A bathroom exhaust fan, otherwise known as an extractor fan, is a device used to remove excess water from your bathroom, reducing the build-up of damp and helping to avoid condensation and mold. People have many questions about bathroom exhaust fans, however, so below, we have put together some quick answers to some of the most common questions. Visit Terra Bloom for the perfect ventilation for your bathroom

Do You Need a Bathroom Exhaust Fan?

Whether or not you need an exhaust fan for your bathroom will depend slightly on the layout of your home. Every bathroom needs ventilation of some sort, which could be an extractor fan or simply a window. If your bathroom does not have a window, you certainly need an extractor fan. If you have a small window, you may well also want an extractor fan – the amount of steam that can build up is more than you might think!

What Does a Bathroom Exhaust Fan Do?

As steam builds up in the air of your bathroom, it causes condensation and adds more and more moisture to the air. This can lead to mold growth and rot in your bathroom, so it is important to remove as much of the moisture as possible. There are several different types of bathroom exhaust fans, but all of them do the same thing: moving the wet, moisture-filled air out of your bathroom and to the outside through a duct or pipe of some sort. It is basically the same principle as an AC unit.

What Size Bathroom Exhaust Fan Do I Need?

Many different sizes of bathroom fans are available, and sizes are usually measured in reference to the impeller: the revolving part within the fan that moves the air around. The standard sizes of impellers are 4-inch and 6-inch sizes, and the smaller of these should be enough for most domestic bathrooms. If you are trying to ventilate a large bathroom or a kitchen, a 6-inch fan might be a better bet.

Can I Install a Bathroom Exhaust Fan Myself?

If you are replacing an older bathroom exhaust fan with a new one with the same fittings, then it should be an easy DIY project, as long as the ducting and wires are still functional. However, most installation projects will require rewiring and some level of drilling holes through walls to fit the new fan. It is generally recommended that you hire a professional to help with installation. Installing a new bathroom exhaust fan should only take a few hours, so it should not be too disruptive.

Does a Bathroom Exhaust Fan Need External Venting?

In short, yes. A bathroom exhaust fan needs to connect up to the outside of the building in order to vent the moisture into the open. If you connect it up to another indoor space, it will just move the damp into that room instead!


Bathroom exhaust fans are an important part of your ventilation system and one that should not be overlooked. If your bathroom extractor fan breaks down, sorting out a replacement immediately is essential: the longer you go without functioning ventilation, the more of a mold problem is likely to arise in your bathroom!