A kitchen extractor fan is a necessary item for any kitchen. An extractor fan not only extracts air, odours, moisture and other elements, including grease, from the kitchen while cooking, it also replaces air in the kitchen. The regulations for extractor fans can vary from country to country, but there are some regulations regarding kitchen extractor fans that typically remain the same.
Change of air
For a typical residential kitchen, an extractor fan must be capable of replacing the air in the kitchen at a rate of 10 to 15 changes of air every hour.
Size of the fan
To be effective, the extractor fan must meet a certain size requirement that is determined by the BTU capacity of your stove. According to Kitchen Range Designs, "10,000 BTU of the range, it is recommended a minimum of 100 CFM." If your stove is 10,000 BTU, the extractor fan needs to change the air at a rate of 2.8 cubic metres (100 cubic feet) per minute.
The ducts for the kitchen extractor fans need to be short and as straight as possible to be most effective. If the extractor fan is able to extract grease, then the duct needs to be made of 18-gauge steel. The brackets and supports for the ducts must only be made from noncombustible material.
If the ducting runs up through a shaft, it must be lined with code-approved noncombustible material, such as gypsum, ceramic, plaster or other materials.
Ducts of the extractor fan that pass horizontally through the wall to the outside grille must have a cover than can be easily removed. This ensures that the duct can be easily inspected as well as cleaned -- especially if the extractor fan extracts grease as well.