What Fan Should You Use?

What Fan Should You Use?

By Kira Jopp on Thu 12 December 2019

It’s a daunting task when choosing an extractor fan to meet your needs. With so much choice available, it can become overwhelming trying to find the right fan. With that in mind, this blog will guide you through what you should look for when choosing an extractor fan for your home.


Where do you need an extractor fan?

You need an extractor in every “wet” room within your home.


What is a wet room?

A wet room is typically a toilet, bathroom, shower, en-suite, utility room or kitchen. The reason for this is due to excess moisture that is often created when these rooms are in use. The excess moisture can build up over time, if left unchecked, and result in damp and mould developing in the room.

By having an extractor fan in these rooms means that the excess moisture is removed from the room; thereby preventing damp and mould from developing. However, there isn’t a one size fits all approach regarding the type of extractor fan that you should install.

The Building Regulations set minimum flow rates that an extractor fan installed in a wet room should be able achieve when correctly installed. The flow rates are as follows:

  • 6 l/sec for toilets and en-suites
  • 15 l/sec for bathrooms/showers
  • 30 l/sec for utility rooms and kitchens when the fan is installed adjacent to the hob – this is the flow rate expected from a cooker hood
  • 60 l/sec for kitchens when a cooker isn’t present


What do you need to look out for?

Once you know where you need to install your extractor fan, then you need to establish where in that room you’re going to install the fan. Here you need to consider the zone and in turn the fan’s IP rating.

A fan’s IP rating acts as a guide to the fan’s protection from dirt, dust and water and is comprised of two numbers. The first number indicates the fan’s protection from dirt and dust and the second number indicates its protection from water. For a fan to be installed in Zone 2 or 1 of a toilet or bathroom, it must achieve at least an IPX4.

You need to also make sure that the fan performs when it is installed in your home. To help you make an informed decision, you should refer to the fan’s performance graphs, which will indicate the flow rate the fan can achieve versus the system pressure of the fan.

A good barometer of establishing the installed performance of your desired fan is to use 10Pa as an example system pressure. This will help you establish whether your desired fan will extract the required 15l/sec in a bathroom with 100mm flexible ducting.


You can get a shortlist of fans to meet your specification by using Airflow's SelectAir tool. Click here to use Airflow SelectAir.