Sub Floor Ventilation Systems

Fresh Ventilation’s exclusive design is based on years of knowledge, experience and trialling competing products.  Our systems use components that have been carefully selected for their purpose to ensure that you get superior performance, proven reliability and lower operating costs.

We use Australian made components, including ducting and fittings, and German made centrifugal fans with both AC and EC motors available.

What Makes Fresh Ventilation Different

Fresh Ventilation is a family owned and operated business. Our business has specialised in the installation of premium quality ventilation systems for over 10 years.

Effective sub floor ventilation requires quality components and proper installation. Given that no two sub floor areas are the same, there is no one-size-fits-all solution to sub floor ventilation. This is why we place a strong emphasis on customised solutions and after-sales support to help you get the most from your system.

Our focus is on premium products and expert advice to create ventilation systems that actually work.

Why Premium Components and Proper Installation Matter

System Design

  • Instead of using a single larger fan, we use smaller fans but more of them.
  • More fans allow greater coverage, better efficiency and more extraction points.
  • A single larger fan makes more noise, uses more power and requires longer duct runs to cover the same area as two smaller fans. This is inefficient and leads to uneven duct lengths and subsequently uneven air flow.
  • Our smaller fans use the same size ducting as our exhaust grilles and we allow one exhaust grille per fan. This allows air to be freely exhausted without a reduction in air flow due to pressure buildup.
  • Larger fans need reducers to reduce the duct size so that they can be connected to exhaust grilles. This results in a reduction of air flow due to resistance.
  • Our systems are designed to properly ventilate your sub floor area. We believe in doing the job right the first time.
Sub Floor Ventilation System


  • Our 150mm AC and EC motor centrifugal fans have capacities of  560 m³/h and 735 m³/h respectively.
  • The single speed AC motor consumes 52 W and the variable speed EC motor consumes 49 W when running at a similar 580 m³/h capacity.
  • Our fans make less noise and use less power. Some larger fans use almost 200 W when operating and have less capacity than two of our smaller fans.
  • Our fans have a 5 year replacement warranty.


  • Our duct is manufactured in Australia from two layers of high grade metallised polyester bonded together with fire rated resin encapsulating spring steel wire.
  • Our duct is not prone to tearing or unravelling like single layer competing products.
V-Flex Duct

Exhaust Grilles

  • Our exhaust grilles are anodised aluminium, not plastic.
  • Our grilles are weather proof and have a rodent proof mesh behind them.
  • Our grilles are easy to install since they replace two standard bricks. The back box fills the hole left after removing two bricks and the anodised grille clips into the back box and covers any gaps with a 25mm flange. They don’t require partial removal of bricks to create a round hole.
Sub Floor Ventilation Grille


  • Our digital timer has a battery backup. It won’t lose time and start running in the middle of the night.
  • Our digital timer can be programmed differently on different days of the week. This is ideal when you want different operation on the weekends.

AC Motors vs EC Motors

AC motors are cheaper than EC motors but still provide excellent performance. They are very quiet during operation and move large volumes of air through ducting. They operate at one fixed speed where they are most efficient.

In real world use, EC motors provide even higher air flow, are extremely quiet during operation, are capable of silent operation at reduced fan speeds, have smoother fan rotation, and consume almost no power at reduced fan speeds. EC motors have adjustable speed and are very efficient at all speeds.

AC Motor Centrifugal Fans

Our AC motor centrifugal fans have the following qualities:

  • Single speed
  • Approximately 560 m³/h air flow and 52 W power usage
  • Very low noise during operation
  • R2E190 motor manufactured by ebm-papst in Germany
  • Custom Australian made fan housing
  • 5 year warranty
  • IP 44 protection rating.
AC Motor Centrifugal Fans

EC Motor Centrifugal Fans

Our EC motor centrifugal fans have the following qualities:

  • Variable speed
  • 310 m³/h air flow and 10 W power usage
  • 445 m³/h air flow and 24 W power usage
  • 580 m³/h air flow and 49 W power usage
  • 735 m³/h air flow and 83 W power usage
  • Extremely low noise during operation
  • Can be silent at reduced fan speeds during operation
  • R3G190 motor manufactured by ebm-papst in Germany
  • Custom Australian made fan housing
  • 5 year warranty
  • IP 54 protection rating.
EC Motor Centrifugal Fans

Negative Pressure, Positive Pressure or Balanced Pressure?

Installing the most suitable sub floor ventilation system in your home can help get rid of air pollutants that can harm your health and your family’s wellbeing. Fresh Ventilation offers efficient solutions that can eradicate stale, moist air in the sub floor area and replace it with cleaner, fresher and drier air. We have three different types of ducted sub floor ventilation systems that you can choose from.

All of our systems are available in any of the three pressure configurations – the components don’t change, the way they are installed determines the configuration.

Depending on how your sub floor ventilation fans are installed, they will either blow air into your sub floor area (positive pressure) or suck air out of your sub floor area (negative pressure).  If you have two or more fans installed, it is possible for fans to both blow air in and suck air out of your sub floor area (balanced pressure).

Ducted Sub Floor Ventilation System

Sub Floor Ventilation System Sizing and Fan Selection

When determining which sub floor ventilation system is most suited to your home, it is important to consider:

  • Fan configuration (negative, positive or balanced)
  • Proper system sizing to ensure sufficient air flow and effective ventilation coverage
  • Construction materials of your home and its surroundings to ensure quiet and unobtrusive operation
  • Design effectiveness
  • Aesthetics
  • Price.

We recommend you Contact Us to arrange a free site inspection and quote.  Alternatively, we are often able to provide accurate quotes on the spot based on information you provide via email/telephone and any diagrams/images you have available.

Sub Floor Ventilation System Design

All of our sub floor ventilation systems are available as DIY kits if you would like to install them yourself. We offer installation assistance and guidance by way of telephone conversations and personalised duct layouts with each kit.  Please visit our Online Store if DIY is more suited to your needs.


Online Shop


Solutions for Ventilation Problems