Rangehoods: What You Need To Know
What is the purpose of a rangehood?
Rangehoods extract and filter cooking by-products from the kitchen environment. Cooking by-products can be heat, steam, grease and odour.
Why do rangehoods have filters?
Some cooking by-products such as heat and odour need to be extracted from the kitchen and expelled into the atmosphere. However, other by-products such as steam and grease need to be filtered from the air before entering the fan motor and ducting.
This stops a build-up of fat deposits which can affect the operation of the fan motor. Filters are placed in the entry point of most rangehoods to help this process along.
How does a rangehood filter work?
Most filters operate in the same way. When someone is cooking over the stove, cooking by-products are produced. Most of the by-products are created due to heat. As hot air rises, they are carried up to the rangehood. This is why the most effective rangehoods are positioned above the stove or cooking surface. When the by-products reach the rangehood, they are sucked into the filtration zone.
What is a baffle filter and how does it work?
Baffle filters are usually found in high quality commercial kitchens. This is not only due to their superior extraction and filtration performance but because they offer a protective guard preventing flames from the cooking surface passing up into the ducting. They also offer a catchment area within the filters that enables the filter to operate between cleans without loss of extraction or filtration. Baffle filters are formed by a series of interlocking “blades” or “vanes”.
These vanes are setup so that one sits inside the other so that when the air is pulled through the filters, the air flow is forced to pass in an ‘S’ pattern. This ‘S’ pattern forces the heavier dirty particles to contact the top surface of the vanes, whilst the finer particles are captured on the inner return surface. This contact causes condensation and the particles rest on the vane surface. The uniform ‘S’ pattern means the vanes are evenly spaced apart creating a clean and consistent path for the air to pass through. This ensures that the baffle generates less turbulence than the ‘random’ paths generated by the mesh filter.
As the baffle filter ‘fills’ with grease and moisture, the available surface area on the upper vane surface decreases. This then leads to the condensate dripping into the lower vane, where the surplus by-products are stored without affecting or blocking the air flow. As most baffle filters are made from a solid stainless-steel construction, the ease of cleaning is noteworthy. The filters can be easily soaked or placed in the dishwasher and are restored to new without deterioration.