If you are having a brand new kitchen put in, in all likelihood you will be putting in a kitchen extractor fan, and this article talks you through all you need to know about which size and type of fan to choose. 

In this article we will not be discussing cooker extractor hoods, which are a different thing entirely (generally these are rectangular items above your cooker or oven). What we are talking about are the square fans that go in the wall or ceiling. 

There are plenty of kitchen extractor fans out there, but which is the right one for you? To start with, you need to get the right size of fan, which is 6 inches, or 150mm. If a fan is described as a kitchen fan but is anything other than 6 inches, it almost certainly isn't the right fan for you. This measurement is the pipe or spigot which protrudes from the rear of the extractor fan, not the diameter of the front of the fan! 

4 inch (100mm) fans should only be used in bath rooms, toilets and shower rooms, never in kitchens. This is because they are not powerful enough to meet building regulations requirements. Currently, the requirements are as follows: for a toilet or WC, the minimum extract rate required is 6 litres per second. In a bath room, shower room or wet room, you should install a fan with an extraction rate of at least 15 litres per second. The rate needed for utility rooms is 30 litres per second. For kitchens, there are 2 different rates required. If the extractor fan is to be installed adjacent to the hob, it only needs to extract at a rate of 30 litres a second. However, if it is to be installed anywhere else in the kitchen, then the extract rate must be a minimum of 60 litres per second, or put another way, 260 metres cubed per hour. 

Now, there isn't a 4 inch fan on the market that's going to extract at anywhere near the required rate, so you must get a 6 inch fan. There are also 9 and 12 inch fans available that are described as kitchen fans, and they can indeed fulfil that purpose, but almost always in commercial premises, they would be overkill for a domestic situation. 

There are a few types of extractor fan available for a kitchen. The most common type has a pullcord attached so you can operate it whenever you like, it just comes on when you pull the cord, and off when you pull it again. Usually the code will have a "P" at the end, for "Pullcord". Usually this type of fan will suffice. Or you can get a fan with an over-run timer (usually the code will have a "T" at the end for "Timer". This fan will continue to operate for a few minutes after you turn it off to help clear any smells or condensation after you leave the room. 

Fans with a humidistat tend to be the most expensive type of fan, and operate independently of whether you've turned them on or not. They will come on automatically when the humidity level in the room reaches a certain level, and will go off when it drops below that level. These fans generally have an "H" at the end of the code number, for "Humidistat". 

And that's it! Your guide to buying the right extractor fan for your kitchen.