Recently there seems to have been an increase in the amount of ‘ventless’ professional cooking equipment, but does this in turn make kitchen ventilation systems redundant?
Not according to Ian Levin, commercial director of canopy designer, manufacturer and installer, Kitchen Vent Technical (KVT). “No cooking equipment can be truly ventless. The word ‘ventless’ when used in this context, has been misappropriated and what is really meant by the term, is that the piece of equipment has no direct extract connection to atmosphere,” he explained.
“Most ‘ventless’ cooking equipment is ventilated, using purpose-designed, integral recirculating systems employing varying efficiencies of filtration to reduce particulate and odours before reintroducing the same air back into the space – hopefully with less contamination. Pieces of equipment employing this type of ventilation are invariably light duty, and most of them have the cooking process enclosed.”
Levin continued: “The idea or filtering and recirculating air is nothing new and for at least the last 25 years, kitchen ventilation specialists have been designing and manufacturing stand-alone recirculating systems which will handle light to medium duty equipment and cooking processes with varying degrees of success.
“As soon as heavy-duty cooking loads are reached, then even the best designed recirculation systems tend to fail and filtration replacement costs and cleaning regimes become impractically expensive. High heat output equipment also causes problems with a build-up of temperature within the kitchen space, to the point where air conditioning must be installed as standard – not a very green approach.”
Emphasising that ventless or air recirculation systems can only be used on electrically-powered equipment, he detailed: “Gas, charcoal and wood powered cooking equipment must all have direct connections to atmosphere for both extract and return supply air because there is no recirculating system currently available which can safely and efficiently remove the very toxic products of combustion from the air flow.
“There are strict requirements for the design and use of recirculation systems in commercial kitchens within the UK, all of which are clearly stated within DW172 (2018). Even kitchens with ‘ventless’ or recirculation systems operating in them must have background air movement to create a minimum of 10l/s per person occupying the kitchen and realistically should provide at least 20 air changes per hour in order to reduce humidity, heat-gain and excess particulate as well as retaining odours within the cooking space.”
Levin added: “It should be noted that even electrically powered cooking appliances still produce quantities of toxic/carcinogenic materials from the cooking process itself and proper ventilation of this effluent must be treated seriously. Even the best filtration systems will not achieve 100% efficiency and anyone working long hours in a ‘ventless’ kitchen could be exposed to increasing levels of these substances as time progresses, so the occupational health risks must always be considered when designing and selecting equipment.”
At competitor, Trivent, MD Ian Wilman believes: “Whilst there is an increase in the use of self-venting catering equipment, this tends to be utilised within smaller operations utilising relatively small amounts of light duty equipment such as deli operations etc.
“We are noticing catering designs where a percentage of proven selfventing appliances are utilised to reduce the size of the kitchen ventilation system but not replace it. Self-venting equipment may appear more cost effective to the operator, although consideration needs to be given to what the integrated vent system actually provides; such appliances would normally be designed to possibly reclaim a percentage of generated heat, filter out grease (to varying levels dependent upon the appliance) but not treat any odour generated by cooking proteins.”
Wilman stated: “Whilst in our opinion there is a market for certain appliances to be self-venting, the operation and effluents generated by specific equipment needs to be assessed, especially when you consider the levels of odour treatment often imposed by the planners and environmental health even when discharging extracted air directly to atmosphere at roof level, when the self-venting systems are normally applying minimal treatments then introducing the air back into the space for the catering staff to breathe.
“In our opinion, the larger schemes designed for steakhouses, production kitchens etc still require a full kitchen ventilation system designed, manufactured and installed compliant with BESA specifications DW172 and TR19 in order to provide a safe working environment for the catering team and building owner.”
While fixed canopies remain the core product of Trivent’s business, it is also looking to constantly improve manufacturing practices and products to meet demand. Therefore, Wilman revealed: “The major changes of late would be the requirement to ensure maximum energy efficiency and extended lifespans of our kitchen ventilation systems.
“We are seeing an increase in the request for recirculation systems which are designed with up to five stages of filtration to clean the air before being discharged back into the space, which proves effective in situation when there is no conceivable ductwork route to atmosphere.
“The maintenance of a kitchen ventilation system remains a contentious issue; our engineers pride themselves in providing fully accessible systems that can be maintained and cleaned in line with good health and safety practices, but we often report on systems that simply do not comply and have no regard for the cleaning contractor and the safe systems of work that they would need employ.”
Likewise, KVT is always developing products to keep ahead of market trend changes and the team is experienced in designing recirculating systems – bespoke as well as standard products. Levin explained: “Recirculating systems are best applied with full knowledge of the cooking appliance selection process, to ensure a good match in ability. In other words: distributor and vent manufacturer must work together. Again, this is something which our team has gained vast experience in during the past 30 years. Simply putting any recirculating canopy above a standard range of equipment without knowledge of how the two will work together, will inevitably lead to a failure in performance.”
On the subject of mobile ventilation systems, Levin feels: “Mobile recirculation tables have their benefits when used occasionally for display cooking but really are not suitable for long term use as a main ventilation method when employed for prolonged periods of time. If used in this way ‘frontof-house’, they can recirculate odours which become progressively annoying to customers in the dining area.”
Trivent’s Wilman agreed, saying: “Whilst a mobile ventilation system may seem to provide a flexible concept that would suit operations that are looking to scale their business, in reality we feel these would prove impractical and the benefits would not justify the cost.
“From a practical perspective, a mobile ventilation system would ideally be designed as a low level system mounted directly onto the appliance it serves. If the ventilation system was independent it could potentially generate issues due to physical size and weight, potentially resulting in engineers being required to move the system with it not being truly mobile. If the system is ducted to atmosphere, the ductwork connections would also need to be modified to suit new locations.”
So, with all these new technologies available, has Trivent shifted course? Not according to Wilman, who concluded: “Our business model remains predominantly unchanged, however, with the uncertainty of our imminent departure (or not) from the European Union, we feel that our stock management systems and approved quality supply chain will prove invaluable as the uncertainty unravels into reality.”