Build a Bathroom Ventilation Kit

A bathroom ventilation system powered by an inline fan has many benefits vs a standard ceiling mounted fan. This customisable solution offers a wide range of choices in terms of internal and external vent. As well as this high level of customisation inline fans tend to be more powerful, and can be installed in a roof cavity not directly above – therefore minimising audible noise within the room. The following page is designed to break up the process of putting a kit together into 4 steps. These are as follows:

  1. Select an intake vent
  2. Select Ducting
  3. Select Motor
  4. Select outlet vent

Step 1

Let’s pick an intake vent

An intake vent is installed on your ceiling & will be visible in the bathroom. All options below include a duct spiggot suitable for connecting to 150mm ducting. Simply scroll through to view all options.

Step 2

Let’s add some ducting

You will need flexible ducting to connect the intake vent to the inline fan and also to connect the other end of the inline fan to the external vent. Note we sell our ducting in 6m lengths & it can be cut to suit your requirements. As a rule of thumb keep your ducting as straight & direct as possible to maximise fan performance. Adding a draft stopper will prevent drafts when the fan is not operational. Duct tape is commonly used to secure everything in place.

Step 3

Let’s pick a motor to power the system

To make this process easy we have provided 3 options below. An entry level Axial motor designed for smaller bathrooms and short duct runs. A capable mixflow fan suitable for medium/large bathrooms, and finally a premium ‘silent’ mixflow option. Both mixflow fans have 2 speed motors with a switch on the side of the motor, meaning you can choose if the fan will run at high or low speed.


Suitable for bathroom up to 23m3.

Based on 15 air changes per hour at freeflow (no ducting).


Suitable for bathroom up to 34m3.

Based on 15 air changes per hour at freeflow (no ducting).


Suitable for bathroom up to 37m3.

Based on 15 air changes per hour at freeflow (no ducting).


Entry level fan is designed for smaller bathrooms and not recommended to be used with any more than 6m of ducting all up.

Medium/Large options are both 2 speed fans, allowing you to select high or low speed via a control on the unit. The PREMIUM option offers sound absorption to ensure the quietest operation possible.

Our room size recommendations are based on 15 air changes per hour, and do not account for pressure loss when adding ducting & vents. If you require more information on room size calculation view our Exhaust fan buying guide below.


Step 4

Let’s pick an external vent

Finish your system off with an external vent – we have options to go on an external wall, under eave or roof mounted options. Note vents with gravity shutters can only be wall mounted, for under eave something like a fixed flyscreen vent is most common. We also have some premium options, in particular the Japanese ‘Nasta’ range are a superb high end choice.

has been added to your cart.