filters for removal & replacement will inevitably mean reaching above head height, so suitable access equipment and or safe working procedures may be required.

Of course, no grease filtration system is going to be 100% effective and therefore there will always be some grease that passes through the filters and accumulates on the internal surfaces of the filter housings, fans and ductwork. Once again, the amount of grease carried through any filtration system will depend very much on the type of cooking and ingredients used. If left unattended, the hidden deposits of grease will not only adversely impact hygiene, but can also cause a serious fire risks. Thus it is important to have the complete extract system deep-cleaned on a maximum of a six-monthly cycle and even as often as three-monthly where usage is particularly heavy.