Kitchen Duct Cleaning Case Studies
Here at Impact Hygiene, we have put together a case study in order for our customers to read to gain more information regarding our kitchen duct cleaning service.
The Regulatory Reform (Fire Safety) Order 2005, states the ‘responsible person’ within an organisation must carry out their own fire risk assessment including the ventilation system. There has since been an increased awareness by insurance companies and consequently cooked food retailers, regarding responsibilities and requirements for kitchen extraction cleaning.
The individual insurance companies insist that the kitchen duct is cleaned by a qualified contractor; they generally quote the standards as laid out by the B&ES, formerly known as HVCA TR 19 Guidelines; which are benchmark industry standards.
We were asked by a well-known national retailer to take a look at their extraction systems, in their restaurants as there was no regular cleaning or maintenance in place. This client wanted a ‘clean and report’ of a sample store with a view to rolling this process out to their other restaurants.
System Description – The system we have been asked to look at is a standard stainless steel ceiling and wall mounted canopy frame; which has a built in aluminium plenum chamber in two sections. One of these sections has four mesh filers, and the other has one mesh filter above the fryer.
The duct vents are vertical in the form of spiral duct straight to atmosphere from the plenum to the fan.
Current Situation – Our team figured out that the duct system has not been cleaned within the last twelve months, there is no formal contract or arrangement for cleaning present. The plenum, filters and canopy were accessible to clean manually; however, there are no access panel fitted in the ducting. 80% of it was accessible to clean with a telescopic pole, the remaining 20% contains only very light debris contamination and no build-up of grease.
The fan has not been inspected from the roof due to heavy snow, but it was visible looking through the plenum, and no build-up of grease was evident. Our team deemed this inspection to be sufficient.
The first metre of duct was well above the recommended maximum (50 microns) with readings in excess of 500 microns.
The grease contamination was extremely heavy – in excess of 250 microns in the plenum above the fryers. It was also exceptionally heavy with loose deposits in the horizontal plenum lip just below the duct; which were off the scales of microns.
Due to this we have scarped a small section here to add perspective. Although this contamination was more loose debris than grease, it was still a potential fire risk.
Post Clean Verification – A certificate of cleaning and inspection has been issued to the restaurant, and all the plenum chamber and canopy has been cleaned in addition to 80% of the ductwork. The inaccessible 20% is not consider to be a sufficient fire risk to warrant any further action.
Recommendations – After we issued a certificate of cleaning and inspection we then gave the client some recommendations in order to help them benefit the hygiene and cleanliness of their restaurant. These were the following recommendations:
The cleaning frequency should depend on the rate of accumulation, the risk vulnerability of the system and site, and any particular warranties imposed by customer’s insurers. In our opinion we would recommend cleaning intervals annually.
The plenum section above the fryer has a heavy duty use, this should be cleaned every six months in order to meet hygiene standards.
The filters should be taken down weekly and cleaned by staff in order to prevent the build-up of grease. The existing mesh filters are of poor quality, however, due to their thickness of 20mm they cannot be replaced with 45mm baffle without modification to the filter housing. Due to this we would recommend that they are replaces with higher quality mesh filters as a minimum. The fryer filter has already been replaced since our visit.
A certificate/inspection of cleanliness should be issued every six months when an inspection/clean is carried out.
A schematic drawing has now been produced which clearly identifies that the system has been cleaned. If access panels are fitted in the future, these will be identified and numbered.
We have taken one before and after photograph in the following sections:
- Showing internal plenum beyond the filter.
- Sample areas of accessible ducting.
- The external and internal of all access panels.
Adding Extra Value –In addition to the above service we now also make recommendations with regard to the condition of the kitchen equipment and structure. E.g. ceiling tiles and kitchen walls, as we are also able to deep clean these aspects of a catering environment when need be.