Grease Hood Cleaning, Water Waste & "Fatbergs"

Mitigating fire risk is priority number one when it comes to managing fats, oils, and grease (FOG) in commercial kitchens and for good reason. FOG build-up in kitchen exhaust systems is well-known for causing fires that have damaged property and at their worst, have claimed lives. That’s why standards, codes, and regulations ensure that hoods and ducts are routinely inspected. If inspections find considerable grease build-up, then it’s time for grease hood cleaning! Yet the process of grease filter and hood cleaning can adversely affect our environment, a topic that also deserves its fair share of attention.

Conventionally, kitchen grease filters can be kept clean through regular cleaning undertaken by staff, which involves removing trapped grease from the face of the filters and surrounding components (i.e. tracks). To do so, they will use around four to 12 litres of water per filter each time they perform this task. Other options involve soaking and filter exchange services, which also involves the use of water.

Sanitary day at the restaurant. Staff wash down the grease filters in the kitchen.

Routine grease hood cleaning is also carried out to remove FOG build-up that [unfortunately] bypasses the kitchen grease filters. Degreasers and pressure washers are used to ensure all areas are cleaned back to bare metal and according to regulations. The grease hood cleaning process involves a lot of water and degreasing chemical agents (eco-friendly or otherwise). Restaurants can expect to use about 190 litres of water per vent hood and can expect to go through more than 11,000 litres of water each year ($$$) once filter cleaning is factored in.

If the financial burden of water waste and grease hood cleaning isn’t enough, consider that it’s not just water going down the drain.

Water mixed with FOG and chemicals wash into grease traps, but in countries such as the UK this contaminated wastewater goes down drains that lead straight to the sewer system in 70% of cases.

Not only does this wastewater need to be processed by local water treatment plants before it can be re-used, but it may also lead to complications known as ‘Fatbergs’ along the way. The term refers to the build-up of solidified waste matter in sewer systems, caused by the discharge from grease and cooking oils that are flushed below ground. Partly created from waste practices of local restaurants and cafes, the Thames Water’s infamous Whitechapel Fatberg is a great example of what FOG can do. The Cranfield University sponsors PHDs into the mechanics of FOG within commercial kitchens, as research suggests that the vast majority of commercial kitchens in the UK don’t currently have a FOG solution in place.

So it’s fair to say that grease hood cleaning plays its part in the “relocation” of build-up from one system (kitchen exhaust on the left) to another (sewers on the right) in countries where grease traps are not yet installed:

Yet there are solutions!

In more and more regions of the world, the FOG waste that is pumped out of grease traps is recycled and used to either manufacture stock feed or to produce biodiesel.

Innovations like Shepherd Filters also help to alleviate environmental problems caused by FOG by offering a much greener solution for restaurants with sustainability in mind.

Unlike regular metal filters that allow between 60-80% of grease to penetrate the kitchen exhaust system, Shepherd Filters Filters capture up to 98% of this airborne grease right there at the filter!

With less grease penetrating the rest of the kitchen exhaust system, benefits are endless:

Immediate financial savings can be made by reducing the labour (or contractor) costs associated with cleaning metal grease filters. The frequency and extent of routine grease hood cleaning also reduce dramatically.

Minimising the need for filter and grease hood cleaning saves water. It also basically eliminates the need for potentially harsh chemicals normally used to maintain a clean system.

Shepherd Filters are made from 100% Australian wool, which is fully bio-degradable. The used filter media can be safely disposed of in your regular waste bin. Wool is carbon-neutral and will breakdown in landfill.

Energy savings that come with a cleaner kitchen exhaust system, rooftop, fans, and other HVAC equipment results in a more efficient operation, not to mention less maintenance. Wool is also a renewable material source.