Maintaining and replacing the hood filter in your commercial ventilation system is more important than you might think. The hood filter is a metal square or rectangle that fits into the opening on your hood ventilation system. Its purpose is to filter out grease from the smoke rising off your cooking equipment. If this smoke were left unfiltered, it would build up over time in the ventilation system and become a major fire risk (often cited as the cause of pub fires).
Therefore maintaining and replacing these filters is an important task. This essential maintenance work should be part of your Fire Risk Assessment and documentation relating to the regular servicing and maintenance of your kitchen extract system should be maintained for the Fire Officer, the Environmental Health Officer and, in many cases, for your insurers who may require this as part of your insurance policy and cover.
Unless your cooking equipment is burning charcoal or some other sort of solid fuel (which in the average pub is highly unlikely), your hood ventilation system is using a baffle filter.
Galvanised – these filters are the least expensive option. They are rarely used in open kitchens where customers can see them because they have a dull appearance.
Aluminium – these hood filters have an appealing sheen to them, making them usable in open kitchens, but they are prone to corrosion after repeated cleanings.
Stainless Steel – these filters are by far the most durable. They are also appealing to look at and can be used in an open kitchen. They are less prone to corrosion than aluminium as long as they are not cleaned using bleach or other chemicals.
Hood filters should be cleaned every day to keep them free of grease and maximize their filtering capability. If you have a high temp dishwasher, run your hood filters through the dishwasher. Make sure you don’t use any bleach when you clean hood filters as this will cause rapid corrosion.
If your dishwasher uses any kind of chemical, do not use it to clean hood filters. Instead, clean the grease out of your hood filters with hot soapy water and dry them immediately after.
If grease is allowed to build up in hood filters, the risk of fire in your kitchen becomes very high. The more packed with grease filters become, the less they filter from the smoke passing through your ventilation system. That means the unfiltered grease ends up in the ducting, and if enough builds up, it could catch fire, potentially causing thousands of pounds worth of damage.
Conduct regular visual inspections of your kitchen’s hood filters, if corrosion, dents, or wear has created holes or disfiguration in the baffles, then it’s time to replace them. It’s important to replace worn hood filters as quickly as possible otherwise, grease will build up in the ducting of your ventilation system, and this can pose a very serious fire risk.
Your ventilation and extraction system and the associated covers, hoods, flues and filter holders should undergo a thorough deep clean. at the very least, annually. No matter how scrupulous you are with cleaning, maintenance and replacement of filters there will be a build up of fats and oils from your cooking activities in the extraction system. Unless the system is overhauled and deep cleaned annually you pose a significant fire risk from accumulated oils and fats. There are many commercial deep cleaning contractors and specialist extraction system cleaning contractors to choose from as this is a job you wouldn’t ordinarily consider undertaking yourself.
The exhaust system in your kitchen is one of those essential pieces of equipment that you must have in order to operate. And if your hood is like the ones in most kitchens , it has two settings: “on” and “off.” When your line is operating at full tilt during the dinner rush, the “on” setting is probably perfect, quickly sending heat and fumes straight from your cooking equipment outside. But what about afternoons or during quiet times? You probably still have the ventilation on but your equipment is not creating nearly as much exhaust.
Your exhaust system needs some regular maintenance to run at optimal levels. If too much smoke is building up in your kitchen, or if the system seems like it’s on overdrive all the time, re-balancing by a trained technician is in order. A re-balance ensures the system is keeping the kitchen safe but not sucking up too much energy by working too hard. Make it part of the annual deep clean procedure.
Your kitchen ventilation system should be pulling as much of the stuff you don’t want in your kitchen as possible. To maximise smoke and heat capture, make sure your cooking equipment is pushed all the way up against the wall underneath the hood. This prevents clean air from getting sucked up from behind the equipment and puts the maximum amount of hood over your line. And if your hood doesn’t have side panels, you can install them easily and cheaply, they help trap smoke and fumes, making the exhaust system more efficient.
If you really want to save some money on kitchen ventilation then install a demand control, it senses the cooking volume in your kitchen and adjusts fan speed accordingly. A ventilation control can reduce kitchen exhaust energy usage by 30% – 50% and can be either ordered with a new exhaust system or installed on an older unit.
Clean and maintain hood filters – the dirtier the filter, the harder your exhaust has to work to suck air through them.
If you happen to be designing a new kitchen, you should account for a few factors in order to maximize ventilation efficiency. Group heavy cooking equipment together. Whatever you’re going to be cooking with the most should all be right next to each other underneath the hood. If you have a single heavy cooking appliance, like a griddle, and other lighter cooking equipment, it’s a good idea to separate the heavy piece from the lighter pieces and give it a dedicated high volume exhaust. This allows you to run the lighter equipment under a hood that doesn’t have to be on full blast all the time. Create a big overhang, the greater the depth of the hood the more it will capture smoke and allow you to run your exhaust system more efficiently.
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