How to Choose the Size of Your Extractor Fan

What You'll Need

An extractor fan is a really useful type of fan to fit in a bathroom or kitchen. It is designed to remove bad smells and moisture from the air. There are lots of different sizes and types of extractor fans available. You will need to spend time choosing the best extractor fan for your needs so that it can do the job you want properly.

The size of the extractor fan will depend on a number of things including the size of the room, the type of room and your personal preferences. Install an exterior fan which is too small and it won't work properly. Install one that's too big and it will be a waste and allow too much hot air out of the room.

Step 1 - Measuring the Room

Use your tape measure to measure the height, width and length of a room. An approximate measure will sufice.

Step 2 - Calculating the Volume

Now you need to calculate the volume of your room so that you can work out which size extractor fan you need. You simply need to multiply the width by the length by the height. This will show you the volume.

Step 4 - Getting Your Head around the Maths

You now need to consider the maths and what it means when you're choosing the extractor fans for your room. For an extractor fan to be efficient it will need to be able to completely change all of the air in a room 10 times every hour when it's turned on. This means that the bigger your room, the more powerful and bigger extractor fan you will need.

A bigger extractor fan will be required in certain circumstances including if you use a shower in the bathroom or intend to position the fan in the kitchen over a cooker.

Step 5 - Working out the Airflow

To work out the airflow of the extractor fan required you will need to take the volume of the room and multiply it by 10. This is because the complete air will need to be changed 10 times per hour.

This means that if your kitchen has a volume of 30m3 then you will need to multiply it by 10 getting the air flow of 300 m3/h. This will provide the room with the best and most efficient extractor fan for your requirements.

Step 6 - Choosing a Fan

Now you need to choose an extractor fan. Choose one which is the same rating as the requirements that you have just calculated. This will ensure that the air in your room is changed 10 times per hour. It also means that you're not wasting time fitting a fan that is too large or too powerful.