Why You Need A Bathroom Exhaust Fan

Why You Need A Bathroom Exhaust Fan

The humble bathroom exhaust fan. Unassumingly nestled in its position in the ceiling or wall, it quietly (well, hopefully quietly) goes about its job with minimal fuss while you’re having a shower or enjoying a relaxing bath.

For many of us, it can become an ‘out of sight, out of mind’ fixture of the bathroom, so much so that we may even forget just how essential ceiling exhaust fans really are.

If you’re building a new home or renovating an existing bathroom, here is why wall or ceiling mounted fans are so vital. We’ll also look at what you need to consider when buying a new or replacement bathroom exhaust fan. 

What Your Bathroom Exhaust Fan Actually Does

Bathroom exhaust fans are vital to maintaining a healthy level of air quality in your bathroom. In doing so it also helps to maintain fresh air throughout your entire home. Also known as an extractor fan, its primary purpose is to draw out any odours and moist air in the bathroom. 

As the humidity that comes from running a hot shower or bath condenses, the resulting moisture can seep into the walls. Mould then forms, often unseen behind the walls of the home, which can lead to a multitude of health concerns. The Victorian Government’s Better Health website lists numerous potential health problems including:

  • Nasal congestion
  • Sneezing
  • Coughing
  • Respiratory infections
  • Skin irritations

Breathing in mould spores can also exacerbate existing allergies and asthmatic conditions. 

An exhaust fan in prime working condition will significantly reduce the humidity levels of a well-ventilated bathroom. It will therefore restrict the growth and spread of mould throughout your home. So yes, exhaust fans are absolutely a vital part of any bathroom build or renovation, and a licensed electrical contractor will be able to assist with the installation process

Considerations When Buying an Exhaust Fan

So if you are building a new bathroom or renovating an existing one, and you’re shopping around for the best exhaust fans on the market, what should you consider to ensure that you’re getting what you need from it? Here are some key factors to bear in mind.

The Type of fan

Bathroom exhaust fans come in a variety of styles, including ceiling mounted, wall mounted, window fans and inline fans. You can also buy exhaust fans with lights, heating, or all three features in the one unit. The choice you make may depend on factors such as room size and aesthetic appeal.   

Your Room Size

The size of the bathroom will determine just how powerful an exhaust fan you need to provide sufficient ventilation. In Australia, exhaust fan capacity is measured in cubic metres per hour (m3/hr), which is determined by the size of the room, and gauges the quantity of air that the fan draws out. The general rule of thumb for a bathroom with a shower is to aim for about 15-20 hourly changes of air in the room. 

To determine the correct exhaust fan, you can use the following formula: 

“room size in cubic metres (measured by length x width x height) multiplied by the number of hourly air changes you want = total m3/hr capacity”

Noise Levels

Noisy exhaust fans can be distracting, whether you’re taking a quick five-minute shower or enjoying a relaxing hour-long bath. Shop around to find a bathroom exhaust fan that isn’t overbearingly loud and still provides you with the ventilation functionality that you need. 

Ventilation Efficiency

Like most powered appliances in the home, you’ll want to find one that provides optimal energy efficiency. It’s better for the environment, and better for your household budget. 

Steam Temperatures

Hotter steam created by hotter water usage (especially when using the shower) results in a greater amount of condensation when it makes contact with bathroom mirrors or cooler tiled surfaces. You will certainly need to consider this when you’re determining the number of air changes you want in the room.

Bathroom Surfaces

Speaking of tiled surfaces, if your bathroom is tiled from top to bottom, that will display more condensation than a bathroom that is only tiled partially. This may mean you’ll need a bathroom exhaust fan with a greater rate of extraction. 


Best Exhaust Fan Placement

You will also need to consider the placement of the exhaust fan in your bathroom. If you want it to operate to its full potential, and no doubt you do, exhaust fans require a flow of air that is balanced and consistent. Essentially the amount of air that the fan extracts needs to be equal to the volume of air coming into the room.

A window is typically the most effective source of incoming airflow, but a vent or grille in an exterior wall or door can also do the job. For correct exhaust fan placement, we recommend installing parallel to the incoming airflow source. This will help generate the vital cross-ventilation needed to manage any excess vapour and unwanted smells. 

A lack of airflow coming into the room will reduce the effectiveness of your exhaust fan. Be careful though to not position your fan too close to a door or window. Some distance is necessary to encourage air circulation throughout the entire room, otherwise that circulation will  be concentrated to just the immediate area of installation.

Can I Install the Exhaust Fan Myself? 

In short, you can – in some cases. Some ceiling exhaust fans are 100% DIY, but if you’ve purchased a model that requires electrical wiring, you’ll need a licensed electrical contractor to finish the job for you to ensure it’s completed safely and to Australian regulations.

When you need expert assistance to tie up all the electrical loose ends with your bathroom exhaust fan, be sure to give Upside Down a call. We can get your fan and any other home rewiring needs sorted so everything works safely and efficiently. 

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.

Last Edited on: 14th September 2022